Commit Graph

113 Commits

Author SHA1 Message Date
Christoph Hellwig
5b7252a268
riscv: there is no <asm/handle_irq.h>
So don't list it as generic-y.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-24 10:54:23 -07:00
Linus Torvalds
527cd20771 RISC-V changes for 4.17
This tag contains the new features we'd like to incorporate into the
 RISC-V port for 4.17.  We might have a bit more stuff land later in the
 merge window, but I wanted to get this out earlier just so everyone can
 see where we currently stand.
 
 A short summary of the changes is:
 
 * We've added support for dynamic ftrace on RISC-V targets.
 * There have been a handful of cleanups to our atomic and locking
   routines.  They now more closely match the released RISC-V memory
   model draft.
 * Our module loading support has been cleaned up and is now enabled by
   default, despite some limitations still existing.
 * A patch to define COMMANDLINE_FORCE instead of COMMANDLINE_OVERRIDE so
   the generic device tree code picks up handling all our command line
   stuff.
 
 There's more information in the merge commits for each patch set.
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Merge tag 'riscv-for-linus-4.17-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux

Pull RISC-V updates from Palmer Dabbelt:
 "This contains the new features we'd like to incorporate into the
  RISC-V port for 4.17. We might have a bit more stuff land later in the
  merge window, but I wanted to get this out earlier just so everyone
  can see where we currently stand.

  A short summary of the changes is:

   - We've added support for dynamic ftrace on RISC-V targets.

   - There have been a handful of cleanups to our atomic and locking
     routines. They now more closely match the released RISC-V memory
     model draft.

   - Our module loading support has been cleaned up and is now enabled
     by default, despite some limitations still existing.

   - A patch to define COMMANDLINE_FORCE instead of COMMANDLINE_OVERRIDE
     so the generic device tree code picks up handling all our command
     line stuff.

  There's more information in the merge commits for each patch set"

* tag 'riscv-for-linus-4.17-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux: (21 commits)
  RISC-V: Rename CONFIG_CMDLINE_OVERRIDE to CONFIG_CMDLINE_FORCE
  RISC-V: Add definition of relocation types
  RISC-V: Enable module support in defconfig
  RISC-V: Support SUB32 relocation type in kernel module
  RISC-V: Support ADD32 relocation type in kernel module
  RISC-V: Support ALIGN relocation type in kernel module
  RISC-V: Support RVC_BRANCH/JUMP relocation type in kernel modulewq
  RISC-V: Support HI20/LO12_I/LO12_S relocation type in kernel module
  RISC-V: Support CALL relocation type in kernel module
  RISC-V: Support GOT_HI20/CALL_PLT relocation type in kernel module
  RISC-V: Add section of GOT.PLT for kernel module
  RISC-V: Add sections of PLT and GOT for kernel module
  riscv/atomic: Strengthen implementations with fences
  riscv/spinlock: Strengthen implementations with fences
  riscv/barrier: Define __smp_{store_release,load_acquire}
  riscv/ftrace: Add HAVE_FUNCTION_GRAPH_RET_ADDR_PTR support
  riscv/ftrace: Add DYNAMIC_FTRACE_WITH_REGS support
  riscv/ftrace: Add ARCH_SUPPORTS_FTRACE_OPS support
  riscv/ftrace: Add dynamic function graph tracer support
  riscv/ftrace: Add dynamic function tracer support
  ...
2018-04-04 16:43:47 -07:00
Palmer Dabbelt
7a8e7da422
RISC-V: Fixes to module loading
This cleans up the module support that was commited earlier to work with
what's actually emitted from our GCC port as it lands upstream.  Most of
the work here is adding new relocations to the kernel.

There's some limitations on module loading imposed by the kernel:

* The kernel doesn't support linker relaxation, which is necessary to
  support R_RISCV_ALIGN.  In order to get reliable module building
  you're going to need to a GCC that supports the new '-mno-relax',
  which IIRC isn't going to be out until 8.1.0.  It's somewhat unlikely
  that R_RISCV_ALIGN will appear in a module even without '-mno-relax'
  support, so issues shouldn't be common.

* There is no large code model for RISC-V, which means modules must be
  loaded within a 32-bit signed offset of the kernel.  We don't
  currently have any mechanism for ensuring this memory remains free or
  moving pages around, so issues here might be common.

I fixed a singcle merge conflict in arch/riscv/kernel/Makefile.
2018-04-02 20:43:14 -07:00
Palmer Dabbelt
2c9046b71b
RISC-V: Assorted memory model fixes
These fixes fall into three categories

* The definiton of __smp_{store_release,load_acquire}, which allow us to
  emit a full fence when unnecessary.
* Fixes to avoid relying on the behavior of "*.aqrl" atomics, as those
  are specified in the currently released RISC-V memory model draft in
  a way that makes them useless for Linux.  This might change in the
  future, but now the code matches the memory model spec as it's written
  so at least we're getting closer to something sane.  The actual fix is
  to delete the RISC-V specific atomics and drop back to generic
  versions that use the new fences from above.
* Cleanups to our atomic macros, which are mostly non-functional
  changes.

Unfortunately I haven't given these as thorough of a testing as I
probably should have, but I've poked through the code and they seem
generally OK.
2018-04-02 20:36:33 -07:00
Zong Li
e21d54219c
RISC-V: Add definition of relocation types
Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 20:00:56 -07:00
Zong Li
b8bde0ef12
RISC-V: Add section of GOT.PLT for kernel module
Separate the function symbol address from .plt to .got.plt section.

The original plt entry has trampoline code with symbol address,
there is a 32-bit padding bwtween jar instruction and symbol address.

Extract the symbol address to .got.plt to reduce the module size.

Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 20:00:54 -07:00
Zong Li
ab1ef68e54
RISC-V: Add sections of PLT and GOT for kernel module
The address of external symbols will locate more than 32-bit offset
in 64-bit kernel with sv39 or sv48 virtual addressing.

Module loader emits the GOT and PLT entries for data symbols and
function symbols respectively.

The PLT entry is a trampoline code for jumping to the 64-bit
real address. The GOT entry is just the data symbol address.

Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 20:00:54 -07:00
Andrea Parri
5ce6c1f353
riscv/atomic: Strengthen implementations with fences
Atomics present the same issue with locking: release and acquire
variants need to be strengthened to meet the constraints defined
by the Linux-kernel memory consistency model [1].

Atomics present a further issue: implementations of atomics such
as atomic_cmpxchg() and atomic_add_unless() rely on LR/SC pairs,
which do not give full-ordering with .aqrl; for example, current
implementations allow the "lr-sc-aqrl-pair-vs-full-barrier" test
below to end up with the state indicated in the "exists" clause.

In order to "synchronize" LKMM and RISC-V's implementation, this
commit strengthens the implementations of the atomics operations
by replacing .rl and .aq with the use of ("lightweigth") fences,
and by replacing .aqrl LR/SC pairs in sequences such as:

  0:      lr.w.aqrl  %0, %addr
          bne        %0, %old, 1f
          ...
          sc.w.aqrl  %1, %new, %addr
          bnez       %1, 0b
  1:

with sequences of the form:

  0:      lr.w       %0, %addr
          bne        %0, %old, 1f
          ...
          sc.w.rl    %1, %new, %addr   /* SC-release   */
          bnez       %1, 0b
          fence      rw, rw            /* "full" fence */
  1:

following Daniel's suggestion.

These modifications were validated with simulation of the RISC-V
memory consistency model.

C lr-sc-aqrl-pair-vs-full-barrier

{}

P0(int *x, int *y, atomic_t *u)
{
	int r0;
	int r1;

	WRITE_ONCE(*x, 1);
	r0 = atomic_cmpxchg(u, 0, 1);
	r1 = READ_ONCE(*y);
}

P1(int *x, int *y, atomic_t *v)
{
	int r0;
	int r1;

	WRITE_ONCE(*y, 1);
	r0 = atomic_cmpxchg(v, 0, 1);
	r1 = READ_ONCE(*x);
}

exists (u=1 /\ v=1 /\ 0:r1=0 /\ 1:r1=0)

[1] https://marc.info/?l=linux-kernel&m=151930201102853&w=2
    https://groups.google.com/a/groups.riscv.org/forum/#!topic/isa-dev/hKywNHBkAXM
    https://marc.info/?l=linux-kernel&m=151633436614259&w=2

Suggested-by: Daniel Lustig <dlustig@nvidia.com>
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Albert Ou <albert@sifive.com>
Cc: Daniel Lustig <dlustig@nvidia.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jade Alglave <j.alglave@ucl.ac.uk>
Cc: Luc Maranget <luc.maranget@inria.fr>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Akira Yokosawa <akiyks@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-riscv@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 19:59:44 -07:00
Andrea Parri
0123f4d76c
riscv/spinlock: Strengthen implementations with fences
Current implementations map locking operations using .rl and .aq
annotations.  However, this mapping is unsound w.r.t. the kernel
memory consistency model (LKMM) [1]:

Referring to the "unlock-lock-read-ordering" test reported below,
Daniel wrote:

  "I think an RCpc interpretation of .aq and .rl would in fact
   allow the two normal loads in P1 to be reordered [...]

   The intuition would be that the amoswap.w.aq can forward from
   the amoswap.w.rl while that's still in the store buffer, and
   then the lw x3,0(x4) can also perform while the amoswap.w.rl
   is still in the store buffer, all before the l1 x1,0(x2)
   executes.  That's not forbidden unless the amoswaps are RCsc,
   unless I'm missing something.

   Likewise even if the unlock()/lock() is between two stores.
   A control dependency might originate from the load part of
   the amoswap.w.aq, but there still would have to be something
   to ensure that this load part in fact performs after the store
   part of the amoswap.w.rl performs globally, and that's not
   automatic under RCpc."

Simulation of the RISC-V memory consistency model confirmed this
expectation.

In order to "synchronize" LKMM and RISC-V's implementation, this
commit strengthens the implementations of the locking operations
by replacing .rl and .aq with the use of ("lightweigth") fences,
resp., "fence rw,  w" and "fence r , rw".

C unlock-lock-read-ordering

{}
/* s initially owned by P1 */

P0(int *x, int *y)
{
        WRITE_ONCE(*x, 1);
        smp_wmb();
        WRITE_ONCE(*y, 1);
}

P1(int *x, int *y, spinlock_t *s)
{
        int r0;
        int r1;

        r0 = READ_ONCE(*y);
        spin_unlock(s);
        spin_lock(s);
        r1 = READ_ONCE(*x);
}

exists (1:r0=1 /\ 1:r1=0)

[1] https://marc.info/?l=linux-kernel&m=151930201102853&w=2
    https://groups.google.com/a/groups.riscv.org/forum/#!topic/isa-dev/hKywNHBkAXM
    https://marc.info/?l=linux-kernel&m=151633436614259&w=2

Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Albert Ou <albert@sifive.com>
Cc: Daniel Lustig <dlustig@nvidia.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jade Alglave <j.alglave@ucl.ac.uk>
Cc: Luc Maranget <luc.maranget@inria.fr>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Akira Yokosawa <akiyks@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-riscv@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 19:59:43 -07:00
Andrea Parri
8d235b174a
riscv/barrier: Define __smp_{store_release,load_acquire}
Introduce __smp_{store_release,load_acquire}, and rely on the generic
definitions for smp_{store_release,load_acquire}. This avoids the use
of full ("rw,rw") fences on SMP.

Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 19:59:43 -07:00
Alan Kao
aea4c671fb
riscv/ftrace: Add DYNAMIC_FTRACE_WITH_REGS support
Cc: Greentime Hu <greentime@andestech.com>
Signed-off-by: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 19:59:13 -07:00
Alan Kao
71e736a7d6
riscv/ftrace: Add ARCH_SUPPORTS_FTRACE_OPS support
Cc: Greentime Hu <greentime@andestech.com>
Signed-off-by: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 19:59:12 -07:00
Alan Kao
c15ac4fd60
riscv/ftrace: Add dynamic function tracer support
We now have dynamic ftrace with the following added items:

* ftrace_make_call, ftrace_make_nop (in kernel/ftrace.c)
  The two functions turn each recorded call site of filtered functions
  into a call to ftrace_caller or nops

* ftracce_update_ftrace_func (in kernel/ftrace.c)
  turns the nops at ftrace_call into a call to a generic entry for
  function tracers.

* ftrace_caller (in kernel/mcount-dyn.S)
  The entry where each _mcount call sites calls to once they are
  filtered to be traced.

Also, this patch fixes the semantic problems in mcount.S, which will be
treated as only a reference implementation once we have the dynamic
ftrace.

Cc: Greentime Hu <greentime@andestech.com>
Signed-off-by: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 19:59:12 -07:00
Palmer Dabbelt
cc6c98485f RISC-V: Move to the new GENERIC_IRQ_MULTI_HANDLER handler
The existing mechanism for handling IRQs on RISC-V is pretty ugly: the irq
entry code selects the handler via Kconfig dependencies.

Use the new generic IRQ handling infastructure, which allows boot time
registration of the low level entry handler.

This does add an additional load to the interrupt latency, but there's a
lot of tuning left to be done there on RISC-V so it's OK for now.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Stafford Horne <shorne@gmail.com>
Cc: jonas@southpole.se
Cc: catalin.marinas@arm.com
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux@armlinux.org.uk
Cc: stefan.kristiansson@saunalahti.fi
Cc: openrisc@lists.librecores.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lkml.kernel.org/r/20180307235731.22627-3-palmer@sifive.com
2018-03-14 21:46:29 +01:00
Andrea Parri
ab4af60534
riscv/barrier: Define __smp_{mb,rmb,wmb}
Introduce __smp_{mb,rmb,wmb}, and rely on the generic definitions
for smp_{mb,rmb,wmb}. A first consequence is that smp_{mb,rmb,wmb}
map to a compiler barrier on !SMP (while their definition remains
unchanged on SMP). As a further consequence, smp_load_acquire and
smp_store_release have "fence rw,rw" instead of "fence iorw,iorw".

Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-02-26 08:44:50 -08:00
Linus Torvalds
413879a10b RISC-V changes for 4.16
This tag contains the fixes we'd like to target for the 4.16 merge
 window.  It's not as much as I was originally hoping to do but between
 glibc, the chip, and FOSDEM there just wasn't enough time to get
 everything put together.  As such, this merge window is essentially just
 going to be small changes.  This includes mostly cleanups:
 
 * A build fix failure to the audit test cases.  RISC-V doesn't have
   renameat because the generic syscall ABI moved to renameat2 by the
   time of our port.  The syscall audit test cases don't understand this,
   so I added a trivial fix.  This went through mailing list review
   during the 4.15 merge window, but nobody has picked it up so I think
   it's best to just do this here.
 * The removal of our command-line argument processing code.  The
   "mem_end" stuff was broken and the rest duplicated generic device tree
   code.  The generic code was already being called.
 * Some unused/redundant code has been removed, including
   __ARCH_HAVE_MMU, current_pgdir, and the initialization of init_mm.pgd.
 * SUM is disabled upon taking a trap, which means that user memory is
   protected during traps taking inside copy_{to,from}_user().
 * The sptbr CSR has been renamed to satp in C code.  We haven't changed
   the assembly code in order to maintain compatibility with binutils
   2.29, which doesn't understand the new name.
 
 Additionally, we're adding some new features:
 
 * Basic ftrace support, thanks to Alan Kao!
 * Support for ZONE_DMA32.  This is necessary for all the normal reasons,
   but also to deal with a deficiency in the Xilinx PCIe controller we're
   using on our FPGA-based systems.  While the ZONE_DMA32 addition should
   be sufficient for most uses, it doesn't complete the fix for the
   Xilinx controller.
 * TLB shootdowns now only target the harts where they're necessary,
   instead of applying to all harts in the system.
 
 These patches have all been sitting on our linux-next branch for a while
 now.  Due to time constraints this is all I feel comfortable submitting
 during the 4.16 merge window, hopefully we'll do better next time!
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Merge tag 'riscv-for-linus-4.16-merge_window' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux

Pull RISC-V updates from Palmer Dabbelt:
 "This contains the fixes we'd like to target for the 4.16 merge window.
  It's not as much as I was originally hoping to do but between glibc,
  the chip, and FOSDEM there just wasn't enough time to get everything
  put together. As such, this merge window is essentially just going to
  be small changes. This includes mostly cleanups:

   - A build fix failure to the audit test cases.

     RISC-V doesn't have renameat because the generic syscall ABI moved
     to renameat2 by the time of our port. The syscall audit test cases
     don't understand this, so I added a trivial fix. This went through
     mailing list review during the 4.15 merge window, but nobody has
     picked it up so I think it's best to just do this here.

   - The removal of our command-line argument processing code. The
     "mem_end" stuff was broken and the rest duplicated generic device
     tree code. The generic code was already being called.

   - Some unused/redundant code has been removed, including
     __ARCH_HAVE_MMU, current_pgdir, and the initialization of
     init_mm.pgd.

   - SUM is disabled upon taking a trap, which means that user memory is
     protected during traps taking inside copy_{to,from}_user().

   - The sptbr CSR has been renamed to satp in C code. We haven't
     changed the assembly code in order to maintain compatibility with
     binutils 2.29, which doesn't understand the new name.

  Additionally, we're adding some new features:

   - Basic ftrace support, thanks to Alan Kao!

   - Support for ZONE_DMA32.

     This is necessary for all the normal reasons, but also to deal with
     a deficiency in the Xilinx PCIe controller we're using on our
     FPGA-based systems. While the ZONE_DMA32 addition should be
     sufficient for most uses, it doesn't complete the fix for the
     Xilinx controller.

   - TLB shootdowns now only target the harts where they're necessary,
     instead of applying to all harts in the system.

  These patches have all been sitting on our linux-next branch for a
  while now. Due to time constraints this is all I feel comfortable
  submitting during the 4.16 merge window, hopefully we'll do better
  next time!"

[ Note to self: "harts" is RISC-V speak for "hardware threads".  I had
  to look that up.    - Linus ]

* tag 'riscv-for-linus-4.16-merge_window' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux:
  riscv: inline set_pgdir into its only caller
  riscv: rename sptbr to satp
  riscv: don't read back satp in paging_init
  riscv: remove the unused current_pgdir function
  riscv: add ZONE_DMA32
  RISC-V: Limit the scope of TLB shootdowns
  riscv: disable SUM in the exception handler
  riscv: remove redundant unlikely()
  riscv: remove unused __ARCH_HAVE_MMU define
  riscv/ftrace: Add basic support
  RISC-V: Remove mem_end command line processing
  RISC-V: Remove duplicate command-line parsing logic
  audit: Avoid build failures on systems without renameat
2018-02-07 11:33:08 -08:00
Linus Torvalds
3879ae653a The core framework has a handful of patches this time around, mostly due
to the clk rate protection support added by Jerome Brunet. This feature
 will allow consumers to lock in a certain rate on the output of a clk so
 that things like audio playback don't hear pops when the clk frequency
 changes due to shared parent clks changing rates. Currently the clk
 API doesn't guarantee the rate of a clk stays at the rate you request
 after clk_set_rate() is called, so this new API will allow drivers
 to express that requirement. Beyond this, the core got some debugfs
 pretty printing patches and a couple minor non-critical fixes.
 
 Looking outside of the core framework diff we have some new driver
 additions and the removal of a legacy TI clk driver. Both of these hit
 high in the dirstat. Also, the removal of the asm-generic/clkdev.h file
 causes small one-liners in all the architecture Kbuild files. Overall, the
 driver diff seems to be the normal stuff that comes all the time to
 fix little problems here and there and to support new hardware.
 
 Core:
  - Clk rate protection
  - Symbolic clk flags in debugfs output
  - Clk registration enabled clks while doing bookkeeping updates
 
 New Drivers:
  - Spreadtrum SC9860
  - HiSilicon hi3660 stub
  - Qualcomm A53 PLL, SPMI clkdiv, and MSM8916 APCS
  - Amlogic Meson-AXG
  - ASPEED BMC
 
 Removed Drivers:
  - TI OMAP 3xxx legacy clk (non-DT) support
  - asm*/clkdev.h got removed (not really a driver)
 
 Updates:
  - Renesas FDP1-0 module clock on R-Car M3-W
  - Renesas LVDS module clock on R-Car V3M
  - Misc fixes to pr_err() prints
  - Qualcomm MSM8916 audio fixes
  - Qualcomm IPQ8074 rounded out support for more peripherals
  - Qualcomm Alpha PLL variants
  - Divider code was using container_of() on bad pointers
  - Allwinner DE2 clks on H3
  - Amlogic minor data fixes and dropping of CLK_IGNORE_UNUSED
  - Mediatek clk driver compile test support
  - AT91 PMC clk suspend/resume restoration support
  - PLL issues fixed on si5351
  - Broadcom IProc PLL calculation updates
  - DVFS support for Armada mvebu CPU clks
  - Allwinner fixed post-divider support
  - TI clkctrl fixes and support for newer SoCs
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Merge tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux

Pull clk updates from Stephen Boyd:
 "The core framework has a handful of patches this time around, mostly
  due to the clk rate protection support added by Jerome Brunet.

  This feature will allow consumers to lock in a certain rate on the
  output of a clk so that things like audio playback don't hear pops
  when the clk frequency changes due to shared parent clks changing
  rates. Currently the clk API doesn't guarantee the rate of a clk stays
  at the rate you request after clk_set_rate() is called, so this new
  API will allow drivers to express that requirement.

  Beyond this, the core got some debugfs pretty printing patches and a
  couple minor non-critical fixes.

  Looking outside of the core framework diff we have some new driver
  additions and the removal of a legacy TI clk driver. Both of these hit
  high in the dirstat. Also, the removal of the asm-generic/clkdev.h
  file causes small one-liners in all the architecture Kbuild files.

  Overall, the driver diff seems to be the normal stuff that comes all
  the time to fix little problems here and there and to support new
  hardware.

  Summary:

  Core:
   - Clk rate protection
   - Symbolic clk flags in debugfs output
   - Clk registration enabled clks while doing bookkeeping updates

  New Drivers:
   - Spreadtrum SC9860
   - HiSilicon hi3660 stub
   - Qualcomm A53 PLL, SPMI clkdiv, and MSM8916 APCS
   - Amlogic Meson-AXG
   - ASPEED BMC

  Removed Drivers:
   - TI OMAP 3xxx legacy clk (non-DT) support
   - asm*/clkdev.h got removed (not really a driver)

  Updates:
   - Renesas FDP1-0 module clock on R-Car M3-W
   - Renesas LVDS module clock on R-Car V3M
   - Misc fixes to pr_err() prints
   - Qualcomm MSM8916 audio fixes
   - Qualcomm IPQ8074 rounded out support for more peripherals
   - Qualcomm Alpha PLL variants
   - Divider code was using container_of() on bad pointers
   - Allwinner DE2 clks on H3
   - Amlogic minor data fixes and dropping of CLK_IGNORE_UNUSED
   - Mediatek clk driver compile test support
   - AT91 PMC clk suspend/resume restoration support
   - PLL issues fixed on si5351
   - Broadcom IProc PLL calculation updates
   - DVFS support for Armada mvebu CPU clks
   - Allwinner fixed post-divider support
   - TI clkctrl fixes and support for newer SoCs"

* tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (125 commits)
  clk: aspeed: Handle inverse polarity of USB port 1 clock gate
  clk: aspeed: Fix return value check in aspeed_cc_init()
  clk: aspeed: Add reset controller
  clk: aspeed: Register gated clocks
  clk: aspeed: Add platform driver and register PLLs
  clk: aspeed: Register core clocks
  clk: Add clock driver for ASPEED BMC SoCs
  clk: mediatek: adjust dependency of reset.c to avoid unexpectedly being built
  clk: fix reentrancy of clk_enable() on UP systems
  clk: meson-axg: fix potential NULL dereference in axg_clkc_probe()
  clk: Simplify debugfs registration
  clk: Fix debugfs_create_*() usage
  clk: Show symbolic clock flags in debugfs
  clk: renesas: r8a7796: Add FDP clock
  clk: Move __clk_{get,put}() into private clk.h API
  clk: sunxi: Use CLK_IS_CRITICAL flag for critical clks
  clk: Improve flags doc for of_clk_detect_critical()
  arch: Remove clkdev.h asm-generic from Kbuild
  clk: sunxi-ng: a83t: Add M divider to TCON1 clock
  clk: Prepare to remove asm-generic/clkdev.h
  ...
2018-02-01 16:56:07 -08:00
Linus Torvalds
2382dc9a3e dma mapping changes for Linux 4.16:
This pull requests contains a consolidation of the generic no-IOMMU code,
 a well as the glue code for swiotlb.  All the code is based on the x86
 implementation with hooks to allow all architectures that aren't cache
 coherent to use it.  The x86 conversion itself has been deferred because
 the x86 maintainers were a little busy in the last months.
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Merge tag 'dma-mapping-4.16' of git://git.infradead.org/users/hch/dma-mapping

Pull dma mapping updates from Christoph Hellwig:
 "Except for a runtime warning fix from Christian this is all about
  consolidation of the generic no-IOMMU code, a well as the glue code
  for swiotlb.

  All the code is based on the x86 implementation with hooks to allow
  all architectures that aren't cache coherent to use it.

  The x86 conversion itself has been deferred because the x86
  maintainers were a little busy in the last months"

* tag 'dma-mapping-4.16' of git://git.infradead.org/users/hch/dma-mapping: (57 commits)
  MAINTAINERS: add the iommu list for swiotlb and xen-swiotlb
  arm64: use swiotlb_alloc and swiotlb_free
  arm64: replace ZONE_DMA with ZONE_DMA32
  mips: use swiotlb_{alloc,free}
  mips/netlogic: remove swiotlb support
  tile: use generic swiotlb_ops
  tile: replace ZONE_DMA with ZONE_DMA32
  unicore32: use generic swiotlb_ops
  ia64: remove an ifdef around the content of pci-dma.c
  ia64: clean up swiotlb support
  ia64: use generic swiotlb_ops
  ia64: replace ZONE_DMA with ZONE_DMA32
  swiotlb: remove various exports
  swiotlb: refactor coherent buffer allocation
  swiotlb: refactor coherent buffer freeing
  swiotlb: wire up ->dma_supported in swiotlb_dma_ops
  swiotlb: add common swiotlb_map_ops
  swiotlb: rename swiotlb_free to swiotlb_exit
  x86: rename swiotlb_dma_ops
  powerpc: rename swiotlb_dma_ops
  ...
2018-01-31 11:32:27 -08:00
Christoph Hellwig
4889dec6c8
riscv: inline set_pgdir into its only caller
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30 19:16:17 -08:00
Christoph Hellwig
7549cdf59d
riscv: rename sptbr to satp
satp is the name used by the current privileged spec 1.10, use it
instead of the old name.  The most recent release binutils release
(2.29) doesn't know about the satp name yet, so stick to the name from
the previous privileged ISA release and comment on the fact.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30 19:16:12 -08:00
Christoph Hellwig
0ca7a0b7c1
riscv: remove the unused current_pgdir function
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30 19:16:00 -08:00
Andrew Waterman
f1b65f20fb
RISC-V: Limit the scope of TLB shootdowns
RISC-V systems perform TLB shootdows via the SBI, which currently
performs an IPI to each of the remote harts which then performs a local
TLB flush.  This process is a bit on the slow side, but we can at least
speed it up for some common cases by restricting the set of harts to
shoot down to the actual set of harts that are currently participating
in the given mm context, as opposed to the entire system.

This should provide a measurable performance increase, but we haven't
measured it.  Regardless, it seems like obviously the right thing to do
here.

Signed-off-by: Andrew Waterman <andrew@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2018-01-30 19:13:33 -08:00
Tobias Klauser
0b5030c8c0
riscv: remove unused __ARCH_HAVE_MMU define
The __ARCH_HAVE_MMU define is (and was) used nowhere in the tree and
also doesn't appear to be used by any libc.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30 19:11:43 -08:00
Alan Kao
10626c32e3
riscv/ftrace: Add basic support
This patch contains basic ftrace support for RV64I platform.
Specifically, function tracer (HAVE_FUNCTION_TRACER), function graph
tracer (HAVE_FUNCTION_GRAPH_TRACER), and a frame pointer test
(HAVE_FUNCTION_GRAPH_FP_TEST) are implemented following the
instructions in Documentation/trace/ftrace-design.txt.

Note that the functions in both ftrace.c and setup.c should not be
hooked with the compiler's -pg option: to prevent infinite self-
referencing for the former, and to ignore early setup stuff for the
latter.

Signed-off-by: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30 19:10:54 -08:00
Linus Torvalds
49f9c3552c init_task out-of-lining
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Merge tag 'init_task-20180117' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull init_task initializer cleanups from David Howells:
 "It doesn't seem useful to have the init_task in a header file rather
  than in a normal source file. We could consolidate init_task handling
  instead and expand out various macros.

  Here's a series of patches that consolidate init_task handling:

   (1) Make THREAD_SIZE available to vmlinux.lds for cris, hexagon and
       openrisc.

   (2) Alter the INIT_TASK_DATA linker script macro to set
       init_thread_union and init_stack rather than defining these in C.

       Insert init_task and init_thread_into into the init_stack area in
       the linker script as appropriate to the configuration, with
       different section markers so that they end up correctly ordered.

       We can then get merge ia64's init_task.c into the main one.

       We then have a bunch of single-use INIT_*() macros that seem only
       to be macros because they used to be used per-arch. We can then
       expand these in place of the user and get rid of a few lines and
       a lot of backslashes.

   (3) Expand INIT_TASK() in place.

   (4) Expand in place various small INIT_*() macros that are defined
       conditionally. Expand them and surround them by #if[n]def/#endif
       in the .c file as it takes fewer lines.

   (5) Expand INIT_SIGNALS() and INIT_SIGHAND() in place.

   (6) Expand INIT_STRUCT_PID in place.

  These macros can then be discarded"

* tag 'init_task-20180117' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  Expand INIT_STRUCT_PID and remove
  Expand the INIT_SIGNALS and INIT_SIGHAND macros and remove
  Expand various INIT_* macros and remove
  Expand INIT_TASK() in init/init_task.c and remove
  Construct init thread stack in the linker script rather than by union
  openrisc: Make THREAD_SIZE available to vmlinux.lds
  hexagon: Make THREAD_SIZE available to vmlinux.lds
  cris: Make THREAD_SIZE available to vmlinux.lds
2018-01-29 09:08:34 -08:00
Christoph Hellwig
c5cd037d1c dma-mapping: provide a generic asm/dma-mapping.h
For architectures that just use the generic dma_noop_ops we can provide
a generic version of dma-mapping.h.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-01-15 09:35:05 +01:00
David Howells
0500871f21 Construct init thread stack in the linker script rather than by union
Construct the init thread stack in the linker script rather than doing it
by means of a union so that ia64's init_task.c can be got rid of.

The following symbols are then made available from INIT_TASK_DATA() linker
script macro:

	init_thread_union
	init_stack

INIT_TASK_DATA() also expands the region to THREAD_SIZE to accommodate the
size of the init stack.  init_thread_union is given its own section so that
it can be placed into the stack space in the right order.  I'm assuming
that the ia64 ordering is correct and that the task_struct is first and the
thread_info second.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Tested-by: Will Deacon <will.deacon@arm.com> (arm64)
Tested-by: Palmer Dabbelt <palmer@sifive.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
2018-01-09 23:21:02 +00:00
Christoph Hellwig
b8ee205af4 riscv: remove the unused dma_capable helper
Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-01-09 16:28:39 +01:00
Christoph Hellwig
1125203c13
riscv: rename SR_* constants to match the spec
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-07 15:14:39 -08:00
Christoph Hellwig
c163fb38ca
riscv: remove CONFIG_MMU ifdefs
The RISC-V port doesn't suport a nommu mode, so there is no reason
to provide some code only under a CONFIG_MMU ifdef.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-07 15:14:39 -08:00
Palmer Dabbelt
9e49a4ed07
RISC-V: Make __NR_riscv_flush_icache visible to userspace
We were hoping to avoid making this visible to userspace, but it looks
like we're going to have to because QEMU's user-mode emulation doesn't
want to emulate a vDSO.  Having vDSO-only system calls was a bit
unothodox anyway, so I think in this case it's OK to just make the
actual system call number public.

This patch simply moves the definition of __NR_riscv_flush_icache
availiable to userspace, which results in the deletion of the now empty
vdso-syscalls.h.

Changes since v1:

* I've moved the definition into uapi/asm/syscalls.h rathen than
  uapi/asm/unistd.h.  This allows me to keep asm/unistd.h, so we can
  keep the syscall table macros sane.
* As a side effect of the above, this no longer disables all system
  calls on RISC-V.  Whoops!

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-07 15:14:37 -08:00
Stephen Boyd
e0af0c1610 arch: Remove clkdev.h asm-generic from Kbuild
Now that every architecture is using the generic clkdev.h file
and we no longer include asm/clkdev.h anywhere in the tree, we
can remove it.

Cc: Russell King <linux@armlinux.org.uk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: <linux-arch@vger.kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2018-01-03 09:02:11 -08:00
Palmer Dabbelt
3cfa500808
RISC-V: Resurrect smp_mb__after_spinlock()
I removed this last week because of an incorrect comment:
smp_mb__after_spinlock() is actually still used, and is necessary on
RISC-V.  It's been resurrected, with a comment that describes what it
actually does this time.  Thanks to Andrea for finding the bug!

Fixes: 3343eb6806 ("RISC-V: Remove smb_mb__{before,after}_spinlock()")
CC: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-12-11 07:51:07 -08:00
Hendrik Brueckner
c895f6f703 bpf: correct broken uapi for BPF_PROG_TYPE_PERF_EVENT program type
Commit 0515e5999a ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT
program type") introduced the bpf_perf_event_data structure which
exports the pt_regs structure.  This is OK for multiple architectures
but fail for s390 and arm64 which do not export pt_regs.  Programs
using them, for example, the bpf selftest fail to compile on these
architectures.

For s390, exporting the pt_regs is not an option because s390 wants
to allow changes to it.  For arm64, there is a user_pt_regs structure
that covers parts of the pt_regs structure for use by user space.

To solve the broken uapi for s390 and arm64, introduce an abstract
type for pt_regs and add an asm/bpf_perf_event.h file that concretes
the type.  An asm-generic header file covers the architectures that
export pt_regs today.

The arch-specific enablement for s390 and arm64 follows in separate
commits.

Reported-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Fixes: 0515e5999a ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT program type")
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-and-tested-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-05 15:02:40 +01:00
Palmer Dabbelt
3b62de26cf
RISC-V: Fixes for clean allmodconfig build
Olaf said: Here's a short series of patches that produces a working
allmodconfig. Would be nice to see them go in so we can add build
coverage.

I've dropped patches 8 and 10 from the original set:

* [PATCH 08/10] (RISC-V: Set __ARCH_WANT_RENAMEAT to pick up generic
  version) has a better fix that I've sent out for review, we don't want
  renameat.
* [PATCH 10/10] (input: joystick: riscv has get_cycles) has already been
  taken into Dmitry Torokhov's tree.
2017-12-01 13:31:31 -08:00
Palmer Dabbelt
7382fbdeae
RISC-V: __io_writes should respect the length argument 2017-12-01 13:14:36 -08:00
Palmer Dabbelt
07f8ba7439 RISC-V: User-Visible Changes
This merge contains the user-visible, ABI-breaking changes that we want
to make sure we have in Linux before our first release.   Highlights
include:

* VDSO entries for clock_get/gettimeofday/getcpu have been added.  These
  are simple syscalls now, but we want to let glibc use them from the
  start so we can make them faster later.
* A VDSO entry for instruction cache flushing has been added so
  userspace can flush the instruction cache.
* The VDSO symbol versions for __vdso_cmpxchg{32,64} have been removed,
  as those VDSO entries don't actually exist.

Conflicts:
        arch/riscv/include/asm/tlbflush.h
2017-12-01 13:12:10 -08:00
Palmer Dabbelt
da894ff100 RISC-V: __io_writes should respect the length argument
Whoops -- I must have just been being an idiot again.  Thanks to Segher
for finding the bug :).

CC: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-12-01 13:09:57 -08:00
Andrew Waterman
921ebd8f2c RISC-V: Allow userspace to flush the instruction cache
Despite RISC-V having a direct 'fence.i' instruction available to
userspace (which we can't trap!), that's not actually viable when
running on Linux because the kernel might schedule a process on another
hart.  There is no way for userspace to handle this without invoking the
kernel (as it doesn't know the thread->hart mappings), so we've defined
a RISC-V specific system call to flush the instruction cache.

This patch adds both a system call and a VDSO entry.  If possible, we'd
like to avoid having the system call be considered part of the
user-facing ABI and instead restrict that to the VDSO entry -- both just
in general to avoid having additional user-visible ABI to maintain, and
because we'd prefer that users just call the VDSO entry because there
might be a better way to do this in the future (ie, one that doesn't
require entering the kernel).

Signed-off-by: Andrew Waterman <andrew@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30 12:58:29 -08:00
Andrew Waterman
08f051eda3 RISC-V: Flush I$ when making a dirty page executable
The RISC-V ISA allows for instruction caches that are not coherent WRT
stores, even on a single hart.  As a result, we need to explicitly flush
the instruction cache whenever marking a dirty page as executable in
order to preserve the correct system behavior.

Local instruction caches aren't that scary (our implementations actually
flush the cache, but RISC-V is defined to allow higher-performance
implementations to exist), but RISC-V defines no way to perform an
instruction cache shootdown.  When explicitly asked to do so we can
shoot down remote instruction caches via an IPI, but this is a bit on
the slow side.

Instead of requiring an IPI to all harts whenever marking a page as
executable, we simply flush the currently running harts.  In order to
maintain correct behavior, we additionally mark every other hart as
needing a deferred instruction cache which will be taken before anything
runs on it.

Signed-off-by: Andrew Waterman <andrew@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30 12:58:25 -08:00
Olof Johansson
741fc3ff3a RISC-V: Add missing include
Fixes:

include/asm-generic/mm_hooks.h:20:11: warning: 'struct vm_area_struct' declared inside parameter list will not be visible outside of this definition or declaration
include/asm-generic/mm_hooks.h:19:38: warning: 'struct mm_struct' declared inside parameter list will not be visible outside of this definition or declaration

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30 10:34:47 -08:00
Olof Johansson
4a41d5dbb0 RISC-V: Use define for get_cycles like other architectures
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30 10:12:21 -08:00
Olof Johansson
fe2726af9f RISC-V: io.h: type fixes for warnings
include <linux/types.h> for __iomem definition. Also, add volatile to
iounmap() like other architectures have it to avoid "discarding
volatile" warnings from some drivers.

Finally, explicitly promote the base address for INB/OUTB functions to
avoid some old legacy drivers complaining about int-to-ptr promotions.
The drivers are unlikely to work but they're included in allmodconfig
so the warnings are noisy.

Fixes, among other warnings, these with allmodconfig:

../arch/riscv/include/asm/io.h:24:21: error: expected '=', ',', ';', 'asm' or '__attribute__' before '*' token
 extern void __iomem *ioremap(phys_addr_t offset, unsigned long size);

sound/pci/echoaudio/echoaudio.c: In function 'snd_echo_free':
sound/pci/echoaudio/echoaudio.c:1879:10: warning: passing argument 1 of 'iounmap' discards 'volatile' qualifier from pointer target type [-Wdiscarded-qualifiers]

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30 10:01:10 -08:00
Olof Johansson
5e6f82b0fe RISC-V: use RISCV_{INT,SHORT} instead of {INT,SHORT} for asm macros
INT and SHORT are used by some drivers that pull in the include files,
so prefixing helps avoid namespace conflicts. Other constructs in the
same file already uses this.

Fixes, among others, these warnings with allmodconfig:

../sound/core/pcm_misc.c:43:0: warning: "INT" redefined
 #define INT __force int

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30 10:01:10 -08:00
Olof Johansson
5ddf755e44 RISC-V: use generic serial.h
Fixes this from allmodconfig:

drivers/tty/serial/earlycon.c:27:10: fatal error: asm/serial.h: No such file or directory

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30 10:01:10 -08:00
Palmer Dabbelt
bf73055273 RISC-V: remove spin_unlock_wait()
This was removed from the other architectures in commit
952111d7db ("arch: Remove spin_unlock_wait() arch-specific
definitions").  That landed between when we got upstream and when our
patches were reviewed, so this is a followup patch.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-28 14:06:31 -08:00
Palmer Dabbelt
c901e45a99 RISC-V: sfence.vma orderes the instruction cache
This is just a comment change, but it's one that bit me on the mailing
list.  It turns out that issuing a `sfence.vma` enforces instruction
cache ordering in addition to TLB ordering.  This isn't explicitly
called out in the ISA manual, but Andrew will be making that more clear
in a future revision.

CC: Andrew Waterman <andrew@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-28 14:06:17 -08:00
Palmer Dabbelt
21db403660 RISC-V: Add READ_ONCE in arch_spin_is_locked()
This was just incorrect in the original version.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-28 14:05:04 -08:00
Palmer Dabbelt
9347ce54cd RISC-V: __test_and_op_bit_ord should be strongly ordered
I mis-read the documentation.  After looking at it again the
documentation is actually as clear as it can be, it's just that I didn't
actually read it in order and therefor did the wrong thing.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-28 14:04:05 -08:00
Palmer Dabbelt
3343eb6806 RISC-V: Remove smb_mb__{before,after}_spinlock()
These are obselete.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-28 14:03:55 -08:00
Palmer Dabbelt
61a60d35b7 RISC-V: Remove __smp_bp__{before,after}_atomic
These duplicate the asm-generic definitions are therefor aren't useful.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-28 14:03:48 -08:00
Palmer Dabbelt
8286d51a6c RISC-V: Comment on why {,cmp}xchg is ordered how it is
This is another memory model FIXME.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-28 14:03:29 -08:00
Palmer Dabbelt
4650d02ad2 RISC-V: Remove unused arguments from ATOMIC_OP
Our atomics are generated from a complicated series of preprocessor
macros, each of which is slightly different from the last.  When writing
the macros I'd accidentally left some unused arguments floating around.
This patch removes the unused macro arguments.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-11-28 13:53:24 -08:00
Linus Torvalds
b293fca43b RISC-V Port for Linux 4.15 v9
This tag contains the core RISC-V Linux port, which has been through
 nine rounds of review on various mailing lists.  The port is not
 complete: there's some cleanup patches moving through the review
 process, a whole bunch of drivers that need some work, and a lot of
 feature additions that will be needed.
 
 The patches contained in this tag have been through nine rounds of
 review on the various mailing lists.  I have some outstanding cleanup
 patches, but since there's been so much review on these patches I
 thought it would be best to submit them as-is and then submit explicit
 cleanup patches so everyone can review them.  This first patch set is
 big enough that it's a bit of a pain to constantly rewrite, and it's
 caused a few headaches with various contributors.
 
 The port is definately a work in progress.  While what's there builds
 and boots with 4.14, it's a bit hard to actually see anything happen
 because there are no device drivers yet.  I maintain a staging branch
 that contains all the device drivers and cleanup that actually works,
 but those patches won't all be ready for a while.  I'd like to get what
 we currently have into your tree so everyone can start working from a
 single base -- of particular importance is allowing the glibc
 upstreaming process to proceed so we can sort out any possibly lingering
 user-visible ABI problems we might have.
 
 Copied below is the ChangeLog that contains the history of this patch
 set:
 
 (v9) As per suggestions on our v8 patch set, I've split the core architecture code
 out from our drivers and would like to submit this patch set to be included
 into linux-next, with the goal being to be merged in during the next merge
 window.  This patch set is based on 4.14-rc2, but if it's better to have it
 based on something else then I can change it around.
 
 This patch set contains just the core arch code for RISC-V, so while it builds
 an nominally boots, you can't print or take an interrupt so it's not that
 useful.  If you're looking to actually boot a system it would probably be
 better to use the full patch set listed below.
 
 We've collected a handful of tags from reviewers, and the remainder of the
 patch set only got minimal feedback last time.  Here's what changed:
 
  * We now use the device tree to initialize the timer driver so it's less
    tighly coupled with the arch port.
  * I cleaned up the defconfigs -- there's actually now just one, and it's
    empty.  For now I think we're OK with what the kernel sets as defaults, but
    I anticipate we'll begin to expand this as people start to use the port
    more.
  * The VDSO symbols version is sane.
  * We WFI while spinning in the boot loop.
  * A handful of comments have been added.
 
 While there are still a handful of FIXMEs in this patch set, we've started to
 get enough interest from various users and contributors that maintaining an out
 of tree patch set is starting to become a big burden.  Hopefully the patches
 are good enough to merge now, which will at least get everyone working in a
 more reasonable manner as we clean up the remaining issues.
 
 This patch set is also availiable on github
 
   https://github.com/riscv/riscv-linux/tree/riscv-for-submission-v9-arch
 
 as is the entire patch set necessary to get a more functional RISC-V system up
 and running, including a handful of patches that aren't ready for upstream yet.
 
   https://github.com/riscv/riscv-linux/tree/riscv-for-submission-v9
 
 Hopefully I've managed to get everyone's feedback
 
 Here's the change highlights from the whole patch set:
 
 (v8) I know it may not be the ideal time to submit a patch set right now, as
 it's the middle of the merge window, but things have calmed down quite a bit in
 the last month so I thought it would be good to get everyone on the same page.
 There's been a handful of changes since the last patch set, but most of them
 are fairly minor:
 
 * We changed PAGE_OFFSET to allowing mapping more physical memory on 64-bit
   systems.  This is user configurable, as it triggers a different code model
   that generates slightly less efficient code.
 * The device tree binding documentation is back, I'd managed to lose it at some
   point.
 * We now pass the atomic64 test suite.  The SBI timer driver has been
 * refactored.
 
 (v7) It's been a while since my last patch set, but the changes han been fairly
 minimal:
 
  * The PCI cleanup patches have been dropped, we'll do them as a separate patch
    set later.
  * We've the Kconfig entries from CONFIG_ISA_* to CONFIG_RISCV_ISA_*, to make
    grep easier.
  * There have been a handful of memory model related tweaks in I/O land,
    particularly relating the PCI and the upcoming platform specification.
    There are significant comments in the relevant files.  This is still a WIP,
    but I think we're close to getting as good as we're going to get until we
    end up with some more specifications.
 
 (v6) As it's been only a day since the v5 patch set, the changes are pretty
 minimal:
 
  * The patch set is now based on linux-next/master, which I believe is a better
    base now that we're getting closer to upstream.
  * EARLY_PRINTK is no longer an option.  Since the SBI console is reasonable,
    there's no penalty to enabling it (and thus no benefit to disabling it).
  * The mmap syscalls were refactored a bit.
 
 (v5) Things have really started to calm down, so this is fairly similar to the
 v4 patch set.  The most interesting changes include:
 
  * We've moved back to a single patch set.
 
  * SMP support has been fixed, I was accidentally running on a non-SMP
    configuration.  There were various mistakes all over the tree as a result of
    this.
 
  * The cmpxchg syscalls have been removed, as they were deemed a bad idea.  As
    a result, RISC-V Linux systems mandate the A extension.  The corresponding
    Kconfig entry to enable builds on non-A systems has been removed.
 
  * A few more atomic fixes: mostly fence changes, but those resulted in a
    handful of additional macros that were no longer necessary.
 
  * riscv_early_sie has been removed.
 
 (v4) There have only been a few changes since the v3 patch set:
 
  * The cmpxchg64 syscall is no longer enabled on 32-bit systems.  It's not
    possible to provide this on SMP systems, and it's not necessary as glibc
    knows not to call it.
 
  * We provide a ELF_HWCAP so users can determine the ISA of the machine the
    kernel is running on.
 
  * The multi-line comments are in a better form.
 
  * There were a handful of headers that could be replaced with the asm-generic
    versions, and a few unnecessary definitions.
 
  * We no longer use printk, but instead use pr_*.
 
  * A few Kconfig and defconfig entries have been cleaned up.
 
 (v3) A highlight of the changes since the v2 patch set includes:
 
  * We've split out all our drivers into separate patch sets, which I've already
    sent out to the relevant maintainers.  I haven't included those patches in
    this patch set, but some of them are necessary to build our port.  A git
    tree that contains all our patch sets merged together lives at
    <https://github.com/riscv/riscv-linux/tree/riscv-for-submission-v3>.
 
  * The patch set is now split up differently: rather than being split per
    directory it is split per topic.  Hopefully this will make it easier to
    review the port on the mailing list.  The split is a bit rough, so you
    probably still want to look at the patch set as a whole.
 
  * atomic.h has been completely rewritten and is hopefully now correct.  I've
    attempted to sanitize the various other memory model related code as well,
    and I think it should all be sane now aside from a handful of FIXMEs
    commented in the code.
 
  * We've changed the cmpexchg syscall to always exist and to not be
    multiplexed.  There is also a VDSO entry for compare and exchange, which
    allows kernels with the A extension to execute user code without the A
    extension reasonably fast.
 
  * Our user-visible register state now contains enough space for the Q
    extension for 128-bit floating point, as well as a few words to allow
    extensibility to future ISA extensions like the eventual V extension for
    vectors.
 
  * A handful of driver cleanups, but these have been split into separate patch
    sets now so I won't duplicate them here.
 
 (v2) A highlight of the changes since the v1 patch set includes:
 
   * We've split out our drivers into the right places, which means now there's
     a lot more patches.  I'll be submitting these patches to various subsystem
     maintainers and including them in any future RISC-V patch sets until
     they've been merged.
 
   * The SBI console driver has been completely rewritten to use the HVC helpers
     and is now significantly smaller.
 
   * We've begun to use weaker barriers as opposed to just the big "fence".
     There's still some work to do here, specifically:
     - We need fences in the relaxed MMIO functions.
     - The non-relaxed MMIO functions are missing R/W bits on their fences.
     - Many AMOs need the aq and rl bits set.
 
   * We now have thread_info in task_struct.  As a result, sscratch now contains
     TP instead of SP.  This was necessary because thread_info is no longer on
     the stack.
 
   * A few shared routines have been added that we use instead of creating
     another arch copy.
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Merge tag 'riscv-for-linus-4.15-arch-v9-premerge' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux

Pull RISC-V architecture support from Palmer Dabbelt:
 "This contains the core RISC-V Linux port, which has been through nine
  rounds of review on various mailing lists. The port is not complete:
  there's some cleanup patches moving through the review process, a
  whole bunch of drivers that need some work, and a lot of feature
  additions that will be needed.

  The patches contained in this tag have been through nine rounds of
  review on the various mailing lists. I have some outstanding cleanup
  patches, but since there's been so much review on these patches I
  thought it would be best to submit them as-is and then submit explicit
  cleanup patches so everyone can review them. This first patch set is
  big enough that it's a bit of a pain to constantly rewrite, and it's
  caused a few headaches with various contributors.

  The port is definately a work in progress. While what's there builds
  and boots with 4.14, it's a bit hard to actually see anything happen
  because there are no device drivers yet. I maintain a staging branch
  that contains all the device drivers and cleanup that actually works,
  but those patches won't all be ready for a while. I'd like to get what
  we currently have into your tree so everyone can start working from a
  single base -- of particular importance is allowing the glibc
  upstreaming process to proceed so we can sort out any possibly
  lingering user-visible ABI problems we might have.

  Copied below is the ChangeLog that contains the history of this patch
  set:

   (v9) As per suggestions on our v8 patch set, I've split the core
        architecture code out from our drivers and would like to submit
        this patch set to be included into linux-next, with the goal
        being to be merged in during the next merge window. This patch
        set is based on 4.14-rc2, but if it's better to have it based on
        something else then I can change it around.

        This patch set contains just the core arch code for RISC-V, so
        while it builds an nominally boots, you can't print or take an
        interrupt so it's not that useful. If you're looking to actually
        boot a system it would probably be better to use the full patch
        set listed below.

        We've collected a handful of tags from reviewers, and the
        remainder of the patch set only got minimal feedback last time.
        Here's what changed:

         - We now use the device tree to initialize the timer driver so
           it's less tighly coupled with the arch port.

         - I cleaned up the defconfigs -- there's actually now just one,
           and it's empty. For now I think we're OK with what the kernel
           sets as defaults, but I anticipate we'll begin to expand this
           as people start to use the port more.

         - The VDSO symbols version is sane.

         - We WFI while spinning in the boot loop.

         - A handful of comments have been added.

        While there are still a handful of FIXMEs in this patch set,
        we've started to get enough interest from various users and
        contributors that maintaining an out of tree patch set is
        starting to become a big burden. Hopefully the patches are good
        enough to merge now, which will at least get everyone working in
        a more reasonable manner as we clean up the remaining issues.

   (v8) I know it may not be the ideal time to submit a patch set right
        now, as it's the middle of the merge window, but things have
        calmed down quite a bit in the last month so I thought it would
        be good to get everyone on the same page. There's been a handful
        of changes since the last patch set, but most of them are fairly
        minor:

         - We changed PAGE_OFFSET to allowing mapping more physical
           memory on 64-bit systems. This is user configurable, as it
           triggers a different code model that generates slightly less
           efficient code.

         - The device tree binding documentation is back, I'd managed to
           lose it at some point.

         - We now pass the atomic64 test suite

         - The SBI timer driver has been refactored.

   (v7) It's been a while since my last patch set, but the changes han
        been fairly minimal:

         - The PCI cleanup patches have been dropped, we'll do them as a
           separate patch set later.

         - We've the Kconfig entries from CONFIG_ISA_* to
           CONFIG_RISCV_ISA_*, to make grep easier.

         - There have been a handful of memory model related tweaks in
           I/O land, particularly relating the PCI and the upcoming
           platform specification. There are significant comments in the
           relevant files. This is still a WIP, but I think we're close
           to getting as good as we're going to get until we end up with
           some more specifications.

   (v6) As it's been only a day since the v5 patch set, the changes are
        pretty minimal:

         - The patch set is now based on linux-next/master, which I
           believe is a better base now that we're getting closer to
           upstream.

         - EARLY_PRINTK is no longer an option. Since the SBI console is
           reasonable, there's no penalty to enabling it (and thus no
           benefit to disabling it).

         - The mmap syscalls were refactored a bit.

   (v5) Things have really started to calm down, so this is fairly
        similar to the v4 patch set. The most interesting changes
        include:

         - We've moved back to a single patch set.

         - SMP support has been fixed, I was accidentally running on a
           non-SMP configuration. There were various mistakes all over
           the tree as a result of this.

         - The cmpxchg syscalls have been removed, as they were deemed a
           bad idea. As a result, RISC-V Linux systems mandate the A
           extension. The corresponding Kconfig entry to enable builds
           on non-A systems has been removed.

         - A few more atomic fixes: mostly fence changes, but those
           resulted in a handful of additional macros that were no
           longer necessary.

         - riscv_early_sie has been removed.

   (v4) There have only been a few changes since the v3 patch set:

         - The cmpxchg64 syscall is no longer enabled on 32-bit systems.
           It's not possible to provide this on SMP systems, and it's
           not necessary as glibc knows not to call it.

         - We provide a ELF_HWCAP so users can determine the ISA of the
           machine the kernel is running on.

         - The multi-line comments are in a better form.

         - There were a handful of headers that could be replaced with
           the asm-generic versions, and a few unnecessary definitions.

         - We no longer use printk, but instead use pr_*.

         - A few Kconfig and defconfig entries have been cleaned up.

   (v3) A highlight of the changes since the v2 patch set includes:

         - We've split out all our drivers into separate patch sets,
           which I've already sent out to the relevant maintainers. I
           haven't included those patches in this patch set, but some of
           them are necessary to build our port.

         - The patch set is now split up differently: rather than being
           split per directory it is split per topic. Hopefully this
           will make it easier to review the port on the mailing list.
           The split is a bit rough, so you probably still want to look
           at the patch set as a whole.

         - atomic.h has been completely rewritten and is hopefully now
           correct. I've attempted to sanitize the various other memory
           model related code as well, and I think it should all be sane
           now aside from a handful of FIXMEs commented in the code.

         - We've changed the cmpexchg syscall to always exist and to not
           be multiplexed. There is also a VDSO entry for compare and
           exchange, which allows kernels with the A extension to
           execute user code without the A extension reasonably fast.

         - Our user-visible register state now contains enough space for
           the Q extension for 128-bit floating point, as well as a few
           words to allow extensibility to future ISA extensions like
           the eventual V extension for vectors.

         - A handful of driver cleanups, but these have been split into
           separate patch sets now so I won't duplicate them here.

   (v2) A highlight of the changes since the v1 patch set includes:

         - We've split out our drivers into the right places, which
           means now there's a lot more patches. I'll be submitting
           these patches to various subsystem maintainers and including
           them in any future RISC-V patch sets until they've been
           merged.

         - The SBI console driver has been completely rewritten to use
           the HVC helpers and is now significantly smaller.

         - We've begun to use weaker barriers as opposed to just the big
           "fence". There's still some work to do here, specifically:
            - We need fences in the relaxed MMIO functions.
            - The non-relaxed MMIO functions are missing R/W bits on their fences.
            - Many AMOs need the aq and rl bits set.

         - We now have thread_info in task_struct. As a result, sscratch
           now contains TP instead of SP. This was necessary because
           thread_info is no longer on the stack.

         - A few shared routines have been added that we use instead of
           creating another arch copy"

Reviewed-by: Arnd Bergmann <arnd@arndb.de>

* tag 'riscv-for-linus-4.15-arch-v9-premerge' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux:
  RISC-V: Build Infrastructure
  RISC-V: User-facing API
  RISC-V: Paging and MMU
  RISC-V: Device, timer, IRQs, and the SBI
  RISC-V: Task implementation
  RISC-V: ELF and module implementation
  RISC-V: Generic library routines and assembly
  RISC-V: Atomic and Locking Code
  RISC-V: Init and Halt Code
  dt-bindings: RISC-V CPU Bindings
  lib: Add shared copies of some GCC library routines
  MAINTAINERS: Add RISC-V
2017-11-15 10:49:15 -08:00
Palmer Dabbelt
fbe934d69e RISC-V: Build Infrastructure
This patch contains all the build infrastructure that actually enables
the RISC-V port.  This includes Makefiles, linker scripts, and Kconfig
files.  It also contains the only top-level change, which adds RISC-V to
the list of architectures that need a sed run to produce the ARCH
variable when building locally.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:49 -07:00
Palmer Dabbelt
e2c0cdfba7 RISC-V: User-facing API
This patch contains code that is in some way visible to the user:
including via system calls, the VDSO, module loading and signal
handling.  It also contains some generic code that is ABI visible.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:48 -07:00
Palmer Dabbelt
07037db5d4 RISC-V: Paging and MMU
This patch contains code to manage the RISC-V MMU, including definitions
of the page tables and the page walking code.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:47 -07:00
Palmer Dabbelt
6d60b6ee0c RISC-V: Device, timer, IRQs, and the SBI
This patch contains code that interfaces with devices that are mandated
by the RISC-V supervisor specification and that don't have explicit
drivers anywhere else in the tree.  This includes the staticly defined
interrupts, the CSR-mapped timer, and virtualized SBI devices.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:47 -07:00
Palmer Dabbelt
7db91e57a0 RISC-V: Task implementation
This patch contains the implementation of tasks on RISC-V, most of which
is involved in task switching.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:46 -07:00
Palmer Dabbelt
2129a235c0 RISC-V: ELF and module implementation
This patch contains the code that interfaces with ELF objects on RISC-V
systems, the vast majority of which is present to load kernel modules.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:46 -07:00
Palmer Dabbelt
5d8544e2d0 RISC-V: Generic library routines and assembly
This patch contains code that is more specific to the RISC-V ISA than it
is to Linux.  It contains string and math operations, C wrappers for
various assembly instructions, stack walking code, and uaccess.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:45 -07:00
Palmer Dabbelt
fab957c11e RISC-V: Atomic and Locking Code
This contains all the code that directly interfaces with the RISC-V
memory model.  While this code corforms to the current RISC-V ISA
specifications (user 2.2 and priv 1.10), the memory model is somewhat
underspecified in those documents.  There is a working group that hopes
to produce a formal memory model by the end of the year, but my
understanding is that the basic definitions we're relying on here won't
change significantly.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:45 -07:00
Palmer Dabbelt
76d2a0493a RISC-V: Init and Halt Code
This contains the various __init C functions, the initial assembly
kernel entry point, and the code to reset the system.  When a file was
init-related this patch contains the entire file.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:44 -07:00