Commit Graph

133 Commits

Author SHA1 Message Date
Palmer Dabbelt
41fb9d54f1
Revert "RISC-V: Make BSS section as the last section in vmlinux.lds.S"
At least BBL relies on the flat binaries containing all the bytes in the
actual image to exist in the file.  Before this revert the flat images
dropped the trailing zeros, which caused BBL to put its copy of the
device tree where Linux thought the BSS was, which wreaks all sorts of
havoc.  Manifesting the bug is a bit subtle because BBL aligns
everything to 2MiB page boundaries, but with large enough kernels you're
almost certain to get bitten by the bug.

While moving the sections around isn't a great long-term fix, it will at
least avoid producing broken images.

This reverts commit 22e6a2e14c.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2019-02-11 15:24:45 -08:00
Guo Ren
28198c4639
riscv: fixup max_low_pfn with PFN_DOWN.
max_low_pfn should be pfn_size not byte_size.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Signed-off-by: Mao Han <mao_han@c-sky.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-23 17:51:53 -08:00
Andreas Schwab
2bb10639f1
RISC-V: fix bad use of of_node_put
of_find_node_by_type already calls of_node_put, don't call it again.

Fixes: 94f9bf118f ("RISC-V: Fix of_node_* refcount")
Signed-off-by: Andreas Schwab <schwab@suse.de>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-23 12:56:19 -08:00
Vincent Chen
99fd6e875d
RISC-V: Add _TIF_NEED_RESCHED check for kernel thread when CONFIG_PREEMPT=y
The cond_resched() can be used to yield the CPU resource if
CONFIG_PREEMPT is not defined. Otherwise, cond_resched() is a dummy
function. In order to avoid kernel thread occupying entire CPU,
when CONFIG_PREEMPT=y, the kernel thread needs to follow the
rescheduling mechanism like a user thread.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-23 12:56:19 -08:00
Palmer Dabbelt
801009424e
Fix a handful of audit-related issue
This is sort of a mix between a new feature and a bug fix.  I've managed
to screw up merging this patch set a handful of times but I think it's
OK this time around.  The main new feature here is audit support for
RISC-V, with some fixes to audit-related bugs that cropped up along the
way:

* The addition of NR_syscalls into unistd.h, which is necessary for
  CONFIG_FTRACE_SYSCALLS.
* The definition of CREATE_TRACE_POINTS so
  __tracepoint_sys_{enter,exit} get defined.
* A fix for trace_sys_exit() so we can enable
  CONFIG_HAVE_SYSCALL_TRACEPOINTS.
2019-01-07 08:45:47 -08:00
David Abdurachmanov
775800b0f1
riscv: fix trace_sys_exit hook
Fix compilation error.

Signed-off-by: David Abdurachmanov <david.abdurachmanov@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-07 08:22:43 -08:00
David Abdurachmanov
008e901b70
riscv: define CREATE_TRACE_POINTS in ptrace.c
Define CREATE_TRACE_POINTS in order to create functions and structures
for the trace events. This is needed if HAVE_SYSCALL_TRACEPOINTS and
CONFIG_FTRACE_SYSCALLS are enabled, otherwise we get linking errors:

[..]
  MODPOST vmlinux.o
kernel/trace/trace_syscalls.o: In function `.L0 ':
trace_syscalls.c:(.text+0x1152): undefined reference to `__tracepoint_sys_enter'
trace_syscalls.c:(.text+0x126c): undefined reference to `__tracepoint_sys_enter'
trace_syscalls.c:(.text+0x1328): undefined reference to `__tracepoint_sys_enter'
trace_syscalls.c:(.text+0x14aa): undefined reference to `__tracepoint_sys_enter'
trace_syscalls.c:(.text+0x1684): undefined reference to `__tracepoint_sys_exit'
trace_syscalls.c:(.text+0x17a0): undefined reference to `__tracepoint_sys_exit'
trace_syscalls.c:(.text+0x185c): undefined reference to `__tracepoint_sys_exit'
trace_syscalls.c:(.text+0x19de): undefined reference to `__tracepoint_sys_exit'
arch/riscv/kernel/ptrace.o: In function `.L0 ':
ptrace.c:(.text+0x4dc): undefined reference to `__tracepoint_sys_enter'
ptrace.c:(.text+0x632): undefined reference to `__tracepoint_sys_exit'
make: *** [Makefile:1036: vmlinux] Error 1

Signed-off-by: David Abdurachmanov <david.abdurachmanov@gmail.com>
Fixes: b78002b395b4 ("riscv: add HAVE_SYSCALL_TRACEPOINTS to Kconfig")
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-07 08:22:42 -08:00
David Abdurachmanov
0aea89430a
riscv: audit: add audit hook in do_syscall_trace_enter/exit()
This patch adds auditing functions on entry to and exit from every system
call invocation.

Signed-off-by: David Abdurachmanov <david.abdurachmanov@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-07 08:22:40 -08:00
David Abdurachmanov
efe75c494f
riscv: add audit support
On RISC-V (riscv) audit is supported through generic lib/audit.c.
The patch adds required arch specific definitions.

Signed-off-by: David Abdurachmanov <david.abdurachmanov@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-07 08:22:39 -08:00
Zong Li
2cffc95690
RISC-V: Support MODULE_SECTIONS mechanism on RV32
This patch supports dynamic generate got and plt sections mechanism on
rv32. It contains the modification as follows:
 - Always enable MODULE_SECTIONS (both rv64 and rv32)
 - Change the fixed size type.

This patch had been tested by following modules:

btrfs 6795991 0 - Live 0xa544b000
test_static_keys 17304 0 - Live 0xa28be000
zstd_compress 1198986 1 btrfs, Live 0xa2a25000
zstd_decompress 608112 1 btrfs, Live 0xa24e7000
lzo 8787 0 - Live 0xa2049000
xor 27461 1 btrfs, Live 0xa2041000
zram 78849 0 - Live 0xa2276000
netdevsim 55909 0 - Live 0xa202d000
tun 211534 0 - Live 0xa21b5000
fuse 566049 0 - Live 0xa25fb000
nfs_layout_flexfiles 192597 0 - Live 0xa229b000
ramoops 74895 0 - Live 0xa2019000
xfs 3973221 0 - Live 0xa507f000
libcrc32c 3053 2 btrfs,xfs, Live 0xa34af000
lzo_compress 17302 2 btrfs,lzo, Live 0xa347d000
lzo_decompress 7178 2 btrfs,lzo, Live 0xa3451000
raid6_pq 142086 1 btrfs, Live 0xa33a4000
reed_solomon 31022 1 ramoops, Live 0xa31eb000
test_bitmap 3734 0 - Live 0xa31af000
test_bpf 1588736 0 - Live 0xa2c11000
test_kmod 41161 0 - Live 0xa29f8000
test_module 1356 0 - Live 0xa299e000
test_printf 6024 0 [permanent], Live 0xa2971000
test_static_key_base 5797 1 test_static_keys, Live 0xa2931000
test_user_copy 4382 0 - Live 0xa28c9000
xxhash 70501 2 zstd_compress,zstd_decompress, Live 0xa2055000

Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-07 08:19:20 -08:00
Andreas Schwab
37a107ff6d
riscv: don't stop itself in smp_send_stop
Add IPI_CPU_STOP message and use it in smp_send_stop to stop other cpus,
but not itself.  Mark cpu offline on reception of IPI_CPU_STOP.

Signed-off-by: Andreas Schwab <schwab@suse.de>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-07 08:19:19 -08:00
Paul Walmsley
8fd6e05c74
arch: riscv: support kernel command line forcing when no DTB passed
CONFIG_CMDLINE_FORCE doesn't work on RISC-V when no DTB is passed into
the kernel.  This is because the code that forces the kernel command
line only runs if a valid DTB is present at boot.  During debugging,
it's useful to have the ability to force kernel command lines even
when no DTB is present.  This patch adds support for doing so.

Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: linux-riscv@lists.infradead.org
Cc: linux-kernel@vger.kernel.org (open list)
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-07 08:08:00 -08:00
Anup Patel
22e6a2e14c
RISC-V: Make BSS section as the last section in vmlinux.lds.S
The objcopy only emits loadable sections when creating flat kernel
Image. To have minimal possible size of flat kernel Image, we should
have all non-loadable sections after loadable sections.

Currently, execption table section (loadable section) is after BSS
section (non-loadable section) in the RISC-V vmlinux.lds.S. This
is not optimal for having minimal flat kernel Image size hence this
patch makes BSS section as the last section in RISC-V vmlinux.lds.S.

In addition, we make BSS section aligned to 16byte instead of PAGE
aligned which further reduces flat kernel Image size by few KBs.

The flat kernel Image size of Linux-4.20-rc4 using GCC 8.2.0 is
8819980 bytes with current RISC-V vmlinux.lds.S and it reduces to
7991740 bytes with this patch applied. In summary, this patch reduces
Linux-4.20-rc4 flat kernel Image size by 809 KB.

Signed-off-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-01-07 07:59:25 -08:00
Linus Torvalds
96d4f267e4 Remove 'type' argument from access_ok() function
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.

It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access.  But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.

A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model.  And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.

This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.

There were a couple of notable cases:

 - csky still had the old "verify_area()" name as an alias.

 - the iter_iov code had magical hardcoded knowledge of the actual
   values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
   really used it)

 - microblaze used the type argument for a debug printout

but other than those oddities this should be a total no-op patch.

I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something.  Any missed conversion should be trivially fixable, though.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-03 18:57:57 -08:00
Palmer Dabbelt
358f3fff52
RISC-V: Move from EARLY_PRINTK to SBI earlycon
Now that we have earlycon support in the SBI console driver there is no
reason to have our arch-specific early printk support.  This patch set
turns on SBI earlycon support and removes the old early printk.
2018-12-21 08:15:39 -08:00
David Abdurachmanov
397182e0db
riscv: remove unused variable in ftrace
Noticed while building kernel-4.20.0-0.rc5.git2.1.fc30 for
Fedora 30/RISCV.

[..]
BUILDSTDERR: arch/riscv/kernel/ftrace.c: In function 'prepare_ftrace_return':
BUILDSTDERR: arch/riscv/kernel/ftrace.c:135:6: warning: unused variable 'err' [-Wunused-variable]
BUILDSTDERR:   int err;
BUILDSTDERR:       ^~~
[..]

Signed-off-by: David Abdurachmanov <david.abdurachmanov@gmail.com>
Fixes: e949b6db51 ("riscv/function_graph: Simplify with function_graph_enter()")
Reviewed-by: Olof Johansson <olof@lixom.net>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-12-21 08:11:26 -08:00
Yangtao Li
cd378dbb3d
RISC-V: add of_node_put()
use of_node_put() to release the refcount.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-12-21 08:11:08 -08:00
Atish Patra
94f9bf118f
RISC-V: Fix of_node_* refcount
Fix of_node* refcount at various places by using of_node_put.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-12-21 08:10:49 -08:00
Anup Patel
7ba12bb676
RISC-V: Remove EARLY_PRINTK support
The EARLY_PRINTK using SBI console calls is not required
any more because we now have RISC-V SBI support in generic
earlycon framework.

Signed-off-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-12-17 10:23:46 -08:00
Linus Torvalds
0f1f692375 While rewriting the function graph tracer, I discovered a design flaw that
was introduced by a patch that tried to fix one bug, but by doing so created
 another bug. As both bugs corrupt the output (but they do not crash the
 kernel), I decided to fix the design such that it could have both bugs
 fixed. The original fix, fixed time reporting of the function graph tracer
 when doing a max_depth of one. This was code that can test how much the
 kernel interferes with userspace. But in doing so, it could corrupt the time
 keeping of the function profiler.
 
 The issue is that the curr_ret_stack variable was being used for two
 different meanings. One was to keep track of the stack pointer on the
 ret_stack (shadow stack used by the function graph tracer), and the other
 use case was the graph call depth.  Although, the two may be closely
 related, where they got updated was the issue that lead to the two different
 bugs that required the two use cases to be updated differently.
 
 The big issue with this fix is that it requires changing each architecture.
 The good news is, I was able to remove a lot of code that was duplicated
 within the architectures and place it into a single location. Then I could
 make the fix in one place.
 
 I pushed this code into linux-next to let it settle over a week, and before
 doing so, I cross compiled all the affected architectures to make sure that
 they built fine.
 
 In the mean time, I also pulled in a patch that fixes the sched_switch
 previous tasks state output, that was not actually correct.
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Merge tag 'trace-v4.20-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "While rewriting the function graph tracer, I discovered a design flaw
  that was introduced by a patch that tried to fix one bug, but by doing
  so created another bug.

  As both bugs corrupt the output (but they do not crash the kernel), I
  decided to fix the design such that it could have both bugs fixed. The
  original fix, fixed time reporting of the function graph tracer when
  doing a max_depth of one. This was code that can test how much the
  kernel interferes with userspace. But in doing so, it could corrupt
  the time keeping of the function profiler.

  The issue is that the curr_ret_stack variable was being used for two
  different meanings. One was to keep track of the stack pointer on the
  ret_stack (shadow stack used by the function graph tracer), and the
  other use case was the graph call depth. Although, the two may be
  closely related, where they got updated was the issue that lead to the
  two different bugs that required the two use cases to be updated
  differently.

  The big issue with this fix is that it requires changing each
  architecture. The good news is, I was able to remove a lot of code
  that was duplicated within the architectures and place it into a
  single location. Then I could make the fix in one place.

  I pushed this code into linux-next to let it settle over a week, and
  before doing so, I cross compiled all the affected architectures to
  make sure that they built fine.

  In the mean time, I also pulled in a patch that fixes the sched_switch
  previous tasks state output, that was not actually correct"

* tag 'trace-v4.20-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  sched, trace: Fix prev_state output in sched_switch tracepoint
  function_graph: Have profiler use curr_ret_stack and not depth
  function_graph: Reverse the order of pushing the ret_stack and the callback
  function_graph: Move return callback before update of curr_ret_stack
  function_graph: Use new curr_ret_depth to manage depth instead of curr_ret_stack
  function_graph: Make ftrace_push_return_trace() static
  sparc/function_graph: Simplify with function_graph_enter()
  sh/function_graph: Simplify with function_graph_enter()
  s390/function_graph: Simplify with function_graph_enter()
  riscv/function_graph: Simplify with function_graph_enter()
  powerpc/function_graph: Simplify with function_graph_enter()
  parisc: function_graph: Simplify with function_graph_enter()
  nds32: function_graph: Simplify with function_graph_enter()
  MIPS: function_graph: Simplify with function_graph_enter()
  microblaze: function_graph: Simplify with function_graph_enter()
  arm64: function_graph: Simplify with function_graph_enter()
  ARM: function_graph: Simplify with function_graph_enter()
  x86/function_graph: Simplify with function_graph_enter()
  function_graph: Create function_graph_enter() to consolidate architecture code
2018-11-30 09:32:34 -08:00
Steven Rostedt (VMware)
e949b6db51 riscv/function_graph: Simplify with function_graph_enter()
The function_graph_enter() function does the work of calling the function
graph hook function and the management of the shadow stack, simplifying the
work done in the architecture dependent prepare_ftrace_return().

Have riscv use the new code, and remove the shadow stack management as well as
having to set up the trace structure.

This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.

Cc: Greentime Hu <greentime@andestech.com>
Cc: Alan Kao <alankao@andestech.com>
Cc: stable@kernel.org
Fixes: 03274a3ffb ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-11-27 20:31:16 -05:00
Patrick Stählin
5d8f81ba1d
RISC-V: recognize S/U mode bits in print_isa
Removes the warning about an unsupported ISA when reading /proc/cpuinfo
on QEMU. The "S" extension is not being returned as it is not accessible
from userspace.

Signed-off-by: Patrick Stählin <me@packi.ch>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-11-20 05:19:28 -08:00
Anup Patel
c0fbcd9918
RISC-V: Build flat and compressed kernel images
This patch extends Linux RISC-V build system to build and install:
Image - Flat uncompressed kernel image
Image.gz - Flat and GZip compressed kernel image

Quiet a few bootloaders (such as Uboot, UEFI, etc) are capable of
booting flat and compressed kernel images. In case of Uboot, booting
Image or Image.gz is achieved using bootm command.

The flat and uncompressed kernel image (i.e. Image) is very useful
in pre-silicon developent and testing because we can create back-door
HEX files for RAM on FPGAs from Image.

Signed-off-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-11-20 05:19:09 -08:00
Olof Johansson
ef3a614066
RISC-V: Silence some module warnings on 32-bit
Fixes:

arch/riscv/kernel/module.c: In function 'apply_r_riscv_32_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:23:27: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_pcrel_hi20_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:104:23: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_hi20_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:146:23: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_got_hi20_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:190:60: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_call_plt_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:214:24: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_call_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:236:23: note: format string is defined here

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-11-12 18:12:24 -08:00
Andreas Schwab
732e8e4130
RISC-V: properly determine hardware caps
On the Hifive-U platform, cpu 0 is a masked cpu with less capabilities
than the other cpus.  Ignore it for the purpose of determining the
hardware capabilities of the system.

Signed-off-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-31 12:13:43 -07:00
Palmer Dabbelt
d26c4bbf99
RISC-V: SMP cleanup and new features
This patch series now has evolved to contain several related changes.

1. Updated the assorted cleanup series by Palmer.
The original cleanup patch series can be found here.
http://lists.infradead.org/pipermail/linux-riscv/2018-August/001232.html

2. Implemented decoupling linux logical CPU ids from hart id.
Some of the work has been inspired from ARM64.
Tested on QEMU & HighFive Unleashed board with/without SMP enabled.

3. Included Anup's cleanup and IPI stat patch.

All the patch series have been combined to avoid conflicts as a lot of
common code is changed different patch sets. Atish has mostly addressed
review comments and fixed checkpatch errors from Palmer's and Anup's
series.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:41:43 -07:00
Palmer Dabbelt
a6de21baf6
RISC-V: Fix some RV32 bugs and build failures
This patch set fixes up various failures in the RV32I port.  The fixes
are all nominally independent, but are really only testable together
because the RV32I port fails to build without all of them.  The patch
set includes:

* The removal of tishift on RV32I targets, as 128-bit integers are not
  supported by the toolchain.
* The removal of swiotlb from RV32I targets, since all physical
  addresses can be mapped by all hardware on all existing RV32I targets.
* The addition of ummodi3 and udivmoddi4 from an old version of GCC that
  was licensed under GPLv2 as generic code, along with their use on
  RV32I targets.
* A fix to our page alignment logic within ioremap for RV32I targets.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:39:08 -07:00
Palmer Dabbelt
4e4101cfef
riscv: Add support to no-FPU systems
This patchset adds an option, CONFIG_FPU, to enable/disable floating-
point support within the kernel.  The kernel's new behavior will be as
follows:

* with CONFIG_FPU=y
  All FPU codes are reserved.  If no FPU is found during booting, a
  global flag will be set, and those functions will be bypassed with
  condition check to that flag.

* with CONFIG_FPU=n
  No floating-point instructions in kernel and all related settings
  are excluded.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:38:26 -07:00
Christoph Hellwig
f31b8de988
RISC-V: remove the unused return_to_handler export
This export is not only not needed, but also breaks symbol versioning
due to being an undeclared assembly export.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:38:12 -07:00
Jim Wilson
b8c8a9590e
RISC-V: Add FP register ptrace support for gdb.
Add a variable and a macro to describe FP registers, assuming only D is
supported.  FP code is conditional on CONFIG_FPU.  The FP regs and FCSR
are copied separately to avoid copying struct padding.  Tested by hand and
with the gdb testsuite.

Signed-off-by: Jim Wilson <jimw@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:38:04 -07:00
Palmer Dabbelt
86e581e310
RISC-V: Mask out the F extension on systems without D
The RISC-V Linux port doesn't support systems that have the F extension
but don't have the D extension -- we actually don't support systems
without D either, but Alan's patch set is rectifying that soon.  For now
I think we can leave this in a semi-broken state and just wait for
Alan's patch set to get merged for proper non-FPU support -- the patch
set is starting to look good, so doing something in-between doesn't seem
like it's worth the work.

I don't think it's worth fretting about support for systems with F but
not D for now: our glibc ABIs are IMAC and IMAFDC so they probably won't
end up being popular.  We can always extend this in the future.

CC: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:38:00 -07:00
Palmer Dabbelt
1760debb51
RISC-V: Don't set cacheinfo.{physical_line_partition,attributes}
These are just hard coded in the RISC-V port, which doesn't make any
sense.  We should probably be setting these from device tree entries
when they exist, but for now I think it's saner to just leave them all
as their default values.

Reviewed-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:37:41 -07:00
Anup Patel
8b20d2db0a
RISC-V: Show IPI stats
This patch provides arch_show_interrupts() implementation to
show IPI stats via /proc/interrupts.

Now the contents of /proc/interrupts" will look like below:
           CPU0       CPU1       CPU2       CPU3
  8:         17          7          6         14  SiFive PLIC   8  virtio0
 10:         10         10          9         11  SiFive PLIC  10  ttyS0
IPI0:       170        673        251         79  Rescheduling interrupts
IPI1:         1         12         27          1  Function call interrupts

Signed-off-by: Anup Patel <anup@brainfault.org>
[Atish - Fixed checkpatch errors]
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>

Changes since v2:
 - Remove use of IPI_CALL_WAKEUP because it's being removed

Changes since v1:
 - Add stub inline show_ipi_stats() function for !CONFIG_SMP
 - Make ipi_names[] dynamically sized at compile time
 - Minor beautification of ipi_names[] using tabs

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:37 -07:00
Anup Patel
4b26d22fdf
RISC-V: Show CPU ID and Hart ID separately in /proc/cpuinfo
Currently, /proc/cpuinfo show logical CPU ID as Hart ID which
is in-correct. This patch shows CPU ID and Hart ID separately
in /proc/cpuinfo using cpuid_to_hardid_map().

With this patch, contents of /proc/cpuinfo looks as follows:
processor	: 0
hart		: 1
isa		: rv64imafdc
mmu		: sv48

processor	: 1
hart		: 0
isa		: rv64imafdc
mmu		: sv48

processor	: 2
hart		: 2
isa		: rv64imafdc
mmu		: sv48

processor	: 3
hart		: 3
isa		: rv64imafdc
mmu		: sv48

Signed-off-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:37 -07:00
Atish Patra
f99fb607fb
RISC-V: Use Linux logical CPU number instead of hartid
Setup the cpu_logical_map during boot. Moreover, every SBI call
and PLIC context are based on the physical hartid. Use the logical
CPU to hartid mapping to pass correct hartid to respective functions.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:37 -07:00
Atish Patra
6825c7a80f
RISC-V: Add logical CPU indexing for RISC-V
Currently, both Linux CPU id and hart id are same.
This is not recommended as it will lead to discontinuous CPU
indexing in Linux. Moreover, kdump kernel will run from CPU0
which would be absent if we follow existing scheme.

Implement a logical mapping between Linux CPU id and hart
id to decouple these two. Always mark the boot processor as
CPU0 and all other CPUs get the logical CPU id based on their
booting order.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:37 -07:00
Atish Patra
a37d56fc40
RISC-V: Use WRITE_ONCE instead of direct access
The secondary harts spin on couple of per cpu variables until both of
these are non-zero so it's not necessary to have any ordering here.
However, WRITE_ONCE should be used to avoid tearing.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:37 -07:00
Palmer Dabbelt
46373cb442
RISC-V: Use mmgrab()
commit f1f1007644 ("mm: add new mmgrab() helper") added a
helper that we missed out on.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:36 -07:00
Palmer Dabbelt
177fae4515
RISC-V: Rename im_okay_therefore_i_am to found_boot_cpu
The old name was a bit odd.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:36 -07:00
Palmer Dabbelt
b2f8cfa7ac
RISC-V: Rename riscv_of_processor_hart to riscv_of_processor_hartid
It's a bit confusing exactly what this function does: it actually
returns the hartid of an OF processor node, failing with -1 on invalid
nodes.  I've changed the name to _hartid() in order to make that a bit
more clear, as well as adding a comment.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
[Atish: code comment formatting update]
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:36 -07:00
Atish Patra
6db170ff4c
RISC-V: Disable preemption before enabling interrupts
Currently, irq is enabled before preemption disabling happens.
If the scheduler fired right here and cpu is scheduled then it
may blow up.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
[Atish: Commit text and code comment formatting update]
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:36 -07:00
Palmer Dabbelt
b18d6f0525
RISC-V: Comment on the TLB flush in smp_callin()
This isn't readily apparent from reading the code.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
[Atish: code comment formatting update]
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:36 -07:00
Palmer Dabbelt
19ccf29bb1
RISC-V: Filter ISA and MMU values in cpuinfo
We shouldn't be directly passing device tree values to userspace, both
because there could be mistakes in device trees and because the kernel
doesn't support arbitrary ISAs.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
[Atish: checkpatch fix and code comment formatting update]
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:35 -07:00
Palmer Dabbelt
566d6c428e
RISC-V: Don't set cacheinfo.{physical_line_partition,attributes}
These are just hard coded in the RISC-V port, which doesn't make any
sense.  We should probably be setting these from device tree entries
when they exist, but for now I think it's saner to just leave them all
as their default values.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:35 -07:00
Anup Patel
1ed4237ab6
RISC-V: No need to pass scause as arg to do_IRQ()
The scause is already part of pt_regs so no need to pass
scause as separate arg to do_IRQ().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:03:35 -07:00
Zong Li
51858aaf9b
RISC-V: Use swiotlb on RV64 only
Only RV64 supports swiotlb. On RV32, it don't select the SWIOTLB.

Signed-off-by: Zong Li <zong@andestech.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:02:56 -07:00
Alan Kao
9411ec60c2
Auto-detect whether a FPU exists
We expect that a kernel with CONFIG_FPU=y can still support no-FPU
machines. To do so, the kernel should first examine the existence of a
FPU, then do nothing if a FPU does exist; otherwise, it should
disable/bypass all FPU-related functions.

In this patch, a new global variable, has_fpu, is created and determined
when parsing the hardware capability from device tree during booting.
This variable is used in those FPU-related functions.

Signed-off-by: Alan Kao <alankao@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Cc: Vincent Chen <vincentc@andestech.com>
Cc: Zong Li <zong@andestech.com>
Cc: Nick Hu <nickhu@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:02:23 -07:00
Alan Kao
9671f70614
Allow to disable FPU support
FPU codes have been separated from common part in previous patches.
This patch add the CONFIG_FPU option and some stubs, so that a no-FPU
configuration is allowed.

Signed-off-by: Alan Kao <alankao@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Cc: Vincent Chen <vincentc@andestech.com>
Cc: Zong Li <zong@andestech.com>
Cc: Nick Hu <nickhu@andestech.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:02:23 -07:00
Alan Kao
007f5c3589
Refactor FPU code in signal setup/return procedures
FPU-related logic is separated from normal signal handling path in
this patch.  Kernel can easily be configured to exclude those procedures
for no-FPU systems.

Signed-off-by: Alan Kao <alankao@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Cc: Vincent Chen <vincentc@andestech.com>
Cc: Zong Li <zong@andestech.com>
Cc: Nick Hu <nickhu@andestech.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:02:23 -07:00
Alan Kao
e68ad867f7
Extract FPU context operations from entry.S
We move __fstate_save and __fstate_restore to a new source
file, fpu.S.

Signed-off-by: Alan Kao <alankao@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Cc: Vincent Chen <vincentc@andestech.com>
Cc: Zong Li <zong@andestech.com>
Cc: Nick Hu <nickhu@andestech.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:02:22 -07:00