Commit Graph

949571 Commits

Author SHA1 Message Date
Ganesh Goudar
4ff753feab powerpc/pseries: Avoid using addr_to_pfn in real mode
When an UE or memory error exception is encountered the MCE handler
tries to find the pfn using addr_to_pfn() which takes effective
address as an argument, later pfn is used to poison the page where
memory error occurred, recent rework in this area made addr_to_pfn
to run in real mode, which can be fatal as it may try to access
memory outside RMO region.

Have two helper functions to separate things to be done in real mode
and virtual mode without changing any functionality. This also fixes
the following error as the use of addr_to_pfn is now moved to virtual
mode.

Without this change following kernel crash is seen on hitting UE.

[  485.128036] Oops: Kernel access of bad area, sig: 11 [#1]
[  485.128040] LE SMP NR_CPUS=2048 NUMA pSeries
[  485.128047] Modules linked in:
[  485.128067] CPU: 15 PID: 6536 Comm: insmod Kdump: loaded Tainted: G OE 5.7.0 #22
[  485.128074] NIP:  c00000000009b24c LR: c0000000000398d8 CTR: c000000000cd57c0
[  485.128078] REGS: c000000003f1f970 TRAP: 0300   Tainted: G OE (5.7.0)
[  485.128082] MSR:  8000000000001003 <SF,ME,RI,LE>  CR: 28008284  XER: 00000001
[  485.128088] CFAR: c00000000009b190 DAR: c0000001fab00000 DSISR: 40000000 IRQMASK: 1
[  485.128088] GPR00: 0000000000000001 c000000003f1fbf0 c000000001634300 0000b0fa01000000
[  485.128088] GPR04: d000000002220000 0000000000000000 00000000fab00000 0000000000000022
[  485.128088] GPR08: c0000001fab00000 0000000000000000 c0000001fab00000 c000000003f1fc14
[  485.128088] GPR12: 0000000000000008 c000000003ff5880 d000000002100008 0000000000000000
[  485.128088] GPR16: 000000000000ff20 000000000000fff1 000000000000fff2 d0000000021a1100
[  485.128088] GPR20: d000000002200000 c00000015c893c50 c000000000d49b28 c00000015c893c50
[  485.128088] GPR24: d0000000021a0d08 c0000000014e5da8 d0000000021a0818 000000000000000a
[  485.128088] GPR28: 0000000000000008 000000000000000a c0000000017e2970 000000000000000a
[  485.128125] NIP [c00000000009b24c] __find_linux_pte+0x11c/0x310
[  485.128130] LR [c0000000000398d8] addr_to_pfn+0x138/0x170
[  485.128133] Call Trace:
[  485.128135] Instruction dump:
[  485.128138] 3929ffff 7d4a3378 7c883c36 7d2907b4 794a1564 7d294038 794af082 3900ffff
[  485.128144] 79291f24 790af00e 78e70020 7d095214 <7c69502a> 2fa30000 419e011c 70690040
[  485.128152] ---[ end trace d34b27e29ae0e340 ]---

Fixes: 9ca766f989 ("powerpc/64s/pseries: machine check convert to use common event code")
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200724063946.21378-1-ganeshgr@linux.ibm.com
2020-10-22 14:34:45 +11:00
Christophe Leroy
592bbe9c50 powerpc/uaccess: Don't use "m<>" constraint with GCC 4.9
GCC 4.9 sometimes fails to build with "m<>" constraint in
inline assembly.

  CC      lib/iov_iter.o
In file included from ./arch/powerpc/include/asm/cmpxchg.h:6:0,
                 from ./arch/powerpc/include/asm/atomic.h:11,
                 from ./include/linux/atomic.h:7,
                 from ./include/linux/crypto.h:15,
                 from ./include/crypto/hash.h:11,
                 from lib/iov_iter.c:2:
lib/iov_iter.c: In function 'iovec_from_user.part.30':
./arch/powerpc/include/asm/uaccess.h:287:2: error: 'asm' operand has impossible constraints
  __asm__ __volatile__(    \
  ^
./include/linux/compiler.h:78:42: note: in definition of macro 'unlikely'
 # define unlikely(x) __builtin_expect(!!(x), 0)
                                          ^
./arch/powerpc/include/asm/uaccess.h:583:34: note: in expansion of macro 'unsafe_op_wrap'
 #define unsafe_get_user(x, p, e) unsafe_op_wrap(__get_user_allowed(x, p), e)
                                  ^
./arch/powerpc/include/asm/uaccess.h:329:10: note: in expansion of macro '__get_user_asm'
  case 4: __get_user_asm(x, (u32 __user *)ptr, retval, "lwz"); break; \
          ^
./arch/powerpc/include/asm/uaccess.h:363:3: note: in expansion of macro '__get_user_size_allowed'
   __get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err); \
   ^
./arch/powerpc/include/asm/uaccess.h💯2: note: in expansion of macro '__get_user_nocheck'
  __get_user_nocheck((x), (ptr), sizeof(*(ptr)), false)
  ^
./arch/powerpc/include/asm/uaccess.h:583:49: note: in expansion of macro '__get_user_allowed'
 #define unsafe_get_user(x, p, e) unsafe_op_wrap(__get_user_allowed(x, p), e)
                                                 ^
lib/iov_iter.c:1663:3: note: in expansion of macro 'unsafe_get_user'
   unsafe_get_user(len, &uiov[i].iov_len, uaccess_end);
   ^
make[1]: *** [scripts/Makefile.build:283: lib/iov_iter.o] Error 1

Define a UPD_CONSTR macro that is "<>" by default and
only "" with GCC prior to GCC 5.

Fixes: fcf1f26895 ("powerpc/uaccess: Add pre-update addressing to __put_user_asm_goto()")
Fixes: 2f279eeb68 ("powerpc/uaccess: Add pre-update addressing to __get_user_asm() and __put_user_asm()")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/212d3bc4a52ca71523759517bb9c61f7e477c46a.1603179582.git.christophe.leroy@csgroup.eu
2020-10-22 14:26:09 +11:00
Oliver O'Halloran
99f6e9795a powerpc/eeh: Fix eeh_dev_check_failure() for PE#0
In commit 269e583357 ("powerpc/eeh: Delete eeh_pe->config_addr") the
following simplification was made:

-       if (!pe->addr && !pe->config_addr) {
+       if (!pe->addr) {
                eeh_stats.no_cfg_addr++;
                return 0;
        }

This introduced a bug which causes EEH checking to be skipped for
devices in PE#0.

Before the change above the check would always pass since at least one
of the two PE addresses would be non-zero in all circumstances. On
PowerNV pe->config_addr would be the BDFN of the first device added to
the PE. The zero BDFN is reserved for the PHB's root port, but this is
fine since for obscure platform reasons the root port is never
assigned to PE#0.

Similarly, on pseries pe->addr has always been non-zero for the
reasons outlined in commit 42de19d5ef ("powerpc/pseries/eeh: Allow
zero to be a valid PE configuration address").

We can fix the problem by deleting the block entirely The original
purpose of this test was to avoid performing EEH checks on devices
that were not on an EEH capable bus. In modern Linux the edev->pe
pointer will be NULL for devices that are not on an EEH capable bus.
The code block immediately above this one already checks for the
edev->pe == NULL case so this test (new and old) is entirely
redundant.

Ideally we'd delete eeh_stats.no_cfg_addr too since nothing increments
it any more. Unfortunately, that information is exposed via
/proc/powerpc/eeh which means it's technically ABI. We could make it
hard-coded, but that's a change for another patch.

Fixes: 269e583357 ("powerpc/eeh: Delete eeh_pe->config_addr")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201021232554.1434687-1-oohall@gmail.com
2020-10-22 10:38:53 +11:00
Jordan Niethe
ec613a57fa powerpc/64s: Remove TM from Power10 features
ISA v3.1 removes transactional memory and hence it should not be present
in cpu_features or cpu_user_features2. Remove CPU_FTR_TM_COMP from
CPU_FTRS_POWER10. Remove PPC_FEATURE2_HTM_COMP and
PPC_FEATURE2_HTM_NOSC_COMP from COMMON_USER2_POWER10.

Fixes: a3ea40d5c7 ("powerpc: Add POWER10 architected mode")
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200827035529.900-1-jniethe5@gmail.com
2020-10-20 23:33:51 +11:00
Michael Neuling
d1781f2370 selftests/powerpc: Make alignment handler test P9N DD2.1 vector CI load workaround
alignment_handler currently only tests the unaligned cases but it can
also be useful for testing the workaround for the P9N DD2.1 vector CI
load issue fixed by p9_hmi_special_emu(). This workaround was
introduced in 5080332c2c ("powerpc/64s: Add workaround for P9 vector
CI load issue").

This changes the loop to start from offset 0 rather than 1 so that we
test the kernel emulation in p9_hmi_special_emu().

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201013043741.743413-2-mikey@neuling.org
2020-10-20 08:00:42 +11:00
Michael Neuling
1da4a0272c powerpc: Fix undetected data corruption with P9N DD2.1 VSX CI load emulation
__get_user_atomic_128_aligned() stores to kaddr using stvx which is a
VMX store instruction, hence kaddr must be 16 byte aligned otherwise
the store won't occur as expected.

Unfortunately when we call __get_user_atomic_128_aligned() in
p9_hmi_special_emu(), the buffer we pass as kaddr (ie. vbuf) isn't
guaranteed to be 16B aligned. This means that the write to vbuf in
__get_user_atomic_128_aligned() has the bottom bits of the address
truncated. This results in other local variables being
overwritten. Also vbuf will not contain the correct data which results
in the userspace emulation being wrong and hence undetected user data
corruption.

In the past we've been mostly lucky as vbuf has ended up aligned but
this is fragile and isn't always true. CONFIG_STACKPROTECTOR in
particular can change the stack arrangement enough that our luck runs
out.

This issue only occurs on POWER9 Nimbus <= DD2.1 bare metal.

The fix is to align vbuf to a 16 byte boundary.

Fixes: 5080332c2c ("powerpc/64s: Add workaround for P9 vector CI load issue")
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201013043741.743413-1-mikey@neuling.org
2020-10-20 07:59:21 +11:00
Vasant Hegde
358ab796ce powerpc/powernv/dump: Handle multiple writes to ack attribute
Even though we use self removing sysfs helper, we still need
to make sure we do the final kobject delete conditionally.
sysfs_remove_file_self() will handle parallel calls to remove
the sysfs attribute file and returns true only in the caller
that removed the attribute file. The other parallel callers
are returned false. Do the final kobject delete checking
the return value of sysfs_remove_file_self().

Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201017164236.264713-1-hegdevasant@linux.vnet.ibm.com
2020-10-19 22:58:52 +11:00
Vasant Hegde
0a43ae3e2b powerpc/powernv/dump: Fix race while processing OPAL dump
Every dump reported by OPAL is exported to userspace through a sysfs
interface and notified using kobject_uevent(). The userspace daemon
(opal_errd) then reads the dump and acknowledges that the dump is
saved safely to disk. Once acknowledged the kernel removes the
respective sysfs file entry causing respective resources to be
released including kobject.

However it's possible the userspace daemon may already be scanning
dump entries when a new sysfs dump entry is created by the kernel.
User daemon may read this new entry and ack it even before kernel can
notify userspace about it through kobject_uevent() call. If that
happens then we have a potential race between
dump_ack_store->kobject_put() and kobject_uevent which can lead to
use-after-free of a kernfs object resulting in a kernel crash.

This patch fixes this race by protecting the sysfs file
creation/notification by holding a reference count on kobject until we
safely send kobject_uevent().

The function create_dump_obj() returns the dump object which if used
by caller function will end up in use-after-free problem again.
However, the return value of create_dump_obj() function isn't being
used today and there is no need as well. Hence change it to return
void to make this fix complete.

Fixes: c7e64b9ce0 ("powerpc/powernv Platform dump interface")
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201017164210.264619-1-hegdevasant@linux.vnet.ibm.com
2020-10-19 22:52:08 +11:00
Srikar Dronamraju
84dbf66c63 powerpc/smp: Use GFP_ATOMIC while allocating tmp mask
Qian Cai reported a regression where CPU Hotplug fails with the latest
powerpc/next

BUG: sleeping function called from invalid context at mm/slab.h:494
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/88
no locks held by swapper/88/0.
irq event stamp: 18074448
hardirqs last  enabled at (18074447): [<c0000000001a2a7c>] tick_nohz_idle_enter+0x9c/0x110
hardirqs last disabled at (18074448): [<c000000000106798>] do_idle+0x138/0x3b0
do_idle at kernel/sched/idle.c:253 (discriminator 1)
softirqs last  enabled at (18074440): [<c0000000000bbec4>] irq_enter_rcu+0x94/0xa0
softirqs last disabled at (18074439): [<c0000000000bbea0>] irq_enter_rcu+0x70/0xa0
CPU: 88 PID: 0 Comm: swapper/88 Tainted: G        W         5.9.0-rc8-next-20201007 #1
Call Trace:
[c00020000a4bfcf0] [c000000000649e98] dump_stack+0xec/0x144 (unreliable)
[c00020000a4bfd30] [c0000000000f6c34] ___might_sleep+0x2f4/0x310
[c00020000a4bfdb0] [c000000000354f94] slab_pre_alloc_hook.constprop.82+0x124/0x190
[c00020000a4bfe00] [c00000000035e9e8] __kmalloc_node+0x88/0x3a0
slab_alloc_node at mm/slub.c:2817
(inlined by) __kmalloc_node at mm/slub.c:4013
[c00020000a4bfe80] [c0000000006494d8] alloc_cpumask_var_node+0x38/0x80
kmalloc_node at include/linux/slab.h:577
(inlined by) alloc_cpumask_var_node at lib/cpumask.c:116
[c00020000a4bfef0] [c00000000003eedc] start_secondary+0x27c/0x800
update_mask_by_l2 at arch/powerpc/kernel/smp.c:1267
(inlined by) add_cpu_to_masks at arch/powerpc/kernel/smp.c:1387
(inlined by) start_secondary at arch/powerpc/kernel/smp.c:1420
[c00020000a4bff90] [c00000000000c468] start_secondary_resume+0x10/0x14

Allocating a temporary mask while performing a CPU Hotplug operation
with CONFIG_CPUMASK_OFFSTACK enabled, leads to calling a sleepable
function from a atomic context. Fix this by allocating the temporary
mask with GFP_ATOMIC flag. Also instead of having to allocate twice,
allocate the mask in the caller so that we only have to allocate once.
If the allocation fails, assume the mask to be same as sibling mask, which
will make the scheduler to drop this domain for this CPU.

Fixes: 70a94089d7 ("powerpc/smp: Optimize update_coregroup_mask")
Fixes: 3ab33d6dc3 ("powerpc/smp: Optimize update_mask_by_l2")
Reported-by: Qian Cai <cai@redhat.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201019042716.106234-3-srikar@linux.vnet.ibm.com
2020-10-19 21:32:34 +11:00
Srikar Dronamraju
966730a6e8 powerpc/smp: Remove unnecessary variable
Commit 3ab33d6dc3 ("powerpc/smp: Optimize update_mask_by_l2")
introduced submask_fn in update_mask_by_l2 to track the right submask.
However commit f6606cfdfb ("powerpc/smp: Dont assume l2-cache to be
superset of sibling") introduced sibling_mask in update_mask_by_l2 to
track the same submask. Remove sibling_mask in favour of submask_fn.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201019042716.106234-2-srikar@linux.vnet.ibm.com
2020-10-19 21:32:34 +11:00
Ganesh Goudar
8d0e210127 powerpc/mce: Avoid nmi_enter/exit in real mode on pseries hash
Use of nmi_enter/exit in real mode handler causes the kernel to panic
and reboot on injecting SLB mutihit on pseries machine running in hash
MMU mode, because these calls try to accesses memory outside RMO
region in real mode handler where translation is disabled.

Add check to not to use these calls on pseries machine running in hash
MMU mode.

Fixes: 116ac378bb ("powerpc/64s: machine check interrupt update NMI accounting")
Cc: stable@vger.kernel.org # v5.8+
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201009064005.19777-2-ganeshgr@linux.ibm.com
2020-10-16 20:13:55 +11:00
Aneesh Kumar K.V
d4263b12a1 powerpc/opal_elog: Handle multiple writes to ack attribute
Even though we use self removing sysfs helper, we still need
to make sure we do the final kobject delete conditionally.
sysfs_remove_file_self() will handle parallel calls to remove
the sysfs attribute file and returns true only in the caller
that removed the attribute file. The other parallel callers
are returned false. Do the final kobject delete checking
the return value of sysfs_remove_file_self().

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201014064813.109515-1-aneesh.kumar@linux.ibm.com
2020-10-16 14:25:12 +11:00
Qian Cai
ffd0b25ca0 Revert "powerpc/pci: unmap legacy INTx interrupts when a PHB is removed"
This reverts commit 3a3181e16f which
causes memory corruptions on POWER9 powernv. eg:

  pci_bus 0035:08: busn_res: [bus 08-0c] is released
  =============================================================================
  BUG kmalloc-16 (Tainted: G        W  O     ): Object already free
  -----------------------------------------------------------------------------
  Disabling lock debugging due to kernel taint
  INFO: Allocated in pcibios_scan_phb+0x104/0x3e0 age=1960714 cpu=4 pid=1
  	__slab_alloc+0xa4/0xf0
  	__kmalloc+0x294/0x330
  	pcibios_scan_phb+0x104/0x3e0
  	pcibios_init+0x84/0x124
  	do_one_initcall+0xac/0x528
  	kernel_init_freeable+0x35c/0x3fc
  	kernel_init+0x24/0x148
  	ret_from_kernel_thread+0x5c/0x80
  INFO: Freed in pcibios_remove_bus+0x70/0x90 age=0 cpu=16 pid=1717146
  	kfree+0x49c/0x510
  	pcibios_remove_bus+0x70/0x90
  	pci_remove_bus+0xe4/0x110
  	pci_remove_bus_device+0x74/0x170
  	pci_remove_bus_device+0x4c/0x170
  	pci_stop_and_remove_bus_device_locked+0x34/0x50
  	remove_store+0xc0/0xe0
  	dev_attr_store+0x30/0x50
  	sysfs_kf_write+0x68/0xb0
  	kernfs_fop_write+0x114/0x260
  	vfs_write+0xe4/0x260
  	ksys_write+0x74/0x130
  	system_call_exception+0xf8/0x1d0
  	system_call_common+0xe8/0x218
  INFO: Slab 0x0000000099caaf22 objects=178 used=174 fp=0x00000000006a64b0 flags=0x7fff8000000201
  INFO: Object 0x00000000f360132d @offset=30192 fp=0x0000000000000000

Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201014182811.12027-1-cai@lca.pw
2020-10-15 13:42:49 +11:00
Oliver O'Halloran
996f9e0f93 selftests/powerpc: Fix eeh-basic.sh exit codes
The kselftests test running infrastructure expects tests to finish with an
exit code of 4 if the test decided it should be skipped. Currently
eeh-basic.sh exits with the number of devices that failed to recover, so if
four devices didn't recover we'll report a skip instead of a fail.

Fix this by checking if the return code is non-zero and report success
and failure by returning 0 or 1 respectively. For the cases where should
actually skip return 4.

Fixes: 85d86c8aa5 ("selftests/powerpc: Add basic EEH selftest")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201014024711.1138386-1-oohall@gmail.com
2020-10-14 22:03:39 +11:00
Srikar Dronamraju
a2d0230b91 cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_reboot_notifier
The patch avoids allocating cpufreq_policy on stack hence fixing frame
size overflow in 'powernv_cpufreq_reboot_notifier':

  drivers/cpufreq/powernv-cpufreq.c: In function powernv_cpufreq_reboot_notifier:
  drivers/cpufreq/powernv-cpufreq.c:906:1: error: the frame size of 2064 bytes is larger than 2048 bytes

Fixes: cf30af76 ("cpufreq: powernv: Set the cpus to nominal frequency during reboot/kexec")
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200922080254.41497-1-srikar@linux.vnet.ibm.com
2020-10-08 21:17:16 +11:00
Christophe Leroy
9686e431c6 powerpc/time: Make get_tb() common to PPC32 and PPC64
mftbu() is always defined now, so the #ifdef can be removed
and replaced by an IS_ENABLED(CONFIG_PPC64) inside the
PPC32 version of get_tb().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/47e49717d2643169ffcbe5d507f184cf49f0fe95.1601556145.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:16 +11:00
Christophe Leroy
1156a6285c powerpc/time: Make get_tbl() common to PPC32 and PPC64
On PPC64, get_tbl() is defined as an alias of get_tb() which return
the result of mftb(). That exactly the same as what the PPC32 version
does. We don't need two versions.

Remove the PPC64 definition of get_tbl() and use the PPC32 version
for both.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a8eaabb87d69534e533ebac805163e08146e05bd.1601556145.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:16 +11:00
Christophe Leroy
e8d5bf30ea powerpc/time: Remove get_tbu()
get_tbu() is redundant with mftbu() and is not used anymore.

Remove it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1746e2d11ea90c3f45877e1fcc6c79ce96cf6b98.1601556145.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:15 +11:00
Christophe Leroy
942e89115b powerpc/time: Avoid using get_tbl() and get_tbu() internally
get_tbl() is confusing as it returns the content of TBL register
on PPC32 but the concatenation of TBL and TBU on PPC64.

Use mftb() instead.

Do the same with get_tbu() for consistency allthough it's name
is less confusing.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/41573406a4eab98838decaa91649086fef1e6119.1601556145.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:15 +11:00
Christophe Leroy
ff125fbcd4 powerpc/time: Make mftb() common to PPC32 and PPC64
No need to have two versions that are identical.

CONFIG_PPC_CELL is only selected by PPC64 targets.
CONFIG_E500 is the only PPC64 target selecting CONFIG_FSL_BOOK3E.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/6bf23ec744aab4ba63506a011f6a145ea35d620d.1601556145.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:15 +11:00
Christophe Leroy
15c102153e powerpc/time: Rename mftbl() to mftb()
On PPC64, we have mftb().
On PPC32, we have mftbl() and an #define mftb() mftbl().

mftb() and mftbl() are equivalent, their purpose is to read the
content of SPRN_TRBL, as returned by 'mftb' simplified instruction.

binutils seems to define 'mftbl' instruction as an equivalent
of 'mftb'.

However in both 32 bits and 64 bits documentation, only 'mftb' is
defined, and when performing a disassembly with objdump, the displayed
instruction is 'mftb'

No need to have two ways to do the same thing with different
names, rename mftbl() to have only mftb().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/94dc68d3d9ef9eb549796d4b938b6ba0305a049b.1601556145.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:15 +11:00
Christophe Leroy
865418795a powerpc/32s: Remove #ifdef CONFIG_PPC_BOOK3S_32 in head_book3s_32.S
head_book3s_32.S is only built when CONFIG_PPC_BOOK3S_32 is selected.

Remove all conditions based on CONFIG_PPC_BOOK3S_32 in the file.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1b68632425d8866d147aea9005004e4594672211.1601975100.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:15 +11:00
Christophe Leroy
533090e5a9 powerpc/32s: Rename head_32.S to head_book3s_32.S
Unlike PPC64 which had a single head_64.S, PPC32 are multiple ones.
There is the head_32.S, selected by default based on the value of BITS
and overridden based on some CONFIG_ values. This leads to thinking
that it may be selected by different types of PPC32 platform but
indeed it ends up being selected by book3s/32 only.

Make that explicit by:
- Not doing any default selection based on BITS.
- Renaming head_32.S to head_book3s_32.S.
- Get head_book3s_32.S selected only by CONFIG_PPC_BOOK3S_32.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Fix head_$(BITS).o reference in arch/powerpc/Makefile]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/319d379f696412681c66a987cc75e6abf8f958d2.1601975100.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:14 +11:00
Christophe Leroy
69a1593abd powerpc/32s: Setup the early hash table at all time.
At the time being, an early hash table is set up when
CONFIG_KASAN is selected.

There is nothing wrong with setting such an early hash table
all the time, even if it is not used. This is a statically
allocated 256 kB table which lies in the init data section.

This makes the code simpler and may in the future allow to
setup early IO mappings with fixmap instead of hard coding BATs.

Put create_hpte() and flush_hash_pages() in the .ref.text section
in order to avoid warning for the reference to early_hash[]. This
reference is removed by MMU_init_hw_patch() before init memory is
freed.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b8f8101c368b8a6451844a58d7bd7d83c14cf2aa.1601566529.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:14 +11:00
Christophe Leroy
63f9d9df5e powerpc/time: Remove ifdef in get_dec() and set_dec()
Move SPRN_PIT definition in reg.h.

This allows to remove ifdef in get_dec() and set_dec() and
makes them more readable.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/3c9a6eb0fc040868ac59be66f338d08fd017668d.1601549945.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:14 +11:00
Christophe Leroy
6601ec1c2b powerpc: Remove get_tb_or_rtc()
601 is gone, get_tb_or_rtc() is equivalent to get_tb().

Replace the former by the later.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/3e8a13ee83418630c753c30cb722ae682d5b2d39.1601362098.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:14 +11:00
Christophe Leroy
a4c5a35542 powerpc: Remove __USE_RTC()
Now that PowerPC 601 is gone, __USE_RTC() is never true.

Remove it.

That also leads to removing get_rtc() and get_rtcl()

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4757e1ed21fe1968c761ae081d1f3d790a9673f8.1601362098.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:14 +11:00
Christophe Leroy
2e38ea4866 powerpc: Tidy up a bit after removal of PowerPC 601.
The removal of the 601 left some standalone blocks from
former if/else. Drop the { } and re-indent.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/31c4cd093963f22831bf388449056ee045533d3b.1601362098.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:13 +11:00
Christophe Leroy
8b14e1dff0 powerpc: Remove support for PowerPC 601
PowerPC 601 has been retired.

Remove all associated specific code.

CPU_FTRS_PPC601 has CPU_FTR_COHERENT_ICACHE and CPU_FTR_COMMON.

CPU_FTR_COMMON is already present via other CPU_FTRS.
None of the remaining CPU selects CPU_FTR_COHERENT_ICACHE.

So CPU_FTRS_PPC601 can be removed from the possible features,
hence can be removed completely.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/60b725d55e21beec3335175c20b77903ff98284f.1601362098.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:13 +11:00
Christophe Leroy
f0ed73f3fa powerpc: Remove PowerPC 601
Powerpc 601 is 25 years old.

It is not selected by any defconfig.

It requires a lot of special handling as it deviates from the
standard 6xx.

Retire it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/00a6948d659e017f8ca63437d1384222c3aede57.1601362098.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:13 +11:00
Christophe Leroy
d2a5cd83ee powerpc: Drop SYNC_601() ISYNC_601() and SYNC()
Those macros are now empty at all time. Drop them.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7990bb63fc53e460bfa94f8040184881d9e6fbc3.1601362098.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:13 +11:00
Christophe Leroy
e42a64002a powerpc: Remove CONFIG_PPC601_SYNC_FIX
This config option isn't in any defconfig.

The very first versions of Powerpc 601 have a bug which
requires additional sync before and/or after some instructions.

This was more than 25 years ago and time has come to retire
those buggy versions of the 601 from the kernel.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/55b46bff16705b1ae7bf0a60ccd522b1010ebf75.1601362098.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:13 +11:00
Christophe Leroy
ca1d3443b4 powerpc: Remove SYNC on non 6xx
SYNC is usefull for Powerpc 601 only. On everything else,
SYNC is empty.

Remove it from code that is not made to run on 6xx.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/27951fa6c9a8f80724d1bc81a6117ac32343a55d.1601362098.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:12 +11:00
Vaibhav Jain
13135b461c powerpc/papr_scm: Add PAPR command family to pass-through command-set
Add NVDIMM_FAMILY_PAPR to the list of valid 'dimm_family_mask'
acceptable by papr_scm. This is needed as since commit
92fe2aa859 ("libnvdimm: Validate command family indices") libnvdimm
performs a validation of 'nd_cmd_pkg.nd_family' received as part of
ND_CMD_CALL processing to ensure only known command families can use
the general ND_CMD_CALL pass-through functionality.

Without this change the ND_CMD_CALL pass-through targeting
NVDIMM_FAMILY_PAPR error out with -EINVAL.

Fixes: 92fe2aa859 ("libnvdimm: Validate command family indices")
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200913211904.24472-1-vaibhav@linux.ibm.com
2020-10-08 12:50:53 +11:00
Aneesh Kumar K.V
fbf2f134c8 powerpc/lmb-size: Use addr #size-cells value when fetching lmb-size
Make it consistent with other usages.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201007114836.282468-5-aneesh.kumar@linux.ibm.com
2020-10-08 12:50:52 +11:00
Aneesh Kumar K.V
950805f4d9 powerpc/book3s64/radix: Make radix_mem_block_size 64bit
Similar to commit 89c140bbae ("pseries: Fix 64 bit logical memory block panic")
make sure different variables tracking lmb_size are updated to be 64 bit.

Fixes: af9d00e93a ("powerpc/mm/radix: Create separate mappings for hot-plugged memory")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201007114836.282468-4-aneesh.kumar@linux.ibm.com
2020-10-08 12:50:52 +11:00
Aneesh Kumar K.V
301d2ea657 powerpc/memhotplug: Make lmb size 64bit
Similar to commit 89c140bbae ("pseries: Fix 64 bit logical memory block panic")
make sure different variables tracking lmb_size are updated to be 64 bit.

This was found by code audit.

Cc: stable@vger.kernel.org
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201007114836.282468-3-aneesh.kumar@linux.ibm.com
2020-10-08 12:50:52 +11:00
Aneesh Kumar K.V
ec72024e35 powerpc/drmem: Make lmb_size 64 bit
Similar to commit 89c140bbae ("pseries: Fix 64 bit logical memory block panic")
make sure different variables tracking lmb_size are updated to be 64 bit.

This was found by code audit.

Cc: stable@vger.kernel.org
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Acked-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201007114836.282468-2-aneesh.kumar@linux.ibm.com
2020-10-08 12:50:52 +11:00
Nicholas Piggin
792254a772 powerpc/security: Fix link stack flush instruction
The inline execution path for the hardware assisted branch flush
instruction failed to set CTR to the correct value before bcctr,
causing a crash when the feature is enabled.

Fixes: 4d24e21cc6 ("powerpc/security: Allow for processors that flush the link stack using the special bcctr")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201007080605.64423-1-npiggin@gmail.com
2020-10-08 12:50:52 +11:00
Kajol Jain
09b791d955 powerpc/hv-gpci: Add sysfs files inside hv-gpci device to show cpumask
Patch here adds a cpumask attr to hv_gpci pmu along with ABI documentation.

Primary use to expose the cpumask is for the perf tool which has the
capability to parse the driver sysfs folder and understand the
cpumask file. Having cpumask file will reduce the number of perf command
line parameters (will avoid "-C" option in the perf tool
command line). It can also notify the user which is
the current cpu used to retrieve the counter data.

command:# cat /sys/devices/hv_gpci/cpumask
0

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201003074943.338618-5-kjain@linux.ibm.com
2020-10-07 22:34:49 +11:00
Kajol Jain
dcb5cdf60a powerpc/perf/hv-gpci: Add cpu hotplug support
Patch here adds cpu hotplug functions to hv_gpci pmu.
A new cpuhp_state "CPUHP_AP_PERF_POWERPC_HV_GPCI_ONLINE" enum
is added.

The online callback function updates the cpumask only if its
empty. As the primary intention of adding hotplug support
is to designate a CPU to make HCALL to collect the
counter data.

The offline function test and clear corresponding cpu in a cpumask
and update cpumask to any other active cpu.

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201003074943.338618-4-kjain@linux.ibm.com
2020-10-07 22:34:48 +11:00
Kajol Jain
435387dd1f Documentation/ABI: Add ABI documentation for hv-gpci format
This patch adds ABI documentation for hv-gpci event format.

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201003074943.338618-3-kjain@linux.ibm.com
2020-10-07 22:34:48 +11:00
Kajol Jain
264a034099 Documentation/ABI: Add ABI documentation for hv-24x7 format
This patch adds ABI documentation for hv-24x7 format.

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201003074943.338618-2-kjain@linux.ibm.com
2020-10-07 22:34:48 +11:00
Kajol Jain
0f9866f7e8 powerpc/perf/hv-gpci: Fix starting index value
Commit 9e9f601084 ("powerpc/perf/{hv-gpci, hv-common}: generate
requests with counters annotated") adds a framework for defining
gpci counters.
In this patch, they adds starting_index value as '0xffffffffffffffff'.
which is wrong as starting_index is of size 32 bits.

Because of this, incase we try to run hv-gpci event we get error.

In power9 machine:

command#: perf stat -e hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
          -C 0 -I 1000
event syntax error: '..bie_count_and_time_tlbie_instructions_issued/'
                                  \___ value too big for format, maximum is 4294967295

This patch fix this issue and changes starting_index value to '0xffffffff'

After this patch:

command#: perf stat -e hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ -C 0 -I 1000
     1.000085786              1,024      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
     2.000287818              1,024      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
     2.439113909             17,408      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/

Fixes: 9e9f601084 ("powerpc/perf/{hv-gpci, hv-common}: generate requests with counters annotated")
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201003074943.338618-1-kjain@linux.ibm.com
2020-10-07 22:34:48 +11:00
Oliver O'Halloran
8175bd580e powerpc/pseries/eeh: Fix use of uninitialised variable
If the RTAS call to query the PE address for a device fails we jump the
err: label where an error message is printed along with the return code.
However, the printed return code is from the "ret" variable which isn't set
at that point since we assigned the result to "addr" instead. Fix this by
consistently using the "ret" variable for the result of the RTAS call
helpers an dropping the "addr" local variable"

Fixes: 98ba956f6a ("powerpc/pseries/eeh: Rework device EEH PE determination")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201007040903.819081-2-oohall@gmail.com
2020-10-07 22:34:47 +11:00
Oliver O'Halloran
269e583357 powerpc/eeh: Delete eeh_pe->config_addr
The eeh_pe->config_addr field was supposed to be removed in
commit 35d64734b6 ("powerpc/eeh: Clean up PE addressing") which made it
largely unused. Finish the job.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201007040903.819081-1-oohall@gmail.com
2020-10-07 22:34:47 +11:00
Scott Cheloha
72cdd117c4 pseries/hotplug-memory: hot-add: skip redundant LMB lookup
During memory hot-add, dlpar_add_lmb() calls memory_add_physaddr_to_nid()
to determine which node id (nid) to use when later calling __add_memory().

This is wasteful.  On pseries, memory_add_physaddr_to_nid() finds an
appropriate nid for a given address by looking up the LMB containing the
address and then passing that LMB to of_drconf_to_nid_single() to get the
nid.  In dlpar_add_lmb() we get this address from the LMB itself.

In short, we have a pointer to an LMB and then we are searching for
that LMB *again* in order to find its nid.

If we call of_drconf_to_nid_single() directly from dlpar_add_lmb() we
can skip the redundant lookup.  The only error handling we need to
duplicate from memory_add_physaddr_to_nid() is the fallback to the
default nid when drconf_to_nid_single() returns -1 (NUMA_NO_NODE) or
an invalid nid.

Skipping the extra lookup makes hot-add operations faster, especially
on machines with many LMBs.

Consider an LPAR with 126976 LMBs.  In one test, hot-adding 126000
LMBs on an upatched kernel took ~3.5 hours while a patched kernel
completed the same operation in ~2 hours:

Unpatched (12450 seconds):
Sep  9 04:06:31 ltc-brazos1 drmgr[810169]: drmgr: -c mem -a -q 126000
Sep  9 04:06:31 ltc-brazos1 kernel: pseries-hotplug-mem: Attempting to hot-add 126000 LMB(s)
[...]
Sep  9 07:34:01 ltc-brazos1 kernel: pseries-hotplug-mem: Memory at 20000000 (drc index 80000002) was hot-added

Patched (7065 seconds):
Sep  8 21:49:57 ltc-brazos1 drmgr[877703]: drmgr: -c mem -a -q 126000
Sep  8 21:49:57 ltc-brazos1 kernel: pseries-hotplug-mem: Attempting to hot-add 126000 LMB(s)
[...]
Sep  8 23:27:42 ltc-brazos1 kernel: pseries-hotplug-mem: Memory at 20000000 (drc index 80000002) was hot-added

It should be noted that the speedup grows more substantial when
hot-adding LMBs at the end of the drconf range.  This is because we
are skipping a linear LMB search.

To see the distinction, consider smaller hot-add test on the same
LPAR.  A perf-stat run with 10 iterations showed that hot-adding 4096
LMBs completed less than 1 second faster on a patched kernel:

Unpatched:
 Performance counter stats for 'drmgr -c mem -a -q 4096' (10 runs):

        104,753.42 msec task-clock                #    0.992 CPUs utilized            ( +-  0.55% )
             4,708      context-switches          #    0.045 K/sec                    ( +-  0.69% )
             2,444      cpu-migrations            #    0.023 K/sec                    ( +-  1.25% )
               394      page-faults               #    0.004 K/sec                    ( +-  0.22% )
   445,902,503,057      cycles                    #    4.257 GHz                      ( +-  0.55% )  (66.67%)
     8,558,376,740      stalled-cycles-frontend   #    1.92% frontend cycles idle     ( +-  0.88% )  (49.99%)
   300,346,181,651      stalled-cycles-backend    #   67.36% backend cycles idle      ( +-  0.76% )  (50.01%)
   258,091,488,691      instructions              #    0.58  insn per cycle
                                                  #    1.16  stalled cycles per insn  ( +-  0.22% )  (66.67%)
    70,568,169,256      branches                  #  673.660 M/sec                    ( +-  0.17% )  (50.01%)
     3,100,725,426      branch-misses             #    4.39% of all branches          ( +-  0.20% )  (49.99%)

           105.583 +- 0.589 seconds time elapsed  ( +-  0.56% )

Patched:
 Performance counter stats for 'drmgr -c mem -a -q 4096' (10 runs):

        104,055.69 msec task-clock                #    0.993 CPUs utilized            ( +-  0.32% )
             4,606      context-switches          #    0.044 K/sec                    ( +-  0.20% )
             2,463      cpu-migrations            #    0.024 K/sec                    ( +-  0.93% )
               394      page-faults               #    0.004 K/sec                    ( +-  0.25% )
   442,951,129,921      cycles                    #    4.257 GHz                      ( +-  0.32% )  (66.66%)
     8,710,413,329      stalled-cycles-frontend   #    1.97% frontend cycles idle     ( +-  0.47% )  (50.06%)
   299,656,905,836      stalled-cycles-backend    #   67.65% backend cycles idle      ( +-  0.39% )  (50.02%)
   252,731,168,193      instructions              #    0.57  insn per cycle
                                                  #    1.19  stalled cycles per insn  ( +-  0.20% )  (66.66%)
    68,902,851,121      branches                  #  662.173 M/sec                    ( +-  0.13% )  (49.94%)
     3,100,242,882      branch-misses             #    4.50% of all branches          ( +-  0.15% )  (49.98%)

           104.829 +- 0.325 seconds time elapsed  ( +-  0.31% )

This is consistent.  An add-by-count hot-add operation adds LMBs
greedily, so LMBs near the start of the drconf range are considered
first.  On an otherwise idle LPAR with so many LMBs we would expect to
find the LMBs we need near the start of the drconf range, hence the
smaller speedup.

Signed-off-by: Scott Cheloha <cheloha@linux.ibm.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200916145122.3408129-1-cheloha@linux.ibm.com
2020-10-06 23:22:27 +11:00
Andrew Donnellan
dc9af82ea0 selftests/powerpc: Add a rtas_filter selftest
Add a selftest to test the basic functionality of CONFIG_RTAS_FILTER.

Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
[mpe: Change rmo_start/end to 32-bit to avoid build errors on ppc64]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200820044512.7543-2-ajd@linux.ibm.com
2020-10-06 23:22:27 +11:00
Andrew Donnellan
bd59380c5b powerpc/rtas: Restrict RTAS requests from userspace
A number of userspace utilities depend on making calls to RTAS to retrieve
information and update various things.

The existing API through which we expose RTAS to userspace exposes more
RTAS functionality than we actually need, through the sys_rtas syscall,
which allows root (or anyone with CAP_SYS_ADMIN) to make any RTAS call they
want with arbitrary arguments.

Many RTAS calls take the address of a buffer as an argument, and it's up to
the caller to specify the physical address of the buffer as an argument. We
allocate a buffer (the "RMO buffer") in the Real Memory Area that RTAS can
access, and then expose the physical address and size of this buffer in
/proc/powerpc/rtas/rmo_buffer. Userspace is expected to read this address,
poke at the buffer using /dev/mem, and pass an address in the RMO buffer to
the RTAS call.

However, there's nothing stopping the caller from specifying whatever
address they want in the RTAS call, and it's easy to construct a series of
RTAS calls that can overwrite arbitrary bytes (even without /dev/mem
access).

Additionally, there are some RTAS calls that do potentially dangerous
things and for which there are no legitimate userspace use cases.

In the past, this would not have been a particularly big deal as it was
assumed that root could modify all system state freely, but with Secure
Boot and lockdown we need to care about this.

We can't fundamentally change the ABI at this point, however we can address
this by implementing a filter that checks RTAS calls against a list
of permitted calls and forces the caller to use addresses within the RMO
buffer.

The list is based off the list of calls that are used by the librtas
userspace library, and has been tested with a number of existing userspace
RTAS utilities. For compatibility with any applications we are not aware of
that require other calls, the filter can be turned off at build time.

Cc: stable@vger.kernel.org
Reported-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200820044512.7543-1-ajd@linux.ibm.com
2020-10-06 23:22:27 +11:00
Athira Rajeev
3b6c3adbb2 powerpc/perf: Exclude pmc5/6 from the irrelevant PMU group constraints
PMU counter support functions enforces event constraints for group of
events to check if all events in a group can be monitored. Incase of
event codes using PMC5 and PMC6 ( 500fa and 600f4 respectively ), not
all constraints are applicable, say the threshold or sample bits. But
current code includes pmc5 and pmc6 in some group constraints (like
IC_DC Qualifier bits) which is actually not applicable and hence
results in those events not getting counted when scheduled along with
group of other events. Patch fixes this by excluding PMC5/6 from
constraints which are not relevant for it.

Fixes: 7ffd948 ("powerpc/perf: factor out power8 pmu functions")
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1600672204-1610-1-git-send-email-atrajeev@linux.vnet.ibm.com
2020-10-06 23:22:27 +11:00