BMC/Intel-BMC/linux.git/arch/powerpc/kernel, branch dev-5.8

powerpc: Fix P10 PVR revision in /proc/cpuinfo for SMT4 cores

2020-08-26T09:49:18+00:00

commit 030a2c689fb46e1690f7ded8b194bab7678efb28 upstream. On POWER10 bit 12 in the PVR indicates if the core is SMT4 or SMT8. Bit 12 is set for SMT4. Without this patch, /proc/cpuinfo on a SMT4 DD1 POWER10 looks like this: cpu : POWER10, altivec supported revision : 17.0 (pvr 0080 1100) Fixes: a3ea40d5c736 ("powerpc: Add POWER10 architected mode") Cc: stable@vger.kernel.org # v5.8 Signed-off-by: Michael Neuling Reviewed-by: Vaidyanathan Srinivasan Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200803035600.1820371-1-mikey@neuling.org Signed-off-by: Greg Kroah-Hartman

powerpc/watchpoint: Fix DAWR exception for CACHEOP

2020-08-19T06:26:45+00:00

[ Upstream commit f3c832f1350bcf1e6906113ee3168066f4235dbe ] 'ea' returned by analyse_instr() needs to be aligned down to cache block size for CACHEOP instructions. analyse_instr() does not set size for CACHEOP, thus size also needs to be calculated manually. Fixes: 27985b2a640e ("powerpc/watchpoint: Don't ignore extraneous exceptions blindly") Fixes: 74c6881019b7 ("powerpc/watchpoint: Prepare handler to handle more than one watchpoint") Signed-off-by: Ravi Bangoria Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200723090813.303838-4-ravi.bangoria@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/watchpoint: Fix DAWR exception constraint

2020-08-19T06:26:44+00:00

[ Upstream commit f6780ce619f8daa285760302d56e95892087bd1f ] Pedro Miraglia Franco de Carvalho noticed that on p8/p9, DAR value is inconsistent with different type of load/store. Like for byte,word etc. load/stores, DAR is set to the address of the first byte of overlap between watch range and real access. But for quadword load/ store it's sometime set to the address of the first byte of real access whereas sometime set to the address of the first byte of overlap. This issue has been fixed in p10. In p10(ISA 3.1), DAR is always set to the address of the first byte of overlap. Commit 27985b2a640e ("powerpc/watchpoint: Don't ignore extraneous exceptions blindly") wrongly assumes that DAR is set to the address of the first byte of overlap for all load/stores on p8/p9 as well. Fix that. With the fix, we now rely on 'ea' provided by analyse_instr(). If analyse_instr() fails, generate event unconditionally on p8/p9, and on p10 generate event only if DAR is within a DAWR range. Note: 8xx is not affected. Fixes: 27985b2a640e ("powerpc/watchpoint: Don't ignore extraneous exceptions blindly") Fixes: 74c6881019b7 ("powerpc/watchpoint: Prepare handler to handle more than one watchpoint") Reported-by: Pedro Miraglia Franco de Carvalho Signed-off-by: Ravi Bangoria Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200723090813.303838-3-ravi.bangoria@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/watchpoint: Fix 512 byte boundary limit

2020-08-19T06:26:44+00:00

[ Upstream commit 3190ecbfeeb2ab17778887ce3fa964615d6460fd ] Milton Miller reported that we are aligning start and end address to wrong size SZ_512M. It should be SZ_512. Fix that. While doing this change I also found a case where ALIGN() comparison fails. Within a given aligned range, ALIGN() of two addresses does not match when start address is pointing to the first byte and end address is pointing to any other byte except the first one. But that's not true for ALIGN_DOWN(). ALIGN_DOWN() of any two addresses within that range will always point to the first byte. So use ALIGN_DOWN() instead of ALIGN(). Fixes: e68ef121c1f4 ("powerpc/watchpoint: Use builtin ALIGN*() macros") Reported-by: Milton Miller Signed-off-by: Ravi Bangoria Tested-by: Jordan Niethe Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200723090813.303838-2-ravi.bangoria@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/vdso: Fix vdso cpu truncation

2020-08-19T06:26:35+00:00

[ Upstream commit a9f675f950a07d5c1dbcbb97aabac56f5ed085e3 ] The code in vdso_cpu_init that exposes the cpu and numa node to userspace via SPRG_VDSO incorrctly masks the cpu to 12 bits. This means that any kernel running on a box with more than 4096 threads (NR_CPUS advertises a limit of of 8192 cpus) would expose userspace to two cpu contexts running at the same time with the same cpu number. Note: I'm not aware of any distro shipping a kernel with support for more than 4096 threads today, nor of any system image that currently exceeds 4096 threads. Found via code browsing. Fixes: 18ad51dd342a7eb09dbcd059d0b451b616d4dafc ("powerpc: Add VDSO version of getcpu") Signed-off-by: Milton Miller Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200715233704.1352257-1-anton@ozlabs.org Signed-off-by: Sasha Levin

powerpc/rtas: don't online CPUs for partition suspend

2020-08-19T06:26:35+00:00

[ Upstream commit ec2fc2a9e9bbad9023aab65bc472ce7a3ca8608f ] Partition suspension, used for hibernation and migration, requires that the OS place all but one of the LPAR's processor threads into one of two states prior to calling the ibm,suspend-me RTAS function: * the architected offline state (via RTAS stop-self); or * the H_JOIN hcall, which does not return until the partition resumes execution Using H_CEDE as the offline mode, introduced by commit 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU into an appropriate offline state"), means that any threads which are offline from Linux's point of view must be moved to one of those two states before a partition suspension can proceed. This was eventually addressed in commit 120496ac2d2d ("powerpc: Bring all threads online prior to migration/hibernation"), which added code to temporarily bring up any offline processor threads so they can call H_JOIN. Conceptually this is fine, but the implementation has had multiple races with cpu hotplug operations initiated from user space[1][2][3], the error handling is fragile, and it generates user-visible cpu hotplug events which is a lot of noise for a platform feature that's supposed to minimize disruption to workloads. With commit 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU into an appropriate offline state") reverted, this code becomes unnecessary, so remove it. Since any offline CPUs now are truly offline from the platform's point of view, it is no longer necessary to bring up CPUs only to have them call H_JOIN and then go offline again upon resuming. Only active threads are required to call H_JOIN; stopped threads can be left alone. [1] commit a6717c01ddc2 ("powerpc/rtas: use device model APIs and serialization during LPM") [2] commit 9fb603050ffd ("powerpc/rtas: retry when cpu offline races with suspend/migration") [3] commit dfd718a2ed1f ("powerpc/rtas: Fix a potential race between CPU-Offline & Migration") Fixes: 120496ac2d2d ("powerpc: Bring all threads online prior to migration/hibernation") Signed-off-by: Nathan Lynch Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200612051238.1007764-3-nathanl@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/64s/hash: Fix hash_preload running with interrupts enabled

2020-07-27T07:02:09+00:00

Commit 2f92447f9f96 ("powerpc/book3s64/hash: Use the pte_t address from the caller") removed the local_irq_disable from hash_preload, but it was required for more than just the page table walk: the hash pte busy bit is effectively a lock which may be taken in interrupt context, and the local update flag test must not be preempted before it's used. This solves apparent lockups with perf interrupting __hash_page_64K. If get_perf_callchain then also takes a hash fault on the same page while it is already locked, it will loop forever taking hash faults, which looks like this: cpu 0x49e: Vector: 100 (System Reset) at [c00000001a4f7d70] pc: c000000000072dc8: hash_page_mm+0x8/0x800 lr: c00000000000c5a4: do_hash_page+0x24/0x38 sp: c0002ac1cc69ac70 msr: 8000000000081033 current = 0xc0002ac1cc602e00 paca = 0xc00000001de1f280 irqmask: 0x03 irq_happened: 0x01 pid = 20118, comm = pread2_processe Linux version 5.8.0-rc6-00345-g1fad14f18bc6 49e:mon> t [c0002ac1cc69ac70] c00000000000c5a4 do_hash_page+0x24/0x38 (unreliable) --- Exception: 300 (Data Access) at c00000000008fa60 __copy_tofrom_user_power7+0x20c/0x7ac [link register ] c000000000335d10 copy_from_user_nofault+0xf0/0x150 [c0002ac1cc69af70] c00032bf9fa3c880 (unreliable) [c0002ac1cc69afa0] c000000000109df0 read_user_stack_64+0x70/0xf0 [c0002ac1cc69afd0] c000000000109fcc perf_callchain_user_64+0x15c/0x410 [c0002ac1cc69b060] c000000000109c00 perf_callchain_user+0x20/0x40 [c0002ac1cc69b080] c00000000031c6cc get_perf_callchain+0x25c/0x360 [c0002ac1cc69b120] c000000000316b50 perf_callchain+0x70/0xa0 [c0002ac1cc69b140] c000000000316ddc perf_prepare_sample+0x25c/0x790 [c0002ac1cc69b1a0] c000000000317350 perf_event_output_forward+0x40/0xb0 [c0002ac1cc69b220] c000000000306138 __perf_event_overflow+0x88/0x1a0 [c0002ac1cc69b270] c00000000010cf70 record_and_restart+0x230/0x750 [c0002ac1cc69b620] c00000000010d69c perf_event_interrupt+0x20c/0x510 [c0002ac1cc69b730] c000000000027d9c performance_monitor_exception+0x4c/0x60 [c0002ac1cc69b750] c00000000000b2f8 performance_monitor_common_virt+0x1b8/0x1c0 --- Exception: f00 (Performance Monitor) at c0000000000cb5b0 pSeries_lpar_hpte_insert+0x0/0x160 [link register ] c0000000000846f0 __hash_page_64K+0x210/0x540 [c0002ac1cc69ba50] 0000000000000000 (unreliable) [c0002ac1cc69bb00] c000000000073ae0 update_mmu_cache+0x390/0x3a0 [c0002ac1cc69bb70] c00000000037f024 wp_page_copy+0x364/0xce0 [c0002ac1cc69bc20] c00000000038272c do_wp_page+0xdc/0xa60 [c0002ac1cc69bc70] c0000000003857bc handle_mm_fault+0xb9c/0x1b60 [c0002ac1cc69bd50] c00000000006c434 __do_page_fault+0x314/0xc90 [c0002ac1cc69be20] c00000000000c5c8 handle_page_fault+0x10/0x2c --- Exception: 300 (Data Access) at 00007fff8c861fe8 SP (7ffff6b19660) is in userspace Fixes: 2f92447f9f96 ("powerpc/book3s64/hash: Use the pte_t address from the caller") Reported-by: Athira Rajeev Reported-by: Anton Blanchard Signed-off-by: Nicholas Piggin Reviewed-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200727060947.10060-1-npiggin@gmail.com

powerpc/pseries/svm: Fix incorrect check for shared_lppaca_size

2020-07-14T11:57:26+00:00

Early secure guest boot hits the below crash while booting with vcpus numbers aligned with page boundary for PAGE size of 64k and LPPACA size of 1k i.e 64, 128 etc. Partition configured for 64 cpus. CPU maps initialized for 1 thread per core ------------[ cut here ]------------ kernel BUG at arch/powerpc/kernel/paca.c:89! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries This is due to the BUG_ON() for shared_lppaca_total_size equal to shared_lppaca_size. Instead the code should only BUG_ON() if we have exceeded the total_size, which indicates we've overflowed the array. Fixes: bd104e6db6f0 ("powerpc/pseries/svm: Use shared memory for LPPACA structures") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Satheesh Rajendran Reviewed-by: Laurent Dufour Reviewed-by: Thiago Jung Bauermann [mpe: Reword change log to clarify we're fixing not removing the check] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200619070113.16696-1-sathnaga@linux.vnet.ibm.com

powerpc/64s/exception: Fix 0x1500 interrupt handler crash

2020-07-08T10:41:06+00:00

A typo caused the interrupt handler to branch immediately to the common "unknown interrupt" handler and skip the special case test for denormal cause. This does not affect KVM softpatch handling (e.g., for POWER9 TM assist) because the KVM test was moved to common code by commit 9600f261acaa ("powerpc/64s/exception: Move KVM test to common code") just before this bug was introduced. Fixes: 3f7fbd97d07d ("powerpc/64s/exception: Clean up SRR specifiers") Reported-by: Paul Menzel Signed-off-by: Nicholas Piggin Tested-by: Paul Menzel [mpe: Split selftest into a separate patch] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200708074942.1713396-1-npiggin@gmail.com

Merge tag 'powerpc-5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2020-06-21T17:02:53+00:00

Pull powerpc fixes from Michael Ellerman: - One fix for the interrupt rework we did last release which broke KVM-PR - Three commits fixing some fallout from the READ_ONCE() changes interacting badly with our 8xx 16K pages support, which uses a pte_t that is a structure of 4 actual PTEs - A cleanup of the 8xx pte_update() to use the newly added pmd_off() - A fix for a crash when handling an oops if CONFIG_DEBUG_VIRTUAL is enabled - A minor fix for the SPU syscall generation Thanks to Aneesh Kumar K.V, Christian Zigotzky, Christophe Leroy, Mike Rapoport, Nicholas Piggin. * tag 'powerpc-5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/8xx: Provide ptep_get() with 16k pages mm: Allow arches to provide ptep_get() mm/gup: Use huge_ptep_get() in gup_hugepte() powerpc/syscalls: Use the number when building SPU syscall table powerpc/8xx: use pmd_off() to access a PMD entry in pte_update() powerpc/64s: Fix KVM interrupt using wrong save area powerpc: Fix kernel crash in show_instructions() w/DEBUG_VIRTUAL