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2020-07-29powerpc/32s: Remove TAUException wart in traps.cMichael Ellerman
All 32 and 64-bit builds that don't have CONFIG_TAU_INT enabled (all of them), get a definition of TAUException() in traps.c. On 64-bit it's completely useless, and just wastes ~120 bytes of text. On 32-bit it allows the kernel to link because head_32.S calls it unconditionally. Instead follow the example of altivec_assist_exception(), and if CONFIG_TAU_INT is not enabled just point it at unknown_exception using the preprocessor. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724131728.1643966-6-mpe@ellerman.id.au
2020-07-29powerpc/32s: Fix CONFIG_BOOK3S_601 usesMichael Ellerman
We have two uses of CONFIG_BOOK3S_601, which doesn't exist. Fix them to use CONFIG_PPC_BOOK3S_601 which is the correct symbol. Fixes: 12c3f1fd87bf ("powerpc/32s: get rid of CPU_FTR_601 feature") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724131728.1643966-5-mpe@ellerman.id.au
2020-07-29powerpc/64e: Drop dead BOOK3E_MMU_TLB_STATS codeMichael Ellerman
This code was merged 11 years ago in commit 13363ab9b9d0 ("powerpc: Add definitions used by exception handling on 64-bit Book3E") but was never able to be built because CONFIG_BOOK3E_MMU_TLB_STATS never existed. Remove it. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724131728.1643966-4-mpe@ellerman.id.au
2020-07-29powerpc/52xx: Fix comment about CONFIG_BDI*Michael Ellerman
There's a comment in lite5200_sleep.S that refers to "CONFIG_BDI*". This confuses scripts/checkkconfigsymbols.py, which thinks it should be able to find CONFIG_BDI. Change the comment to refer to CONFIG_BDI_SWITCH which is presumably roughly what it was referring to. AFAICS there never has been a CONFIG_BDI. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724131728.1643966-3-mpe@ellerman.id.au
2020-07-29powerpc/configs: Remove dead symbolsMichael Ellerman
Remove references to symbols that no longer exist as reported by scripts/checkkconfigsymbols.py. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724131728.1643966-2-mpe@ellerman.id.au
2020-07-29powerpc/configs: Drop old symbols from ppc6xx_defconfigMichael Ellerman
ppc6xx_defconfig refers to quite a few symbols that no longer exist, as reported by scripts/checkkconfigsymbols.py, remove them. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724131728.1643966-1-mpe@ellerman.id.au
2020-07-29powerpc/mm: Limit resize_hpt_for_hotplug() call to hash guests onlyBharata B Rao
During memory hotplug and unplug, resize_hpt_for_hotplug() gets called for both hash and radix guests but it should be called only for hash guests. Though the call does nothing in the radix guest case, it is cleaner to push this call into hash specific memory hotplug routines. Reported-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Bharata B Rao <bharata@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200727095704.1432916-1-bharata@linux.ibm.com
2020-07-29powerpc/mm: Remove custom stack expansion checkingMichael Ellerman
We have powerpc specific logic in our page fault handling to decide if an access to an unmapped address below the stack pointer should expand the stack VMA. The logic aims to prevent userspace from doing bad accesses below the stack pointer. However as long as the stack is < 1MB in size, we allow all accesses without further checks. Adding some debug I see that I can do a full kernel build and LTP run, and not a single process has used more than 1MB of stack. So for the majority of processes the logic never even fires. We also recently found a nasty bug in this code which could cause userspace programs to be killed during signal delivery. It went unnoticed presumably because most processes use < 1MB of stack. The generic mm code has also grown support for stack guard pages since this code was originally written, so the most heinous case of the stack expanding into other mappings is now handled for us. Finally although some other arches have special logic in this path, from what I can tell none of x86, arm64, arm and s390 impose any extra checks other than those in expand_stack(). So drop our complicated logic and like other architectures just let the stack expand as long as its within the rlimit. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Tested-by: Daniel Axtens <dja@axtens.net> Link: https://lore.kernel.org/r/20200724092528.1578671-4-mpe@ellerman.id.au
2020-07-29powerpc: Allow 4224 bytes of stack expansion for the signal frameMichael Ellerman
We have powerpc specific logic in our page fault handling to decide if an access to an unmapped address below the stack pointer should expand the stack VMA. The code was originally added in 2004 "ported from 2.4". The rough logic is that the stack is allowed to grow to 1MB with no extra checking. Over 1MB the access must be within 2048 bytes of the stack pointer, or be from a user instruction that updates the stack pointer. The 2048 byte allowance below the stack pointer is there to cover the 288 byte "red zone" as well as the "about 1.5kB" needed by the signal delivery code. Unfortunately since then the signal frame has expanded, and is now 4224 bytes on 64-bit kernels with transactional memory enabled. This means if a process has consumed more than 1MB of stack, and its stack pointer lies less than 4224 bytes from the next page boundary, signal delivery will fault when trying to expand the stack and the process will see a SEGV. The total size of the signal frame is the size of struct rt_sigframe (which includes the red zone) plus __SIGNAL_FRAMESIZE (128 bytes on 64-bit). The 2048 byte allowance was correct until 2008 as the signal frame was: struct rt_sigframe { struct ucontext uc; /* 0 1440 */ /* --- cacheline 11 boundary (1408 bytes) was 32 bytes ago --- */ long unsigned int _unused[2]; /* 1440 16 */ unsigned int tramp[6]; /* 1456 24 */ struct siginfo * pinfo; /* 1480 8 */ void * puc; /* 1488 8 */ struct siginfo info; /* 1496 128 */ /* --- cacheline 12 boundary (1536 bytes) was 88 bytes ago --- */ char abigap[288]; /* 1624 288 */ /* size: 1920, cachelines: 15, members: 7 */ /* padding: 8 */ }; 1920 + 128 = 2048 Then in commit ce48b2100785 ("powerpc: Add VSX context save/restore, ptrace and signal support") (Jul 2008) the signal frame expanded to 2304 bytes: struct rt_sigframe { struct ucontext uc; /* 0 1696 */ <-- /* --- cacheline 13 boundary (1664 bytes) was 32 bytes ago --- */ long unsigned int _unused[2]; /* 1696 16 */ unsigned int tramp[6]; /* 1712 24 */ struct siginfo * pinfo; /* 1736 8 */ void * puc; /* 1744 8 */ struct siginfo info; /* 1752 128 */ /* --- cacheline 14 boundary (1792 bytes) was 88 bytes ago --- */ char abigap[288]; /* 1880 288 */ /* size: 2176, cachelines: 17, members: 7 */ /* padding: 8 */ }; 2176 + 128 = 2304 At this point we should have been exposed to the bug, though as far as I know it was never reported. I no longer have a system old enough to easily test on. Then in 2010 commit 320b2b8de126 ("mm: keep a guard page below a grow-down stack segment") caused our stack expansion code to never trigger, as there was always a VMA found for a write up to PAGE_SIZE below r1. That meant the bug was hidden as we continued to expand the signal frame in commit 2b0a576d15e0 ("powerpc: Add new transactional memory state to the signal context") (Feb 2013): struct rt_sigframe { struct ucontext uc; /* 0 1696 */ /* --- cacheline 13 boundary (1664 bytes) was 32 bytes ago --- */ struct ucontext uc_transact; /* 1696 1696 */ <-- /* --- cacheline 26 boundary (3328 bytes) was 64 bytes ago --- */ long unsigned int _unused[2]; /* 3392 16 */ unsigned int tramp[6]; /* 3408 24 */ struct siginfo * pinfo; /* 3432 8 */ void * puc; /* 3440 8 */ struct siginfo info; /* 3448 128 */ /* --- cacheline 27 boundary (3456 bytes) was 120 bytes ago --- */ char abigap[288]; /* 3576 288 */ /* size: 3872, cachelines: 31, members: 8 */ /* padding: 8 */ /* last cacheline: 32 bytes */ }; 3872 + 128 = 4000 And commit 573ebfa6601f ("powerpc: Increase stack redzone for 64-bit userspace to 512 bytes") (Feb 2014): struct rt_sigframe { struct ucontext uc; /* 0 1696 */ /* --- cacheline 13 boundary (1664 bytes) was 32 bytes ago --- */ struct ucontext uc_transact; /* 1696 1696 */ /* --- cacheline 26 boundary (3328 bytes) was 64 bytes ago --- */ long unsigned int _unused[2]; /* 3392 16 */ unsigned int tramp[6]; /* 3408 24 */ struct siginfo * pinfo; /* 3432 8 */ void * puc; /* 3440 8 */ struct siginfo info; /* 3448 128 */ /* --- cacheline 27 boundary (3456 bytes) was 120 bytes ago --- */ char abigap[512]; /* 3576 512 */ <-- /* size: 4096, cachelines: 32, members: 8 */ /* padding: 8 */ }; 4096 + 128 = 4224 Then finally in 2017, commit 1be7107fbe18 ("mm: larger stack guard gap, between vmas") exposed us to the existing bug, because it changed the stack VMA to be the correct/real size, meaning our stack expansion code is now triggered. Fix it by increasing the allowance to 4224 bytes. Hard-coding 4224 is obviously unsafe against future expansions of the signal frame in the same way as the existing code. We can't easily use sizeof() because the signal frame structure is not in a header. We will either fix that, or rip out all the custom stack expansion checking logic entirely. Fixes: ce48b2100785 ("powerpc: Add VSX context save/restore, ptrace and signal support") Cc: stable@vger.kernel.org # v2.6.27+ Reported-by: Tom Lane <tgl@sss.pgh.pa.us> Tested-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724092528.1578671-2-mpe@ellerman.id.au
2020-07-29powerpc/pseries: Add KVM guest doorbell restrictionsNicholas Piggin
KVM guests have certain restrictions and performance quirks when using doorbells. This patch moves the EPAPR KVM guest test so it can be shared with PSERIES, and uses that in doorbell setup code to apply the KVM guest quirks and improves IPI performance for two cases: - PowerVM guests may now use doorbells even if they are secure. - KVM guests no longer use doorbells if XIVE is available. There is a valid complaint that "KVM guest" is not a very reasonable thing to test for, it's preferable for the hypervisor to advertise particular behaviours to the guest so they could change if the hypervisor implementation or configuration changes. However in this case we were already assuming a KVM guest worst case, so this patch is about containing those quirks. If KVM later advertises fast doorbells, we should test for that and override the quirks. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Tested-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200726035155.1424103-4-npiggin@gmail.com
2020-07-29powerpc/pseries: Use doorbells even if XIVE is availableNicholas Piggin
KVM supports msgsndp in guests by trapping and emulating the instruction, so it was decided to always use XIVE for IPIs if it is available. However on PowerVM systems, msgsndp can be used and gives better performance. On large systems, high XIVE interrupt rates can have sub-linear scaling, and using msgsndp can reduce the load on the interrupt controller. So switch to using core local doorbells even if XIVE is available. This reduces performance for KVM guests with an SMT topology by about 50% for ping-pong context switching between SMT vCPUs. An option vector (or dt-cpu-ftrs) could be defined to disable msgsndp to get KVM performance back. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Tested-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200726035155.1424103-3-npiggin@gmail.com
2020-07-29powerpc: Inline doorbell sending functionsNicholas Piggin
These are only called in one place for a given platform, so inline them for performance. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Tested-by: Cédric Le Goater <clg@kaod.org> [mpe: Fix build errors related to KVM] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200726035155.1424103-2-npiggin@gmail.com
2020-07-29powerpc/perf: Fix MMCRA_BHRB_DISABLE define for binutils < 2.28Athira Rajeev
Commit 9908c826d5ed ("powerpc/perf: Add Power10 PMU feature to DT CPU features") defines MMCRA_BHRB_DISABLE as `0x2000000000UL`. Binutils version less than 2.28 doesn't support UL suffix. arch/powerpc/kernel/cpu_setup_power.S: Assembler messages: arch/powerpc/kernel/cpu_setup_power.S:250: Error: found 'L', expected: ')' arch/powerpc/kernel/cpu_setup_power.S:250: Error: junk at end of line, first unrecognized character is `L' arch/powerpc/kernel/cpu_setup_power.S:250: Error: found 'L', expected: ')' arch/powerpc/kernel/cpu_setup_power.S:250: Error: found 'L', expected: ')' arch/powerpc/kernel/cpu_setup_power.S:250: Error: junk at end of line, first unrecognized character is `L' arch/powerpc/kernel/cpu_setup_power.S:250: Error: found 'L', expected: ')' arch/powerpc/kernel/cpu_setup_power.S:250: Error: found 'L', expected: ')' arch/powerpc/kernel/cpu_setup_power.S:250: Error: operand out of range (0x0000002000000000 is not between 0xffffffffffff8000 and 0x000000000000ffff) Fix this by wrapping it with the `_UL` macro. Fixes: 9908c826d5ed ("Add Power10 PMU feature to DT CPU features") Suggested-by: Michael Ellerman <mpe@ellerman.id.au> 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/1595996214-5833-1-git-send-email-atrajeev@linux.vnet.ibm.com
2020-07-27powerpc/fadump: Fix build error with CONFIG_PRESERVE_FA_DUMP=yMichael Ellerman
skiroot_defconfig fails: arch/powerpc/kernel/fadump.c:48:17: error: ‘cpus_in_fadump’ defined but not used 48 | static atomic_t cpus_in_fadump; Fix it by moving the definition into the #ifdef where it's used. Fixes: ba608c4fa12c ("powerpc/fadump: fix race between pstore write and fadump crash trigger") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200727070341.595634-1-mpe@ellerman.id.au
2020-07-27powerpc/powernv/pci.h: delete duplicated wordRandy Dunlap
Drop the repeated word "for". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200726003809.20454-10-rdunlap@infradead.org
2020-07-27powerpc/smu.h: delete duplicated wordRandy Dunlap
Drop the repeated word "the". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200726003809.20454-9-rdunlap@infradead.org
2020-07-27powerpc/reg.h: delete duplicated wordRandy Dunlap
Drop the repeated word "a". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200726003809.20454-8-rdunlap@infradead.org
2020-07-27powerpc/ppc_asm.h: delete duplicated wordRandy Dunlap
Drop the repeated word "in". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200726003809.20454-7-rdunlap@infradead.org
2020-07-27powerpc/hw_breakpoint.h: delete duplicated wordRandy Dunlap
Drop the repeated word "the". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200726003809.20454-6-rdunlap@infradead.org
2020-07-27powerpc/epapr_hcalls.h: delete duplicated wordsRandy Dunlap
Drop the repeated words "file" and "the". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200726003809.20454-5-rdunlap@infradead.org
2020-07-27powerpc/cputime.h: delete duplicated wordRandy Dunlap
Drop the repeated word "use". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200726003809.20454-4-rdunlap@infradead.org
2020-07-27powerpc/book3s/radix-4k.h: delete duplicated wordRandy Dunlap
Drop the repeated word "per". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200726003809.20454-3-rdunlap@infradead.org
2020-07-27powerpc/book3s/mmu-hash.h: delete duplicated wordRandy Dunlap
Drop the repeated word "below". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200726003809.20454-2-rdunlap@infradead.org
2020-07-27powerpc/lib: remove memcpy_flushcache redundant returnLi RongQing
Align it with other architectures and none of the callers has been interested its return Signed-off-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1556278590-14727-1-git-send-email-lirongqing@baidu.com
2020-07-27powerpc/ptdump: Refactor update of pg_stateChristophe Leroy
In note_page(), the pg_state is updated the same way in two places. Add note_page_update_state() to do it. Also include the display of boundary markers there as it is missing "no level" leg, leading to a mismatch when the first two markers are at the same address and the first displayed area uses that address. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a284a809f01c705bbaab303b06fda216f147a99a.1593429426.git.christophe.leroy@csgroup.eu
2020-07-27powerpc/ptdump: Refactor update of st->last_paChristophe Leroy
st->last_pa is always updated in note_page() so it can be done outside the if/elseif/else block. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/610d6b1a60ad0bedef865a90153c1110cfaa507e.1593429426.git.christophe.leroy@csgroup.eu
2020-07-27powerpc/32s: Use dedicated segment for modules with STRICT_KERNEL_RWXChristophe Leroy
When STRICT_KERNEL_RWX is set, we want to set NX bit on vmalloc segments. But modules require exec. Use a dedicated segment for modules. There is not much space above kernel, and we don't waste vmalloc space to do alignment. Therefore, we take the segment before PAGE_OFFSET for modules. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/eb8faba9148b6cf17c696ba776b4e8ee2f6313bf.1593428200.git.christophe.leroy@csgroup.eu
2020-07-27powerpc/32s: Kernel space starts at TASK_SIZEChristophe Leroy
Kernel space starts at TASK_SIZE. Select kernel page table when address is over TASK_SIZE. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/893425e32cd0a003539573b2d115e0ffa98bc26c.1593428200.git.christophe.leroy@csgroup.eu
2020-07-27powerpc/32: Set user/kernel boundary at TASK_SIZE instead of PAGE_OFFSETChristophe Leroy
User space stops at TASK_SIZE. At the moment, kernel space starts at PAGE_OFFSET. In order to use space between TASK_SIZE and PAGE_OFFSET for modules, make TASK_SIZE the limit between user and kernel space. Note that fault.c already considers TASK_SIZE as the boundary between user and kernel space. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b38b52cd8dabbb56fbd6f9219d6f3cdccbb43b44.1593428200.git.christophe.leroy@csgroup.eu
2020-07-27powerpc/32s: Only leave NX unset on segments used for modulesChristophe Leroy
Instead of leaving NX unset on all segments above the start of vmalloc space, only leave NX unset on segments used for modules. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7172c0f5253419315e434a1816ee3d6ed6505bc0.1593428200.git.christophe.leroy@csgroup.eu
2020-07-27powerpc: Use MODULES_VADDR if definedChristophe Leroy
In order to allow allocation of modules outside of vmalloc space, use MODULES_VADDR and MODULES_END when MODULES_VADDR is defined. Redefine module_alloc() when MODULES_VADDR defined. Unmap corresponding KASAN shadow memory. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7ecf5fff1eef67d450e73fc412b6ec3818483d75.1593428200.git.christophe.leroy@csgroup.eu
2020-07-27powerpc/lib: Prepare code-patching for modules allocated outside vmalloc spaceChristophe Leroy
Use is_vmalloc_or_module_addr() instead of is_vmalloc_addr() Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7d884db0e5a6f521331639d8c0f13e520d5a4fef.1593428200.git.christophe.leroy@csgroup.eu
2020-07-27powerpc/papr_scm: Make some symbols staticWei Yongjun
The sparse tool complains as follows: arch/powerpc/platforms/pseries/papr_scm.c:97:1: warning: symbol 'papr_nd_regions' was not declared. Should it be static? arch/powerpc/platforms/pseries/papr_scm.c:98:1: warning: symbol 'papr_ndr_lock' was not declared. Should it be static? Those variables are not used outside of papr_scm.c, so this commit marks them static. Fixes: 85343a8da2d9 ("powerpc/papr/scm: Add bad memory ranges to nvdimm bad ranges") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200725091949.75234-1-weiyongjun1@huawei.com
2020-07-27powerpc/64s: allow for clang's objdump differencesBill Wendling
Clang's objdump emits slightly different output from GNU's objdump, causing a list of warnings to be emitted during relocatable builds. E.g., clang's objdump emits this: c000000000000004: 2c 00 00 48 b 0xc000000000000030 ... c000000000005c6c: 10 00 82 40 bf 2, 0xc000000000005c7c while GNU objdump emits: c000000000000004: 2c 00 00 48 b c000000000000030 <__start+0x30> ... c000000000005c6c: 10 00 82 40 bne c000000000005c7c <masked_interrupt+0x3c> Adjust llvm-objdump's output to remove the extraneous '0x' and convert 'bf' and 'bt' to 'bne' and 'beq' resp. to more closely match GNU objdump's output. Note that clang's objdump doesn't yet output the relocation symbols on PPC. Signed-off-by: Bill Wendling <morbo@google.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/191c67db31264b69cf6b566fd69851beb3dd0abb.1595630874.git.morbo@google.com
2020-07-27powerpc: Implement smp_cond_load_relaxed()Nicholas Piggin
This implements smp_cond_load_relaxed() with the slowpath busy loop using the preferred SMT priority pattern. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Waiman Long <longman@redhat.com> [mpe: Make it 64-bit only to fix build errors on 32-bit] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724131423.1362108-7-npiggin@gmail.com
2020-07-27powerpc/qspinlock: Optimised atomic_try_cmpxchg_lock() that adds the lock hintNicholas Piggin
This brings the behaviour of the uncontended fast path back to roughly equivalent to simple spinlocks -- a single atomic op with lock hint. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Waiman Long <longman@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724131423.1362108-6-npiggin@gmail.com
2020-07-27powerpc/pseries: Implement paravirt qspinlocks for SPLPARNicholas Piggin
This implements the generic paravirt qspinlocks using H_PROD and H_CONFER to kick and wait. This uses an un-directed yield to any CPU rather than the directed yield to a pre-empted lock holder that paravirtualised simple spinlocks use, that requires no kick hcall. This is something that could be investigated and improved in future. Performance results can be found in the commit which added queued spinlocks. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Waiman Long <longman@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724131423.1362108-5-npiggin@gmail.com
2020-07-27powerpc/64s: Implement queued spinlocks and rwlocksNicholas Piggin
These have shown significantly improved performance and fairness when spinlock contention is moderate to high on very large systems. With this series including subsequent patches, on a 16 socket 1536 thread POWER9, a stress test such as same-file open/close from all CPUs gets big speedups, 11620op/s aggregate with simple spinlocks vs 384158op/s (33x faster), where the difference in throughput between the fastest and slowest thread goes from 7x to 1.4x. Thanks to the fast path being identical in terms of atomics and barriers (after a subsequent optimisation patch), single threaded performance is not changed (no measurable difference). On smaller systems, performance and fairness seems to be generally improved. Using dbench on tmpfs as a test (that starts to run into kernel spinlock contention), a 2-socket OpenPOWER POWER9 system was tested with bare metal and KVM guest configurations. Results can be found here: https://github.com/linuxppc/issues/issues/305#issuecomment-663487453 Observations are: - Queued spinlocks are equal when contention is insignificant, as expected and as measured with microbenchmarks. - When there is contention, on bare metal queued spinlocks have better throughput and max latency at all points. - When virtualised, queued spinlocks are slightly worse approaching peak throughput, but significantly better throughput and max latency at all points beyond peak, until queued spinlock maximum latency rises when clients are 2x vCPUs. The regressions haven't been analysed very well yet, there are a lot of things that can be tuned, particularly the paravirtualised locking, but the numbers already look like a good net win even on relatively small systems. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Waiman Long <longman@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724131423.1362108-4-npiggin@gmail.com
2020-07-26powerpc: Move spinlock implementation to simple_spinlockNicholas Piggin
To prepare for queued spinlocks. This is a simple rename except to update preprocessor guard name and a file reference. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Waiman Long <longman@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724131423.1362108-3-npiggin@gmail.com
2020-07-26powerpc/pseries: Move some PAPR paravirt functions to their own fileNicholas Piggin
These functions will be used by the queued spinlock implementation, and may be useful elsewhere too, so move them out of spinlock.h. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Waiman Long <longman@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724131423.1362108-2-npiggin@gmail.com
2020-07-26powerpc/numa: Limit possible nodes to within num_possible_nodesSrikar Dronamraju
MAX_NUMNODES is a theoretical maximum number of nodes thats is supported by the kernel. Device tree properties exposes the number of possible nodes on the current platform. The kernel would detected this and would use it for most of its resource allocations. If the platform now increases the nodes to over what was already exposed, then it may lead to inconsistencies. Hence limit it to the already exposed nodes. Suggested-by: Nathan Lynch <nathanl@linux.ibm.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/20200724105809.24733-1-srikar@linux.vnet.ibm.com
2020-07-26powerpc/perf: Initialize power10 PMU registers in cpu setup routineAthira Rajeev
Initialize Monitor Mode Control Register 3 (MMCR3) SPR which is new in power10. For PowerISA v3.1, BHRB disable is controlled via Monitor Mode Control Register A (MMCRA) bit, namely "BHRB Recording Disable (BHRBRD)". This patch also initializes MMCRA BHRBRD to disable BHRB feature at boot for power10. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Reviewed-by: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1595489557-2047-1-git-send-email-atrajeev@linux.vnet.ibm.com
2020-07-26powerpc/powernv/sriov: Remove vfs_expandedOliver O'Halloran
Previously iov->vfs_expanded was used for two purposes. 1) To work out how much we need to multiple the per-VF BAR size to figure out the total space required for the IOV BAR. 2) To indicate that IOV is not usable with this device (vfs_expanded == 0). We don't really need the field for either since the multiple in 1) is always the number PEs supported by the PHB. Similarly, we don't really need it in 2) either since the IOV data field will be NULL if we can't use IOV with the device. Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200722065715.1432738-16-oohall@gmail.com
2020-07-26powerpc/powernv/sriov: Make single PE mode a per-BAR settingOliver O'Halloran
Using single PE BARs to map an SR-IOV BAR is really a choice about what strategy to use when mapping a BAR. It doesn't make much sense for this to be a global setting since a device might have one large BAR which needs to be mapped with single PE windows and another smaller BAR that can be mapped with a regular segmented window. Make the segmented vs single decision a per-BAR setting and clean up the logic that decides which mode to use. Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200722065715.1432738-15-oohall@gmail.com
2020-07-26powerpc/powernv/sriov: Refactor M64 BAR setupOliver O'Halloran
Split up the logic so that we have one branch that handles setting up a segmented window and another that handles setting up single PE windows for each VF. Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200722065715.1432738-14-oohall@gmail.com
2020-07-26powerpc/powernv/sriov: Move M64 BAR allocation into a helperOliver O'Halloran
I want to refactor the loop this code is currently inside of. Hoist it on out. Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200722065715.1432738-13-oohall@gmail.com
2020-07-26powerpc/powernv/sriov: De-indent setup and teardownOliver O'Halloran
Remove the IODA2 PHB checks. We already assume IODA2 in several places so there's not much point in wrapping most of the setup and teardown process in an if block. Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200722065715.1432738-12-oohall@gmail.com
2020-07-26powerpc/powernv/sriov: Drop iov->pe_num_map[]Oliver O'Halloran
Currently the iov->pe_num_map[] does one of two things depending on whether single PE mode is being used or not. When it is, this contains an array which maps a vf_index to the corresponding PE number. When single PE mode is not being used this contains a scalar which is the base PE for the set of enabled VFs (for for VFn is base + n). The array was necessary because when calling pnv_ioda_alloc_pe() there is no guarantee that the allocated PEs would be contigious. We can now allocate contigious blocks of PEs so this is no longer an issue. This allows us to drop the if (single_mode) {} .. else {} block scattered through the SR-IOV code which is a nice clean up. This also fixes a bug in pnv_pci_sriov_disable() which is the non-atomic bitmap_clear() to manipulate the PE allocation map. Other users of the map assume it will be accessed with atomic ops. Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200722065715.1432738-11-oohall@gmail.com
2020-07-26powerpc/powernv/pci: Refactor pnv_ioda_alloc_pe()Oliver O'Halloran
Rework the PE allocation logic to allow allocating blocks of PEs rather than individually. We'll use this to allocate contigious blocks of PEs for the SR-IOVs. This patch also adds code to pnv_ioda_alloc_pe() and pnv_ioda_reserve_pe() to use the existing, but unused, phb->pe_alloc_mutex. Currently these functions use atomic bit ops to release a currently allocated PE number. However, the pnv_ioda_alloc_pe() wants to have exclusive access to the bit map while scanning for hole large enough to accomodate the allocation size. Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200722065715.1432738-10-oohall@gmail.com
2020-07-26powerpc/powernv/sriov: Factor out M64 BAR setupOliver O'Halloran
The sequence required to use the single PE BAR mode is kinda janky and requires a little explanation. The API was designed with P7-IOC style windows where the setup process is something like: 1. Configure the window start / end address 2. Enable the window 3. Map the segments of each window to the PE For Single PE BARs the process is: 1. Set the PE for segment zero on a disabled window 2. Set the range 3. Enable the window Move the OPAL calls into their own helper functions where the quirks can be contained. Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200722065715.1432738-9-oohall@gmail.com