- 04 Oct, 2018 5 commits
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Mark Hairgrove authored
This threshold is no longer used now that all invalidates issue a single ATSD to each active NPU. Signed-off-by:
Mark Hairgrove <mhairgrove@nvidia.com> Reviewed-by:
Alistair Popple <alistair@popple.id.au> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au>
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Mark Hairgrove authored
Prior to this change only two types of ATSDs were issued to the NPU: invalidates targeting a single page and invalidates targeting the whole address space. The crossover point happened at the configurable atsd_threshold which defaulted to 2M. Invalidates that size or smaller would issue per-page invalidates for the whole range. The NPU supports more invalidation sizes however: 64K, 2M, 1G, and all. These invalidates target addresses aligned to their size. 2M is a common invalidation size for GPU-enabled applications because that is a GPU page size, so reducing the number of invalidates by 32x in that case is a clear improvement. ATSD latency is high in general so now we always issue a single invalidate rather than multiple. This will over-invalidate in some cases, but for any invalidation size over 2M it matches or improves the prior behavior. There's also an improvement for single-page invalidates since the prior version issued two invalidates for that case instead of one. With this change all issued ATSDs now perform a flush, so the flush parameter has been removed from all the helpers. To show the benefit here are some performance numbers from a microbenchmark which creates a 1G allocation then uses mprotect with PROT_NONE to trigger invalidates in strides across the allocation. One NPU (1 GPU): mprotect rate (GB/s) Stride Before After Speedup 64K 5.3 5.6 5% 1M 39.3 57.4 46% 2M 49.7 82.6 66% 4M 286.6 285.7 0% Two NPUs (6 GPUs): mprotect rate (GB/s) Stride Before After Speedup 64K 6.5 7.4 13% 1M 33.4 67.9 103% 2M 38.7 93.1 141% 4M 356.7 354.6 -1% Anything over 2M is roughly the same as before since both cases issue a single ATSD. Signed-off-by: -
Mark Hairgrove authored
There are two types of ATSDs issued to the NPU: invalidates targeting a specific virtual address and invalidates targeting the whole address space. In both cases prior to this change, the sequence was: for each NPU - Write the target address to the XTS_ATSD_AVA register - EIEIO - Write the launch value to issue the ATSD First, a target address is not required when invalidating the whole address space, so that write and the EIEIO have been removed. The AP (size) field in the launch is not needed either. Second, for per-address invalidates the above sequence is inefficient in the common case of multiple NPUs because an EIEIO is issued per NPU. This unnecessarily forces the launches of later ATSDs to be ordered with the launches of earlier ones. The new sequence only issues a single EIEIO: for each NPU - Write the target address to the XTS_ATSD_AVA register EIEIO for each NPU - Write the launch value to issue the ATSD Performance results were gathered using a microbenchmark which creates a 1G allocation then uses mprotect with PROT_NONE to trigger invalidates in strides across the allocation. With only a single NPU active (one GPU) the difference is in the noise for both types of invalidates (+/-1%). With two NPUs active (on a 6-GPU system) the effect is more noticeable: mprotect rate (GB/s) Stride Before After Speedup 64K 5.9 6.5 10% 1M 31.2 33.4 7% 2M 36.3 38.7 7% 4M 322.6 356.7 11% Signed-off-by: -
Masahiro Yamada authored
Clean up the leftover of commit f2910f0e ("powerpc: remove old GCC version checks"). Signed-off-by:
Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by:
Nicholas Piggin <npiggin@gmail.com> Signed-off-by:
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Daniel Axtens authored
When enumerating page size definitions to check hardware support, we construct a constant which is (1U << (def->shift - 10)). However, the array of page size definitions is only initalised for various MMU_PAGE_* constants, so it contains a number of 0-initialised elements with def->shift == 0. This means we end up shifting by a very large number, which gives the following UBSan splat: ================================================================================ UBSAN: Undefined behaviour in /home/dja/dev/linux/linux/arch/powerpc/mm/tlb_nohash.c:506:21 shift exponent 4294967286 is too large for 32-bit type 'unsigned int' CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc3-00045-ga604f927b012-dirty #6 Call Trace: [c00000000101bc20] [c000000000a13d54] .dump_stack+0xa8/0xec (unreliable) [c00000000101bcb0] [c0000000004f20a8] .ubsan_epilogue+0x18/0x64 [c00000000101bd30] [c0000000004f2b10] .__ubsan_handle_shift_out_of_bounds+0x110/0x1a4 [c00000000101be20] [c000000000d21760] .early_init_mmu+0x1b4/0x5a0 [c00000000101bf10] [c000000000d1ba28] .early_setup+0x100/0x130 [c00000000101bf90] [c000000000000528] start_here_multiplatform+0x68/0x80 ================================================================================ Fix this by first checking if the element exists (shift != 0) before constructing the constant. Signed-off-by:
Daniel Axtens <dja@axtens.net> Signed-off-by:
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- 03 Oct, 2018 31 commits
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Christophe Leroy authored
Add call to early_memtest() so that kernel compiled with CONFIG_MEMTEST really perform memtest at startup when requested via 'memtest' boot parameter. Tested-by:
Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by:
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Christophe Leroy authored
When a process allocates a hugepage, the following leak is reported by kmemleak. This is a false positive which is due to the pointer to the table being stored in the PGD as physical memory address and not virtual memory pointer. unreferenced object 0xc30f8200 (size 512): comm "mmap", pid 374, jiffies 4872494 (age 627.630s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<e32b68da>] huge_pte_alloc+0xdc/0x1f8 [<9e0df1e1>] hugetlb_fault+0x560/0x8f8 [<7938ec6c>] follow_hugetlb_page+0x14c/0x44c [<afbdb405>] __get_user_pages+0x1c4/0x3dc [<b8fd7cd9>] __mm_populate+0xac/0x140 [<3215421e>] vm_mmap_pgoff+0xb4/0xb8 [<c148db69>] ksys_mmap_pgoff+0xcc/0x1fc [<4fcd760f>] ret_from_syscall+0x0/0x38 See commit a984506c ("powerpc/mm: Don't report PUDs as memory leaks when using kmemleak") for detailed explanation. To fix that, this patch tells kmemleak to ignore the allocated hugepage table. Signed-off-by: -
Michael Neuling authored
The comments in this file don't conform to the coding style so take them to "Comment Formatting Re-Education Camp". Suggested-by:
Michael Neuling <mikey@neuling.org> [mpe: Reflow some comments and add full stops, fix spelling of Sergeant.] Signed-off-by:
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Petr Vorel authored
for 64bit configs which use for CONFIG_LOG_BUF_SHIFT the same or higher value than the default (currently 17). Signed-off-by:
Petr Vorel <pvorel@suse.cz> Signed-off-by:
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YueHaibing authored
Remove duplicated include. Signed-off-by:
YueHaibing <yuehaibing@huawei.com> Reviewed-by:
Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by:
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Michal Suchanek authored
The code in machine_check_exception excludes 64s hvmode when incrementing the MCE counter only to call opal_machine_check to increment it specifically for this case. Remove the exclusion and special case. Fixes: a43c1590 ("powerpc/pseries: Flush SLB contents on SLB MCE errors.") Signed-off-by:
Michal Suchanek <msuchanek@suse.de> Signed-off-by:
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Breno Leitao authored
On a kernel TM Bad thing program exception, the Machine State Register (MSR) is not being properly displayed. The exception code dumps a 32-bits value but MSR is a 64 bits register for all platforms that have HTM enabled. This patch dumps the MSR value as a 64-bits value instead of 32 bits. In order to do so, the 'reason' variable could not be used, since it trimmed MSR to 32-bits (int). Signed-off-by:
Breno Leitao <leitao@debian.org> Signed-off-by:
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Breno Leitao authored
Currently msr_tm_active() is a wrapper around MSR_TM_ACTIVE() if CONFIG_PPC_TRANSACTIONAL_MEM is set, or it is just a function that returns false if CONFIG_PPC_TRANSACTIONAL_MEM is not set. This function is not necessary, since MSR_TM_ACTIVE() just do the same and could be used, removing the dualism and simplifying the code. This patchset remove every instance of msr_tm_active() and replaced it by MSR_TM_ACTIVE(). Signed-off-by:
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Breno Leitao authored
There is a mismatch between function pnv_platform_error_reboot() definition and declaration regarding function modifiers. In the declaration part, it contains the function attribute __noreturn, while function definition itself lacks it. This was reported by sparse tool as an error: arch/powerpc/platforms/powernv/opal.c:538:6: error: symbol 'pnv_platform_error_reboot' redeclared with different type (originally declared at arch/powerpc/platforms/powernv/powernv.h:11) - different modifiers I checked and the function is already being considered as being 'noreturn' by the compiler, thus, I understand this patch does not change any code being generated. Signed-off-by:
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Breno Leitao authored
This patch adds a new test for the new PTRACE_SYSEMU ptrace request. This test also relies on PTRACE_GETREGS and PTRACE_SETREGS requests to run properly, since the trace instruction (gettid() syscall) is being modified at run-time (by PTRACE_SETREGS) and re-executed three times. PTRACE_GETREGS is being used to check that the registers are still sane. This test basically creates a child process that executes syscalls and the parent process check if it is being traced appropriately. The parent process guarantees that the SYSCALLs are being traced, with PTRACE_SYSEMU, and ptrace stops the child application before a syscall is executed. The way the tests validates it, is by guaranteeing that the system calls arguments, as argv[0] (r3) which is the same register that will have the syscall return value on powerpc, are not being corrupted on PTRACE_SYSEMU with a return value, i.e, it continues to have the current arguments instead, meaning that the registers where not clobbered. This test is basically the same test for x86 located at tools/testing/selftests/x86/ptrace_syscall.c, limited to test PTRACE_SYSEMU request, and ported to PowerPC. Signed-off-by:
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Breno Leitao authored
This is a patch that adds support for PTRACE_SYSEMU ptrace request in PowerPC architecture. When ptrace(PTRACE_SYSEMU, ...) request is called, it will be handled by the arch independent function ptrace_resume(), which will tag the task with the TIF_SYSCALL_EMU flag. This flag needs to be handled from a platform dependent point of view, which is what this patch does. This patch adds this task's flag as part of the _TIF_SYSCALL_DOTRACE, which is the MACRO that is used to trace syscalls at entrance/exit. Since TIF_SYSCALL_EMU is now part of _TIF_SYSCALL_DOTRACE, if the task has _TIF_SYSCALL_DOTRACE set, it will hit do_syscall_trace_enter() at syscall entrance and do_syscall_trace_leave() at syscall leave. do_syscall_trace_enter() needs to handle the TIF_SYSCALL_EMU flag properly, which will interrupt the syscall executing if TIF_SYSCALL_EMU is set. The output values should not be changed, i.e. the return value (r3) should contain the original syscall argument on exit. With this flag set, the syscall is not executed fundamentally, because do_syscall_trace_enter() is returning -1 which is bigger than NR_syscall, thus, skipping the syscall execution and exiting userspace. Signed-off-by:
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Breno Leitao authored
Moving TIF_32BIT to use bit 20 instead of 4 in the task flag field. This change is making room for an upcoming new task macro (_TIF_SYSCALL_EMU) which is preferred to set a bit in the lower 16-bits part of the word. This upcoming flag macro will take part in a composed macro (_TIF_SYSCALL_DOTRACE) which will contain other flags as well, and it is preferred that the whole _TIF_SYSCALL_DOTRACE macro only sets the lower 16 bits of a word, so, it could be handled using immediate operations (as load immediate, add immediate, ...) where the immediate operand (SI) is limited to 16-bits. Another possible solution would be using the LOAD_REG_IMMEDIATE() macro to load a full 64-bits word immediate, but it takes 5 operations instead of one. Having TIF_32BITS being redefined to use an upper bit is not a problem since there is only one place in the assembly code where TIF_32BIT is being used, and it could be replaced with an operation with right shift (addis), since it is used alone, i.e. not being part of a composed macro, which has different bits set, and would require LOAD_REG_IMMEDIATE(). Tested on a 64 bits Big Endian machine running a 32 bits task. Signed-off-by:
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Christophe Leroy authored
On PPC64, as register r13 points to the paca_struct at all time, this patch adds a copy of the canary there, which is copied at task_switch. That new canary is then used by using the following GCC options: -mstack-protector-guard=tls -mstack-protector-guard-reg=r13 -mstack-protector-guard-offset=offsetof(struct paca_struct, canary)) Signed-off-by:
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Christophe Leroy authored
This functionality was tentatively added in the past (commit 6533b7c1 ("powerpc: Initial stack protector (-fstack-protector) support")) but had to be reverted (commit f2574030 ("powerpc: Revert the initial stack protector support") because of GCC implementing it differently whether it had been built with libc support or not. Now, GCC offers the possibility to manually set the stack-protector mode (global or tls) regardless of libc support. This time, the patch selects HAVE_STACKPROTECTOR only if -mstack-protector-guard=tls is supported by GCC. On PPC32, as register r2 points to current task_struct at all time, the stack_canary located inside task_struct can be used directly by using the following GCC options: -mstack-protector-guard=tls -mstack-protector-guard-reg=r2 -mstack-protector-guard-offset=offsetof(struct task_struct, stack_canary)) The protector is disabled for prom_init and bootx_init as it is too early to handle it properly. $ echo CORRUPT_STACK > /sys/kernel/debug/provoke-crash/DIRECT [ 134.943666] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: lkdtm_CORRUPT_STACK+0x64/0x64 [ 134.943666] [ 134.955414] CPU: 0 PID: 283 Comm: sh Not tainted 4.18.0-s3k-dev-12143-ga3272be41209 #835 [ 134.963380] Call Trace: [ 134.965860] [c6615d60] [c001f76c] panic+0x118/0x260 (unreliable) [ 134.971775] [c6615dc0] [c001f654] panic+0x0/0x260 [ 134.976435] [c6615dd0] [c032c368] lkdtm_CORRUPT_STACK_STRONG+0x0/0x64 [ 134.982769] [c6615e00] [ffffffff] 0xffffffff Signed-off-by:
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zhong jiang authored
Move the dereference of xc below the NULL test. Signed-off-by:
zhong jiang <zhongjiang@huawei.com> Signed-off-by:
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Naveen N. Rao authored
When CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is not set, we look up dtl_idx in the lppaca to determine the number of entries in the buffer. Since lppaca is in big endian, we need to do an endian conversion before using this in our calculation to determine the number of entries in the buffer. Without this, we do not iterate over the existing entries in the DTL buffer properly. Fixes: 7c105b63 ("powerpc: Add CONFIG_CPU_LITTLE_ENDIAN kernel config option.") Signed-off-by:
Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by:
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Naveen N. Rao authored
When CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is not set, we register the DTL buffer for a cpu when the associated file under powerpc/dtl in debugfs is opened. When doing so, we need to set the size of the buffer being registered in the second u32 word of the buffer. This needs to be in big endian, but we are not doing the conversion resulting in the below error showing up in dmesg: dtl_start: DTL registration for cpu 0 (hw 0) failed with -4 Fix this in the obvious manner. Fixes: 7c105b63 ("powerpc: Add CONFIG_CPU_LITTLE_ENDIAN kernel config option.") Signed-off-by:
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Christophe Leroy authored
PPC32 uses nonrecoverable_exception() while PPC64 uses unrecoverable_exception(). Both functions are doing almost the same thing. This patch removes nonrecoverable_exception() Signed-off-by:
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Rob Herring authored
In preparation to remove the node name pointer from struct device_node, convert printf users to use the %pOFn format specifier. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Arnd Bergmann <arnd@arndb.de> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by:
Rob Herring <robh@kernel.org> Signed-off-by:
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Rob Herring authored
In preparation to remove the node name pointer from struct device_node, convert printf users to use the %pOFn format specifier. Signed-off-by:
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Rob Herring authored
Instead of calling both of_irq_parse_one() and irq_create_of_mapping(), call of_irq_get() instead which does essentially the same thing. of_irq_get() also calls irq_find_host() for deferred probe support, but this should be fine as irq_create_of_mapping() also calls that internally. This gets us closer to making the former 2 functions static. In the process of simplifying request_event_sources_irqs(), combine the the pr_err() and WARN_ON() calls to just a WARN(). Signed-off-by:
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Rob Herring authored
Instead of calling both of_irq_parse_one() and irq_create_of_mapping(), call of_irq_parse_and_map() instead which does the same thing. This gets us closer to making the former 2 functions static. Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
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Aneesh Kumar K.V authored
Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by:
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Aneesh Kumar K.V authored
We need to make sure pmd_trans_huge returns false for a pmd migration entry. We mark the migration entry by clearing the _PAGE_PRESENT bit. We keep the _PAGE_PTE bit set to indicate a leaf page table entry. Hence we need to make sure we check for pmd_present() so that pmd_trans_huge won't return true on pmd migration entry. Signed-off-by:
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Aneesh Kumar K.V authored
Make sure we are operating on THP and hugetlb entries in the respective hash fault handling routines. No functional change in this patch. If we walked the table wrongly before, we will retry the access. Signed-off-by:
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Aneesh Kumar K.V authored
Update few code paths to check for pmd_large. set_pmd_at: We want to use this to store swap pte at pmd level. For swap ptes we don't want to set H_PAGE_THP_HUGE. Hence check for pmd_large in set_pmd_at. This remove the false WARN_ON when using this with swap pmd entry. pmd_page: We don't really use them on pmd migration entries. But they can also work with migration entries and we don't differentiate at the pte level. Hence update pmd_page to work with pmd migration entries too __find_linux_pte: lockless page table walk need to handle pmd migration entries. pmd_trans_huge check will return false on them. We don't set thp = 1 for such entries, but update hpage_shift correctly. Without this we will walk pmd migration entries as a pte page pointer which is wrong. Signed-off-by:
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Aneesh Kumar K.V authored
This make hugetlb directory pointer similar to other page able entries. A hugepd entry is identified by lack of _PAGE_PTE bit set and directory size stored in HUGEPD_SHIFT_MASK. We update that to also look at _PAGE_PRESENT Signed-off-by:
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Aneesh Kumar K.V authored
With this patch we use 0x8000000000000000UL (_PAGE_PRESENT) to indicate a valid pgd/pud/pmd entry. We also switch the p**_present() to look at this bit. With pmd_present, we have a special case. We need to make sure we consider a pmd marked invalid during THP split as present. Right now we clear the _PAGE_PRESENT bit during a pmdp_invalidate. Inorder to consider this special case we add a new pte bit _PAGE_INVALID (mapped to _RPAGE_SW0). This bit is only used with _PAGE_PRESENT cleared. Hence we are not really losing a pte bit for this special case. pmd_present is also updated to look at _PAGE_INVALID. Signed-off-by:
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Vaibhav Jain authored
Ever since fast reboot is enabled by default in opal, opal_cec_reboot() will use fast-reset instead of full IPL to perform system reboot. This leaves the user with no direct way to force a full IPL reboot except changing an nvram setting that persistently disables fast-reset for all subsequent reboots. This patch provides a more direct way for the user to force a one-shot full IPL reboot by passing the command line argument 'full' to the reboot command. So the user will be able to tweak the reboot behavior via: $ sudo reboot full # Force a full ipl reboot skipping fast-reset or $ sudo reboot # default reboot path (usually fast-reset) The reboot command passes the un-parsed command argument to the kernel via the 'Reboot' syscall which is then passed on to the arch function pnv_restart(). The patch updates pnv_restart() to handle this cmd-arg and issues opal_cec_reboot2 with OPAL_REBOOT_FULL_IPL to force a full IPL reset. Signed-off-by:
Vaibhav Jain <vaibhav@linux.ibm.com> Acked-by:
Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by:
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Michael Ellerman authored
In power7_marked_instr_event() there is a switch case that is missing a break or an explicit fallthrough, it's not immediately clear which it should be. The function determines based on the PMU event code, whether the event is a "marked" event (which then requires us to configure the PMU in a certain way). On Power7 there is no specific bit(s) in the event to tell us that, we just have to know. Rather than having a full list of every event and whether they are marked, we pull apart the event code and for events with certain values of certain fields we can say that those are all marked events. We take the psel (bits 0-7) of the event, and look at bits 4-7. For a value of 6 we say that if the entire psel == 0x64 then if the pmc == 3 the event is marked, else not, and otherwise we continue. It is then that we fallthrough to the 8 case, where we return true if the unit == 0xd. The question is should the 6 case also fallthrough and check for unit == 0xd, or should it return. Looking at the full list of events we see that there are zero events where (psel >> 4) == 0x6 and unit == 0xd. So the answer is it doesn't really matter, there are no valid event codes that will return a different result whether we fallthrough or break. But equally, testing the 6 case events against unit == 0xd is slightly bogus, as there are no such events. So to make the code clearer, and avoid any future confusion, have the 6 case break rather than falling through. Signed-off-by:
Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
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Michael Ellerman authored
This reverts commits: 5e46e29e ("powerpc/64s/hash: convert SLB miss handlers to C") 8fed04d0 ("powerpc/64s/hash: remove user SLB data from the paca") 655deecf ("powerpc/64s/hash: SLB allocation status bitmaps") 2e162674 ("powerpc/64s/hash: provide arch_setup_exec hooks for hash slice setup") 89ca4e12 ("powerpc/64s/hash: Add a SLB preload cache") This series had a few bugs, and the fixes are not all trivial. So revert most of it for now. Signed-off-by:
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- 19 Sep, 2018 4 commits
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Hari Bathini authored
Firmware-Assisted Dump (FADump) needs to be registered again after any memory hot add/remove operation to update the crash memory ranges. But currently, the kernel returns '-EEXIST' if we try to register without uregistering it first. This could expose the system to racing issues while unregistering and registering FADump from userspace during udev events. Spare the userspace of this and let it be taken care of in the kernel space for a simpler interface. Since this change, running 'echo 1 > /sys/kernel/fadump_registered' would result in re-regisering (unregistering and registering) FADump, if it was already registered. Signed-off-by:
Hari Bathini <hbathini@linux.ibm.com> Acked-by:
Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by:
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Suraj Jitindar Singh authored
In lparcfg_write we hard code kbuf_sz and then use this as the variable length of kbuf creating a variable length array. Since we're hard coding the length anyway just define the array using this as the length and remove the need for kbuf_sz, thus removing the variable length array. Signed-off-by:
Suraj Jitindar Singh <sjitindarsingh@gmail.com> Reviewed-by:
Joel Stanley <joel@jms.id.au> Signed-off-by:
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Suraj Jitindar Singh authored
In prom_check_platform_support() we retrieve and parse the "ibm,arch-vec-5-platform-support" property of the chosen node. Currently we use a variable length array however to avoid this use an array of constant length 8. This property is used to indicate the supported options of vector 5 bytes 23-26 of the ibm,architecture.vec node. Each of these options is a pair of bytes, thus for 4 options we have a max length of 8 bytes. Signed-off-by:
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Anton Blanchard authored
This re-applies commit b91c1e3e ("powerpc: Fix duplicate const clang warning in user access code") (Jun 2015) which was undone in commits: f2ca8090 ("powerpc/sparse: Constify the address pointer in __get_user_nosleep()") (Feb 2017) d466f6c5 ("powerpc/sparse: Constify the address pointer in __get_user_nocheck()") (Feb 2017) f84ed59a ("powerpc/sparse: Constify the address pointer in __get_user_check()") (Feb 2017) We see a large number of duplicate const errors in the user access code when building with llvm/clang: include/linux/pagemap.h:576:8: warning: duplicate 'const' declaration specifier [-Wduplicate-decl-specifier] ret = __get_user(c, uaddr); The problem is we are doing const __typeof__(*(ptr)), which will hit the warning if ptr is marked const. Removing const does not seem to have any effect on GCC code generation. Signed-off-by:
Anton Blanchard <anton@samba.org> Signed-off-by:
Nick Desaulniers <ndesaulniers@google.com> Signed-off-by:
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