- 24 Jul, 2018 38 commits
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Nicholas Piggin authored
The RAW console does not need writes to be atomic, so relax opal_put_chars to be able to do partial writes, and implement an _atomic variant which does not take a spinlock. This API is used in xmon, so the less locking that is used, the better chance there is that a crash can be debugged. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by:
Nicholas Piggin <npiggin@gmail.com> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au>
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Nicholas Piggin authored
OPAL console writes do not have to synchronously flush firmware / hardware buffers unless they are going through the udbg path. Remove the unconditional flushing from opal_put_chars. Flush if there was no space in the buffer as an optimisation (callers loop waiting for success in that case). udbg flushing is moved to udbg_opal_putc. Signed-off-by:
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Nicholas Piggin authored
opal_put_chars deals with partial writes because in OPALv1, opal_console_write_buffer_space did not work correctly. That firmware is not supported. This reworks the opal_put_chars code to no longer deal with partial writes by turning them into full writes. Partial write handling is still supported in terms of what gets returned to the caller, but it may not go to the console atomically. A warning message is printed in this case. This allows console flushing to be moved out of the opal_write_lock spinlock. That could cause the lock to be held for long periods if the console is busy (especially if it was being spammed by firmware), which is dangerous because the lock is taken by xmon to debug the system. Flushing outside the lock improves the situation a bit. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by:
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Nicholas Piggin authored
A new console flushing firmware API was introduced to replace event polling loops, and implemented in opal-kmsg with affddff6 ("powerpc/powernv: Add a kmsg_dumper that flushes console output on panic"), to flush the console in the panic path. The OPAL console driver has other situations where interrupts are off and it needs to flush the console synchronously. These still use a polling loop. So move the opal-kmsg flush code to opal_flush_console, and use the new function in opal-kmsg and opal_put_chars. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by:
Russell Currey <ruscur@russell.cc> Signed-off-by:
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Nicholas Piggin authored
Use the more refined and tested event polling loop from opal_put_chars as the fallback console flush in the opal-kmsg path. This loop is used by the console driver today, whereas the opal-kmsg fallback is not likely to have been used for years. Use WARN_ONCE rather than a printk when the fallback is invoked to prepare for moving the console flush into a common function. Reviewed-by:
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Nicholas Piggin authored
OPAL_CONSOLE_FLUSH is documented as being able to return OPAL_BUSY, so implement the standard OPAL_BUSY handling for it. Reviewed-by:
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Nicholas Piggin authored
The OPAL console driver does not delay in case it gets OPAL_BUSY or OPAL_BUSY_EVENT from firmware. It can't yet be made to sleep because it is called under spinlock, but it can be changed to the standard OPAL_BUSY loop form, and a delay added to keep it from hitting the firmware too frequently. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by:
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Nicholas Piggin authored
The intention here is to consume and discard the remaining buffer upon error. This works if there has not been a previous partial write. If there has been, then total_len is no longer total number of bytes to copy. total_len is always "bytes left to copy", so it should be added to written bytes. This code may not be exercised any more if partial writes will not be hit, but this is a small bugfix before a larger change. Reviewed-by:
Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by:
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Mukesh Ojha authored
Fixes: 8034f715 ("powernv/opal-dump: Convert to irq domain") Converts all the return explicit number to a more proper IRQ_HANDLED, which looks proper incase of interrupt handler returning case. Here, It also removes error message like "nobody cared" which was getting unveiled while returning -1 or 0 from handler. Signed-off-by:
Mukesh Ojha <mukesh02@linux.vnet.ibm.com> Reviewed-by:
Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by:
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Mukesh Ojha authored
Moves the return value check of 'opal_dump_info' to a proper place which was previously unnecessarily filling all the dump info even on failure. Signed-off-by:
Stewart Smith <stewart@linux.vnet.ibm.com> Acked-by:
Jeremy Kerr <jk@ozlabs.org> Signed-off-by:
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Cyril Bur authored
Since commit dc310669 ("powerpc: tm: Always use fp_state and vr_state to store live registers") tm_reclaim_thread() doesn't use the parameter anymore, both callers have to bother getting it as they have no need for a struct thread_info either. Just remove it and adjust the callers. Signed-off-by:
Cyril Bur <cyrilbur@gmail.com> Signed-off-by:
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Cyril Bur authored
In commit eb5c3f1c ("powerpc: Always save/restore checkpointed regs during treclaim/trecheckpoint") __tm_recheckpoint was modified to no longer take the second parameter 'unsigned long orig_msr' as part of a TM rewrite to simplify the reclaiming/recheckpointing process. There is a comment in the asm file where the function is delcared which has an incorrect prototype with the 'orig_msr' parameter. This patch corrects the comment. Signed-off-by:
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Simon Guo authored
This patch reworked selftest memcmp_64 so that memcmp selftest can cover more test cases. It adds testcases for: - memcmp over 4K bytes size. - s1/s2 with different/random offset on 16 bytes boundary. - enter/exit_vmx_ops pairness. Signed-off-by:
Simon Guo <wei.guo.simon@gmail.com> [mpe: Add -maltivec to fix build on some toolchains] Signed-off-by:
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Simon Guo authored
This patch is based on the previous VMX patch on memcmp(). To optimize ppc64 memcmp() with VMX instruction, we need to think about the VMX penalty brought with: If kernel uses VMX instruction, it needs to save/restore current thread's VMX registers. There are 32 x 128 bits VMX registers in PPC, which means 32 x 16 = 512 bytes for load and store. The major concern regarding the memcmp() performance in kernel is KSM, who will use memcmp() frequently to merge identical pages. So it will make sense to take some measures/enhancement on KSM to see whether any improvement can be done here. Cyril Bur indicates that the memcmp() for KSM has a higher possibility to fail (unmatch) early in previous bytes in following mail. https://patchwork.ozlabs.org/patch/817322/#1773629 And I am taking a follow-up on this with this patch. Per some testing, it shows KSM memcmp() will fail early at previous 32 bytes. More specifically: - 76% cases will fail/unmatch before 16 bytes; - 83% cases will fail/unmatch before 32 bytes; - 84% cases will fail/unmatch before 64 bytes; So 32 bytes looks a better choice than other bytes for pre-checking. The early failure is also true for memcmp() for non-KSM case. With a non-typical call load, it shows ~73% cases fail before first 32 bytes. This patch adds a 32 bytes pre-checking firstly before jumping into VMX operations, to avoid the unnecessary VMX penalty. It is not limited to KSM case. And the testing shows ~20% improvement on memcmp() average execution time with this patch. And note the 32B pre-checking is only performed when the compare size is long enough (>=4K currently) to allow VMX operation. The detail data and analysis is at: https://github.com/justdoitqd/publicFiles/blob/master/memcmp/README.mdSigned-off-by:
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Simon Guo authored
This patch add VMX primitives to do memcmp() in case the compare size is equal or greater than 4K bytes. KSM feature can benefit from this. Test result with following test program(replace the "^>" with ""): ------ ># cat tools/testing/selftests/powerpc/stringloops/memcmp.c >#include <malloc.h> >#include <stdlib.h> >#include <string.h> >#include <time.h> >#include "utils.h" >#define SIZE (1024 * 1024 * 900) >#define ITERATIONS 40 int test_memcmp(const void *s1, const void *s2, size_t n); static int testcase(void) { char *s1; char *s2; unsigned long i; s1 = memalign(128, SIZE); if (!s1) { perror("memalign"); exit(1); } s2 = memalign(128, SIZE); if (!s2) { perror("memalign"); exit(1); } for (i = 0; i < SIZE; i++) { s1[i] = i & 0xff; s2[i] = i & 0xff; } for (i = 0; i < ITERATIONS; i++) { int ret = test_memcmp(s1, s2, SIZE); if (ret) { printf("return %d at[%ld]! should have returned zero\n", ret, i); abort(); } } return 0; } int main(void) { return test_harness(testcase, "memcmp"); } ------ Without this patch (but with the first patch "powerpc/64: Align bytes before fall back to .Lshort in powerpc64 memcmp()." in the series): 4.726728762 seconds time elapsed ( +- 3.54%) With VMX patch: 4.234335473 seconds time elapsed ( +- 2.63%) There is ~+10% improvement. Testing with unaligned and different offset version (make s1 and s2 shift random offset within 16 bytes) can archieve higher improvement than 10%.. Signed-off-by: -
Simon Guo authored
Some old tool chains don't know about instructions like vcmpequd. This patch adds .long macro for vcmpequd and vcmpequb, which is a preparation to optimize ppc64 memcmp with VMX instructions. Signed-off-by:
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Simon Guo authored
Currently memcmp() 64bytes version in powerpc will fall back to .Lshort (compare per byte mode) if either src or dst address is not 8 bytes aligned. It can be opmitized in 2 situations: 1) if both addresses are with the same offset with 8 bytes boundary: memcmp() can compare the unaligned bytes within 8 bytes boundary firstly and then compare the rest 8-bytes-aligned content with .Llong mode. 2) If src/dst addrs are not with the same offset of 8 bytes boundary: memcmp() can align src addr with 8 bytes, increment dst addr accordingly, then load src with aligned mode and load dst with unaligned mode. This patch optmizes memcmp() behavior in the above 2 situations. Tested with both little/big endian. Performance result below is based on little endian. Following is the test result with src/dst having the same offset case: (a similar result was observed when src/dst having different offset): (1) 256 bytes Test with the existing tools/testing/selftests/powerpc/stringloops/memcmp: - without patch 29.773018302 seconds time elapsed ( +- 0.09% ) - with patch 16.485568173 seconds time elapsed ( +- 0.02% ) -> There is ~+80% percent improvement (2) 32 bytes To observe performance impact on < 32 bytes, modify tools/testing/selftests/powerpc/stringloops/memcmp.c with following: ------- #include <string.h> #include "utils.h" -#define SIZE 256 +#define SIZE 32 #define ITERATIONS 10000 int test_memcmp(const void *s1, const void *s2, size_t n); -------- - Without patch 0.244746482 seconds time elapsed ( +- 0.36%) - with patch 0.215069477 seconds time elapsed ( +- 0.51%) -> There is ～+13% improvement (3) 0~8 bytes To observe <8 bytes performance impact, modify tools/testing/selftests/powerpc/stringloops/memcmp.c with following: ------- #include <string.h> #include "utils.h" -#define SIZE 256 -#define ITERATIONS 10000 +#define SIZE 8 +#define ITERATIONS 1000000 int test_memcmp(const void *s1, const void *s2, size_t n); ------- - Without patch 1.845642503 seconds time elapsed ( +- 0.12% ) - With patch 1.849767135 seconds time elapsed ( +- 0.26% ) -> They are nearly the same. (-0.2%) Signed-off-by: -
Aneesh Kumar K.V authored
This patch adds error reporting to H_ENTER and H_READ hcalls. A failure for both these hcalls are mostly fatal and it would be good to log the failure reason. Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [mpe: Split out of larger patch] Signed-off-by:
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Aneesh Kumar K.V authored
Switch from printk to pr_fmt() / pr_xxx(). Signed-off-by:
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Aneesh Kumar K.V authored
We do this in some part. This patch make sure we always try to search for hpte without holding lock and redo the compare with lock held once match found. Signed-off-by:
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Aneesh Kumar K.V authored
No functional change Signed-off-by:
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Aneesh Kumar K.V authored
When computing the starting slot number for a hash page table group we used to do this hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL; Multiplying with 8 (HPTES_PER_GROUP) imply the last three bits are 0. Hence we really don't need to clear then separately. Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by:
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Aneesh Kumar K.V authored
We do this only with VMEMMAP config so that our page_to_[nid/section] etc are not impacted. Signed-off-by:
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Aneesh Kumar K.V authored
With SPARSEMEM config enabled, we make sure that we don't add sections beyond MAX_PHYSMEM_BITS range. This results in not building vmemmap mapping for range beyond max range. But our memblock layer looks the device tree and create mapping for the full memory range. Prevent this by checking against MAX_PHSYSMEM_BITS when doing memblock_add. We don't do similar check for memeblock_reserve_range. If reserve range is beyond MAX_PHYSMEM_BITS we expect that to be configured with 'nomap'. Any other reserved range should come from existing memblock ranges which we already filtered while adding. This avoids crash as below when running on a system with system ram config above MAX_PHSYSMEM_BITS Unable to handle kernel paging request for data at address 0xc00a001000000440 Faulting instruction address: 0xc000000001034118 cpu 0x0: Vector: 300 (Data Access) at [c00000000124fb30] pc: c000000001034118: __free_pages_bootmem+0xc0/0x1c0 lr: c00000000103b258: free_all_bootmem+0x19c/0x22c sp: c00000000124fdb0 msr: 9000000002001033 dar: c00a001000000440 dsisr: 40000000 current = 0xc00000000120dd00 paca = 0xc000000001f60000^I irqmask: 0x03^I irq_happened: 0x01 pid = 0, comm = swapper [c00000000124fe20] c00000000103b258 free_all_bootmem+0x19c/0x22c [c00000000124fee0] c000000001010a68 mem_init+0x3c/0x5c [c00000000124ff00] c00000000100401c start_kernel+0x298/0x5e4 [c00000000124ff90] c00000000000b57c start_here_common+0x1c/0x520 Signed-off-by: -
Michael Ellerman authored
Similarly as we just did for 32-bit, add phony targets for generating a little endian and Book3E allmodconfig. These aren't covered by the regular allmodconfig, which is big endian and Book3S due to the way the Kconfig symbols are structured. Signed-off-by: -
Michael Ellerman authored
Because the allmodconfig logic just sets every symbol to M or Y, it has the effect of always generating a 64-bit config, because CONFIG_PPC64 becomes Y. So to make it easier for folks to test 32-bit code, provide a phony defconfig target that generates a 32-bit allmodconfig. The 32-bit port has several mutually exclusive CPU types, we choose the Book3S variants as that's what the help text in Kconfig says is most common. Signed-off-by: -
Michael Ellerman authored
When I added the spectre_v2 information in sysfs, I included the availability of the ori31 speculation barrier. Although the ori31 barrier can be used to mitigate v2, it's primarily intended as a spectre v1 mitigation. Spectre v2 is mitigated by hardware changes. So rework the sysfs files to show the ori31 information in the spectre_v1 file, rather than v2. Currently we display eg: $ grep . spectre_v* spectre_v1:Mitigation: __user pointer sanitization spectre_v2:Mitigation: Indirect branch cache disabled, ori31 speculation barrier enabled After: $ grep . spectre_v* spectre_v1:Mitigation: __user pointer sanitization, ori31 speculation barrier enabled spectre_v2:Mitigation: Indirect branch cache disabled Fixes: d6fbe1c5 ("powerpc/64s: Wire up cpu_show_spectre_v2()") Cc: stable@vger.kernel.org # v4.17+ Signed-off-by:
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Nicholas Piggin authored
There is an asynchronous aspect to smp_send_nmi_ipi. The caller waits for all CPUs to call in to the handler, but it does not wait for completion of the handler. This is a needless complication, so remove it and always wait synchronously. The synchronous wait allows the caller to easily time out and clear the wait for completion (zero nmi_ipi_busy_count) in the case of badly behaved handlers. This would have prevented the recent smp_send_stop NMI IPI bug from causing the system to hang. Signed-off-by:
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Nicholas Piggin authored
When the masked interrupt handler clears MSR[EE] for an interrupt in the PACA_IRQ_MUST_HARD_MASK set, it does not set PACA_IRQ_HARD_DIS. This makes them get out of synch. With that taken into account, it's only low level irq manipulation (and interrupt entry before reconcile) where they can be out of synch. This makes the code less surprising. It also allows the IRQ replay code to rely on the IRQ_HARD_DIS value and not have to mtmsrd again in this case (e.g., for an external interrupt that has been masked). The bigger benefit might just be that there is not such an element of surprise in these two bits of state. Signed-off-by:
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Ram Pai authored
The test case assumes execute-permissions of unallocated keys are enabled by default, which is incorrect. Reviewed-by:
Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by:
Ram Pai <linuxram@us.ibm.com> Signed-off-by:
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Ram Pai authored
Only when the key is allocated, its permission are enabled. Reviewed-by:
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Ram Pai authored
Applications need the ability to associate an address-range with some key and latter revert to its initial default key. Pkey-0 comes close to providing this function but falls short, because the current implementation disallows applications to explicitly associate pkey-0 to the address range. Lets make pkey-0 less special and treat it almost like any other key. Thus it can be explicitly associated with any address range, and can be freed. This gives the application more flexibility and power. The ability to free pkey-0 must be used responsibily, since pkey-0 is associated with almost all address-range by default. Even with this change pkey-0 continues to be slightly more special from the following point of view. (a) it is implicitly allocated. (b) it is the default key assigned to any address-range. (c) its permissions cannot be modified by userspace. NOTE: (c) is specific to powerpc only. pkey-0 is associated by default with all pages including kernel pages, and pkeys are also active in kernel mode. If any permission is denied on pkey-0, the kernel running in the context of the application will be unable to operate. Tested on powerpc. Signed-off-by:
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Ram Pai authored
execute-only key is allocated dynamically. This is a problem. When a thread implicitly creates an execute-only key, and resets the UAMOR for that key, the UAMOR value does not percolate to all the other threads. Any other thread may ignorantly change the permissions on the key. This can cause the key to be not execute-only for that thread. Preallocate the execute-only key and ensure that no thread can change the permission of the key, by resetting the corresponding bit in UAMOR. Fixes: 5586cf61 ("powerpc: introduce execute-only pkey") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by:
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Ram Pai authored
Total number of pkeys calculation is off by 1. Fix it. Fixes: 4fb158f6 ("powerpc: track allocation status of all pkeys") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by:
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Ram Pai authored
When a thread forks the contents of AMR, IAMR, UAMOR registers in the newly forked thread are not inherited. Save the registers before forking, for content of those registers to be automatically copied into the new thread. Fixes: cf43d3b2 ("powerpc: Enable pkey subsystem") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by:
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Ram Pai authored
Key allocation and deallocation has the side effect of programming the UAMOR/AMR/IAMR registers. This is wrong, since its the responsibility of the application and not that of the kernel, to modify the permission on the key. Do not modify the pkey registers at key allocation/deallocation. This patch also fixes a bug where a sys_pkey_free() resets the UAMOR bits of the key, thus making its permissions unmodifiable from user space. Later if the same key gets reallocated from a different thread this thread will no longer be able to change the permissions on the key. Fixes: cf43d3b2 ("powerpc: Enable pkey subsystem") Cc: stable@vger.kernel.org # v4.16+ Reviewed-by:
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Ram Pai authored
Deny all permissions on all keys, with some exceptions. pkey-0 must allow all permissions, or else everything comes to a screaching halt. Execute-only key must allow execute permission. Fixes: cf43d3b2 ("powerpc: Enable pkey subsystem") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by:
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Ram Pai authored
Currently in a multithreaded application, a key allocated by one thread is not usable by other threads. By "not usable" we mean that other threads are unable to change the access permissions for that key for themselves. When a new key is allocated in one thread, the corresponding UAMOR bits for that thread get enabled, however the UAMOR bits for that key for all other threads remain disabled. Other threads have no way to set permissions on the key, and the current default permissions are that read/write is enabled for all keys, which means the key has no effect for other threads. Although that may be the desired behaviour in some circumstances, having all threads able to control their permissions for the key is more flexible. The current behaviour also differs from the x86 behaviour, which is problematic for users. To fix this, enable the UAMOR bits for all keys, at process creation (in start_thread(), ie exec time). Since the contents of UAMOR are inherited at fork, all threads are capable of modifying the permissions on any key. This is technically an ABI break on powerpc, but pkey support is fairly new on powerpc and not widely used, and this brings us into line with x86. Fixes: cf43d3b2 ("powerpc: Enable pkey subsystem") Cc: stable@vger.kernel.org # v4.16+ Tested-by:
Florian Weimer <fweimer@redhat.com> Signed-off-by:
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- 20 Jul, 2018 2 commits
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Michael Ellerman authored
This logic was shared between multiple tests, but now that we have removed all but one of them we can just move it into that test. Signed-off-by: -
Michael Ellerman authored
Paste on POWER9 only works to accelerators and not on real memory. So these tests just generate a SIGILL. So just delete them. Signed-off-by:
Michael Neuling <mikey@neuling.org> Signed-off-by:
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