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* powerpc: Remove power3 from commentsMichael Ellerman2014-07-281-2/+1
| | | | | | | | There are still a few occurences where it remains, because it helps to explain something that persists. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: use _GLOBAL_TOC for memmoveLi Zhong2014-07-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | memmove may be called from module code copy_pages(btrfs), and it may call memcpy, which may call back to C code, so it needs to use _GLOBAL_TOC to set up r2 correctly. This fixes following error when I tried to boot an le guest: Vector: 300 (Data Access) at [c000000073f97210] pc: c000000000015004: enable_kernel_altivec+0x24/0x80 lr: c000000000058fbc: enter_vmx_copy+0x3c/0x60 sp: c000000073f97490 msr: 8000000002009033 dar: d000000001d50170 dsisr: 40000000 current = 0xc0000000734c0000 paca = 0xc00000000fff0000 softe: 0 irq_happened: 0x01 pid = 815, comm = mktemp enter ? for help [c000000073f974f0] c000000000058fbc enter_vmx_copy+0x3c/0x60 [c000000073f97510] c000000000057d34 memcpy_power7+0x274/0x840 [c000000073f97610] d000000001c3179c copy_pages+0xfc/0x110 [btrfs] [c000000073f97660] d000000001c3c248 memcpy_extent_buffer+0xe8/0x160 [btrfs] [c000000073f97700] d000000001be4be8 setup_items_for_insert+0x208/0x4a0 [btrfs] [c000000073f97820] d000000001be50b4 btrfs_insert_empty_items+0xf4/0x140 [btrfs] [c000000073f97890] d000000001bfed30 insert_with_overflow+0x70/0x180 [btrfs] [c000000073f97900] d000000001bff174 btrfs_insert_dir_item+0x114/0x2f0 [btrfs] [c000000073f979a0] d000000001c1f92c btrfs_add_link+0x10c/0x370 [btrfs] [c000000073f97a40] d000000001c20e94 btrfs_create+0x204/0x270 [btrfs] [c000000073f97b00] c00000000026d438 vfs_create+0x178/0x210 [c000000073f97b50] c000000000270a70 do_last+0x9f0/0xe90 [c000000073f97c20] c000000000271010 path_openat+0x100/0x810 [c000000073f97ce0] c000000000272ea8 do_filp_open+0x58/0xd0 [c000000073f97dc0] c00000000025ade8 do_sys_open+0x1b8/0x300 [c000000073f97e30] c00000000000a008 syscall_exit+0x0/0x7c Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Fix bugs in emulate_step()Paul Mackerras2014-07-221-5/+5
| | | | | | | | | | | | This fixes some bugs in emulate_step(). First, the setting of the carry bit for the arithmetic right-shift instructions was not correct on 64-bit machines because we were masking with a mask of type int rather than unsigned long. Secondly, the sld (shift left doubleword) instruction was using the wrong instruction field for the register containing the shift count. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: fix typo 'CONFIG_PPC_CPU'Paul Bolle2014-06-111-1/+1
| | | | | | | | | Commit cd64d1697cf0 ("powerpc: mtmsrd not defined") added a check for CONFIG_PPC_CPU were a check for CONFIG_PPC_FPU was clearly intended. Fixes: cd64d1697cf0 ("powerpc: mtmsrd not defined") Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Exported functions __clear_user and copy_page use r2 so need ↵Anton Blanchard2014-06-052-2/+2
| | | | | | | | | | | _GLOBAL_TOC() __clear_user and copy_page load from the TOC and are also exported to modules. This means we have to use _GLOBAL_TOC() so that we create the global entry point that sets up the TOC. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* Merge remote-tracking branch 'anton/abiv2' into nextBenjamin Herrenschmidt2014-05-058-48/+48
|\ | | | | | | | | | | | | This series adds support for building the powerpc 64-bit LE kernel using the new ABI v2. We already supported running ABI v2 userspace programs but this adds support for building the kernel itself using the new ABI.
| * powerpc: Add _GLOBAL_TOC for ABIv2 assembly functions exported to modulesAnton Blanchard2014-04-232-2/+2
| | | | | | | | | | | | | | | | If an assembly function that calls back into c code is exported to modules, we need to ensure r2 is setup correctly. There are only two places crazy enough to do it (two of which are my fault). Signed-off-by: Anton Blanchard <anton@samba.org>
| * powerpc: Fix unsafe accesses to parameter area in ELFv2Ulrich Weigand2014-04-234-30/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some of the assembler files in lib/ make use of the fact that in the ELFv1 ABI, the caller guarantees to provide stack space to save the parameter registers r3 ... r10. This guarantee is no longer present in ELFv2 for functions that have no variable argument list and no more than 8 arguments. Change the affected routines to temporarily store registers in the red zone and/or the top of their own stack frame (in the space provided to save r31 .. r29, which is actually not used in these routines). In opal_query_takeover, simply always allocate a stack frame; the routine is not performance critical. Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com> Signed-off-by: Anton Blanchard <anton@samba.org>
| * powerpc: Fix ABIv2 issues with stack offsets in assembly codeAnton Blanchard2014-04-234-30/+30
| | | | | | | | | | | | Fix STK_PARAM and use it instead of hardcoding ABIv1 offsets. Signed-off-by: Anton Blanchard <anton@samba.org>
| * powerpc: No need to use dot symbols when branching to a functionAnton Blanchard2014-04-236-16/+16
| | | | | | | | | | | | | | | | | | binutils is smart enough to know that a branch to a function descriptor is actually a branch to the functions text address. Alan tells me that binutils has been doing this for 9 years. Signed-off-by: Anton Blanchard <anton@samba.org>
* | powerpc: memcpy optimization for 64bit LEPhilippe Bergheaud2014-04-302-2/+16
|/ | | | | | | | | | | | | | | | | | | | Unaligned stores take alignment exceptions on POWER7 running in little-endian. This is a dumb little-endian base memcpy that prevents unaligned stores. Once booted the feature fixup code switches over to the VMX copy loops (which are already endian safe). The question is what we do before that switch over. The base 64bit memcpy takes alignment exceptions on POWER7 so we can't use it as is. Fixing the causes of alignment exception would slow it down, because we'd need to ensure all loads and stores are aligned either through rotate tricks or bytewise loads and stores. Either would be bad for all other 64bit platforms. [ I simplified the loop a bit - Anton ] Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* selftests/powerpc: Import Anton's memcpy / copy_tofrom_user testsMichael Ellerman2014-03-071-0/+2
| | | | | | | | | | | | | | | | Turn Anton's memcpy / copy_tofrom_user test into something that can live in tools/testing/selftests. It requires one turd in arch/powerpc/lib/memcpy_64.S, but it's pretty harmless IMHO. We are sailing very close to the wind with the feature macros. We define them to nothing, which currently means we get a few extra nops and include the unaligned calls. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Add vr save/restore functionsAndreas Schwab2014-01-151-0/+186
| | | | | | | | GCC 4.8 now generates out-of-line vr save/restore functions when optimizing for size. They are needed for the raid6 altivec support. Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* Merge branch 'merge' into nextBenjamin Herrenschmidt2013-12-301-15/+38
|\ | | | | | | | | | | | | Merge a pile of fixes that went into the "merge" branch (3.13-rc's) such as Anton Little Endian fixes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * powerpc: Make 64-bit non-VMX __copy_tofrom_user bi-endianPaul E. McKenney2013-12-301-15/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The powerpc 64-bit __copy_tofrom_user() function uses shifts to handle unaligned invocations. However, these shifts were designed for big-endian systems: On little-endian systems, they must shift in the opposite direction. This commit relies on the C preprocessor to insert the correct shifts into the assembly code. [ This is a rare but nasty LE issue. Most of the time we use the POWER7 optimised __copy_tofrom_user_power7 loop, but when it hits an exception we fall back to the base __copy_tofrom_user loop. - Anton ] Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | powerpc: Move the patch_exception to a common placeKevin Hao2013-12-021-0/+15
|/ | | | | | | So that it can be used by other codes. No function change. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Add VMX optimised xor for RAID5Anton Blanchard2013-10-302-0/+180
| | | | | | | | | | | | | | | | | | | | | | Add a VMX optimised xor, used primarily for RAID5. On a POWER7 blade this is a decent win: 32regs : 17932.800 MB/sec altivec : 19724.800 MB/sec The bigger gain is when the same test is run in SMT4 mode, as it would if there was a lot of work going on: 8regs : 8377.600 MB/sec altivec : 15801.600 MB/sec I tested this against an array created without the patch, and also verified it worked as expected on a little endian kernel. [ Fix !CONFIG_ALTIVEC build -- BenH ] Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Fix Unaligned LE Floating Point Loads and StoresTom Musta2013-10-301-12/+40
| | | | | | | | | | This patch addresses unaligned single precision floating point loads and stores in the single-step code. The old implementation improperly treated an 8 byte structure as an array of two 4 byte words, which is a classic little endian bug. Signed-off-by: Tom Musta <tmusta@gmail.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Fix Unaligned Loads and StoresTom Musta2013-10-301-0/+45
| | | | | | | | | | | This patch modifies the unaligned access routines of the sstep.c module so that it properly reverses the bytes of storage operands in the little endian kernel kernel. This is implemented by breaking an unaligned little endian access into a combination of single byte accesses plus an overal byte reversal operation. Signed-off-by: Tom Musta <tmusta@gmail.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Use generic memcpy code in little endianAnton Blanchard2013-10-111-3/+6
| | | | | | | | We need to fix some endian issues in our memcpy code. For now just enable the generic memcpy routine for little endian builds. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Use generic checksum code in little endianAnton Blanchard2013-10-111-2/+7
| | | | | | | | We need to fix some endian issues in our checksum code. For now just enable the generic checksum routines for little endian builds. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Fix endian issues in VMX copy loopsAnton Blanchard2013-10-112-46/+63
| | | | | | | Fix the permute loops for little endian. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Restore registers on error exit from csum_partial_copy_generic()Paul E. McKenney2013-10-031-14/+40
| | | | | | | | | | | | | | | The csum_partial_copy_generic() function saves the PowerPC non-volatile r14, r15, and r16 registers for the main checksum-and-copy loop. Unfortunately, it fails to restore them upon error exit from this loop, which results in silent corruption of these registers in the presumably rare event of an access exception within that loop. This commit therefore restores these register on error exit from the loop. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Anton Blanchard <anton@samba.org> Cc: stable@vger.kernel.org Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Fix parameter clobber in csum_partial_copy_generic()Paul E. McKenney2013-10-031-2/+2
| | | | | | | | | | | | | | The csum_partial_copy_generic() uses register r7 to adjust the remaining bytes to process. Unfortunately, r7 also holds a parameter, namely the address of the flag to set in case of access exceptions while reading the source buffer. Lacking a quantum implementation of PowerPC, this commit instead uses register r9 to do the adjusting, leaving r7's pointer uncorrupted. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Anton Blanchard <anton@samba.org> Cc: stable@vger.kernel.org Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Remove ksp_limit on ppc64Benjamin Herrenschmidt2013-09-251-1/+2
| | | | | | | | | | | | | | | | | | | | | | | We've been keeping that field in thread_struct for a while, it contains the "limit" of the current stack pointer and is meant to be used for detecting stack overflows. It has a few problems however: - First, it was never actually *used* on 64-bit. Set and updated but not actually exploited - When switching stack to/from irq and softirq stacks, it's update is racy unless we hard disable interrupts, which is costly. This is fine on 32-bit as we don't soft-disable there but not on 64-bit. Thus rather than fixing 2 in order to implement 1 in some hypothetical future, let's remove the code completely from 64-bit. In order to avoid a clutter of ifdef's, we remove the updates from C code completely during interrupt stack switching, and instead maintain it from the asm helper that is used to do the stack switching in the first place. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Unaligned stores and stmw are broken in emulation codeTom Musta2013-08-271-3/+5
| | | | | | | | | | | | | The stmw instruction was incorrectly decoded as an update form instruction and thus the RA register was being clobbered. Also, the utility routine to write memory to unaligned addresses breaks the operation into smaller aligned accesses but was incorrectly incrementing the address by only one; it needs to increment the address by the size of the smaller aligned chunk. Signed-off-by: Tom Musta <tmusta@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Fix little endian lppaca, slb_shadow and dtl_entryAnton Blanchard2013-08-141-2/+2
| | | | | | | | | | | The lppaca, slb_shadow and dtl_entry hypervisor structures are big endian, so we have to byte swap them in little endian builds. LE KVM hosts will also need to be fixed but for now add an #error to remind us. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Fix single step emulation of 32bit overflowed branchesMichael Neuling2013-06-201-1/+1
| | | | | | | Check truncate_if_32bit() on final write to nip. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/pseries: Improve stream generation comments in copypage/userMichael Neuling2013-06-012-13/+18
| | | | | | | No code changes, just documenting what's happening a little better. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* uprobes/powerpc: Add dependency on single step emulationSuzuki K. Poulose2013-01-291-3/+1
| | | | | | | | | | | | | | Uprobes uses emulate_step in sstep.c, but we haven't explicitly specified the dependency. On pseries HAVE_HW_BREAKPOINT protects us, but 44x has no such luxury. Consolidate other users that depend on sstep and create a new config option. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Suzuki K. Poulose <suzuki@in.ibm.com> Cc: linuxppc-dev@ozlabs.org Cc: stable@vger.kernel.org Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Build kernel with -mcmodel=mediumAnton Blanchard2013-01-101-1/+1
| | | | | | | | | | | | | | | | | | | | | Finally remove the two level TOC and build with -mcmodel=medium. Unfortunately we can't build modules with -mcmodel=medium due to the tricks the kernel module loader plays with percpu data: # -mcmodel=medium breaks modules because it uses 32bit offsets from # the TOC pointer to create pointers where possible. Pointers into the # percpu data area are created by this method. # # The kernel module loader relocates the percpu data section from the # original location (starting with 0xd...) to somewhere in the base # kernel percpu data space (starting with 0xc...). We need a full # 64bit relocation for this to work, hence -mcmodel=large. On older kernels we fall back to the two level TOC (-mminimal-toc) Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Fix VMX fix for memcpy caseNishanth Aravamudan2012-10-041-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In 2fae7cdb60240e2e2d9b378afbf6d9fcce8a3890 ("powerpc: Fix VMX in interrupt check in POWER7 copy loops"), Anton inadvertently introduced a regression for memcpy on POWER7 machines. copyuser and memcpy diverge slightly in their use of cr1 (copyuser doesn't use it, but memcpy does) and you end up clobbering that register with your fix. That results in (taken from an FC18 kernel): [ 18.824604] Unrecoverable VMX/Altivec Unavailable Exception f20 at c000000000052f40 [ 18.824618] Oops: Unrecoverable VMX/Altivec Unavailable Exception, sig: 6 [#1] [ 18.824623] SMP NR_CPUS=1024 NUMA pSeries [ 18.824633] Modules linked in: tg3(+) be2net(+) cxgb4(+) ipr(+) sunrpc xts lrw gf128mul dm_crypt dm_round_robin dm_multipath linear raid10 raid456 async_raid6_recov async_memcpy async_pq raid6_pq async_xor xor async_tx raid1 raid0 scsi_dh_rdac scsi_dh_hp_sw scsi_dh_emc scsi_dh_alua squashfs cramfs [ 18.824705] NIP: c000000000052f40 LR: c00000000020b874 CTR: 0000000000000512 [ 18.824709] REGS: c000001f1fef7790 TRAP: 0f20 Not tainted (3.6.0-0.rc6.git0.2.fc18.ppc64) [ 18.824713] MSR: 8000000000009032 <SF,EE,ME,IR,DR,RI> CR: 4802802e XER: 20000010 [ 18.824726] SOFTE: 0 [ 18.824728] CFAR: 0000000000000f20 [ 18.824731] TASK = c000000fa7128400[0] 'swapper/24' THREAD: c000000fa7480000 CPU: 24 GPR00: 00000000ffffffc0 c000001f1fef7a10 c00000000164edc0 c000000f9b9a8120 GPR04: c000000f9b9a8124 0000000000001438 0000000000000060 03ffffff064657ee GPR08: 0000000080000000 0000000000000010 0000000000000020 0000000000000030 GPR12: 0000000028028022 c00000000ff25400 0000000000000001 0000000000000000 GPR16: 0000000000000000 7fffffffffffffff c0000000016b2180 c00000000156a500 GPR20: c000000f968c7a90 c0000000131c31d8 c000001f1fef4000 c000000001561d00 GPR24: 000000000000000a 0000000000000000 0000000000000001 0000000000000012 GPR28: c000000fa5c04f80 00000000000008bc c0000000015c0a28 000000000000022e [ 18.824792] NIP [c000000000052f40] .memcpy_power7+0x5a0/0x7c4 [ 18.824797] LR [c00000000020b874] .pcpu_free_area+0x174/0x2d0 [ 18.824800] Call Trace: [ 18.824803] [c000001f1fef7a10] [c000000000052c14] .memcpy_power7+0x274/0x7c4 (unreliable) [ 18.824809] [c000001f1fef7b10] [c00000000020b874] .pcpu_free_area+0x174/0x2d0 [ 18.824813] [c000001f1fef7bb0] [c00000000020ba88] .free_percpu+0xb8/0x1b0 [ 18.824819] [c000001f1fef7c50] [c00000000043d144] .throtl_pd_exit+0x94/0xd0 [ 18.824824] [c000001f1fef7cf0] [c00000000043acf8] .blkg_free+0x88/0xe0 [ 18.824829] [c000001f1fef7d90] [c00000000018c048] .rcu_process_callbacks+0x2e8/0x8a0 [ 18.824835] [c000001f1fef7e90] [c0000000000a8ce8] .__do_softirq+0x158/0x4d0 [ 18.824840] [c000001f1fef7f90] [c000000000025ecc] .call_do_softirq+0x14/0x24 [ 18.824845] [c000000fa7483650] [c000000000010e80] .do_softirq+0x160/0x1a0 [ 18.824850] [c000000fa74836f0] [c0000000000a94a4] .irq_exit+0xf4/0x120 [ 18.824854] [c000000fa7483780] [c000000000020c44] .timer_interrupt+0x154/0x4d0 [ 18.824859] [c000000fa7483830] [c000000000003be0] decrementer_common+0x160/0x180 [ 18.824866] --- Exception: 901 at .plpar_hcall_norets+0x84/0xd4 [ 18.824866] LR = .check_and_cede_processor+0x48/0x80 [ 18.824871] [c000000fa7483b20] [c00000000007f018] .check_and_cede_processor+0x18/0x80 (unreliable) [ 18.824877] [c000000fa7483b90] [c00000000007f104] .dedicated_cede_loop+0x84/0x150 [ 18.824883] [c000000fa7483c50] [c0000000006bc030] .cpuidle_enter+0x30/0x50 [ 18.824887] [c000000fa7483cc0] [c0000000006bc9f4] .cpuidle_idle_call+0x104/0x720 [ 18.824892] [c000000fa7483d80] [c000000000070af8] .pSeries_idle+0x18/0x40 [ 18.824897] [c000000fa7483df0] [c000000000019084] .cpu_idle+0x1a4/0x380 [ 18.824902] [c000000fa7483ec0] [c0000000008a4c18] .start_secondary+0x520/0x528 [ 18.824907] [c000000fa7483f90] [c0000000000093f0] .start_secondary_prolog+0x10/0x14 [ 18.824911] Instruction dump: [ 18.824914] 38840008 90030000 90e30004 38630008 7ca62850 7cc300d0 78c7e102 7cf01120 [ 18.824923] 78c60660 39200010 39400020 39600030 <7e00200c> 7c0020ce 38840010 409f001c [ 18.824935] ---[ end trace 0bb95124affaaa45 ]--- [ 18.825046] Unrecoverable VMX/Altivec Unavailable Exception f20 at c000000000052d08 I believe the right fix is to make memcpy match usercopy and not use cr1. Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: <stable@kernel.org> [v3.6]
* powerpc/kprobe: Don't emulate store when kprobe stwu r1Tiejun Chen2012-09-181-2/+34
| | | | | | | | | | | | | | | We don't do the real store operation for kprobing 'stwu Rx,(y)R1' since this may corrupt the exception frame, now we will do this operation safely in exception return code after migrate current exception frame below the kprobed function stack. So we only update gpr[1] here and trigger a thread flag to mask this. Note we should make sure if we trigger kernel stack over flow. Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Don't use __put_user() in patch_instructionBenjamin Herrenschmidt2012-09-051-1/+1
| | | | | | | | | | | | | patch_instruction() can be called very early on ppc32, when the kernel isn't yet running at it's linked address. That can cause the ! is_kernel_addr() test in __put_user() to trip and call might_sleep() which is very bad at that point during boot. Use a lower level function instead for now, at least until we get to rework ppc32 boot process to do the code patching later, like ppc64 does. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Fix VMX in interrupt check in POWER7 copy loopsAnton Blanchard2012-08-242-4/+4
| | | | | | | | The enhanced prefetch hint patches corrupt the condition register that was used to check if we are in interrupt. Fix this by using cr1. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: POWER7 copy_to_user/copy_from_user patch applied twiceAnton Blanchard2012-08-241-31/+0
| | | | | | | | "powerpc: Use enhanced touch instructions in POWER7 copy_to_user/copy_from_user" was applied twice. Remove one. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Put the gpr save/restore functions in their own sectionStephen Rothwell2012-07-111-1/+4
| | | | | | | | | | | This allows the linker to know that calls to them do not need to switch TOC and stop errors like the following when linking large configurations: powerpc64-linux-ld: drivers/built-in.o: In function `.gpiochip_is_requested': (.text+0x4): sibling call optimization to `_savegpr0_29' does not allow automatic multiple TOCs; recompile with -mminimal-toc or -fno-optimize-sibling-calls, or make `_savegpr0_29' extern Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Fixes for instructions not using correct register namingMichael Neuling2012-07-101-2/+2
| | | | | | | | | | These macros are using integers where they could be using logical names since they take registers. We are going to enforce this soon, so fix these up now. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Change mtcrf to use real register namesMichael Neuling2012-07-103-9/+9
| | | | | | | | | | mtocrf define is just a wrapper around the real instructions so we can just use real register names here (ie. lower case). Also remove braces in macro so this is possible. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Merge STK_REG/PARAM/FRAMESIZEMichael Neuling2012-07-104-12/+0
| | | | | | | | Merge the defines of STACKFRAMESIZE, STK_REG, STK_PARAM from different places. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Fix usage of register macros getting ready for %r0 changeMichael Neuling2012-07-109-120/+120
| | | | | | | | | | | | | | Anything that uses a constructed instruction (ie. from ppc-opcode.h), need to use the new R0 macro, as %r0 is not going to work. Also convert usages of macros where we are just determining an offset (usually for a load/store), like: std r14,STK_REG(r14)(r1) Can't use STK_REG(r14) as %r14 doesn't work in the STK_REG macro since it's just calculating an offset. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Optimise the 64bit optimised __clear_userAnton Blanchard2012-07-031-1/+62
| | | | | | | | | | | | | | | | | | | | | | | I blame Mikey for this. He elevated my slightly dubious testcase: to benchmark status. And naturally we need to be number 1 at creating zeros. So lets improve __clear_user some more. As Paul suggests we can use dcbz for large lengths. This patch gets the destination cacheline aligned then uses dcbz on whole cachelines. Before: 10485760000 bytes (10 GB) copied, 0.414744 s, 25.3 GB/s After: 10485760000 bytes (10 GB) copied, 0.268597 s, 39.0 GB/s 39 GB/s, a new record. Signed-off-by: Anton Blanchard <anton@samba.org> Tested-by: Olof Johansson <olof@lixom.net> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: POWER7 optimised memcpy using VMX and enhanced prefetchAnton Blanchard2012-07-033-1/+656
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement a POWER7 optimised memcpy using VMX and enhanced prefetch instructions. This is a copy of the POWER7 optimised copy_to_user/copy_from_user loop. Detailed implementation and performance details can be found in commit a66086b8197d (powerpc: POWER7 optimised copy_to_user/copy_from_user using VMX). I noticed memcpy issues when profiling a RAID6 workload: .memcpy .async_memcpy .async_copy_data .__raid_run_ops .handle_stripe .raid5d .md_thread I created a simplified testcase by building a RAID6 array with 4 1GB ramdisks (booting with brd.rd_size=1048576): # mdadm -CR -e 1.2 /dev/md0 --level=6 -n4 /dev/ram[0-3] I then timed how long it took to write to the entire array: # dd if=/dev/zero of=/dev/md0 bs=1M Before: 892 MB/s After: 999 MB/s A 12% improvement. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Use enhanced touch instructions in POWER7 copy_to_user/copy_from_userAnton Blanchard2012-07-031-0/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Version 2.06 of the POWER ISA introduced enhanced touch instructions, allowing us to specify a number of attributes including the length of a stream. This patch adds a software stream for both loads and stores in the POWER7 copy_tofrom_user loop. Since the setup is quite complicated and we have to use an eieio to ensure correct ordering of the "GO" command we only do this for copies above 4kB. To quantify any performance improvements we need a working set bigger than the caches so we operate on a 1GB file: # dd if=/dev/zero of=/tmp/foo bs=1M count=1024 And we compare how fast we can read the file: # dd if=/tmp/foo of=/dev/null bs=1M before: 7.7 GB/s after: 9.6 GB/s A 25% improvement. The worst case for this patch will be a completely L1 cache contained copy of just over 4kB. We can test this with the copy_to_user testcase we used to tune copy_tofrom_user originally: http://ozlabs.org/~anton/junkcode/copy_to_user.c # time ./copy_to_user2 -l 4224 -i 10000000 before: 6.807 s after: 6.946 s A 2% slowdown, which seems reasonable considering our data is unlikely to be completely L1 contained. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: POWER7 optimised copy_page using VMX and enhanced prefetchAnton Blanchard2012-07-034-1/+196
| | | | | | | | | | | | | | | | | | | | | | | | | Implement a POWER7 optimised copy_page using VMX and enhanced prefetch instructions. We use enhanced prefetch hints to prefetch both the load and store side. We copy a cacheline at a time and fall back to regular loads and stores if we are unable to use VMX (eg we are in an interrupt). The following microbenchmark was used to assess the impact of the patch: http://ozlabs.org/~anton/junkcode/page_fault_file.c We test MAP_PRIVATE page faults across a 1GB file, 100 times: # time ./page_fault_file -p -l 1G -i 100 Before: 22.25s After: 18.89s 17% faster Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Rename copyuser_power7_vmx.c to vmx-helper.cAnton Blanchard2012-07-033-7/+7
| | | | | | | | Subsequent patches will add more VMX library functions and it makes sense to keep all the c-code helper functions in the one file. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Use enhanced touch instructions in POWER7 copy_to_user/copy_from_userAnton Blanchard2012-07-031-0/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Version 2.06 of the POWER ISA introduced enhanced touch instructions, allowing us to specify a number of attributes including the length of a stream. This patch adds a software stream for both loads and stores in the POWER7 copy_tofrom_user loop. Since the setup is quite complicated and we have to use an eieio to ensure correct ordering of the "GO" command we only do this for copies above 4kB. To quantify any performance improvements we need a working set bigger than the caches so we operate on a 1GB file: # dd if=/dev/zero of=/tmp/foo bs=1M count=1024 And we compare how fast we can read the file: # dd if=/tmp/foo of=/dev/null bs=1M before: 7.7 GB/s after: 9.6 GB/s A 25% improvement. The worst case for this patch will be a completely L1 cache contained copy of just over 4kB. We can test this with the copy_to_user testcase we used to tune copy_tofrom_user originally: http://ozlabs.org/~anton/junkcode/copy_to_user.c # time ./copy_to_user2 -l 4224 -i 10000000 before: 6.807 s after: 6.946 s A 2% slowdown, which seems reasonable considering our data is unlikely to be completely L1 contained. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: 64bit optimised __clear_userAnton Blanchard2012-07-033-1/+144
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I noticed __clear_user high up in a profile of one of my RAID stress tests. The testcase was doing a dd from /dev/zero which ends up calling __clear_user. __clear_user is basically a loop with a single 4 byte store which is horribly slow. We can do much better by aligning the desination and doing 32 bytes of 8 byte stores in a loop. The following testcase was used to verify the patch: http://ozlabs.org/~anton/junkcode/stress_clear_user.c To show the improvement in performance I ran a dd from /dev/zero to /dev/null on a POWER7 box: Before: # dd if=/dev/zero of=/dev/null bs=1M count=10000 10485760000 bytes (10 GB) copied, 3.72379 s, 2.8 GB/s After: # time dd if=/dev/zero of=/dev/null bs=1M count=10000 10485760000 bytes (10 GB) copied, 0.728318 s, 14.4 GB/s Over 5x faster. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Have patch_instruction detect faultsSteven Rostedt2012-07-031-4/+10
| | | | | | | | | | | | | | For ftrace to use the patch_instruction code, it needs to check for faults on write. Ftrace updates code all over the kernel, and we need to know if code is updated or not due to protections that are placed on some portions of the kernel. If ftrace does not detect a fault, it will error later on, and it will be much more difficult to find the problem. By changing patch_instruction() to detect faults, then ftrace will be able to make use of it too. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Use the new generic strncpy_from_user() and strnlen_user()Paul Mackerras2012-05-271-45/+0
| | | | | | | | | | This is much the same as for SPARC except that we can do the find_zero() function more efficiently using the count-leading-zeroes instructions. Tested on 32-bit and 64-bit PowerPC. Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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