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2012-09-05powerpc: Don't use __put_user() in patch_instructionBenjamin Herrenschmidt
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>
2012-08-24powerpc: Fix VMX in interrupt check in POWER7 copy loopsAnton Blanchard
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>
2012-08-24powerpc: POWER7 copy_to_user/copy_from_user patch applied twiceAnton Blanchard
"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>
2012-07-11powerpc: Put the gpr save/restore functions in their own sectionStephen Rothwell
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>
2012-07-10powerpc: Fixes for instructions not using correct register namingMichael Neuling
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>
2012-07-10powerpc: Change mtcrf to use real register namesMichael Neuling
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>
2012-07-10powerpc: Merge STK_REG/PARAM/FRAMESIZEMichael Neuling
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>
2012-07-10powerpc: Fix usage of register macros getting ready for %r0 changeMichael Neuling
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>
2012-07-03powerpc: Optimise the 64bit optimised __clear_userAnton Blanchard
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>
2012-07-03powerpc: POWER7 optimised memcpy using VMX and enhanced prefetchAnton Blanchard
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>
2012-07-03powerpc: Use enhanced touch instructions in POWER7 copy_to_user/copy_from_userAnton Blanchard
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>
2012-07-03powerpc: POWER7 optimised copy_page using VMX and enhanced prefetchAnton Blanchard
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>
2012-07-03powerpc: Rename copyuser_power7_vmx.c to vmx-helper.cAnton Blanchard
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>
2012-07-03powerpc: Use enhanced touch instructions in POWER7 copy_to_user/copy_from_userAnton Blanchard
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>
2012-07-03powerpc: 64bit optimised __clear_userAnton Blanchard
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>
2012-07-03powerpc: Have patch_instruction detect faultsSteven Rostedt
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>
2012-05-28powerpc: Use the new generic strncpy_from_user() and strnlen_user()Paul Mackerras
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>
2012-04-30powerpc: Remove CONFIG_POWER4_ONLYAnton Blanchard
Remove CONFIG_POWER4_ONLY, the option is badly named and only does two things: - It wraps the MMU segment table code. With feature fixups there is little downside to compiling this in. - It uses the newer mtocrf instruction in various assembly functions. Instead of making this a compile option just do it at runtime via a feature fixup. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-03-28Disintegrate asm/system.h for PowerPCDavid Howells
Disintegrate asm/system.h for PowerPC. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> cc: linuxppc-dev@lists.ozlabs.org
2012-03-21powerpc: Remove FW_FEATURE ISERIES from arch codeStephen Rothwell
This is no longer selectable, so just remove all the dependent code. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-19powerpc: POWER7 optimised copy_to_user/copy_from_user using VMXAnton Blanchard
Implement a POWER7 optimised copy_to_user/copy_from_user using VMX. For large aligned copies this new loop is over 10% faster, and for large unaligned copies it is over 200% faster. If we take a fault we fall back to the old version, this keeps things relatively simple and easy to verify. On POWER7 unaligned stores rarely slow down - they only flush when a store crosses a 4KB page boundary. Furthermore this flush is handled completely in hardware and should be 20-30 cycles. Unaligned loads on the other hand flush much more often - whenever crossing a 128 byte cache line, or a 32 byte sector if either sector is an L1 miss. Considering this information we really want to get the loads aligned and not worry about the alignment of the stores. Microbenchmarks confirm that this approach is much faster than the current unaligned copy loop that uses shifts and rotates to ensure both loads and stores are aligned. We also want to try and do the stores in cacheline aligned, cacheline sized chunks. If the store queue is unable to merge an entire cacheline of stores then the L2 cache will have to do a read/modify/write. Even worse, we will serialise this with the stores in the next iteration of the copy loop since both iterations hit the same cacheline. Based on this, the new loop does the following things: 1 - 127 bytes Get the source 8 byte aligned and use 8 byte loads and stores. Pretty boring and similar to how the current loop works. 128 - 4095 bytes Get the source 8 byte aligned and use 8 byte loads and stores, 1 cacheline at a time. We aren't doing the stores in cacheline aligned chunks so we will potentially serialise once per cacheline. Even so it is much better than the loop we have today. 4096 - bytes If both source and destination have the same alignment get them both 16 byte aligned, then get the destination cacheline aligned. Do cacheline sized loads and stores using VMX. If source and destination do not have the same alignment, we get the destination cacheline aligned, and use permute to do aligned loads. In both cases the VMX loop should be optimal - we always do aligned loads and stores and are always doing stores in cacheline aligned, cacheline sized chunks. To be able to use VMX we must be careful about interrupts and sleeping. We don't use the VMX loop when in an interrupt (which should be rare anyway) and we wrap the VMX loop in disable/enable_pagefault and fall back to the existing copy_tofrom_user loop if we do need to sleep. The VMX breakpoint of 4096 bytes was chosen using this microbenchmark: http://ozlabs.org/~anton/junkcode/copy_to_user.c Since we are using VMX and there is a cost to saving and restoring the user VMX state there are two broad cases we need to benchmark: - Best case - userspace never uses VMX - Worst case - userspace always uses VMX In reality a userspace process will sit somewhere between these two extremes. Since we need to test both aligned and unaligned copies we end up with 4 combinations. The point at which the VMX loop begins to win is: 0% VMX aligned 2048 bytes unaligned 2048 bytes 100% VMX aligned 16384 bytes unaligned 8192 bytes Considering this is a microbenchmark, the data is hot in cache and the VMX loop has better store queue merging properties we set the breakpoint to 4096 bytes, a little below the unaligned breakpoints. Some future optimisations we can look at: - Looking at the perf data, a significant part of the cost when a task is always using VMX is the extra exception we take to restore the VMX state. As such we should do something similar to the x86 optimisation that restores FPU state for heavy users. ie: /* * If the task has used fpu the last 5 timeslices, just do a full * restore of the math state immediately to avoid the trap; the * chances of needing FPU soon are obviously high now */ preload_fpu = tsk_used_math(next_p) && next_p->fpu_counter > 5; and /* * fpu_counter contains the number of consecutive context switches * that the FPU is used. If this is over a threshold, the lazy fpu * saving becomes unlazy to save the trap. This is an unsigned char * so that after 256 times the counter wraps and the behavior turns * lazy again; this to deal with bursty apps that only use FPU for * a short time */ - We could create a paca bit to mirror the VMX enabled MSR bit and check that first, avoiding multiple calls to calling enable_kernel_altivec. That should help with iovec based system calls like readv. - We could have two VMX breakpoints, one for when we know the user VMX state is loaded into the registers and one when it isn't. This could be a second bit in the paca so we can calculate the break points quickly. - One suggestion from Ben was to save and restore the VSX registers we use inline instead of using enable_kernel_altivec. [BenH: Fixed a problem with preempt and fixed build without CONFIG_ALTIVEC] Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-16powerpc: Copy down exception vectors after feature fixupsAnton Blanchard
kdump fails because we try to execute an HV only instruction. Feature fixups are being applied after we copy the exception vectors down to 0 so they miss out on any updates. We have always had this issue but it only became critical in v3.0 when we added CFAR support (breaks POWER5) and v3.1 when we added POWERNV (breaks everyone). Signed-off-by: Anton Blanchard <anton@samba.org> Cc: <stable@kernel.org> [v3.0+] Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-10-31powerpc: various straight conversions from module.h --> export.hPaul Gortmaker
All these files were including module.h just for the basic EXPORT_SYMBOL infrastructure. We can shift them off to the export.h header which is a way smaller footprint and thus realize some compile time gains. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-05-20Merge branch 'merge' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (152 commits) powerpc: Fix hard CPU IDs detection powerpc/pmac: Update via-pmu to new syscore_ops powerpc/kvm: Fix the build for 32-bit Book 3S (classic) processors powerpc/kvm: Fix kvmppc_core_pending_dec powerpc: Remove last piece of GEMINI powerpc: Fix for Pegasos keyboard and mouse powerpc: Make early memory scan more resilient to out of order nodes powerpc/pseries/iommu: Cleanup ddw naming powerpc/pseries/iommu: Find windows after kexec during boot powerpc/pseries/iommu: Remove ddw property when destroying window powerpc/pseries/iommu: Add additional checks when changing iommu mask powerpc/pseries/iommu: Use correct return type in dupe_ddw_if_already_created powerpc: Remove unused/obsolete CONFIG_XICS misc: Add CARMA DATA-FPGA Programmer support misc: Add CARMA DATA-FPGA Access Driver powerpc: Make IRQ_NOREQUEST last to clear, first to set powerpc: Integrated Flash controller device tree bindings powerpc/85xx: Create dts of each core in CAMP mode for P1020RDB powerpc/85xx: Fix PCIe IDSEL for Px020RDB powerpc/85xx: P2020 DTS: re-organize dts files ...
2011-05-20sanitize <linux/prefetch.h> usageLinus Torvalds
Commit e66eed651fd1 ("list: remove prefetching from regular list iterators") removed the include of prefetch.h from list.h, which uncovered several cases that had apparently relied on that rather obscure header file dependency. So this fixes things up a bit, using grep -L linux/prefetch.h $(git grep -l '[^a-z_]prefetchw*(' -- '*.[ch]') grep -L 'prefetchw*(' $(git grep -l 'linux/prefetch.h' -- '*.[ch]') to guide us in finding files that either need <linux/prefetch.h> inclusion, or have it despite not needing it. There are more of them around (mostly network drivers), but this gets many core ones. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-19powerpc: Remove alloc_maybe_bootmem for zalloc versionMilton Miller
Replace all remaining callers of alloc_maybe_bootmem with zalloc_maybe_bootmem. The callsite in pci_dn is followed with a memset to clear the memory, and not zeroing at the other callsites in the celleb fake pci code could lead to following uninitialized memory as pointers or even freeing said pointers on error paths. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-05-19powerpc: Remove ioremap_flagsAnton Blanchard
We have a confusing number of ioremap functions. Make things just a bit simpler by merging ioremap_flags and ioremap_prot. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-05-19powerpc: Simplify 4k/64k copy_page logicAnton Blanchard
To make it easier to add optimised versions of copy_page, remove the 4kB loop for 64kB pages and just do all the work in copy_page. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-27powerpc: Use MSR_64BIT in sstep.c, fix kprobes on BOOK3EMichael Ellerman
We check MSR_SF a lot in sstep.c, to decide if we need to emulate the truncation of values when running in 32-bit mode. Factor out that code into a helper, and convert it and the other uses to use MSR_64BIT. This fixes a bug on BOOK3E where kprobes would end up returning to a 32-bit address, because regs->nip was truncated, because (msr & MSR_SF) was false. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-01-21powerpc: Ensure the else case of feature sections will fitMichael Ellerman
When we create an alternative feature section, the else case must be the same size or smaller than the body. This is because when we patch the else case in we just overwrite the body, so there must be room. Up to now we just did this by inspection, but it's quite easy to enforce it in the assembler, so we should. The only change is to add the ifgt block, but that effects the alignment of the tabs and so the whole macro is modified. Also add a test, but #if 0 it because we don't want to break the build. Anyone who's modifying the feature macros should enable the test. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-12-09powerpc: Hardcode popcnt instructions for old assemblersAnton Blanchard
The popcnt instructions went into binutils relatively recently. As with a number of other instructions, create macros and hardcode them. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-11-29powerpc: Add support for popcnt instructionsAnton Blanchard
POWER5 added popcntb, and POWER7 added popcntw and popcntd. As a first step this patch does all the work out of line, but it would be nice to implement them as inlines with an out of line fallback. The performance issue with hweight was noticed when disabling SMT on a large (192 thread) POWER7 box. The patch improves that testcase by about 8%. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-10-13powerpc/Makefiles: Change to new flag variablesmatt mooney
Replace EXTRA_CFLAGS with ccflags-y and EXTRA_AFLAGS with asflags-y. Signed-off-by: matt mooney <mfm@muteddisk.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-09-02powerpc: mtmsrd not definedSean MacLennan
Replace the BOOK3S_64 specific mtmsrd with the generic MTMSRD macro. Only enable ldstfp when CONFIG_PPC_FPU is set. Signed-off-by: Sean MacLennan <smaclennan@pikatech.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-09-02powerpc: Fix incorrect .stabs entry for copy_32.SSean MacLennan
Signed-off-by: Sean MacLennan <smaclennan@pikatech.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-09-02powerpc: Abstract indexing of lppaca structsPaul Mackerras
Currently we have the lppaca structs as a simple array of NR_CPUS entries, taking up space in the data section of the kernel image. In future we would like to allocate them dynamically, so this abstracts out the accesses to the array, making it easier to change how we locate the lppaca for a given cpu in future. Specifically, lppaca[cpu] changes to lppaca_of(cpu). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-09-02powerpc: Add 64bit csum_and_copy_to_userAnton Blanchard
This adds the equivalent of csum_and_copy_from_user for the receive side so we can copy and checksum in one pass. It is modelled on the generic checksum routine. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-09-02powerpc: Optimise 64bit csum_partial_copy_generic and add ↵Anton Blanchard
csum_and_copy_from_user We use the same core loop as the new csum_partial, adding in the stores and exception handling code. To keep things simple we do all the exception fixup in csum_and_copy_from_user. This wrapper function is modelled on the generic checksum code and is careful to always calculate a complete checksum even if we only copied part of the data to userspace. To test this I forced checksumming on over loopback and ran socklib (a simple TCP benchmark). On a POWER6 575 throughput improved by 19% with this patch. If I forced both the sender and receiver onto the same cpu (with the hope of shifting the benchmark from being cache bandwidth limited to cpu limited), adding this patch improved performance by 55% Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-09-02powerpc: Optimise 64bit csum_partialAnton Blanchard
The main loop of csum_partial runs very slowly on recent POWER CPUs. After some analysis on both POWER6 and POWER7 I came up with routine below. First we get the source aligned to a double word, ignoring any odd alignment to keep things simple. Then we do 64 bytes at a time, with an entry and exit limb of a further 64 bytes. On both POWER6 and POWER7 this should be as fast as we can go since we are limited by the latency of the adde instructions. To test this I forced checksumming on over loopback and ran socklib (a simple TCP benchmark). On a POWER6 575 throughput improved by 11% with this patch. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-07-09Merge commit 'paulus-perf/master' into nextBenjamin Herrenschmidt
2010-07-08powerpc: Fix feature-fixup tests for gcc 4.5Stephen Rothwell
The feature-fixup test declare some extern void variables and then take their addresses. Fix this by declaring them as extern u8 instead. Fixes these warnings (treated as errors): CC arch/powerpc/lib/feature-fixups.o cc1: warnings being treated as errors arch/powerpc/lib/feature-fixups.c: In function 'test_cpu_macros': arch/powerpc/lib/feature-fixups.c:293:23: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:294:9: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:297:2: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:297:2: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c: In function 'test_fw_macros': arch/powerpc/lib/feature-fixups.c:306:23: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:307:9: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:310:2: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:310:2: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c: In function 'test_lwsync_macros': arch/powerpc/lib/feature-fixups.c:321:23: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:322:9: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:326:3: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:326:3: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:329:3: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:329:3: error: taking address of expression of type 'void' Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-07-08powerpc: Fix module building for gcc 4.5 and 64 bitStephen Rothwell
Gcc 4.5 is now generating out of line register save and restore in the function prefix and postfix when we use -Os. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-06-22powerpc, hw_breakpoints: Implement hw_breakpoints for 64-bit server processorsK.Prasad
Implement perf-events based hw-breakpoint interfaces for PowerPC 64-bit server (Book III S) processors. This allows access to a given location to be used as an event that can be counted or profiled by the perf_events subsystem. This is done using the DABR (data breakpoint register), which can also be used for process debugging via ptrace. When perf_event hw_breakpoint support is configured in, the perf_event subsystem manages the DABR and arbitrates access to it, and ptrace then creates a perf_event when it is requested to set a data breakpoint. [Adopted suggestions from Paul Mackerras <paulus@samba.org> to - emulate_step() all system-wide breakpoints and single-step only the per-task breakpoints - perform arch-specific cleanup before unregistration through arch_unregister_hw_breakpoint() ] Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2010-06-22powerpc: Emulate most Book I instructions in emulate_step()Paul Mackerras
This extends the emulate_step() function to handle a large proportion of the Book I instructions implemented on current 64-bit server processors. The aim is to handle all the load and store instructions used in the kernel, plus all of the instructions that appear between l[wd]arx and st[wd]cx., so this handles the Altivec/VMX lvx and stvx and the VSX lxv2dx and stxv2dx instructions (implemented in POWER7). The new code can emulate user mode instructions, and checks the effective address for a load or store if the saved state is for user mode. It doesn't handle little-endian mode at present. For floating-point, Altivec/VMX and VSX instructions, it checks that the saved MSR has the enable bit for the relevant facility set, and if so, assumes that the FP/VMX/VSX registers contain valid state, and does loads or stores directly to/from the FP/VMX/VSX registers, using assembly helpers in ldstfp.S. Instructions supported now include: * Loads and stores, including some but not all VMX and VSX instructions, and lmw/stmw * Atomic loads and stores (l[dw]arx, st[dw]cx.) * Arithmetic instructions (add, subtract, multiply, divide, etc.) * Compare instructions * Rotate and mask instructions * Shift instructions * Logical instructions (and, or, xor, etc.) * Condition register logical instructions * mtcrf, cntlz[wd], exts[bhw] * isync, sync, lwsync, ptesync, eieio * Cache operations (dcbf, dcbst, dcbt, dcbtst) The overflow-checking arithmetic instructions are not included, but they appear not to be ever used in C code. This uses decimal values for the minor opcodes in the switch statements because that is what appears in the Power ISA specification, thus it is easier to check that they are correct if they are in decimal. If this is used to single-step an instruction where a data breakpoint interrupt occurred, then there is the possibility that the instruction is a lwarx or ldarx. In that case we have to be careful not to lose the reservation until we get to the matching st[wd]cx., or we'll never make forward progress. One alternative is to try to arrange that we can return from interrupts and handle data breakpoint interrupts without losing the reservation, which means not using any spinlocks, mutexes, or atomic ops (including bitops). That seems rather fragile. The other alternative is to emulate the larx/stcx and all the instructions in between. This is why this commit adds support for a wide range of integer instructions. Signed-off-by: Paul Mackerras <paulus@samba.org>
2010-05-21powerpc: Fix string library functionsAndreas Schwab
The powerpc strncmp implementation does not correctly handle a zero length, despite the claim in 0119536cd314ef95553604208c25bc35581f7f0a (Add hand-coded assembly strcmp). Additionally, all the length arguments are size_t, not int, so use PPC_LCMPI and eq instead of cmpwi and le throughout. Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-04-07powerpc: Fix handling of strncmp with zero lenJeff Mahoney
Commit 0119536c, which added the assembly version of strncmp to powerpc, mentions that it adds two instructions to the version from boot/string.S to allow it to handle len=0. Unfortunately, it doesn't always return 0 when that is the case. The length is passed in r5, but the return value is passed back in r3. In certain cases, this will happen to work. Otherwise it will pass back the address of the first string as the return value. This patch lifts the len <= 0 handling code from memcpy to handle that case. Reported by: Christian_Sellars@symantec.com Signed-off-by: Jeff Mahoney <jeffm@suse.com> CC: <stable@kernel.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-02-26powerpc: Fix lwsync feature fixup vs. modules on 64-bitBenjamin Herrenschmidt
Anton's commit enabling the use of the lwsync fixup mechanism on 64-bit breaks modules. The lwsync fixup section uses .long instead of the FTR_ENTRY_OFFSET macro used by other fixups sections, and thus will generate 32-bit relocations that our module loader cannot resolve. This changes it to use the same type as other feature sections. Note however that we might want to consider using 32-bit for all the feature fixup offsets and add support for R_PPC_REL32 to module_64.c instead as that would reduce the size of the kernel image. I'll leave that as an exercise for the reader for now... Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-17powerpc: Improve 64bit copy_tofrom_userAnton Blanchard
Here is a patch from Paul Mackerras that improves the ppc64 copy_tofrom_user. The loop now does 32 bytes at a time and as well as pairing loads and stores. A quick test case that reads 8kB over and over shows the improvement: POWER6: 53% faster POWER7: 51% faster #define _XOPEN_SOURCE 500 #include <stdlib.h> #include <stdio.h> #include <unistd.h> #include <fcntl.h> #include <sys/types.h> #include <sys/stat.h> #define BUFSIZE (8 * 1024) #define ITERATIONS 10000000 int main() { char tmpfile[] = "/tmp/copy_to_user_testXXXXXX"; int fd; char *buf[BUFSIZE]; unsigned long i; fd = mkstemp(tmpfile); if (fd < 0) { perror("open"); exit(1); } if (write(fd, buf, BUFSIZE) != BUFSIZE) { perror("open"); exit(1); } for (i = 0; i < 10000000; i++) { if (pread(fd, buf, BUFSIZE, 0) != BUFSIZE) { perror("pread"); exit(1); } } unlink(tmpfile); return 0; } Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-17powerpc: Pair loads and stores in copy_4k_pageAnton Blanchard
A number of our chips like loads and stores to be paired. A small kernel module testcase shows the improvement of pairing loads and stores in copy_4k_page: POWER6: +9% POWER7: +1.5% #include <linux/module.h> #include <linux/mm.h> #define ITERATIONS 10000000 static int __init copypage_init(void) { struct timespec before, after; unsigned long i; struct page *destpage, *srcpage; char *dest, *src; destpage = alloc_page(GFP_KERNEL); srcpage = alloc_page(GFP_KERNEL); dest = page_address(destpage); src = page_address(srcpage); getnstimeofday(&before); for (i = 0; i < ITERATIONS; i++) copy_4K_page(dest, src); getnstimeofday(&after); free_page((unsigned long)dest); free_page((unsigned long)src); printk(KERN_DEBUG "copy_4K_page loop took %lu ns\n", (after.tv_sec - before.tv_sec) * NSEC_PER_SEC + (after.tv_nsec - before.tv_nsec)); return 0; } static void __exit copypage_exit(void) { } module_init(copypage_init) module_exit(copypage_exit) MODULE_LICENSE("GPL"); MODULE_AUTHOR("Anton Blanchard"); Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>