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* ARM: 7527/1: uaccess: explicitly check __user pointer when !CPU_USE_DOMAINSRussell King2015-12-182-12/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The {get,put}_user macros don't perform range checking on the provided __user address when !CPU_HAS_DOMAINS. This patch reworks the out-of-line assembly accessors to check the user address against a specified limit, returning -EFAULT if is is out of range. [will: changed get_user register allocation to match put_user] [rmk: fixed building on older ARM architectures] CRs-Fixed: 504011 Reported-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: stable@vger.kernel.org Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Git-commit: 8404663f81d212918ff85f493649a7991209fa04 Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Signed-off-by: Laura Abbott <lauraa@codeaurora.org> Conflicts: arch/arm/include/asm/assembler.h arch/arm/lib/getuser.S arch/arm/lib/putuser.S Change-Id: I3818045a136fcdf72deb1371b132e090fd7ed643
* ARM: 7670/1: fix the memset fixNicolas Pitre2014-11-241-20/+13
| | | | | | | | | | | | | | | | | | | | | | Commit 455bd4c430b0 ("ARM: 7668/1: fix memset-related crashes caused by recent GCC (4.7.2) optimizations") attempted to fix a compliance issue with the memset return value. However the memset itself became broken by that patch for misaligned pointers. This fixes the above by branching over the entry code from the misaligned fixup code to avoid reloading the original pointer. Also, because the function entry alignment is wrong in the Thumb mode compilation, that fixup code is moved to the end. While at it, the entry instructions are slightly reworked to help dual issue pipelines. Signed-off-by: Nicolas Pitre <nico@linaro.org> Tested-by: Alexander Holler <holler@ahsoftware.de> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Change-Id: Ifdc6b0167104b42d23a72ffe5e6173f6e14c97ee
* ARM: 7668/1: fix memset-related crashes caused by recent GCC (4.7.2) ↵Ivan Djelic2014-11-241-41/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | optimizations Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on assumptions about the implementation of memset and similar functions. The current ARM optimized memset code does not return the value of its first argument, as is usually expected from standard implementations. For instance in the following function: void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter) { memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter)); waiter->magic = waiter; INIT_LIST_HEAD(&waiter->list); } compiled as: 800554d0 <debug_mutex_lock_common>: 800554d0: e92d4008 push {r3, lr} 800554d4: e1a00001 mov r0, r1 800554d8: e3a02010 mov r2, #16 ; 0x10 800554dc: e3a01011 mov r1, #17 ; 0x11 800554e0: eb04426e bl 80165ea0 <memset> 800554e4: e1a03000 mov r3, r0 800554e8: e583000c str r0, [r3, #12] 800554ec: e5830000 str r0, [r3] 800554f0: e5830004 str r0, [r3, #4] 800554f4: e8bd8008 pop {r3, pc} GCC assumes memset returns the value of pointer 'waiter' in register r0; causing register/memory corruptions. This patch fixes the return value of the assembly version of memset. It adds a 'mov' instruction and merges an additional load+store into existing load/store instructions. For ease of review, here is a breakdown of the patch into 4 simple steps: Step 1 ====== Perform the following substitutions: ip -> r8, then r0 -> ip, and insert 'mov ip, r0' as the first statement of the function. At this point, we have a memset() implementation returning the proper result, but corrupting r8 on some paths (the ones that were using ip). Step 2 ====== Make sure r8 is saved and restored when (! CALGN(1)+0) == 1: save r8: - str lr, [sp, #-4]! + stmfd sp!, {r8, lr} and restore r8 on both exit paths: - ldmeqfd sp!, {pc} @ Now <64 bytes to go. + ldmeqfd sp!, {r8, pc} @ Now <64 bytes to go. (...) tst r2, #16 stmneia ip!, {r1, r3, r8, lr} - ldr lr, [sp], #4 + ldmfd sp!, {r8, lr} Step 3 ====== Make sure r8 is saved and restored when (! CALGN(1)+0) == 0: save r8: - stmfd sp!, {r4-r7, lr} + stmfd sp!, {r4-r8, lr} and restore r8 on both exit paths: bgt 3b - ldmeqfd sp!, {r4-r7, pc} + ldmeqfd sp!, {r4-r8, pc} (...) tst r2, #16 stmneia ip!, {r4-r7} - ldmfd sp!, {r4-r7, lr} + ldmfd sp!, {r4-r8, lr} Step 4 ====== Rewrite register list "r4-r7, r8" as "r4-r8". Signed-off-by: Ivan Djelic <ivan.djelic@parrot.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Dirk Behme <dirk.behme@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Change-Id: Ie0c05696ed7c2e0d0a934233947e6a4b935e3405
* samsung update 1codeworkx2012-06-024-9/+64
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* ARM: 6945/1: Add unwinding support for division functionsLaura Abbott2011-05-271-5/+20
| | | | | | | | | | | | The software division functions never had unwinding annotations added. Currently, when a division by zero occurs the backtrace shown will stop at Ldiv0 or some completely unrelated function. Add unwinding annotations in hopes of getting a more useful backtrace when a division by zero occurs. Signed-off-by: Laura Abbott <lauraa@codeaurora.org> Acked-by: Dave Martin <dave.martin@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
*-. Merge branches 'fixes', 'pgt-next' and 'versatile' into develRussell King2011-03-201-1/+6
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| | * ARM: pgtable: add pud-level codeRussell King2011-02-211-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add pud_offset() et.al. between the pgd and pmd code in preparation of using pgtable-nopud.h rather than 4level-fixup.h. This incorporates a fix from Jamie Iles <jamie@jamieiles.com> for uaccess_with_memcpy.c. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | | ARM: 6653/1: bitops: Use BX instead of MOV PC,LRDave Martin2011-02-191-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel doesn't officially need to interwork, but using BX wherever appropriate will help educate people into good assembler coding habits. BX is appropriate here because this code is predicated on __LINUX_ARM_ARCH__ >= 6 Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | | ARM: bitops: switch set/clear/change bitops to use ldrex/strexRussell King2011-02-027-62/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Switch the set/clear/change bitops to use the word-based exclusive operations, which are only present in a wider range of ARM architectures than the byte-based exclusive operations. Tested record: - Nicolas Pitre: ext3,rw,le - Sourav Poddar: nfs,le - Will Deacon: ext3,rw,le - Tony Lindgren: ext3+nfs,le Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org> Tested-by: Sourav Poddar <sourav.poddar@ti.com> Tested-by: Will Deacon <will.deacon@arm.com> Tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | | ARM: bitops: ensure set/clear/change bitops take a word-aligned pointerRussell King2011-02-021-0/+8
|/ / | | | | | | | | | | | | | | | | Add additional instructions to our assembly bitops functions to ensure that they only operate on word-aligned pointers. This will be necessary when we switch these operations to use the word-based exclusive operations. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | ARM: udelay: prevent math rounding resulting in short udelaysRussell King2011-01-101-0/+4
| | | | | | | | | | | | | | | | | | We perform the microseconds to loops calculation using a number of multiplies and shift rights. Each shift right rounds down the resulting value, which can result in delays shorter than requested. Ensure that we always round up. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | Merge branch 'smp' into miscRussell King2011-01-061-2/+4
|\ \ | | | | | | | | | | | | | | | Conflicts: arch/arm/kernel/entry-armv.S arch/arm/mm/ioremap.c
| * | ARM: 6482/2: Fix find_next_zero_bit and related assemblyJames Jones2010-11-241-2/+4
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The find_next_bit, find_first_bit, find_next_zero_bit and find_first_zero_bit functions were not properly clamping to the maxbit argument at the bit level. They were instead only checking maxbit at the byte level. To fix this, add a compare and a conditional move instruction to the end of the common bit-within-the- byte code used by all the functions and be sure not to clobber the maxbit argument before it is used. Cc: <stable@kernel.org> Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org> Tested-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: James Jones <jajones@nvidia.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | ARM: 6384/1: Remove the domain switching on ARMv6k/v7 CPUsCatalin Marinas2010-11-043-61/+64
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes the domain switching functionality via the set_fs and __switch_to functions on cores that have a TLS register. Currently, the ioremap and vmalloc areas share the same level 1 page tables and therefore have the same domain (DOMAIN_KERNEL). When the kernel domain is modified from Client to Manager (via the __set_fs or in the __switch_to function), the XN (eXecute Never) bit is overridden and newer CPUs can speculatively prefetch the ioremap'ed memory. Linux performs the kernel domain switching to allow user-specific functions (copy_to/from_user, get/put_user etc.) to access kernel memory. In order for these functions to work with the kernel domain set to Client, the patch modifies the LDRT/STRT and related instructions to the LDR/STR ones. The user pages access rights are also modified for kernel read-only access rather than read/write so that the copy-on-write mechanism still works. CPU_USE_DOMAINS gets disabled only if the hardware has a TLS register (CPU_32v6K is defined) since writing the TLS value to the high vectors page isn't possible. The user addresses passed to the kernel are checked by the access_ok() function so that they do not point to the kernel space. Tested-by: Anton Vorontsov <cbouatmailru@gmail.com> Cc: Tony Lindgren <tony@atomide.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-armLinus Torvalds2010-08-031-1/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (291 commits) ARM: AMBA: Add pclk support to AMBA bus infrastructure ARM: 6278/2: fix regression in RealView after the introduction of pclk ARM: 6277/1: mach-shmobile: Allow users to select HZ, default to 128 ARM: 6276/1: mach-shmobile: remove duplicate NR_IRQS_LEGACY ARM: 6246/1: mmci: support larger MMCIDATALENGTH register ARM: 6245/1: mmci: enable hardware flow control on Ux500 variants ARM: 6244/1: mmci: add variant data and default MCICLOCK support ARM: 6243/1: mmci: pass power_mode to the translate_vdd callback ARM: 6274/1: add global control registers definition header file for nuc900 mx2_camera: fix type of dma buffer virtual address pointer mx2_camera: Add soc_camera support for i.MX25/i.MX27 arm/imx/gpio: add spinlock protection ARM: Add support for the LPC32XX arch ARM: LPC32XX: Arch config menu supoport and makefiles ARM: LPC32XX: Phytec 3250 platform support ARM: LPC32XX: Misc support functions ARM: LPC32XX: Serial support code ARM: LPC32XX: System suspend support ARM: LPC32XX: GPIO, timer, and IRQ drivers ARM: LPC32XX: Clock driver ...
| * ARM: Remove support for LinkUp Systems L7200 SDP.Russell King2010-06-241-1/+0
| | | | | | | | | | | | | | | | This hasn't been actively maintained for a long time, only receiving the occasional build update when things break. I doubt anyone has one of these on their desks anymore. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | ARM: Fix csum_partial_copy_from_user()Russell King2010-07-261-1/+1
|/ | | | | | | | | | | Using the parent functions frame pointer to access our arguments is completely wrong, whether or not we're building with frame pointers or not. What we should be using is the stack pointer to get at the word above the registers we stacked ourselves. Reported-by: Bosko Radivojevic <bosko.radivojevic@gmail.com> Tested-by: Bosko Radivojevic <bosko.radivojevic@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: 6110/1: Fix Thumb-2 kernel builds when UACCESS_WITH_MEMCPY is enabledCatalin Marinas2010-05-082-0/+2
| | | | | | | | | | | | The patch adds the ENDPROC declarations for the __copy_to_user_std and __clear_user_std functions. Without these, the compiler generates BXL to ARM when compiling the kernel in Thumb-2 mode. Reported-by: Kyungmin Park <kmpark@infradead.org> Tested-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: fix build error in arch/arm/kernel/process.cRussell King2010-04-2110-22/+22
| | | | | | | | | | | | | | | | | | | | | /tmp/ccJ3ssZW.s: Assembler messages: /tmp/ccJ3ssZW.s:1952: Error: can't resolve `.text' {.text section} - `.LFB1077' This is caused because: .section .data .section .text .section .text .previous does not return us to the .text section, but the .data section; this makes use of .previous dangerous if the ordering of previous sections is not known. Fix up the other users of .previous; .pushsection and .popsection are a safer pairing to use than .section and .previous. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* Merge branch 'master' into export-slabhTejun Heo2010-04-051-2/+2
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| * ARM: 6006/1: ARM: Use the correct NOP size in memmove for Thumb-2 kernel buildsCatalin Marinas2010-03-291-2/+2
| | | | | | | | | | | | | | | | | | | | When compiling the kernel to Thumb-2, using a 16-bit NOP in the memmove() implementation causes the preceding ADD PC instruction to branch incorrectly in the middle of a 32-bit LDR or STR instruction. The memmove() code is now similar to the memcpy() template. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Merge branch 'for-rmk' of git://linux-arm.org/linux-2.6Russell King2009-09-192-2/+2
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| * Nicolas Pitre has a new email addressNicolas Pitre2009-09-152-2/+2
| | | | | | | | | | | | | | | | Due to problems at cam.org, my nico@cam.org email address is no longer valid. FRom now on, nico@fluxnic.net should be used instead. Signed-off-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | ARM: 5701/1: ARM: copy_page.S: take into account the size of the cache lineKirill A. Shutemov2009-09-151-8/+8
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Optimized version of copy_page() was written with assumption that cache line size is 32 bytes. On Cortex-A8 cache line size is 64 bytes. This patch tries to generalize copy_page() to work with any cache line size if cache line size is multiple of 16 and page size is multiple of two cache line size. After this optimization we've got ~25% speedup on OMAP3(tested in userspace). There is test for kernelspace which trigger copy-on-write after fork(): #include <stdlib.h> #include <string.h> #include <unistd.h> #define BUF_SIZE (10000*4096) #define NFORK 200 int main(int argc, char **argv) { char *buf = malloc(BUF_SIZE); int i; memset(buf, 0, BUF_SIZE); for(i = 0; i < NFORK; i++) { if (fork()) { wait(NULL); } else { int j; for(j = 0; j < BUF_SIZE; j+= 4096) buf[j] = (j & 0xFF) + 1; break; } } free(buf); return 0; } Before optimization this test takes ~66 seconds, after optimization takes ~56 seconds. Signed-off-by: Siarhei Siamashka <siarhei.siamashka@nokia.com> Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* Merge branch 'for-rmk-2.6.32' of git://git.pengutronix.de/git/ukl/linux-2.6 ↵Russell King2009-08-151-1/+1
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| * Complete irq tracing support for ARMUwe Kleine-König2009-08-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before this patch enabling and disabling irqs in assembler code and by the hardware wasn't tracked completly. I had to transpose two instructions in arch/arm/lib/bitops.h because restore_irqs doesn't preserve the flags with CONFIG_TRACE_IRQFLAGS=y Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
* | Thumb-2: Implement the unified arch/arm/lib functionsCatalin Marinas2009-07-2418-96/+151
| | | | | | | | | | | | | | | | | | | | This patch adds the ARM/Thumb-2 unified support for the arch/arm/lib/* files. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* | Thumb-2: Add some .align statements to the .S filesCatalin Marinas2009-07-241-0/+2
|/ | | | | | | | Since the Thumb-2 instructions can be 16-bit wide, data in the .text sections may not be aligned to a 32-bit word and this leads to unaligned exceptions. This patch does not affect the ARM code generation. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* Merge branch 'copy_user' of git://git.marvell.com/orion into develRussell King2009-06-144-2/+235
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| * [ARM] alternative copy_to_user: more precise fallback thresholdNicolas Pitre2009-05-301-2/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previous size thresholds were guessed from various user space benchmarks using a kernel with and without the alternative uaccess option. This is however not as precise as a kernel based test to measure the real speed of each method. This adds a simple test bench to show the time needed for each method. With this, the optimal size treshold for the alternative implementation can be determined with more confidence. It appears that the optimal threshold for both copy_to_user and clear_user is around 64 bytes. This is not a surprise knowing that the memcpy and memset implementations need at least 64 bytes to achieve maximum throughput. One might suggest that such test be used to determine the optimal threshold at run time instead, but results are near enough to 64 on tested targets concerned by this alternative copy_to_user implementation, so adding some overhead associated with a variable threshold is probably not worth it for now. Signed-off-by: Nicolas Pitre <nico@marvell.com>
| * [ARM] lower overhead with alternative copy_to_user for small copiesNicolas Pitre2009-05-291-9/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because the alternate copy_to_user implementation has a higher setup cost than the standard implementation, the size of the memory area to copy is tested and the standard implementation invoked instead when that size is too small. Still, that test is made after the processor has preserved a bunch of registers on the stack which have to be reloaded right away needlessly in that case, causing a measurable performance regression compared to plain usage of the standard implementation only. To make the size test overhead negligible, let's factorize it out of the alternate copy_to_user function where it is clear to the compiler that no stack frame is needed. Thanks to CONFIG_ARM_UNWIND allowing for frame pointers to be disabled and tail call optimization to kick in, the overhead in the small copy case becomes only 3 assembly instructions. A similar trick is applied to clear_user as well. Signed-off-by: Nicolas Pitre <nico@marvell.com>
| * [ARM] alternative copy_to_user/clear_user implementationLennert Buytenhek2009-05-292-0/+142
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This implements {copy_to,clear}_user() by faulting in the userland pages and then using the regular kernel mem{cpy,set}() to copy the data (while holding the page table lock). This is a win if the regular mem{cpy,set}() implementations are faster than the user copy functions, which is the case e.g. on Feroceon, where 8-word STMs (which memcpy() uses under the right conditions) give significantly higher memory write throughput than a sequence of individual 32bit stores. Here are numbers for page sized buffers on some Feroceon cores: - copy_to_user on Orion5x goes from 51 MB/s to 83 MB/s - clear_user on Orion5x goes from 89MB/s to 314MB/s - copy_to_user on Kirkwood goes from 240 MB/s to 356 MB/s - clear_user on Kirkwood goes from 367 MB/s to 1108 MB/s - copy_to_user on Disco-Duo goes from 248 MB/s to 398 MB/s - clear_user on Disco-Duo goes from 328 MB/s to 1741 MB/s Because the setup cost is non negligible, this is worthwhile only if the amount of data to copy is large enough. The operation falls back to the standard implementation when the amount of data is below a certain threshold. This threshold was determined empirically, however some targets could benefit from a lower runtime determined value for optimal results eventually. In the copy_from_user() case, this technique does not provide any worthwhile performance gain due to the fact that any kind of read access allocates the cache and subsequent 32bit loads are just as fast as the equivalent 8-word LDM. Signed-off-by: Lennert Buytenhek <buytenh@marvell.com> Signed-off-by: Nicolas Pitre <nico@marvell.com> Tested-by: Martin Michlmayr <tbm@cyrius.com>
| * [ARM] allow for alternative __copy_to_user/__clear_user implementationsNicolas Pitre2009-05-292-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This allows for optional alternative implementations of __copy_to_user and __clear_user, with a possible runtime fallback to the standard version when the alternative provides no gain over that standard version. This is done by making the standard __copy_to_user into a weak alias for the symbol __copy_to_user_std. Same thing for __clear_user. Those two functions are particularly good candidates to have alternative implementations for, since they rely on the STRT instruction which has lower performances than STM instructions on some CPU cores such as the ARM1176 and Marvell Feroceon. Signed-off-by: Nicolas Pitre <nico@marvell.com>
* | [ARM] barriers: improve xchg, bitops and atomic SMP barriersRussell King2009-05-281-0/+2
|/ | | | | | | | | | | | | | | | | Mathieu Desnoyers pointed out that the ARM barriers were lacking: - cmpxchg, xchg and atomic add return need memory barriers on architectures which can reorder the relative order in which memory read/writes can be seen between CPUs, which seems to include recent ARM architectures. Those barriers are currently missing on ARM. - test_and_xxx_bit were missing SMP barriers. So put these barriers in. Provide separate atomic_add/atomic_sub operations which do not require barriers. Reported-Reviewed-and-Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* Merge branch 'clps7500' into develRussell King2008-11-271-1/+0
|\ | | | | | | | | | | Conflicts: arch/arm/Kconfig
| * [ARM] clps7500: remove supportRussell King2008-11-271-1/+0
| | | | | | | | | | | | | | | | The CLPS7500 platform has not built since 2.6.22-git7 and there seems to be no interest in fixing it. So, remove the platform support. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | [ARM] remove memzero()Russell King2008-11-271-1/+1
|/ | | | | | | | | As suggested by Andrew Morton, remove memzero() - it's not supported on other architectures so use of it is a potential build breaking bug. Since the compiler optimizes memset(x,0,n) to __memzero() perfectly well, we don't miss out on the underlying benefits of memzero(). Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* Merge branch 'ptebits' into develRussell King2008-10-091-1/+1
|\ | | | | | | | | | | Conflicts: arch/arm/Kconfig
| * [ARM] 5226/1: remove unmatched comment end.Jean-Christophe DUBOIS2008-08-281-1/+1
| | | | | | | | | | | | | | remove unmatched comment end. Signed-off-by: Jean-Christophe DUBOIS <jcd@tribudubois.net> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | [ARM] 5231/1: Do not save the frame pointer in the csum_partial_copy_* functionsCatalin Marinas2008-09-012-8/+4
| | | | | | | | | | | | | | | | | | Since the other assembly functions do not seem to save the frame pointer onto the stack, this patch changes the csum_partial_copy_* functions to behave in the same way. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | [ARM] 5232/1: Do not post-index STRT instruction in clear_user.SCatalin Marinas2008-09-011-1/+1
| | | | | | | | | | | | | | | | | | The last strnebt instruction has a post-index of 1 but the address register is set to 0 in the next instruction, so no need for post-indexing. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | [ARM] 5227/1: Add the ENDPROC declarations to the .S filesCatalin Marinas2008-09-0144-14/+100
|/ | | | | | | | | This declaration specifies the "function" type and size for various assembly functions, mainly needed for generating the correct branch instructions in Thumb-2. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [ARM] Move include/asm-arm/arch-* to arch/arm/*/include/machRussell King2008-08-073-3/+3
| | | | | | This just leaves include/asm-arm/plat-* to deal with. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [ARM] Remove asm/hardware.h, use asm/arch/hardware.h insteadRussell King2008-08-073-3/+3
| | | | | | | | | Remove includes of asm/hardware.h in addition to asm/arch/hardware.h. Then, since asm/hardware.h only exists to include asm/arch/hardware.h, update everything to directly include asm/arch/hardware.h and remove asm/hardware.h. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [ARM] move include/asm-arm to arch/arm/include/asmRussell King2008-08-022-2/+2
| | | | | | | Move platform independent header files to arch/arm/include/asm, leaving those in asm/arch* and asm/plat* alone. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [ARM] cache align memset and memzeroNicolas Pitre2008-06-222-0/+90
| | | | | | | | This is a natural extension following the previous patch. Non Feroceon based targets are unchanged. Signed-off-by: Nicolas Pitre <nico@marvell.com> Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
* [ARM] cache align destination pointer when copying memory for some processorsNicolas Pitre2008-06-222-20/+4
| | | | | | | | | | | | | | | The implementation for memory copy functions on ARM had a (disabled) provision for aligning the source pointer before loading registers with data. Turns out that aligning the _destination_ pointer is much more useful, as the read side is already sufficiently helped with the use of preload. So this changes the definition of the CALGN() macro to target the destination pointer instead, and turns it on for Feroceon processors where the gain is very noticeable. Signed-off-by: Nicolas Pitre <nico@marvell.com> Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
* [ARM] fix cache alignment code in memset.SNicolas Pitre2008-06-221-1/+1
| | | | | | | This code is currently disabled, which explains why no one was affected. Signed-off-by: Nicolas Pitre <nico@marvell.com> Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
* [ARM] spelling fixesSimon Arlott2007-05-201-1/+1
| | | | | | | Spelling fixes in arch/arm/. Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
generated by cgit v1.1 at 2024-12-27 05:43:35 +0000