linux/arch/powerpc/lib, branch v3.13.11

powerpc: Make 64-bit non-VMX __copy_tofrom_user bi-endian

2013-12-30T03:02:30Z

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 Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt

powerpc: Add VMX optimised xor for RAID5

2013-10-30T05:02:28Z

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 Signed-off-by: Benjamin Herrenschmidt

powerpc: Fix Unaligned LE Floating Point Loads and Stores

2013-10-30T05:01:36Z

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 Signed-off-by: Benjamin Herrenschmidt

powerpc: Fix Unaligned Loads and Stores

2013-10-30T05:01:30Z

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 Signed-off-by: Benjamin Herrenschmidt

powerpc: Use generic memcpy code in little endian

2013-10-11T05:48:40Z

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 Signed-off-by: Benjamin Herrenschmidt

powerpc: Use generic checksum code in little endian

2013-10-11T05:48:39Z

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 Signed-off-by: Benjamin Herrenschmidt

powerpc: Fix endian issues in VMX copy loops

2013-10-11T05:48:25Z

Fix the permute loops for little endian. Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt

powerpc: Restore registers on error exit from csum_partial_copy_generic()

2013-10-03T07:22:42Z

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 Signed-off-by: Anton Blanchard Cc: stable@vger.kernel.org Signed-off-by: Benjamin Herrenschmidt

powerpc: Fix parameter clobber in csum_partial_copy_generic()

2013-10-03T07:22:36Z

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 Signed-off-by: Anton Blanchard Cc: stable@vger.kernel.org Signed-off-by: Benjamin Herrenschmidt

powerpc: Remove ksp_limit on ppc64

2013-09-25T04:15:51Z

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