kernel/git/stable/linux.git/arch/nios2, branch linux-4.6.y

nios2: memset: use the right constraint modifier for the %4 output operand

2016-04-27T08:35:55+00:00

Depending on the size of the area to be memset'ed, the nios2 memset implementation either uses a naive loop (for buffers smaller or equal than 8 bytes) or a more optimized implementation (for buffers larger than 8 bytes). This implementation does 4-byte stores rather than 1-byte stores to speed up memset. However, we discovered that on our nios2 platform, memset() was not properly setting the buffer to the expected value. A memset of 0xff would not set the entire buffer to 0xff, but to: 0xff 0x00 0xff 0x00 0xff 0x00 0xff 0x00 ... Which is obviously incorrect. Our investigation has revealed that the problem lies in the incorrect constraints used in the inline assembly. The following piece of assembly, from the nios2 memset implementation, is supposed to create a 4-byte value that repeats 4 times the 1-byte pattern passed as memset argument: /* fill8 %3, %5 (c & 0xff) */ " slli %4, %5, 8\n" " or %4, %4, %5\n" " slli %3, %4, 16\n" " or %3, %3, %4\n" However, depending on the compiler and optimization level, this code might be compiled as: 34: 280a923a slli r5,r5,8 38: 294ab03a or r5,r5,r5 3c: 2808943a slli r4,r5,16 40: 2148b03a or r4,r4,r5 This is wrong because r5 gets used both for %5 and %4, which leads to the final pattern stored in r4 to be 0xff00ff00 rather than the expected 0xffffffff. %4 is defined with the "=r" constraint, i.e as an output operand. However, as explained in http://www.ethernut.de/en/documents/arm-inline-asm.html, this does not prevent gcc from using the same register for an output operand (%4) and input operand (%5). By using the constraint modifier '&', we indicate that the register should be used for output only. With this change, we get the following assembly output: 34: 2810923a slli r8,r5,8 38: 4150b03a or r8,r8,r5 3c: 400e943a slli r7,r8,16 40: 3a0eb03a or r7,r7,r8 Which correctly produces the 0xffffffff pattern when 0xff is passed as the memset() pattern. It is worth mentioning the observed consequence of this bug: we were hitting the kernel BUG() in mm/bootmem.c:__free() that verifies when marking a page as free that it was previously marked as occupied (i.e that the bit was set to 1). The entire bootmem bitmap is set to 0xff bit via a memset() during the bootmem initialization. The bootmem_free() call right after the initialization was finding some bits to be set to 0, which didn't make sense since the bitmap has just been memset'ed to 0xff. Except that due to the bug explained above, the bitmap was in fact initialized to 0xff00ff00. Thanks to Marek Vasut for his help and feedback. Signed-off-by: Romain Perier Acked-by: Marek Vasut Acked-by: Ley Foon Tan

nios2: Replace fdt_translate_address with of_flat_dt_translate_address

2016-03-31T00:15:45+00:00

nios2 builds fail with the following build error. arch/nios2/kernel/prom.c: In function 'early_init_dt_scan_serial': arch/nios2/kernel/prom.c:100:2: error: implicit declaration of function 'fdt_translate_address' Commit c90fe9c0394b ("of: earlycon: Move address translation to of_setup_earlycon()") replaced fdt_translate_address() with of_flat_dt_translate_address() but missed updating the nios2 code. Fixes: c90fe9c0394b ("of: earlycon: Move address translation to of_setup_earlycon()") Cc: Peter Hurley Cc: Rob Herring Signed-off-by: Guenter Roeck Acked-by: Ley Foon Tan

arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections

2016-03-25T23:37:42+00:00

KASAN needs to know whether the allocation happens in an IRQ handler. This lets us strip everything below the IRQ entry point to reduce the number of unique stack traces needed to be stored. Move the definition of __irq_entry to so that the users don't need to pull in . Also introduce the __softirq_entry macro which is similar to __irq_entry, but puts the corresponding functions to the .softirqentry.text section. Signed-off-by: Alexander Potapenko Acked-by: Steven Rostedt Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Cc: Andrey Konovalov Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: Konstantin Serebryany Cc: Dmitry Chernenkov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ipv4: Update parameters for csum_tcpudp_magic to their original types

2016-03-14T03:55:13+00:00

This patch updates all instances of csum_tcpudp_magic and csum_tcpudp_nofold to reflect the types that are usually used as the source inputs. For example the protocol field is populated based on nexthdr which is actually an unsigned 8 bit value. The length is usually populated based on skb->len which is an unsigned integer. This addresses an issue in which the IPv6 function csum_ipv6_magic was generating a checksum using the full 32b of skb->len while csum_tcpudp_magic was only using the lower 16 bits. As a result we could run into issues when attempting to adjust the checksum as there was no protocol agnostic way to update it. With this change the value is still truncated as many architectures use "(len + proto) << 8", however this truncation only occurs for values greater than 16776960 in length and as such is unlikely to occur as we stop the inner headers at ~64K in size. I did have to make a few minor changes in the arm, mn10300, nios2, and score versions of the function in order to support these changes as they were either using things such as an OR to combine the protocol and length, or were using ntohs to convert the length which would have truncated the value. I also updated a few spots in terms of whitespace and type differences for the addresses. Most of this was just to make sure all of the definitions were in sync going forward. Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller

dma-mapping: always provide the dma_map_ops based implementation

2016-01-21T01:09:18+00:00

Move the generic implementation to now that all architectures support it and remove the HAVE_DMA_ATTR Kconfig symbol now that everyone supports them. [valentinrothberg@gmail.com: remove leftovers in Kconfig] Signed-off-by: Christoph Hellwig Cc: "David S. Miller" Cc: Aurelien Jacquiot Cc: Chris Metcalf Cc: David Howells Cc: Geert Uytterhoeven Cc: Haavard Skinnemoen Cc: Hans-Christian Egtvedt Cc: Helge Deller Cc: James Hogan Cc: Jesper Nilsson Cc: Koichi Yasutake Cc: Ley Foon Tan Cc: Mark Salter Cc: Mikael Starvik Cc: Steven Miao Cc: Vineet Gupta Cc: Christian Borntraeger Cc: Joerg Roedel Cc: Sebastian Ott Signed-off-by: Valentin Rothberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

nios2: convert to dma_map_ops

2016-01-21T01:09:18+00:00

Signed-off-by: Christoph Hellwig Cc: Ley Foon Tan Cc: Christian Borntraeger Cc: Joerg Roedel Cc: Sebastian Ott Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

nios2: fix cache coherency

2015-11-26T14:25:58+00:00

There is intermittent cache coherency issue caught in toolchian tests. Revert to use flushd. Signed-off-by: Ley Foon Tan

Merge tag 'nios2-v4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2

2015-11-10T00:36:10+00:00

Pull nios2 updates from Ley Foon Tan: - nios2: Remove unnecessary #ifdef guards - nios2: Switch to generic __xchg() - nios2: Fix unused variable warning * tag 'nios2-v4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2: nios2: Remove unnecessary #ifdef guards nios2: Switch to generic __xchg() nios2: Fix unused variable warning

nios2: Remove unnecessary #ifdef guards

2015-11-09T02:33:30+00:00

__HAVE_ARCH_MEMMOVE and __HAVE_ARCH_MEMSET are unconditionally defined for nios2, so there is no need to protect the function definitions of memmove() and memset(). Signed-off-by: Tobias Klauser Acked-by: Ley Foon Tan

nios2: Switch to generic __xchg()

2015-11-09T02:33:30+00:00

The generic __xchg() implementation present in asm-generic/cmpxchg.h is correct on nios2 and even generates the same code. Switch to this generic implementation to trim down the amount of ad-hoc copies of the code. Signed-off-by: Marek Vasut Acked-by: Ley Foon Tan