kernel/linux.git/arch/arc/include, branch linux-4.20.y

ARC: fix __ffs return value to avoid build warnings

2019-03-05T16:59:38+00:00

[ Upstream commit 4e868f8419cb4cb558c5d428e7ab5629cef864c7 ] | CC mm/nobootmem.o |In file included from ./include/asm-generic/bug.h:18:0, | from ./arch/arc/include/asm/bug.h:32, | from ./include/linux/bug.h:5, | from ./include/linux/mmdebug.h:5, | from ./include/linux/gfp.h:5, | from ./include/linux/slab.h:15, | from mm/nobootmem.c:14: |mm/nobootmem.c: In function '__free_pages_memory': |./include/linux/kernel.h:845:29: warning: comparison of distinct pointer types lacks a cast | (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1))) | ^ |./include/linux/kernel.h:859:4: note: in expansion of macro '__typecheck' | (__typecheck(x, y) && __no_side_effects(x, y)) | ^~~~~~~~~~~ |./include/linux/kernel.h:869:24: note: in expansion of macro '__safe_cmp' | __builtin_choose_expr(__safe_cmp(x, y), \ | ^~~~~~~~~~ |./include/linux/kernel.h:878:19: note: in expansion of macro '__careful_cmp' | #define min(x, y) __careful_cmp(x, y, <) | ^~~~~~~~~~~~~ |mm/nobootmem.c:104:11: note: in expansion of macro 'min' | order = min(MAX_ORDER - 1UL, __ffs(start)); Change __ffs return value from 'int' to 'unsigned long' as it is done in other implementations (like asm-generic, x86, etc...) to avoid build-time warnings in places where type is strictly checked. As __ffs may return values in [0-31] interval changing return type to unsigned is valid. Signed-off-by: Eugeniy Paltsev Signed-off-by: Vineet Gupta Signed-off-by: Sasha Levin

ARC: define ARCH_SLAB_MINALIGN = 8

2019-02-27T09:09:55+00:00

commit b6835ea77729e7faf4656ca637ba53f42b8ee3fd upstream. The default value of ARCH_SLAB_MINALIGN in "include/linux/slab.h" is "__alignof__(unsigned long long)" which for ARC unexpectedly turns out to be 4. This is not a compiler bug, but as defined by ARC ABI [1] Thus slab allocator would allocate a struct which is 32-bit aligned, which is generally OK even if struct has long long members. There was however potetial problem when it had any atomic64_t which use LLOCKD/SCONDD instructions which are required by ISA to take 64-bit addresses. This is the problem we ran into [ 4.015732] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null) [ 4.167881] Misaligned Access [ 4.172356] Path: /bin/busybox.nosuid [ 4.176004] CPU: 2 PID: 171 Comm: rm Not tainted 4.19.14-yocto-standard #1 [ 4.182851] [ 4.182851] [ECR ]: 0x000d0000 => Check Programmer's Manual [ 4.190061] [EFA ]: 0xbeaec3fc [ 4.190061] [BLINK ]: ext4_delete_entry+0x210/0x234 [ 4.190061] [ERET ]: ext4_delete_entry+0x13e/0x234 [ 4.202985] [STAT32]: 0x80080002 : IE K [ 4.207236] BTA: 0x9009329c SP: 0xbe5b1ec4 FP: 0x00000000 [ 4.212790] LPS: 0x9074b118 LPE: 0x9074b120 LPC: 0x00000000 [ 4.218348] r00: 0x00000040 r01: 0x00000021 r02: 0x00000001 ... ... [ 4.270510] Stack Trace: [ 4.274510] ext4_delete_entry+0x13e/0x234 [ 4.278695] ext4_rmdir+0xe0/0x238 [ 4.282187] vfs_rmdir+0x50/0xf0 [ 4.285492] do_rmdir+0x9e/0x154 [ 4.288802] EV_Trap+0x110/0x114 The fix is to make sure slab allocations are 64-bit aligned. Do note that atomic64_t is __attribute__((aligned(8)) which means gcc does generate 64-bit aligned references, relative to beginning of container struct. However the issue is if the container itself is not 64-bit aligned, atomic64_t ends up unaligned which is what this patch ensures. [1] https://github.com/foss-for-synopsys-dwc-arc-processors/toolchain/wiki/files/ARCv2_ABI.pdf Signed-off-by: Alexey Brodkin Cc: # 4.8+ Signed-off-by: Vineet Gupta [vgupta: reworked changelog, added dependency on LL64+LLSC] Signed-off-by: Greg Kroah-Hartman

ARC: perf: map generic branches to correct hardware condition

2019-01-31T07:15:38+00:00

commit 3affbf0e154ee351add6fcc254c59c3f3947fa8f upstream. So far we've mapped branches to "ijmp" which also counts conditional branches NOT taken. This makes us different from other architectures such as ARM which seem to be counting only taken branches. So use "ijmptak" hardware condition which only counts (all jump instructions that are taken) 'ijmptak' event is available on both ARCompact and ARCv2 ISA based cores. Signed-off-by: Eugeniy Paltsev Cc: stable@vger.kernel.org Signed-off-by: Vineet Gupta [vgupta: reworked changelog] Signed-off-by: Greg Kroah-Hartman

ARC: io.h: Implement reads{x}()/writes{x}()

2018-11-30T19:26:29+00:00

Some ARC CPU's do not support unaligned loads/stores. Currently, generic implementation of reads{b/w/l}()/writes{b/w/l}() is being used with ARC. This can lead to misfunction of some drivers as generic functions do a plain dereference of a pointer that can be unaligned. Let's use {get/put}_unaligned() helpers instead of plain dereference of pointer in order to fix. The helpers allow to get and store data from an unaligned address whilst preserving the CPU internal alignment. According to [1], the use of these helpers are costly in terms of performance so we added an initial check for a buffer already aligned so that the usage of the helpers can be avoided, when possible. [1] Documentation/unaligned-memory-access.txt Cc: Alexey Brodkin Cc: Joao Pinto Cc: David Laight Tested-by: Vitor Soares Signed-off-by: Jose Abreu Signed-off-by: Vineet Gupta

ARC: IOC: panic if kernel was started with previously enabled IOC

2018-11-12T18:38:27+00:00

If IOC was already enabled (due to bootloader) it technically needs to be reconfigured with aperture base,size corresponding to Linux memory map which will certainly be different than uboot's. But disabling and reenabling IOC when DMA might be potentially active is tricky business. To avoid random memory issues later, just panic here and ask user to upgrade bootloader to one which doesn't enable IOC This was actually seen as issue on some of the HSDK board with a version of uboot which enabled IOC. There were random issues later with starting of X or peripherals etc. Also while I'm at it, replace hardcoded bits in ARC_REG_IO_COH_PARTIAL and ARC_REG_IO_COH_ENABLE registers by definitions. Inspired by: https://lkml.org/lkml/2018/1/19/557 Signed-off-by: Eugeniy Paltsev Signed-off-by: Vineet Gupta

treewide: remove current_text_addr

2018-10-31T15:54:12+00:00

Prefer _THIS_IP_ defined in linux/kernel.h. Most definitions of current_text_addr were the same as _THIS_IP_, but a few archs had inline assembly instead. This patch removes the final call site of current_text_addr, making all of the definitions dead code. [akpm@linux-foundation.org: fix arch/csky/include/asm/processor.h] Link: http://lkml.kernel.org/r/20180911182413.180715-1-ndesaulniers@google.com Signed-off-by: Nick Desaulniers Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-10-25T18:14:36+00:00

Pull timekeeping updates from Thomas Gleixner: "The timers and timekeeping departement provides: - Another large y2038 update with further preparations for providing the y2038 safe timespecs closer to the syscalls. - An overhaul of the SHCMT clocksource driver - SPDX license identifier updates - Small cleanups and fixes all over the place" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits) tick/sched : Remove redundant cpu_online() check clocksource/drivers/dw_apb: Add reset control clocksource: Remove obsolete CLOCKSOURCE_OF_DECLARE clocksource/drivers: Unify the names to timer-* format clocksource/drivers/sh_cmt: Add R-Car gen3 support dt-bindings: timer: renesas: cmt: document R-Car gen3 support clocksource/drivers/sh_cmt: Properly line-wrap sh_cmt_of_table[] initializer clocksource/drivers/sh_cmt: Fix clocksource width for 32-bit machines clocksource/drivers/sh_cmt: Fixup for 64-bit machines clocksource/drivers/sh_tmu: Convert to SPDX identifiers clocksource/drivers/sh_mtu2: Convert to SPDX identifiers clocksource/drivers/sh_cmt: Convert to SPDX identifiers clocksource/drivers/renesas-ostm: Convert to SPDX identifiers clocksource: Convert to using %pOFn instead of device_node.name tick/broadcast: Remove redundant check RISC-V: Request newstat syscalls y2038: signal: Change rt_sigtimedwait to use __kernel_timespec y2038: socket: Change recvmmsg to use __kernel_timespec y2038: sched: Change sched_rr_get_interval to use __kernel_timespec y2038: utimes: Rework #ifdef guards for compat syscalls ...

ARC: dma [IOC] Enable per device io coherency

2018-09-04T20:21:37+00:00

So far the IOC treatment was global on ARC, being turned on (or off) for all devices in the system. With this patch, this can now be done per device using the "dma-coherent" DT property; IOW with this patch we can use both HW-coherent and regular DMA peripherals simultaneously. The changes involved are too many so enlisting the summary below: 1. common code calls ARC arch_setup_dma_ops() per device. 2. For coherent dma (IOC) it plugs in generic @dma_direct_ops which doesn't need any arch specific backend: No need for any explicit cache flushes or MMU mappings to provide for uncached access - dma_(map|sync)_single* return early as corresponding dma ops callbacks are NULL in generic code. So arch_sync_dma_*() -> dma_cache_*() need not handle the coherent dma case, hence drop ARC __dma_cache_*_ioc() which were no-op anyways 3. For noncoherent dma (non IOC) generic @dma_noncoherent_ops is used which in turns calls ARC specific routines - arch_dma_alloc() no longer checks for @ioc_enable since this is called only for !IOC case. Reviewed-by: Christoph Hellwig Signed-off-by: Eugeniy Paltsev Signed-off-by: Vineet Gupta [vgupta: rewrote changelog]

ARC: atomics: unbork atomic_fetch_##op()

2018-08-31T17:14:51+00:00

In 4.19-rc1, Eugeniy reported weird boot and IO errors on ARC HSDK | INFO: task syslogd:77 blocked for more than 10 seconds. | Not tainted 4.19.0-rc1-00007-gf213acea4e88 #40 | "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this | message. | syslogd D 0 77 76 0x00000000 | | Stack Trace: | __switch_to+0x0/0xac | __schedule+0x1b2/0x730 | io_schedule+0x5c/0xc0 | __lock_page+0x98/0xdc | find_lock_entry+0x38/0x100 | shmem_getpage_gfp.isra.3+0x82/0xbfc | shmem_fault+0x46/0x138 | handle_mm_fault+0x5bc/0x924 | do_page_fault+0x100/0x2b8 | ret_from_exception+0x0/0x8 He bisected to 84c6591103db ("locking/atomics, asm-generic/bitops/lock.h: Rewrite using atomic_fetch_*()") This commit however only unmasked the real issue introduced by commit 4aef66c8ae9 ("locking/atomic, arch/arc: Fix build") which missed the retry-if-scond-failed branch in atomic_fetch_##op() macros. The bisected commit started using atomic_fetch_##op() macros for building the rest of atomics. Fixes: 4aef66c8ae9 ("locking/atomic, arch/arc: Fix build") Reported-by: Eugeniy Paltsev Acked-by: Peter Zijlstra (Intel) Signed-off-by: Will Deacon Signed-off-by: Vineet Gupta [vgupta: wrote changelog]

y2038: Remove stat64 family from default syscall set

2018-08-29T13:42:20+00:00

New architectures should no longer need stat64, which is not y2038 safe and has been replaced by statx(). This removes the 'select __ARCH_WANT_STAT64' statement from asm-generic/unistd.h and instead moves it into the respective asm/unistd.h UAPI header files for each architecture that uses it today. In the generic file, the system call number and entry points are now made conditional, so newly added architectures (e.g. riscv32 or csky) will never need to carry backwards compatiblity for it. arm64 is the only 64-bit architecture using the asm-generic/unistd.h file, and it already sets __ARCH_WANT_NEW_STAT in its headers, and I use the same #ifdef here: future 64-bit architectures therefore won't see newstat or stat64 any more. They don't suffer from the y2038 time_t overflow, but for consistency it seems best to also let them use statx(). Signed-off-by: Arnd Bergmann