1. 09 5月, 2015 2 次提交
    • S
      sched: always use blk_schedule_flush_plug in io_schedule_out · 5596d0d5
      Shaohua Li 提交于
      block plug callback could sleep, so we introduce a parameter
      'from_schedule' and corresponding drivers can use it to destinguish a
      schedule plug flush or a plug finish. Unfortunately io_schedule_out
      still uses blk_flush_plug(). This causes below output (Note, I added a
      might_sleep() in raid1_unplug to make it trigger faster, but the whole
      thing doesn't matter if I add might_sleep). In raid1/10, this can cause
      deadlock.
      
      This patch makes io_schedule_out always uses blk_schedule_flush_plug.
      This should only impact drivers (as far as I know, raid 1/10) which are
      sensitive to the 'from_schedule' parameter.
      
      [  370.817949] ------------[ cut here ]------------
      [  370.817960] WARNING: CPU: 7 PID: 145 at ../kernel/sched/core.c:7306 __might_sleep+0x7f/0x90()
      [  370.817969] do not call blocking ops when !TASK_RUNNING; state=2 set at [<ffffffff81092fcf>] prepare_to_wait+0x2f/0x90
      [  370.817971] Modules linked in: raid1
      [  370.817976] CPU: 7 PID: 145 Comm: kworker/u16:9 Tainted: G        W       4.0.0+ #361
      [  370.817977] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140709_153802- 04/01/2014
      [  370.817983] Workqueue: writeback bdi_writeback_workfn (flush-9:1)
      [  370.817985]  ffffffff81cd83be ffff8800ba8cb298 ffffffff819dd7af 0000000000000001
      [  370.817988]  ffff8800ba8cb2e8 ffff8800ba8cb2d8 ffffffff81051afc ffff8800ba8cb2c8
      [  370.817990]  ffffffffa00061a8 000000000000041e 0000000000000000 ffff8800ba8cba28
      [  370.817993] Call Trace:
      [  370.817999]  [<ffffffff819dd7af>] dump_stack+0x4f/0x7b
      [  370.818002]  [<ffffffff81051afc>] warn_slowpath_common+0x8c/0xd0
      [  370.818004]  [<ffffffff81051b86>] warn_slowpath_fmt+0x46/0x50
      [  370.818006]  [<ffffffff81092fcf>] ? prepare_to_wait+0x2f/0x90
      [  370.818008]  [<ffffffff81092fcf>] ? prepare_to_wait+0x2f/0x90
      [  370.818010]  [<ffffffff810776ef>] __might_sleep+0x7f/0x90
      [  370.818014]  [<ffffffffa0000c03>] raid1_unplug+0xd3/0x170 [raid1]
      [  370.818024]  [<ffffffff81421d9a>] blk_flush_plug_list+0x8a/0x1e0
      [  370.818028]  [<ffffffff819e3550>] ? bit_wait+0x50/0x50
      [  370.818031]  [<ffffffff819e21b0>] io_schedule_timeout+0x130/0x140
      [  370.818033]  [<ffffffff819e3586>] bit_wait_io+0x36/0x50
      [  370.818034]  [<ffffffff819e31b5>] __wait_on_bit+0x65/0x90
      [  370.818041]  [<ffffffff8125b67c>] ? ext4_read_block_bitmap_nowait+0xbc/0x630
      [  370.818043]  [<ffffffff819e3550>] ? bit_wait+0x50/0x50
      [  370.818045]  [<ffffffff819e3302>] out_of_line_wait_on_bit+0x72/0x80
      [  370.818047]  [<ffffffff810935e0>] ? autoremove_wake_function+0x40/0x40
      [  370.818050]  [<ffffffff811de744>] __wait_on_buffer+0x44/0x50
      [  370.818053]  [<ffffffff8125ae80>] ext4_wait_block_bitmap+0xe0/0xf0
      [  370.818058]  [<ffffffff812975d6>] ext4_mb_init_cache+0x206/0x790
      [  370.818062]  [<ffffffff8114bc6c>] ? lru_cache_add+0x1c/0x50
      [  370.818064]  [<ffffffff81297c7e>] ext4_mb_init_group+0x11e/0x200
      [  370.818066]  [<ffffffff81298231>] ext4_mb_load_buddy+0x341/0x360
      [  370.818068]  [<ffffffff8129a1a3>] ext4_mb_find_by_goal+0x93/0x2f0
      [  370.818070]  [<ffffffff81295b54>] ? ext4_mb_normalize_request+0x1e4/0x5b0
      [  370.818072]  [<ffffffff8129ab67>] ext4_mb_regular_allocator+0x67/0x460
      [  370.818074]  [<ffffffff81295b54>] ? ext4_mb_normalize_request+0x1e4/0x5b0
      [  370.818076]  [<ffffffff8129ca4b>] ext4_mb_new_blocks+0x4cb/0x620
      [  370.818079]  [<ffffffff81290956>] ext4_ext_map_blocks+0x4c6/0x14d0
      [  370.818081]  [<ffffffff812a4d4e>] ? ext4_es_lookup_extent+0x4e/0x290
      [  370.818085]  [<ffffffff8126399d>] ext4_map_blocks+0x14d/0x4f0
      [  370.818088]  [<ffffffff81266fbd>] ext4_writepages+0x76d/0xe50
      [  370.818094]  [<ffffffff81149691>] do_writepages+0x21/0x50
      [  370.818097]  [<ffffffff811d5c00>] __writeback_single_inode+0x60/0x490
      [  370.818099]  [<ffffffff811d630a>] writeback_sb_inodes+0x2da/0x590
      [  370.818103]  [<ffffffff811abf4b>] ? trylock_super+0x1b/0x50
      [  370.818105]  [<ffffffff811abf4b>] ? trylock_super+0x1b/0x50
      [  370.818107]  [<ffffffff811d665f>] __writeback_inodes_wb+0x9f/0xd0
      [  370.818109]  [<ffffffff811d69db>] wb_writeback+0x34b/0x3c0
      [  370.818111]  [<ffffffff811d70df>] bdi_writeback_workfn+0x23f/0x550
      [  370.818116]  [<ffffffff8106bbd8>] process_one_work+0x1c8/0x570
      [  370.818117]  [<ffffffff8106bb5b>] ? process_one_work+0x14b/0x570
      [  370.818119]  [<ffffffff8106c09b>] worker_thread+0x11b/0x470
      [  370.818121]  [<ffffffff8106bf80>] ? process_one_work+0x570/0x570
      [  370.818124]  [<ffffffff81071868>] kthread+0xf8/0x110
      [  370.818126]  [<ffffffff81071770>] ? kthread_create_on_node+0x210/0x210
      [  370.818129]  [<ffffffff819e9322>] ret_from_fork+0x42/0x70
      [  370.818131]  [<ffffffff81071770>] ? kthread_create_on_node+0x210/0x210
      [  370.818132] ---[ end trace 7b4deb71e68b6605 ]---
      
      V2: don't change ->in_iowait
      
      Cc: NeilBrown <neilb@suse.de>
      Signed-off-by: NShaohua Li <shli@fb.com>
      Reviewed-by: NJeff Moyer <jmoyer@redhat.com>
      Signed-off-by: NJens Axboe <axboe@fb.com>
      5596d0d5
    • S
      blk: clean up plug · dd6cf3e1
      Shaohua Li 提交于
      Current code looks like inner plug gets flushed with a
      blk_finish_plug(). Actually it's a nop. All requests/callbacks are added
      to current->plug, while only outmost plug is assigned to current->plug.
      So inner plug always has empty request/callback list, which makes
      blk_flush_plug_list() a nop. This tries to make the code more clear.
      Signed-off-by: NShaohua Li <shli@fb.com>
      Reviewed-by: NJeff Moyer <jmoyer@redhat.com>
      Reviewed-by: NChristoph Hellwig <hch@lst.de>
      Signed-off-by: NJens Axboe <axboe@fb.com>
      dd6cf3e1
  2. 06 5月, 2015 9 次提交
  3. 05 5月, 2015 1 次提交
  4. 04 5月, 2015 10 次提交
    • Á
      hwrng: bcm63xx - Fix driver compilation · f440c4ee
      Álvaro Fernández Rojas 提交于
      - s/clk_didsable_unprepare/clk_disable_unprepare
      - s/prov/priv
      - s/error/ret (bcm63xx_rng_probe)
      
      Fixes: 6229c160 ("hwrng: bcm63xx - make use of devm_hwrng_register")
      Signed-off-by: NÁlvaro Fernández Rojas <noltari@gmail.com>
      Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
      Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
      f440c4ee
    • D
      lib: make memzero_explicit more robust against dead store elimination · 7829fb09
      Daniel Borkmann 提交于
      In commit 0b053c95 ("lib: memzero_explicit: use barrier instead
      of OPTIMIZER_HIDE_VAR"), we made memzero_explicit() more robust in
      case LTO would decide to inline memzero_explicit() and eventually
      find out it could be elimiated as dead store.
      
      While using barrier() works well for the case of gcc, recent efforts
      from LLVMLinux people suggest to use llvm as an alternative to gcc,
      and there, Stephan found in a simple stand-alone user space example
      that llvm could nevertheless optimize and thus elimitate the memset().
      A similar issue has been observed in the referenced llvm bug report,
      which is regarded as not-a-bug.
      
      Based on some experiments, icc is a bit special on its own, while it
      doesn't seem to eliminate the memset(), it could do so with an own
      implementation, and then result in similar findings as with llvm.
      
      The fix in this patch now works for all three compilers (also tested
      with more aggressive optimization levels). Arguably, in the current
      kernel tree it's more of a theoretical issue, but imho, it's better
      to be pedantic about it.
      
      It's clearly visible with gcc/llvm though, with the below code: if we
      would have used barrier() only here, llvm would have omitted clearing,
      not so with barrier_data() variant:
      
        static inline void memzero_explicit(void *s, size_t count)
        {
          memset(s, 0, count);
          barrier_data(s);
        }
      
        int main(void)
        {
          char buff[20];
          memzero_explicit(buff, sizeof(buff));
          return 0;
        }
      
        $ gcc -O2 test.c
        $ gdb a.out
        (gdb) disassemble main
        Dump of assembler code for function main:
         0x0000000000400400  <+0>: lea   -0x28(%rsp),%rax
         0x0000000000400405  <+5>: movq  $0x0,-0x28(%rsp)
         0x000000000040040e <+14>: movq  $0x0,-0x20(%rsp)
         0x0000000000400417 <+23>: movl  $0x0,-0x18(%rsp)
         0x000000000040041f <+31>: xor   %eax,%eax
         0x0000000000400421 <+33>: retq
        End of assembler dump.
      
        $ clang -O2 test.c
        $ gdb a.out
        (gdb) disassemble main
        Dump of assembler code for function main:
         0x00000000004004f0  <+0>: xorps  %xmm0,%xmm0
         0x00000000004004f3  <+3>: movaps %xmm0,-0x18(%rsp)
         0x00000000004004f8  <+8>: movl   $0x0,-0x8(%rsp)
         0x0000000000400500 <+16>: lea    -0x18(%rsp),%rax
         0x0000000000400505 <+21>: xor    %eax,%eax
         0x0000000000400507 <+23>: retq
        End of assembler dump.
      
      As gcc, clang, but also icc defines __GNUC__, it's sufficient to define
      this in compiler-gcc.h only to be picked up. For a fallback or otherwise
      unsupported compiler, we define it as a barrier. Similarly, for ecc which
      does not support gcc inline asm.
      
      Reference: https://llvm.org/bugs/show_bug.cgi?id=15495Reported-by: NStephan Mueller <smueller@chronox.de>
      Tested-by: NStephan Mueller <smueller@chronox.de>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Cc: Stephan Mueller <smueller@chronox.de>
      Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
      Cc: mancha security <mancha1@zoho.com>
      Cc: Mark Charlebois <charlebm@gmail.com>
      Cc: Behan Webster <behanw@converseincode.com>
      Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
      7829fb09
    • L
      Linux 4.1-rc2 · 5ebe6afa
      Linus Torvalds 提交于
      5ebe6afa
    • L
      Merge tag 'for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 · 8663da2c
      Linus Torvalds 提交于
      Pull ext4 fixes from Ted Ts'o:
       "Some miscellaneous bug fixes and some final on-disk and ABI changes
        for ext4 encryption which provide better security and performance"
      
      * tag 'for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
        ext4: fix growing of tiny filesystems
        ext4: move check under lock scope to close a race.
        ext4: fix data corruption caused by unwritten and delayed extents
        ext4 crypto: remove duplicated encryption mode definitions
        ext4 crypto: do not select from EXT4_FS_ENCRYPTION
        ext4 crypto: add padding to filenames before encrypting
        ext4 crypto: simplify and speed up filename encryption
      8663da2c
    • L
      Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux · 101a6fd3
      Linus Torvalds 提交于
      Pull drm fixes from Dave Airlie:
       "One intel fix, one rockchip fix, and a bunch of radeon fixes for some
        regressions from audio rework and vm stability"
      
      * 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
        drm/i915/chv: Implement WaDisableShadowRegForCpd
        drm/radeon: fix userptr return value checking (v2)
        drm/radeon: check new address before removing old one
        drm/radeon: reset BOs address after clearing it.
        drm/radeon: fix lockup when BOs aren't part of the VM on release
        drm/radeon: add SI DPM quirk for Sapphire R9 270 Dual-X 2G GDDR5
        drm/radeon: adjust pll when audio is not enabled
        drm/radeon: only enable audio streams if the monitor supports it
        drm/radeon: only mark audio as connected if the monitor supports it (v3)
        drm/radeon/audio: don't enable packets until the end
        drm/radeon: drop dce6_dp_enable
        drm/radeon: fix ordering of AVI packet setup
        drm/radeon: Use drm_calloc_ab for CS relocs
        drm/rockchip: fix error check when getting irq
        MAINTAINERS: add entry for Rockchip drm drivers
      101a6fd3
    • D
      Merge tag 'drm-intel-fixes-2015-04-30' of git://anongit.freedesktop.org/drm-intel into drm-fixes · 71aee819
      Dave Airlie 提交于
      Just a single intel fix
      * tag 'drm-intel-fixes-2015-04-30' of git://anongit.freedesktop.org/drm-intel:
        drm/i915/chv: Implement WaDisableShadowRegForCpd
      71aee819
    • D
      Merge branch 'drm-next0420' of https://github.com/markyzq/kernel-drm-rockchip into drm-fixes · df9ebeb2
      Dave Airlie 提交于
      one fix and maintainers update
      * 'drm-next0420' of https://github.com/markyzq/kernel-drm-rockchip:
        drm/rockchip: fix error check when getting irq
        MAINTAINERS: add entry for Rockchip drm drivers
      df9ebeb2
    • L
      Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi · 61f06db0
      Linus Torvalds 提交于
      Pull SCSI fixes from James Bottomley:
       "This is three logical fixes (as 5 patches).
      
        The 3ware class of drivers were causing an oops with multiqueue by
        tearing down the command mappings after completing the command (where
        the variables in the command used to tear down the mapping were
        no-longer valid).  There's also a fix for the qnap iscsi target which
        was choking on us sending it commands that were too long and a fix for
        the reworked aha1542 allocating GFP_KERNEL under a lock"
      
      * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
        3w-9xxx: fix command completion race
        3w-xxxx: fix command completion race
        3w-sas: fix command completion race
        aha1542: Allocate memory before taking a lock
        SCSI: add 1024 max sectors black list flag
      61f06db0
    • L
      Merge branch 'next' of git://git.infradead.org/users/vkoul/slave-dma · 33332224
      Linus Torvalds 提交于
      Pull slave dmaengine fixes from Vinod Koul:
       "Here are the fixes in dmaengine subsystem for rc2:
      
         - privatecnt fix for slave dma request API by Christopher
      
         - warn fix for PM ifdef in usb-dmac by Geert
      
         - fix hardware dependency for xgene by Jean"
      
      * 'next' of git://git.infradead.org/users/vkoul/slave-dma:
        dmaengine: increment privatecnt when using dma_get_any_slave_channel
        dmaengine: xgene: Set hardware dependency
        dmaengine: usb-dmac: Protect PM-only functions to kill warning
      33332224
    • L
      Merge tag 'powerpc-4.1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux · 180d89f6
      Linus Torvalds 提交于
      Pull powerpc fixes from Michael Ellerman:
       - build fix for SMP=n in book3s_xics.c
       - fix for Daniel's pci_controller_ops on powernv.
       - revert the TM syscall abort patch for now.
       - CPU affinity fix from Nathan.
       - two EEH fixes from Gavin.
       - fix for CR corruption from Sam.
       - selftest build fix.
      
      * tag 'powerpc-4.1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux:
        powerpc/powernv: Restore non-volatile CRs after nap
        powerpc/eeh: Delay probing EEH device during hotplug
        powerpc/eeh: Fix race condition in pcibios_set_pcie_reset_state()
        powerpc/pseries: Correct cpu affinity for dlpar added cpus
        selftests/powerpc: Fix the pmu install rule
        Revert "powerpc/tm: Abort syscalls in active transactions"
        powerpc/powernv: Fix early pci_controller_ops loading.
        powerpc/kvm: Fix SMP=n build error in book3s_xics.c
      180d89f6
  5. 03 5月, 2015 3 次提交
    • J
      ext4: fix growing of tiny filesystems · 2c869b26
      Jan Kara 提交于
      The estimate of necessary transaction credits in ext4_flex_group_add()
      is too pessimistic. It reserves credit for sb, resize inode, and resize
      inode dindirect block for each group added in a flex group although they
      are always the same block and thus it is enough to account them only
      once. Also the number of modified GDT block is overestimated since we
      fit EXT4_DESC_PER_BLOCK(sb) descriptors in one block.
      
      Make the estimation more precise. That reduces number of requested
      credits enough that we can grow 20 MB filesystem (which has 1 MB
      journal, 79 reserved GDT blocks, and flex group size 16 by default).
      Signed-off-by: NJan Kara <jack@suse.cz>
      Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
      Reviewed-by: NEric Sandeen <sandeen@redhat.com>
      2c869b26
    • D
      ext4: move check under lock scope to close a race. · 280227a7
      Davide Italiano 提交于
      fallocate() checks that the file is extent-based and returns
      EOPNOTSUPP in case is not. Other tasks can convert from and to
      indirect and extent so it's safe to check only after grabbing
      the inode mutex.
      Signed-off-by: NDavide Italiano <dccitaliano@gmail.com>
      Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
      Cc: stable@vger.kernel.org
      280227a7
    • L
      ext4: fix data corruption caused by unwritten and delayed extents · d2dc317d
      Lukas Czerner 提交于
      Currently it is possible to lose whole file system block worth of data
      when we hit the specific interaction with unwritten and delayed extents
      in status extent tree.
      
      The problem is that when we insert delayed extent into extent status
      tree the only way to get rid of it is when we write out delayed buffer.
      However there is a limitation in the extent status tree implementation
      so that when inserting unwritten extent should there be even a single
      delayed block the whole unwritten extent would be marked as delayed.
      
      At this point, there is no way to get rid of the delayed extents,
      because there are no delayed buffers to write out. So when a we write
      into said unwritten extent we will convert it to written, but it still
      remains delayed.
      
      When we try to write into that block later ext4_da_map_blocks() will set
      the buffer new and delayed and map it to invalid block which causes
      the rest of the block to be zeroed loosing already written data.
      
      For now we can fix this by simply not allowing to set delayed status on
      written extent in the extent status tree. Also add WARN_ON() to make
      sure that we notice if this happens in the future.
      
      This problem can be easily reproduced by running the following xfs_io.
      
      xfs_io -f -c "pwrite -S 0xaa 4096 2048" \
                -c "falloc 0 131072" \
                -c "pwrite -S 0xbb 65536 2048" \
                -c "fsync" /mnt/test/fff
      
      echo 3 > /proc/sys/vm/drop_caches
      xfs_io -c "pwrite -S 0xdd 67584 2048" /mnt/test/fff
      
      This can be theoretically also reproduced by at random by running fsx,
      but it's not very reliable, though on machines with bigger page size
      (like ppc) this can be seen more often (especially xfstest generic/127)
      Signed-off-by: NLukas Czerner <lczerner@redhat.com>
      Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
      Cc: stable@vger.kernel.org
      d2dc317d
  6. 02 5月, 2015 10 次提交
  7. 01 5月, 2015 5 次提交
    • L
      Merge branch 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs · 64887b68
      Linus Torvalds 提交于
      Pull btrfs fixes from Chris Mason:
       "A few more btrfs fixes.
      
        These range from corners Filipe found in the new free space cache
        writeback to a grab bag of fixes from the list"
      
      * 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
        Btrfs: btrfs_release_extent_buffer_page didn't free pages of dummy extent
        Btrfs: fill ->last_trans for delayed inode in btrfs_fill_inode.
        btrfs: unlock i_mutex after attempting to delete subvolume during send
        btrfs: check io_ctl_prepare_pages return in __btrfs_write_out_cache
        btrfs: fix race on ENOMEM in alloc_extent_buffer
        btrfs: handle ENOMEM in btrfs_alloc_tree_block
        Btrfs: fix find_free_dev_extent() malfunction in case device tree has hole
        Btrfs: don't check for delalloc_bytes in cache_save_setup
        Btrfs: fix deadlock when starting writeback of bg caches
        Btrfs: fix race between start dirty bg cache writeout and bg deletion
      64887b68
    • L
      Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux · 036f351e
      Linus Torvalds 提交于
      Pull arm64 fixes from Will Deacon:
       "Not too much here, but we've addressed a couple of nasty issues in the
        dma-mapping code as well as adding the halfword and byte variants of
        load_acquire/store_release following on from the CSD locking bug that
        you fixed in the core.
      
         - fix perf devicetree warnings at probe time
      
         - fix memory leak in __dma_free()
      
         - ensure DMA buffers are always zeroed
      
         - show IRQ trigger in /proc/interrupts (for parity with ARM)
      
         - implement byte and halfword access for smp_{load_acquire,store_release}"
      
      * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
        arm64: perf: Fix the pmu node name in warning message
        arm64: perf: don't warn about missing interrupt-affinity property for PPIs
        arm64: add missing PAGE_ALIGN() to __dma_free()
        arm64: dma-mapping: always clear allocated buffers
        ARM64: Enable CONFIG_GENERIC_IRQ_SHOW_LEVEL
        arm64: add missing data types in smp_load_acquire/smp_store_release
      036f351e
    • S
      powerpc/powernv: Restore non-volatile CRs after nap · 0aab3747
      Sam Bobroff 提交于
      Patches 7cba160a "powernv/cpuidle: Redesign idle states management"
      and 77b54e9f "powernv/powerpc: Add winkle support for offline cpus"
      use non-volatile condition registers (cr2, cr3 and cr4) early in the system
      reset interrupt handler (system_reset_pSeries()) before it has been determined
      if state loss has occurred. If state loss has not occurred, control returns via
      the power7_wakeup_noloss() path which does not restore those condition
      registers, leaving them corrupted.
      
      Fix this by restoring the condition registers in the power7_wakeup_noloss()
      case.
      
      This is apparent when running a KVM guest on hardware that does not
      support winkle or sleep and the guest makes use of secondary threads. In
      practice this means Power7 machines, though some early unreleased Power8
      machines may also be susceptible.
      
      The secondary CPUs are taken off line before the guest is started and
      they call pnv_smp_cpu_kill_self(). This checks support for sleep
      states (in this case there is no support) and power7_nap() is called.
      
      When the CPU is woken, power7_nap() returns and because the CPU is
      still off line, the main while loop executes again. The sleep states
      support test is executed again, but because the tested values cannot
      have changed, the compiler has optimized the test away and instead we
      rely on the result of the first test, which has been left in cr3
      and/or cr4. With the result overwritten, the wrong branch is taken and
      power7_winkle() is called on a CPU that does not support it, leading
      to it stalling.
      
      Fixes: 7cba160a ("powernv/cpuidle: Redesign idle states management")
      Fixes: 77b54e9f ("powernv/powerpc: Add winkle support for offline cpus")
      [mpe: Massage change log a bit more]
      Signed-off-by: NSam Bobroff <sam.bobroff@au1.ibm.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      0aab3747
    • G
      powerpc/eeh: Delay probing EEH device during hotplug · d91dafc0
      Gavin Shan 提交于
      Commit 1c509148b ("powerpc/eeh: Do probe on pci_dn") probes EEH
      devices in early stage, which is reasonable to pSeries platform.
      However, it's wrong for PowerNV platform because the PE# isn't
      determined until the resources (IO and MMIO) are assigned to
      PE in hotplug case. So we have to delay probing EEH devices
      for PowerNV platform until the PE# is assigned.
      
      Fixes: ff57b454 ("powerpc/eeh: Do probe on pci_dn")
      Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      d91dafc0
    • G
      powerpc/eeh: Fix race condition in pcibios_set_pcie_reset_state() · 1ae79b78
      Gavin Shan 提交于
      When asserting reset in pcibios_set_pcie_reset_state(), the PE
      is enforced to (hardware) frozen state in order to drop unexpected
      PCI transactions (except PCI config read/write) automatically by
      hardware during reset, which would cause recursive EEH error.
      However, the (software) frozen state EEH_PE_ISOLATED is missed.
      When users get 0xFF from PCI config or MMIO read, EEH_PE_ISOLATED
      is set in PE state retrival backend. Unfortunately, nobody (the
      reset handler or the EEH recovery functinality in host) will clear
      EEH_PE_ISOLATED when the PE has been passed through to guest.
      
      The patch sets and clears EEH_PE_ISOLATED properly during reset
      in function pcibios_set_pcie_reset_state() to fix the issue.
      
      Fixes: 28158cd1 ("Enhance pcibios_set_pcie_reset_state()")
      Reported-by: NCarol L. Soto <clsoto@us.ibm.com>
      Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
      Tested-by: NCarol L. Soto <clsoto@us.ibm.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      1ae79b78