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Although the device tree might contain a reserved-memory DT node dedicated as the default CMA pool, users might want to change CMA's parameters using the kernel command line for debugging purposes and whatnot. Honor this by bypassing the reserved memory CMA setup, which will ultimately end up freeing the memblock and allow the command line CMA configuration routine to run. Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Reviewed-by: Phil Elwell <phil@raspberrypi.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
dma_direct_supported tries to find the minimum addressable bitmask based on the end pfn and optional magic that architectures can use to communicate the size of the magic ZONE_DMA that can be used for bounce buffering. But between the DMA offsets that can change per device (or sometimes even region), the fact the ZONE_DMA isn't even guaranteed to be the lowest addresses and failure of having proper interfaces to the MM code this fails at least for one arm subarchitecture. As all the legacy DMA implementations have supported 32-bit DMA masks, and 32-bit masks are guranteed to always work by the API contract (using bounce buffers if needed), we can short cut the complicated check and always return true without breaking existing assumptions. Hopefully we can properly clean up the interaction with the arch defined zones and the bootmem allocator eventually. Fixes: ad3c7b1 ("arm: use swiotlb for bounce buffering on LPAE configs") Reported-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Untangle the way how dma_direct_map_page calls into swiotlb to be able to properly report errors where the swiotlb DMA address overflows the mask separately from overflows in the !swiotlb case. This means that siotlb_map now has to do a little more work that duplicates dma_direct_map_page, but doing so greatly simplifies the calling convention. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Remove the unset dma_mask case as that won't get into mapping calls anymore, and also report the other errors unconditonally and with a slightly improved message. Remove the now pointless report_addr helper. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Konrad Rzeszutek Wilk <konrad@darnok.org>
…mapping Pull dma-mapping fixes from Christoph Hellwig: - give command line cma= precedence over the CONFIG_ option (Nicolas Saenz Julienne) - always allow 32-bit DMA, even for weirdly placed ZONE_DMA - improve the debug printks when memory is not addressable, to help find problems with swiotlb initialization * tag 'dma-mapping-5.6' of git://git.infradead.org/users/hch/dma-mapping: dma-direct: improve DMA mask overflow reporting dma-direct: improve swiotlb error reporting dma-direct: relax addressability checks in dma_direct_supported dma-contiguous: CMA: give precedence to cmdline
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The following lockdep splat ====================================================== WARNING: possible circular locking dependency detected 5.8.0-rc7-00169-g87212851a027-dirty #929 Not tainted ------------------------------------------------------ fsstress/8739 is trying to acquire lock: ffff88bfd0eb0c90 (&fs_info->reloc_mutex){+.+.}-{3:3}, at: btrfs_record_root_in_trans+0x43/0x70 but task is already holding lock: ffff88bfbd16e538 (sb_pagefaults){.+.+}-{0:0}, at: btrfs_page_mkwrite+0x6a/0x4a0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #10 (sb_pagefaults){.+.+}-{0:0}: __sb_start_write+0x129/0x210 btrfs_page_mkwrite+0x6a/0x4a0 do_page_mkwrite+0x4d/0xc0 handle_mm_fault+0x103c/0x1730 exc_page_fault+0x340/0x660 asm_exc_page_fault+0x1e/0x30 -> #9 (&mm->mmap_lock#2){++++}-{3:3}: __might_fault+0x68/0x90 _copy_to_user+0x1e/0x80 perf_read+0x141/0x2c0 vfs_read+0xad/0x1b0 ksys_read+0x5f/0xe0 do_syscall_64+0x50/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #8 (&cpuctx_mutex){+.+.}-{3:3}: __mutex_lock+0x9f/0x930 perf_event_init_cpu+0x88/0x150 perf_event_init+0x1db/0x20b start_kernel+0x3ae/0x53c secondary_startup_64+0xa4/0xb0 -> #7 (pmus_lock){+.+.}-{3:3}: __mutex_lock+0x9f/0x930 perf_event_init_cpu+0x4f/0x150 cpuhp_invoke_callback+0xb1/0x900 _cpu_up.constprop.26+0x9f/0x130 cpu_up+0x7b/0xc0 bringup_nonboot_cpus+0x4f/0x60 smp_init+0x26/0x71 kernel_init_freeable+0x110/0x258 kernel_init+0xa/0x103 ret_from_fork+0x1f/0x30 -> #6 (cpu_hotplug_lock){++++}-{0:0}: cpus_read_lock+0x39/0xb0 kmem_cache_create_usercopy+0x28/0x230 kmem_cache_create+0x12/0x20 bioset_init+0x15e/0x2b0 init_bio+0xa3/0xaa do_one_initcall+0x5a/0x2e0 kernel_init_freeable+0x1f4/0x258 kernel_init+0xa/0x103 ret_from_fork+0x1f/0x30 -> #5 (bio_slab_lock){+.+.}-{3:3}: __mutex_lock+0x9f/0x930 bioset_init+0xbc/0x2b0 __blk_alloc_queue+0x6f/0x2d0 blk_mq_init_queue_data+0x1b/0x70 loop_add+0x110/0x290 [loop] fq_codel_tcf_block+0x12/0x20 [sch_fq_codel] do_one_initcall+0x5a/0x2e0 do_init_module+0x5a/0x220 load_module+0x2459/0x26e0 __do_sys_finit_module+0xba/0xe0 do_syscall_64+0x50/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #4 (loop_ctl_mutex){+.+.}-{3:3}: __mutex_lock+0x9f/0x930 lo_open+0x18/0x50 [loop] __blkdev_get+0xec/0x570 blkdev_get+0xe8/0x150 do_dentry_open+0x167/0x410 path_openat+0x7c9/0xa80 do_filp_open+0x93/0x100 do_sys_openat2+0x22a/0x2e0 do_sys_open+0x4b/0x80 do_syscall_64+0x50/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #3 (&bdev->bd_mutex){+.+.}-{3:3}: __mutex_lock+0x9f/0x930 blkdev_put+0x1d/0x120 close_fs_devices.part.31+0x84/0x130 btrfs_close_devices+0x44/0xb0 close_ctree+0x296/0x2b2 generic_shutdown_super+0x69/0x100 kill_anon_super+0xe/0x30 btrfs_kill_super+0x12/0x20 deactivate_locked_super+0x29/0x60 cleanup_mnt+0xb8/0x140 task_work_run+0x6d/0xb0 __prepare_exit_to_usermode+0x1cc/0x1e0 do_syscall_64+0x5c/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #2 (&fs_devs->device_list_mutex){+.+.}-{3:3}: __mutex_lock+0x9f/0x930 btrfs_run_dev_stats+0x49/0x480 commit_cowonly_roots+0xb5/0x2a0 btrfs_commit_transaction+0x516/0xa60 sync_filesystem+0x6b/0x90 generic_shutdown_super+0x22/0x100 kill_anon_super+0xe/0x30 btrfs_kill_super+0x12/0x20 deactivate_locked_super+0x29/0x60 cleanup_mnt+0xb8/0x140 task_work_run+0x6d/0xb0 __prepare_exit_to_usermode+0x1cc/0x1e0 do_syscall_64+0x5c/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #1 (&fs_info->tree_log_mutex){+.+.}-{3:3}: __mutex_lock+0x9f/0x930 btrfs_commit_transaction+0x4bb/0xa60 sync_filesystem+0x6b/0x90 generic_shutdown_super+0x22/0x100 kill_anon_super+0xe/0x30 btrfs_kill_super+0x12/0x20 deactivate_locked_super+0x29/0x60 cleanup_mnt+0xb8/0x140 task_work_run+0x6d/0xb0 __prepare_exit_to_usermode+0x1cc/0x1e0 do_syscall_64+0x5c/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #0 (&fs_info->reloc_mutex){+.+.}-{3:3}: __lock_acquire+0x1272/0x2310 lock_acquire+0x9e/0x360 __mutex_lock+0x9f/0x930 btrfs_record_root_in_trans+0x43/0x70 start_transaction+0xd1/0x5d0 btrfs_dirty_inode+0x42/0xd0 file_update_time+0xc8/0x110 btrfs_page_mkwrite+0x10c/0x4a0 do_page_mkwrite+0x4d/0xc0 handle_mm_fault+0x103c/0x1730 exc_page_fault+0x340/0x660 asm_exc_page_fault+0x1e/0x30 other info that might help us debug this: Chain exists of: &fs_info->reloc_mutex --> &mm->mmap_lock#2 --> sb_pagefaults Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_pagefaults); lock(&mm->mmap_lock#2); lock(sb_pagefaults); lock(&fs_info->reloc_mutex); *** DEADLOCK *** 3 locks held by fsstress/8739: #0: ffff88bee66eeb68 (&mm->mmap_lock#2){++++}-{3:3}, at: exc_page_fault+0x173/0x660 #1: ffff88bfbd16e538 (sb_pagefaults){.+.+}-{0:0}, at: btrfs_page_mkwrite+0x6a/0x4a0 #2: ffff88bfbd16e630 (sb_internal){.+.+}-{0:0}, at: start_transaction+0x3da/0x5d0 stack backtrace: CPU: 17 PID: 8739 Comm: fsstress Kdump: loaded Not tainted 5.8.0-rc7-00169-g87212851a027-dirty #929 Hardware name: Quanta Tioga Pass Single Side 01-0030993006/Tioga Pass Single Side, BIOS F08_3A18 12/20/2018 Call Trace: dump_stack+0x78/0xa0 check_noncircular+0x165/0x180 __lock_acquire+0x1272/0x2310 ? btrfs_get_alloc_profile+0x150/0x210 lock_acquire+0x9e/0x360 ? btrfs_record_root_in_trans+0x43/0x70 __mutex_lock+0x9f/0x930 ? btrfs_record_root_in_trans+0x43/0x70 ? lock_acquire+0x9e/0x360 ? join_transaction+0x5d/0x450 ? find_held_lock+0x2d/0x90 ? btrfs_record_root_in_trans+0x43/0x70 ? join_transaction+0x3d5/0x450 ? btrfs_record_root_in_trans+0x43/0x70 btrfs_record_root_in_trans+0x43/0x70 start_transaction+0xd1/0x5d0 btrfs_dirty_inode+0x42/0xd0 file_update_time+0xc8/0x110 btrfs_page_mkwrite+0x10c/0x4a0 ? handle_mm_fault+0x5e/0x1730 do_page_mkwrite+0x4d/0xc0 ? __do_fault+0x32/0x150 handle_mm_fault+0x103c/0x1730 exc_page_fault+0x340/0x660 ? asm_exc_page_fault+0x8/0x30 asm_exc_page_fault+0x1e/0x30 RIP: 0033:0x7faa6c9969c4 Was seen in testing. The fix is similar to that of btrfs: open device without device_list_mutex where we're holding the device_list_mutex and then grab the bd_mutex, which pulls in a bunch of dependencies under the bd_mutex. We only ever call btrfs_close_devices() on mount failure or unmount, so we're save to not have the device_list_mutex here. We're already holding the uuid_mutex which keeps us safe from any external modification of the fs_devices. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
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