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2024-09-12dma-mapping: benchmark: Don't starve others when doing the testYicong Yang
[ Upstream commit 54624acf8843375a6de3717ac18df3b5104c39c5 ] The test thread will start N benchmark kthreads and then schedule out until the test time finished and notify the benchmark kthreads to stop. The benchmark kthreads will keep running until notified to stop. There's a problem with current implementation when the benchmark kthreads number is equal to the CPUs on a non-preemptible kernel: since the scheduler will balance the kthreads across the CPUs and when the test time's out the test thread won't get a chance to be scheduled on any CPU then cannot notify the benchmark kthreads to stop. This can be easily reproduced on a VM (simulated with 16 CPUs) with PREEMPT_VOLUNTARY: estuary:/mnt$ ./dma_map_benchmark -t 16 -s 1 rcu: INFO: rcu_sched self-detected stall on CPU rcu: 10-...!: (5221 ticks this GP) idle=ed24/1/0x4000000000000000 softirq=142/142 fqs=0 rcu: (t=5254 jiffies g=-559 q=45 ncpus=16) rcu: rcu_sched kthread starved for 5255 jiffies! g-559 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=12 rcu: Unless rcu_sched kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_sched state:R running task stack:0 pid:16 tgid:16 ppid:2 flags:0x00000008 Call trace __switch_to+0xec/0x138 __schedule+0x2f8/0x1080 schedule+0x30/0x130 schedule_timeout+0xa0/0x188 rcu_gp_fqs_loop+0x128/0x528 rcu_gp_kthread+0x1c8/0x208 kthread+0xec/0xf8 ret_from_fork+0x10/0x20 Sending NMI from CPU 10 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 332 Comm: dma-map-benchma Not tainted 6.10.0-rc1-vanilla-LSE #8 Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015 pstate: 20400005 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : arm_smmu_cmdq_issue_cmdlist+0x218/0x730 lr : arm_smmu_cmdq_issue_cmdlist+0x488/0x730 sp : ffff80008748b630 x29: ffff80008748b630 x28: 0000000000000000 x27: ffff80008748b780 x26: 0000000000000000 x25: 000000000000bc70 x24: 000000000001bc70 x23: ffff0000c12af080 x22: 0000000000010000 x21: 000000000000ffff x20: ffff80008748b700 x19: ffff0000c12af0c0 x18: 0000000000010000 x17: 0000000000000001 x16: 0000000000000040 x15: ffffffffffffffff x14: 0001ffffffffffff x13: 000000000000ffff x12: 00000000000002f1 x11: 000000000001ffff x10: 0000000000000031 x9 : ffff800080b6b0b8 x8 : ffff0000c2a48000 x7 : 000000000001bc71 x6 : 0001800000000000 x5 : 00000000000002f1 x4 : 01ffffffffffffff x3 : 000000000009aaf1 x2 : 0000000000000018 x1 : 000000000000000f x0 : ffff0000c12af18c Call trace: arm_smmu_cmdq_issue_cmdlist+0x218/0x730 __arm_smmu_tlb_inv_range+0xe0/0x1a8 arm_smmu_iotlb_sync+0xc0/0x128 __iommu_dma_unmap+0x248/0x320 iommu_dma_unmap_page+0x5c/0xe8 dma_unmap_page_attrs+0x38/0x1d0 map_benchmark_thread+0x118/0x2c0 kthread+0xec/0xf8 ret_from_fork+0x10/0x20 Solve this by adding scheduling point in the kthread loop, so if there're other threads in the system they may have a chance to run, especially the thread to notify the test end. However this may degrade the test concurrency so it's recommended to run this on an idle system. Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> Acked-by: Barry Song <baohua@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-09-08dma-debug: avoid deadlock between dma debug vs printk and netconsoleRik van Riel
[ Upstream commit bd44ca3de49cc1badcff7a96010fa2c64f04868c ] Currently the dma debugging code can end up indirectly calling printk under the radix_lock. This happens when a radix tree node allocation fails. This is a problem because the printk code, when used together with netconsole, can end up inside the dma debugging code while trying to transmit a message over netcons. This creates the possibility of either a circular deadlock on the same CPU, with that CPU trying to grab the radix_lock twice, or an ABBA deadlock between different CPUs, where one CPU grabs the console lock first and then waits for the radix_lock, while the other CPU is holding the radix_lock and is waiting for the console lock. The trace captured by lockdep is of the ABBA variant. -> #2 (&dma_entry_hash[i].lock){-.-.}-{2:2}: _raw_spin_lock_irqsave+0x5a/0x90 debug_dma_map_page+0x79/0x180 dma_map_page_attrs+0x1d2/0x2f0 bnxt_start_xmit+0x8c6/0x1540 netpoll_start_xmit+0x13f/0x180 netpoll_send_skb+0x20d/0x320 netpoll_send_udp+0x453/0x4a0 write_ext_msg+0x1b9/0x460 console_flush_all+0x2ff/0x5a0 console_unlock+0x55/0x180 vprintk_emit+0x2e3/0x3c0 devkmsg_emit+0x5a/0x80 devkmsg_write+0xfd/0x180 do_iter_readv_writev+0x164/0x1b0 vfs_writev+0xf9/0x2b0 do_writev+0x6d/0x110 do_syscall_64+0x80/0x150 entry_SYSCALL_64_after_hwframe+0x4b/0x53 -> #0 (console_owner){-.-.}-{0:0}: __lock_acquire+0x15d1/0x31a0 lock_acquire+0xe8/0x290 console_flush_all+0x2ea/0x5a0 console_unlock+0x55/0x180 vprintk_emit+0x2e3/0x3c0 _printk+0x59/0x80 warn_alloc+0x122/0x1b0 __alloc_pages_slowpath+0x1101/0x1120 __alloc_pages+0x1eb/0x2c0 alloc_slab_page+0x5f/0x150 new_slab+0x2dc/0x4e0 ___slab_alloc+0xdcb/0x1390 kmem_cache_alloc+0x23d/0x360 radix_tree_node_alloc+0x3c/0xf0 radix_tree_insert+0xf5/0x230 add_dma_entry+0xe9/0x360 dma_map_page_attrs+0x1d2/0x2f0 __bnxt_alloc_rx_frag+0x147/0x180 bnxt_alloc_rx_data+0x79/0x160 bnxt_rx_skb+0x29/0xc0 bnxt_rx_pkt+0xe22/0x1570 __bnxt_poll_work+0x101/0x390 bnxt_poll+0x7e/0x320 __napi_poll+0x29/0x160 net_rx_action+0x1e0/0x3e0 handle_softirqs+0x190/0x510 run_ksoftirqd+0x4e/0x90 smpboot_thread_fn+0x1a8/0x270 kthread+0x102/0x120 ret_from_fork+0x2f/0x40 ret_from_fork_asm+0x11/0x20 This bug is more likely than it seems, because when one CPU has run out of memory, chances are the other has too. The good news is, this bug is hidden behind the CONFIG_DMA_API_DEBUG, so not many users are likely to trigger it. Signed-off-by: Rik van Riel <riel@surriel.com> Reported-by: Konstantin Ovsepian <ovs@meta.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-09-04Revert "change alloc_pages name in dma_map_ops to avoid name conflicts"Greg Kroah-Hartman
This reverts commit 983e6b2636f0099dbac1874c9e885bbe1cf2df05 which is commit 8a2f11878771da65b8ac135c73b47dae13afbd62 upstream. It wasn't needed and caused a build break on s390, so just revert it entirely. Reported-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20240830221217.GA3837758@thelio-3990X Cc: Suren Baghdasaryan <surenb@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andreas Hindborg <a.hindborg@samsung.com> Cc: Benno Lossin <benno.lossin@proton.me> Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Gary Guo <gary@garyguo.net> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wedson Almeida Filho <wedsonaf@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-29change alloc_pages name in dma_map_ops to avoid name conflictsSuren Baghdasaryan
[ Upstream commit 8a2f11878771da65b8ac135c73b47dae13afbd62 ] After redefining alloc_pages, all uses of that name are being replaced. Change the conflicting names to prevent preprocessor from replacing them when it's not intended. Link: https://lkml.kernel.org/r/20240321163705.3067592-18-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Tested-by: Kees Cook <keescook@chromium.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andreas Hindborg <a.hindborg@samsung.com> Cc: Benno Lossin <benno.lossin@proton.me> Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Gary Guo <gary@garyguo.net> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Stable-dep-of: 61ebe5a747da ("mm/vmalloc: fix page mapping if vm_area_alloc_pages() with high order fallback to order 0") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03dma: fix call order in dmam_free_coherentLance Richardson
[ Upstream commit 28e8b7406d3a1f5329a03aa25a43aa28e087cb20 ] dmam_free_coherent() frees a DMA allocation, which makes the freed vaddr available for reuse, then calls devres_destroy() to remove and free the data structure used to track the DMA allocation. Between the two calls, it is possible for a concurrent task to make an allocation with the same vaddr and add it to the devres list. If this happens, there will be two entries in the devres list with the same vaddr and devres_destroy() can free the wrong entry, triggering the WARN_ON() in dmam_match. Fix by destroying the devres entry before freeing the DMA allocation. Tested: kokonut //net/encryption http://sponge2/b9145fe6-0f72-4325-ac2f-a84d81075b03 Fixes: 9ac7849e35f7 ("devres: device resource management") Signed-off-by: Lance Richardson <rlance@google.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-11dma-mapping: benchmark: avoid needless copy_to_user if benchmark failsFedor Pchelkin
[ Upstream commit f7c9ccaadffd13066353332c13d7e9bf73b8f92d ] If do_map_benchmark() has failed, there is nothing useful to copy back to userspace. Suggested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> Acked-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-21swiotlb: extend buffer pre-padding to alloc_align_mask if necessaryPetr Tesarik
commit af133562d5aff41fcdbe51f1a504ae04788b5fc0 upstream. Allow a buffer pre-padding of up to alloc_align_mask, even if it requires allocating additional IO TLB slots. If the allocation alignment is bigger than IO_TLB_SIZE and min_align_mask covers any non-zero bits in the original address between IO_TLB_SIZE and alloc_align_mask, these bits are not preserved in the swiotlb buffer address. To fix this case, increase the allocation size and use a larger offset within the allocated buffer. As a result, extra padding slots may be allocated before the mapping start address. Leave orig_addr in these padding slots initialized to INVALID_PHYS_ADDR. These slots do not correspond to any CPU buffer, so attempts to sync the data should be ignored. The padding slots should be automatically released when the buffer is unmapped. However, swiotlb_tbl_unmap_single() takes only the address of the DMA buffer slot, not the first padding slot. Save the number of padding slots in struct io_tlb_slot and use it to adjust the slot index in swiotlb_release_slots(), so all allocated slots are properly freed. Cc: stable@vger.kernel.org # v6.6+ Fixes: 2fd4fa5d3fb5 ("swiotlb: Fix alignment checks when both allocation and DMA masks are present") Link: https://lore.kernel.org/linux-iommu/20240311210507.217daf8b@meshulam.tesarici.cz/ Signed-off-by: Petr Tesarik <petr.tesarik1@huawei-partners.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Fabio Estevam <festevam@denx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-21swiotlb: Reinstate page-alignment for mappings >= PAGE_SIZEWill Deacon
commit 14cebf689a78e8a1c041138af221ef6eac6bc7da upstream. For swiotlb allocations >= PAGE_SIZE, the slab search historically adjusted the stride to avoid checking unaligned slots. This had the side-effect of aligning large mapping requests to PAGE_SIZE, but that was broken by 0eee5ae10256 ("swiotlb: fix slot alignment checks"). Since this alignment could be relied upon drivers, reinstate PAGE_SIZE alignment for swiotlb mappings >= PAGE_SIZE. Cc: stable@vger.kernel.org # v6.6+ Reported-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Will Deacon <will@kernel.org> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Petr Tesarik <petr.tesarik1@huawei-partners.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Fabio Estevam <festevam@denx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-21swiotlb: Enforce page alignment in swiotlb_alloc()Will Deacon
commit 823353b7cf0ea9dfb09f5181d5fb2825d727200b upstream. When allocating pages from a restricted DMA pool in swiotlb_alloc(), the buffer address is blindly converted to a 'struct page *' that is returned to the caller. In the unlikely event of an allocation bug, page-unaligned addresses are not detected and slots can silently be double-allocated. Add a simple check of the buffer alignment in swiotlb_alloc() to make debugging a little easier if something has gone wonky. Cc: stable@vger.kernel.org # v6.6+ Signed-off-by: Will Deacon <will@kernel.org> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Petr Tesarik <petr.tesarik1@huawei-partners.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Fabio Estevam <festevam@denx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-12dma-mapping: benchmark: handle NUMA_NO_NODE correctlyFedor Pchelkin
[ Upstream commit e64746e74f717961250a155e14c156616fcd981f ] cpumask_of_node() can be called for NUMA_NO_NODE inside do_map_benchmark() resulting in the following sanitizer report: UBSAN: array-index-out-of-bounds in ./arch/x86/include/asm/topology.h:72:28 index -1 is out of range for type 'cpumask [64][1]' CPU: 1 PID: 990 Comm: dma_map_benchma Not tainted 6.9.0-rc6 #29 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:117) ubsan_epilogue (lib/ubsan.c:232) __ubsan_handle_out_of_bounds (lib/ubsan.c:429) cpumask_of_node (arch/x86/include/asm/topology.h:72) [inline] do_map_benchmark (kernel/dma/map_benchmark.c:104) map_benchmark_ioctl (kernel/dma/map_benchmark.c:246) full_proxy_unlocked_ioctl (fs/debugfs/file.c:333) __x64_sys_ioctl (fs/ioctl.c:890) do_syscall_64 (arch/x86/entry/common.c:83) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Use cpumask_of_node() in place when binding a kernel thread to a cpuset of a particular node. Note that the provided node id is checked inside map_benchmark_ioctl(). It's just a NUMA_NO_NODE case which is not handled properly later. Found by Linux Verification Center (linuxtesting.org). Fixes: 65789daa8087 ("dma-mapping: add benchmark support for streaming DMA APIs") Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> Acked-by: Barry Song <baohua@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12dma-mapping: benchmark: fix node id validationFedor Pchelkin
[ Upstream commit 1ff05e723f7ca30644b8ec3fb093f16312e408ad ] While validating node ids in map_benchmark_ioctl(), node_possible() may be provided with invalid argument outside of [0,MAX_NUMNODES-1] range leading to: BUG: KASAN: wild-memory-access in map_benchmark_ioctl (kernel/dma/map_benchmark.c:214) Read of size 8 at addr 1fffffff8ccb6398 by task dma_map_benchma/971 CPU: 7 PID: 971 Comm: dma_map_benchma Not tainted 6.9.0-rc6 #37 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:117) kasan_report (mm/kasan/report.c:603) kasan_check_range (mm/kasan/generic.c:189) variable_test_bit (arch/x86/include/asm/bitops.h:227) [inline] arch_test_bit (arch/x86/include/asm/bitops.h:239) [inline] _test_bit at (include/asm-generic/bitops/instrumented-non-atomic.h:142) [inline] node_state (include/linux/nodemask.h:423) [inline] map_benchmark_ioctl (kernel/dma/map_benchmark.c:214) full_proxy_unlocked_ioctl (fs/debugfs/file.c:333) __x64_sys_ioctl (fs/ioctl.c:890) do_syscall_64 (arch/x86/entry/common.c:83) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Compare node ids with sane bounds first. NUMA_NO_NODE is considered a special valid case meaning that benchmarking kthreads won't be bound to a cpuset of a given node. Found by Linux Verification Center (linuxtesting.org). Fixes: 65789daa8087 ("dma-mapping: add benchmark support for streaming DMA APIs") Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12dma-mapping: benchmark: fix up kthread-related error handlingFedor Pchelkin
[ Upstream commit bb9025f4432f8c158322cf2c04c2b492f23eb511 ] kthread creation failure is invalidly handled inside do_map_benchmark(). The put_task_struct() calls on the error path are supposed to balance the get_task_struct() calls which only happen after all the kthreads are successfully created. Rollback using kthread_stop() for already created kthreads in case of such failure. In normal situation call kthread_stop_put() to gracefully stop kthreads and put their task refcounts. This should be done for all started kthreads. Found by Linux Verification Center (linuxtesting.org). Fixes: 65789daa8087 ("dma-mapping: add benchmark support for streaming DMA APIs") Suggested-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17swiotlb: initialise restricted pool list_head when SWIOTLB_DYNAMIC=yWill Deacon
[ Upstream commit 75961ffb5cb3e5196f19cae7683f35cc88b50800 ] Using restricted DMA pools (CONFIG_DMA_RESTRICTED_POOL=y) in conjunction with dynamic SWIOTLB (CONFIG_SWIOTLB_DYNAMIC=y) leads to the following crash when initialising the restricted pools at boot-time: | Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 | Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP | pc : rmem_swiotlb_device_init+0xfc/0x1ec | lr : rmem_swiotlb_device_init+0xf0/0x1ec | Call trace: | rmem_swiotlb_device_init+0xfc/0x1ec | of_reserved_mem_device_init_by_idx+0x18c/0x238 | of_dma_configure_id+0x31c/0x33c | platform_dma_configure+0x34/0x80 faddr2line reveals that the crash is in the list validation code: include/linux/list.h:83 include/linux/rculist.h:79 include/linux/rculist.h:106 kernel/dma/swiotlb.c:306 kernel/dma/swiotlb.c:1695 because add_mem_pool() is trying to list_add_rcu() to a NULL 'mem->pools'. Fix the crash by initialising the 'mem->pools' list_head in rmem_swiotlb_device_init() before calling add_mem_pool(). Reported-by: Nikita Ioffe <ioffe@google.com> Tested-by: Nikita Ioffe <ioffe@google.com> Fixes: 1aaa736815eb ("swiotlb: allocate a new memory pool when existing pools are full") Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-13dma-direct: Leak pages on dma_set_decrypted() failureRick Edgecombe
[ Upstream commit b9fa16949d18e06bdf728a560f5c8af56d2bdcaf ] On TDX it is possible for the untrusted host to cause set_memory_encrypted() or set_memory_decrypted() to fail such that an error is returned and the resulting memory is shared. Callers need to take care to handle these errors to avoid returning decrypted (shared) memory to the page allocator, which could lead to functional or security issues. DMA could free decrypted/shared pages if dma_set_decrypted() fails. This should be a rare case. Just leak the pages in this case instead of freeing them. Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-03swiotlb: Fix alignment checks when both allocation and DMA masks are presentWill Deacon
[ Upstream commit 51b30ecb73b481d5fac6ccf2ecb4a309c9ee3310 ] Nicolin reports that swiotlb buffer allocations fail for an NVME device behind an IOMMU using 64KiB pages. This is because we end up with a minimum allocation alignment of 64KiB (for the IOMMU to map the buffer safely) but a minimum DMA alignment mask corresponding to a 4KiB NVME page (i.e. preserving the 4KiB page offset from the original allocation). If the original address is not 4KiB-aligned, the allocation will fail because swiotlb_search_pool_area() erroneously compares these unmasked bits with the 64KiB-aligned candidate allocation. Tweak swiotlb_search_pool_area() so that the DMA alignment mask is reduced based on the required alignment of the allocation. Fixes: 82612d66d51d ("iommu: Allow the dma-iommu api to use bounce buffers") Link: https://lore.kernel.org/r/cover.1707851466.git.nicolinc@nvidia.com Reported-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Will Deacon <will@kernel.org> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-03swiotlb: Honour dma_alloc_coherent() alignment in swiotlb_alloc()Will Deacon
[ Upstream commit cbf53074a528191df82b4dba1e3d21191102255e ] core-api/dma-api-howto.rst states the following properties of dma_alloc_coherent(): | The CPU virtual address and the DMA address are both guaranteed to | be aligned to the smallest PAGE_SIZE order which is greater than or | equal to the requested size. However, swiotlb_alloc() passes zero for the 'alloc_align_mask' parameter of swiotlb_find_slots() and so this property is not upheld. Instead, allocations larger than a page are aligned to PAGE_SIZE, Calculate the mask corresponding to the page order suitable for holding the allocation and pass that to swiotlb_find_slots(). Fixes: e81e99bacc9f ("swiotlb: Support aligned swiotlb buffers") Signed-off-by: Will Deacon <will@kernel.org> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Petr Tesarik <petr.tesarik1@huawei-partners.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-03swiotlb: Fix double-allocation of slots due to broken alignment handlingWill Deacon
[ Upstream commit 04867a7a33324c9c562ee7949dbcaab7aaad1fb4 ] Commit bbb73a103fbb ("swiotlb: fix a braino in the alignment check fix"), which was a fix for commit 0eee5ae10256 ("swiotlb: fix slot alignment checks"), causes a functional regression with vsock in a virtual machine using bouncing via a restricted DMA SWIOTLB pool. When virtio allocates the virtqueues for the vsock device using dma_alloc_coherent(), the SWIOTLB search can return page-unaligned allocations if 'area->index' was left unaligned by a previous allocation from the buffer: # Final address in brackets is the SWIOTLB address returned to the caller | virtio-pci 0000:00:07.0: orig_addr 0x0 alloc_size 0x2000, iotlb_align_mask 0x800 stride 0x2: got slot 1645-1649/7168 (0x98326800) | virtio-pci 0000:00:07.0: orig_addr 0x0 alloc_size 0x2000, iotlb_align_mask 0x800 stride 0x2: got slot 1649-1653/7168 (0x98328800) | virtio-pci 0000:00:07.0: orig_addr 0x0 alloc_size 0x2000, iotlb_align_mask 0x800 stride 0x2: got slot 1653-1657/7168 (0x9832a800) This ends badly (typically buffer corruption and/or a hang) because swiotlb_alloc() is expecting a page-aligned allocation and so blindly returns a pointer to the 'struct page' corresponding to the allocation, therefore double-allocating the first half (2KiB slot) of the 4KiB page. Fix the problem by treating the allocation alignment separately to any additional alignment requirements from the device, using the maximum of the two as the stride to search the buffer slots and taking care to ensure a minimum of page-alignment for buffers larger than a page. This also resolves swiotlb allocation failures occuring due to the inclusion of ~PAGE_MASK in 'iotlb_align_mask' for large allocations and resulting in alignment requirements exceeding swiotlb_max_mapping_size(). Fixes: bbb73a103fbb ("swiotlb: fix a braino in the alignment check fix") Fixes: 0eee5ae10256 ("swiotlb: fix slot alignment checks") Signed-off-by: Will Deacon <will@kernel.org> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Petr Tesarik <petr.tesarik1@huawei-partners.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25dma-mapping: clear dev->dma_mem to NULL after freeing itJoakim Zhang
[ Upstream commit b07bc2347672cc8c7293c64499f1488278c5ca3d ] Reproduced with below sequence: dma_declare_coherent_memory()->dma_release_coherent_memory() ->dma_declare_coherent_memory()->"return -EBUSY" error It will return -EBUSY from the dma_assign_coherent_memory() in dma_declare_coherent_memory(), the reason is that dev->dma_mem pointer has not been set to NULL after it's freed. Fixes: cf65a0f6f6ff ("dma-mapping: move all DMA mapping code to kernel/dma") Signed-off-by: Joakim Zhang <joakim.zhang@cixtech.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-28swiotlb: fix out-of-bounds TLB allocations with CONFIG_SWIOTLB_DYNAMICPetr Tesarik
commit 53c87e846e335e3c18044c397cc35178163d7827 upstream. Limit the free list length to the size of the IO TLB. Transient pool can be smaller than IO_TLB_SEGSIZE, but the free list is initialized with the assumption that the total number of slots is a multiple of IO_TLB_SEGSIZE. As a result, swiotlb_area_find_slots() may allocate slots past the end of a transient IO TLB buffer. Reported-by: Niklas Schnelle <schnelle@linux.ibm.com> Closes: https://lore.kernel.org/linux-iommu/104a8c8fedffd1ff8a2890983e2ec1c26bff6810.camel@linux.ibm.com/ Fixes: 79636caad361 ("swiotlb: if swiotlb is full, fall back to a transient memory pool") Cc: stable@vger.kernel.org Signed-off-by: Petr Tesarik <petr.tesarik1@huawei-partners.com> Reviewed-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28swiotlb: do not free decrypted pages if dynamicPetr Tesarik
commit a5e3b127455d073f146a2a4ea3e7117635d34c5c upstream. Fix these two error paths: 1. When set_memory_decrypted() fails, pages may be left fully or partially decrypted. 2. Decrypted pages may be freed if swiotlb_alloc_tlb() determines that the physical address is too high. To fix the first issue, call set_memory_encrypted() on the allocated region after a failed decryption attempt. If that also fails, leak the pages. To fix the second issue, check that the TLB physical address is below the requested limit before decrypting. Let the caller differentiate between unsuitable physical address (=> retry from a lower zone) and allocation failures (=> no point in retrying). Cc: stable@vger.kernel.org Fixes: 79636caad361 ("swiotlb: if swiotlb is full, fall back to a transient memory pool") Signed-off-by: Petr Tesarik <petr.tesarik1@huawei-partners.com> Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-25swiotlb: do not try to allocate a TLB bigger than MAX_ORDER pagesPetr Tesarik
When allocating a new pool at runtime, reduce the number of slabs so that the allocation order is at most MAX_ORDER. This avoids a kernel warning in __alloc_pages(). The warning is relatively benign, because the pool size is subsequently reduced when allocation fails, but it is silly to start with a request that is known to fail, especially since this is the default behavior if the kernel is built with CONFIG_SWIOTLB_DYNAMIC=y and booted without any swiotlb= parameter. Reported-by: Ben Greear <greearb@candelatech.com> Closes: https://lore.kernel.org/netdev/4f173dd2-324a-0240-ff8d-abf5c191be18@candelatech.com/ Fixes: 1aaa736815eb ("swiotlb: allocate a new memory pool when existing pools are full") Signed-off-by: Petr Tesarik <petr.tesarik1@huawei-partners.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-09-27swiotlb: fix the check whether a device has used software IO TLBPetr Tesarik
When CONFIG_SWIOTLB_DYNAMIC=y, devices which do not use the software IO TLB can avoid swiotlb lookup. A flag is added by commit 1395706a1490 ("swiotlb: search the software IO TLB only if the device makes use of it"), the flag is correctly set, but it is then never checked. Add the actual check here. Note that this code is an alternative to the default pool check, not an additional check, because: 1. swiotlb_find_pool() also searches the default pool; 2. if dma_uses_io_tlb is false, the default swiotlb pool is not used. Tested in a KVM guest against a QEMU RAM-backed SATA disk over virtio and *not* using software IO TLB, this patch increases IOPS by approx 2% for 4-way parallel I/O. The write memory barrier in swiotlb_dyn_alloc() is not needed, because a newly allocated pool must always be observed by swiotlb_find_slots() before an address from that pool is passed to is_swiotlb_buffer(). Correctness was verified using the following litmus test: C swiotlb-new-pool (* * Result: Never * * Check that a newly allocated pool is always visible when the * corresponding swiotlb buffer is visible. *) { mem_pools = default; } P0(int **mem_pools, int *pool) { /* add_mem_pool() */ WRITE_ONCE(*pool, 999); rcu_assign_pointer(*mem_pools, pool); } P1(int **mem_pools, int *flag, int *buf) { /* swiotlb_find_slots() */ int *r0; int r1; rcu_read_lock(); r0 = READ_ONCE(*mem_pools); r1 = READ_ONCE(*r0); rcu_read_unlock(); if (r1) { WRITE_ONCE(*flag, 1); smp_mb(); } /* device driver (presumed) */ WRITE_ONCE(*buf, r1); } P2(int **mem_pools, int *flag, int *buf) { /* device driver (presumed) */ int r0 = READ_ONCE(*buf); /* is_swiotlb_buffer() */ int r1; int *r2; int r3; smp_rmb(); r1 = READ_ONCE(*flag); if (r1) { /* swiotlb_find_pool() */ rcu_read_lock(); r2 = READ_ONCE(*mem_pools); r3 = READ_ONCE(*r2); rcu_read_unlock(); } } exists (2:r0<>0 /\ 2:r3=0) (* Not found. *) Fixes: 1395706a1490 ("swiotlb: search the software IO TLB only if the device makes use of it") Reported-by: Jonathan Corbet <corbet@lwn.net> Closes: https://lore.kernel.org/linux-iommu/87a5uz3ob8.fsf@meer.lwn.net/ Signed-off-by: Petr Tesarik <petr@tesarici.cz> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-09-13swiotlb: use the calculated number of areasRoss Lagerwall
Commit 8ac04063354a ("swiotlb: reduce the number of areas to match actual memory pool size") calculated the reduced number of areas in swiotlb_init_remap() but didn't actually use the value. Replace usage of default_nareas accordingly. Fixes: 8ac04063354a ("swiotlb: reduce the number of areas to match actual memory pool size") Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-09-08Revert "dma-contiguous: check for memory region overlap"Zhenhua Huang
This reverts commit 3fa6456ebe13adab3ba1817c8e515a5b88f95dce. The Commit broke the CMA region creation through DT on arm64, as showed below logs with "memblock=debug": [ 0.000000] memblock_phys_alloc_range: 41943040 bytes align=0x200000 from=0x0000000000000000 max_addr=0x00000000ffffffff early_init_dt_alloc_reserved_memory_arch+0x34/0xa0 [ 0.000000] memblock_reserve: [0x00000000fd600000-0x00000000ffdfffff] memblock_alloc_range_nid+0xc0/0x19c [ 0.000000] Reserved memory: overlap with other memblock reserved region >From call flow, region we defined in DT was always reserved before entering into rmem_cma_setup. Also, rmem_cma_setup has one routine cma_init_reserved_mem to ensure the region was reserved. Checking the region not reserved here seems not correct. early_init_fdt_scan_reserved_mem: fdt_scan_reserved_mem __reserved_mem_reserve_reg early_init_dt_reserve_memory memblock_reserve(using “reg” prop case) fdt_init_reserved_mem __reserved_mem_alloc_size *early_init_dt_alloc_reserved_memory_arch* memblock_reserve(dynamic alloc case) __reserved_mem_init_node rmem_cma_setup(region overlap check here should always fail) Example DT can be used to reproduce issue: dump_mem: mem_dump_region { compatible = "shared-dma-pool"; alloc-ranges = <0x0 0x00000000 0x0 0xffffffff>; reusable; size = <0 0x2800000>; }; Signed-off-by: Zhenhua Huang <quic_zhenhuah@quicinc.com>
2023-08-31dma-pool: remove a __maybe_unused label in atomic_pool_expandChristoph Hellwig
Move the #endif a line so that free_page label is only seen by the compile pass when actually used. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chunhui He <hchunhui@mail.ustc.edu.cn> Reviewed-by: Robin Murphy <roin.murphy@arm.com>
2023-08-30dma-contiguous: fix the Kconfig entry for CONFIG_DMA_NUMA_CMAChristoph Hellwig
It makes no sense to expose CONFIG_DMA_NUMA_CMA if CONFIG_NUMA is not enabled, and random config options shouldn't be default unless there is a good reason. Replace the default NUMA with a depends on to fix both issues. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <roin.murphy@arm.com>
2023-08-30dma-debug: don't call __dma_entry_alloc_check_leak() under free_entries_lockSergey Senozhatsky
__dma_entry_alloc_check_leak() calls into printk -> serial console output (qcom geni) and grabs port->lock under free_entries_lock spin lock, which is a reverse locking dependency chain as qcom_geni IRQ handler can call into dma-debug code and grab free_entries_lock under port->lock. Move __dma_entry_alloc_check_leak() call out of free_entries_lock scope so that we don't acquire serial console's port->lock under it. Trimmed-down lockdep splat: The existing dependency chain (in reverse order) is: -> #2 (free_entries_lock){-.-.}-{2:2}: _raw_spin_lock_irqsave+0x60/0x80 dma_entry_alloc+0x38/0x110 debug_dma_map_page+0x60/0xf8 dma_map_page_attrs+0x1e0/0x230 dma_map_single_attrs.constprop.0+0x6c/0xc8 geni_se_rx_dma_prep+0x40/0xcc qcom_geni_serial_isr+0x310/0x510 __handle_irq_event_percpu+0x110/0x244 handle_irq_event_percpu+0x20/0x54 handle_irq_event+0x50/0x88 handle_fasteoi_irq+0xa4/0xcc handle_irq_desc+0x28/0x40 generic_handle_domain_irq+0x24/0x30 gic_handle_irq+0xc4/0x148 do_interrupt_handler+0xa4/0xb0 el1_interrupt+0x34/0x64 el1h_64_irq_handler+0x18/0x24 el1h_64_irq+0x64/0x68 arch_local_irq_enable+0x4/0x8 ____do_softirq+0x18/0x24 ... -> #1 (&port_lock_key){-.-.}-{2:2}: _raw_spin_lock_irqsave+0x60/0x80 qcom_geni_serial_console_write+0x184/0x1dc console_flush_all+0x344/0x454 console_unlock+0x94/0xf0 vprintk_emit+0x238/0x24c vprintk_default+0x3c/0x48 vprintk+0xb4/0xbc _printk+0x68/0x90 register_console+0x230/0x38c uart_add_one_port+0x338/0x494 qcom_geni_serial_probe+0x390/0x424 platform_probe+0x70/0xc0 really_probe+0x148/0x280 __driver_probe_device+0xfc/0x114 driver_probe_device+0x44/0x100 __device_attach_driver+0x64/0xdc bus_for_each_drv+0xb0/0xd8 __device_attach+0xe4/0x140 device_initial_probe+0x1c/0x28 bus_probe_device+0x44/0xb0 device_add+0x538/0x668 of_device_add+0x44/0x50 of_platform_device_create_pdata+0x94/0xc8 of_platform_bus_create+0x270/0x304 of_platform_populate+0xac/0xc4 devm_of_platform_populate+0x60/0xac geni_se_probe+0x154/0x160 platform_probe+0x70/0xc0 ... -> #0 (console_owner){-...}-{0:0}: __lock_acquire+0xdf8/0x109c lock_acquire+0x234/0x284 console_flush_all+0x330/0x454 console_unlock+0x94/0xf0 vprintk_emit+0x238/0x24c vprintk_default+0x3c/0x48 vprintk+0xb4/0xbc _printk+0x68/0x90 dma_entry_alloc+0xb4/0x110 debug_dma_map_sg+0xdc/0x2f8 __dma_map_sg_attrs+0xac/0xe4 dma_map_sgtable+0x30/0x4c get_pages+0x1d4/0x1e4 [msm] msm_gem_pin_pages_locked+0x38/0xac [msm] msm_gem_pin_vma_locked+0x58/0x88 [msm] msm_ioctl_gem_submit+0xde4/0x13ac [msm] drm_ioctl_kernel+0xe0/0x15c drm_ioctl+0x2e8/0x3f4 vfs_ioctl+0x30/0x50 ... Chain exists of: console_owner --> &port_lock_key --> free_entries_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(free_entries_lock); lock(&port_lock_key); lock(free_entries_lock); lock(console_owner); *** DEADLOCK *** Call trace: dump_backtrace+0xb4/0xf0 show_stack+0x20/0x30 dump_stack_lvl+0x60/0x84 dump_stack+0x18/0x24 print_circular_bug+0x1cc/0x234 check_noncircular+0x78/0xac __lock_acquire+0xdf8/0x109c lock_acquire+0x234/0x284 console_flush_all+0x330/0x454 console_unlock+0x94/0xf0 vprintk_emit+0x238/0x24c vprintk_default+0x3c/0x48 vprintk+0xb4/0xbc _printk+0x68/0x90 dma_entry_alloc+0xb4/0x110 debug_dma_map_sg+0xdc/0x2f8 __dma_map_sg_attrs+0xac/0xe4 dma_map_sgtable+0x30/0x4c get_pages+0x1d4/0x1e4 [msm] msm_gem_pin_pages_locked+0x38/0xac [msm] msm_gem_pin_vma_locked+0x58/0x88 [msm] msm_ioctl_gem_submit+0xde4/0x13ac [msm] drm_ioctl_kernel+0xe0/0x15c drm_ioctl+0x2e8/0x3f4 vfs_ioctl+0x30/0x50 ... Reported-by: Rob Clark <robdclark@chromium.org> Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-08-08swiotlb: optimize get_max_slots()Petr Tesarik
Use a simple logical shift and increment to calculate the number of slots taken by the DMA segment boundary. At least GCC-13 is not able to optimize the expression, producing this horrible assembly code on x86: cmpq $-1, %rcx je .L364 addq $2048, %rcx shrq $11, %rcx movq %rcx, %r13 .L331: // rest of the function here... // after function epilogue and return: .L364: movabsq $9007199254740992, %r13 jmp .L331 After the optimization, the code looks more reasonable: shrq $11, %r11 leaq 1(%r11), %rbx Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-08-08swiotlb: move slot allocation explanation comment where it belongsPetr Tesarik
Move the comment down in front of the loop that actually sets the list member of struct io_tlb_slot to zero. Fixes: 26a7e094783d ("swiotlb: refactor swiotlb_tbl_map_single") Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-08-01swiotlb: search the software IO TLB only if the device makes use of itPetr Tesarik
Skip searching the software IO TLB if a device has never used it, making sure these devices are not affected by the introduction of multiple IO TLB memory pools. Additional memory barrier is required to ensure that the new value of the flag is visible to other CPUs after mapping a new bounce buffer. For efficiency, the flag check should be inlined, and then the memory barrier must be moved to is_swiotlb_buffer(). However, it can replace the existing barrier in swiotlb_find_pool(), because all callers use is_swiotlb_buffer() first to verify that the buffer address belongs to the software IO TLB. Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-08-01swiotlb: allocate a new memory pool when existing pools are fullPetr Tesarik
When swiotlb_find_slots() cannot find suitable slots, schedule the allocation of a new memory pool. It is not possible to allocate the pool immediately, because this code may run in interrupt context, which is not suitable for large memory allocations. This means that the memory pool will be available too late for the currently requested mapping, but the stress on the software IO TLB allocator is likely to continue, and subsequent allocations will benefit from the additional pool eventually. Keep all memory pools for an allocator in an RCU list to avoid locking on the read side. For modifications, add a new spinlock to struct io_tlb_mem. The spinlock also protects updates to the total number of slabs (nslabs in struct io_tlb_mem), but not reads of the value. Readers may therefore encounter a stale value, but this is not an issue: - swiotlb_tbl_map_single() and is_swiotlb_active() only check for non-zero value. This is ensured by the existence of the default memory pool, allocated at boot. - The exact value is used only for non-critical purposes (debugfs, kernel messages). Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-08-01swiotlb: determine potential physical address limitPetr Tesarik
The value returned by default_swiotlb_limit() should be constant, because it is used to decide whether DMA can be used. To allow allocating memory pools on the fly, use the maximum possible physical address rather than the highest address used by the default pool. For swiotlb_init_remap(), this is either an arch-specific limit used by memblock_alloc_low(), or the highest directly mapped physical address if the initialization flags include SWIOTLB_ANY. For swiotlb_init_late(), the highest address is determined by the GFP flags. Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-08-01swiotlb: if swiotlb is full, fall back to a transient memory poolPetr Tesarik
Try to allocate a transient memory pool if no suitable slots can be found and the respective SWIOTLB is allowed to grow. The transient pool is just enough big for this one bounce buffer. It is inserted into a per-device list of transient memory pools, and it is freed again when the bounce buffer is unmapped. Transient memory pools are kept in an RCU list. A memory barrier is required after adding a new entry, because any address within a transient buffer must be immediately recognized as belonging to the SWIOTLB, even if it is passed to another CPU. Deletion does not require any synchronization beyond RCU ordering guarantees. After a buffer is unmapped, its physical addresses may no longer be passed to the DMA API, so the memory range of the corresponding stale entry in the RCU list never matches. If the memory range gets allocated again, then it happens only after a RCU quiescent state. Since bounce buffers can now be allocated from different pools, add a parameter to swiotlb_alloc_pool() to let the caller know which memory pool is used. Add swiotlb_find_pool() to find the memory pool corresponding to an address. This function is now also used by is_swiotlb_buffer(), because a simple boundary check is no longer sufficient. The logic in swiotlb_alloc_tlb() is taken from __dma_direct_alloc_pages(), simplified and enhanced to use coherent memory pools if needed. Note that this is not the most efficient way to provide a bounce buffer, but when a DMA buffer can't be mapped, something may (and will) actually break. At that point it is better to make an allocation, even if it may be an expensive operation. Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-08-01swiotlb: add a flag whether SWIOTLB is allowed to growPetr Tesarik
Add a config option (CONFIG_SWIOTLB_DYNAMIC) to enable or disable dynamic allocation of additional bounce buffers. If this option is set, mark the default SWIOTLB as able to grow and restricted DMA pools as unable. However, if the address of the default memory pool is explicitly queried, make the default SWIOTLB also unable to grow. This is currently used to set up PCI BAR movable regions on some Octeon MIPS boards which may not be able to use a SWIOTLB pool elsewhere in physical memory. See octeon_pci_setup() for more details. If a remap function is specified, it must be also called on any dynamically allocated pools, but there are some issues: - The remap function may block, so it should not be called from an atomic context. - There is no corresponding unremap() function if the memory pool is freed. - The only in-tree implementation (xen_swiotlb_fixup) requires that the number of slots in the memory pool is a multiple of SWIOTLB_SEGSIZE. Keep it simple for now and disable growing the SWIOTLB if a remap function was specified. Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-08-01swiotlb: separate memory pool data from other allocator dataPetr Tesarik
Carve out memory pool specific fields from struct io_tlb_mem. The original struct now contains shared data for the whole allocator, while the new struct io_tlb_pool contains data that is specific to one memory pool of (potentially) many. Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-08-01swiotlb: add documentation and rename swiotlb_do_find_slots()Petr Tesarik
Add some kernel-doc comments and move the existing documentation of struct io_tlb_slot to its correct location. The latter was forgotten in commit 942a8186eb445 ("swiotlb: move struct io_tlb_slot to swiotlb.c"). Use the opportunity to give swiotlb_do_find_slots() a more descriptive name and make it clear how it differs from swiotlb_find_slots(). Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-08-01swiotlb: make io_tlb_default_mem local to swiotlb.cPetr Tesarik
SWIOTLB implementation details should not be exposed to the rest of the kernel. This will allow to make changes to the implementation without modifying non-swiotlb code. To avoid breaking existing users, provide helper functions for the few required fields. As a bonus, using a helper function to initialize struct device allows to get rid of an #ifdef in driver core. Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-08-01swiotlb: bail out of swiotlb_init_late() if swiotlb is already allocatedPetr Tesarik
If swiotlb is allocated, immediately return 0, so callers do not have to check io_tlb_default_mem.nslabs explicitly. Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-07-31dma-contiguous: check for memory region overlapBinglei Wang
In the process of parsing the DTS, check whether the memory region specified by the DTS CMA node area overlaps with the kernel text memory space reserved by memblock before calling early_init_fdt_scan_reserved_mem. Signed-off-by: Binglei Wang <l3b2w1@gmail.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-07-31dma-contiguous: support numa CMA for specified nodeYajun Deng
The kernel parameter 'cma_pernuma=' only supports reserving the same size of CMA area for each node. We need to reserve different sizes of CMA area for specified nodes if these devices belong to different nodes. Adding another kernel parameter 'numa_cma=' to reserve CMA area for the specified node. If we want to use one of these parameters, we need to enable DMA_NUMA_CMA. At the same time, print the node id in cma_declare_contiguous_nid() if CONFIG_NUMA is enabled. Signed-off-by: Yajun Deng <yajun.deng@linux.dev> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-07-31dma-contiguous: support per-numa CMA for all architecturesYajun Deng
In the commit b7176c261cdb ("dma-contiguous: provide the ability to reserve per-numa CMA"), Barry adds DMA_PERNUMA_CMA for ARM64. But this feature is architecture independent, so support per-numa CMA for all architectures, and enable it by default if NUMA. Signed-off-by: Yajun Deng <yajun.deng@linux.dev> Tested-by: Yicong Yang <yangyicong@hisilicon.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-07-31dma-mapping: move arch_dma_set_mask() declaration to headerArnd Bergmann
This function has a __weak definition and an override that is only used on freescale powerpc chips. The powerpc definition however does not see the declaration that is in a .c file: arch/powerpc/kernel/dma-mask.c:7:6: error: no previous prototype for 'arch_dma_set_mask' [-Werror=missing-prototypes] Move it into the linux/dma-map-ops.h header where the other arch_dma_* functions are declared. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-07-31swiotlb: unexport is_swiotlb_activeChristoph Hellwig
Drivers have no business looking at dma-mapping or swiotlb internals. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Juergen Gross <jgross@suse.com>
2023-07-09Merge tag 'dma-mapping-6.5-2023-07-09' of ↵Linus Torvalds
git://git.infradead.org/users/hch/dma-mapping Pull dma-mapping fixes from Christoph Hellwig: - swiotlb area sizing fixes (Petr Tesarik) * tag 'dma-mapping-6.5-2023-07-09' of git://git.infradead.org/users/hch/dma-mapping: swiotlb: reduce the number of areas to match actual memory pool size swiotlb: always set the number of areas before allocating the pool
2023-06-29Merge tag 'dma-mapping-6.5-2023-06-28' of ↵Linus Torvalds
git://git.infradead.org/users/hch/dma-mapping Pull dma-mapping updates from Christoph Hellwig: - swiotlb cleanups (Petr Tesarik) - use kvmalloc_array (gaoxu) - a small step towards removing is_swiotlb_active (Christoph Hellwig) - fix a Kconfig typo Sui Jingfeng) * tag 'dma-mapping-6.5-2023-06-28' of git://git.infradead.org/users/hch/dma-mapping: drm/nouveau: stop using is_swiotlb_active swiotlb: use the atomic counter of total used slabs if available swiotlb: remove unused field "used" from struct io_tlb_mem dma-remap: use kvmalloc_array/kvfree for larger dma memory remap dma-mapping: fix a Kconfig typo
2023-06-29swiotlb: reduce the number of areas to match actual memory pool sizePetr Tesarik
Although the desired size of the SWIOTLB memory pool is increased in swiotlb_adjust_nareas() to match the number of areas, the actual allocation may be smaller, which may require reducing the number of areas. For example, Xen uses swiotlb_init_late(), which in turn uses the page allocator. On x86, page size is 4 KiB and MAX_ORDER is 10 (1024 pages), resulting in a maximum memory pool size of 4 MiB. This corresponds to 2048 slots of 2 KiB each. The minimum area size is 128 (IO_TLB_SEGSIZE), allowing at most 2048 / 128 = 16 areas. If num_possible_cpus() is greater than the maximum number of areas, areas are smaller than IO_TLB_SEGSIZE and contiguous groups of free slots will span multiple areas. When allocating and freeing slots, only one area will be properly locked, causing race conditions on the unlocked slots and ultimately data corruption, kernel hangs and crashes. Fixes: 20347fca71a3 ("swiotlb: split up the global swiotlb lock") Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-06-29swiotlb: always set the number of areas before allocating the poolPetr Tesarik
The number of areas defaults to the number of possible CPUs. However, the total number of slots may have to be increased after adjusting the number of areas. Consequently, the number of areas must be determined before allocating the memory pool. This is even explained with a comment in swiotlb_init_remap(), but swiotlb_init_late() adjusts the number of areas after slots are already allocated. The areas may end up being smaller than IO_TLB_SEGSIZE, which breaks per-area locking. While fixing swiotlb_init_late(), move all relevant comments before the definition of swiotlb_adjust_nareas() and convert them to kernel-doc. Fixes: 20347fca71a3 ("swiotlb: split up the global swiotlb lock") Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-06-19dma-mapping: force bouncing if the kmalloc() size is not cache-line-alignedCatalin Marinas
For direct DMA, if the size is small enough to have originated from a kmalloc() cache below ARCH_DMA_MINALIGN, check its alignment against dma_get_cache_alignment() and bounce if necessary. For larger sizes, it is the responsibility of the DMA API caller to ensure proper alignment. At this point, the kmalloc() caches are properly aligned but this will change in a subsequent patch. Architectures can opt in by selecting DMA_BOUNCE_UNALIGNED_KMALLOC. Link: https://lkml.kernel.org/r/20230612153201.554742-15-catalin.marinas@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Tested-by: Isaac J. Manjarres <isaacmanjarres@google.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Jerry Snitselaar <jsnitsel@redhat.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Jonathan Cameron <jic23@kernel.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Mike Snitzer <snitzer@kernel.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Saravana Kannan <saravanak@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19dma-mapping: name SG DMA flag helpers consistentlyRobin Murphy
sg_is_dma_bus_address() is inconsistent with the naming pattern of its corresponding setters and its own kerneldoc, so take the majority vote and rename it sg_dma_is_bus_address() (and fix up the missing underscores in the kerneldoc too). This gives us a nice clear pattern where SG DMA flags are SG_DMA_<NAME>, and the helpers for acting on them are sg_dma_<action>_<name>(). Link: https://lkml.kernel.org/r/20230612153201.554742-14-catalin.marinas@arm.com Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Link: https://lore.kernel.org/r/fa2eca2862c7ffc41b50337abffb2dfd2864d3ea.1685036694.git.robin.murphy@arm.com Tested-by: Isaac J. Manjarres <isaacmanjarres@google.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Joerg Roedel <joro@8bytes.org> Cc: Jonathan Cameron <jic23@kernel.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Mike Snitzer <snitzer@kernel.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Saravana Kannan <saravanak@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19scatterlist: add dedicated config for DMA flagsRobin Murphy
The DMA flags field will be useful for users beyond PCI P2P, so upgrade to its own dedicated config option. [catalin.marinas@arm.com: use #ifdef CONFIG_NEED_SG_DMA_FLAGS in scatterlist.h] [catalin.marinas@arm.com: update PCI_P2PDMA dma_flags comment in scatterlist.h] Link: https://lkml.kernel.org/r/20230612153201.554742-13-catalin.marinas@arm.com Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Isaac J. Manjarres <isaacmanjarres@google.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Jerry Snitselaar <jsnitsel@redhat.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Jonathan Cameron <jic23@kernel.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Mike Snitzer <snitzer@kernel.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Saravana Kannan <saravanak@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>