![Daniel J Blueman](/assets/img/avatar_default.png)
This fixes a SWIOTLB oops With SWIOTLB being enabled and straight-forward page allocation failure [1], the swiotlb_alloc_coherent fall-back path hits an issue [2], resulting in my webcam failing to work. At the time of oops, RDI is clearly a pointer to a structure which has arrived as NULL, leading to the typo in swiotlb_map_single's callsite arguments. Correctly passing the device structure [3] addresses the issue and gets my webcam working again (the allocation failure still occuring). --- [1] skype: page allocation failure. order:3, mode:0x1 Pid: 5895, comm: skype Not tainted 2.6.27-rc6-235c-debug #1 Call Trace: [<ffffffff802b7cf0>] __alloc_pages_internal+0x4a0/0x5d0 [<ffffffff802d5ddd>] alloc_pages_current+0xad/0x110 [<ffffffff802b4ccd>] __get_free_pages+0x1d/0x60 [<ffffffff8046cd39>] swiotlb_alloc_coherent+0x49/0x180 [<ffffffff80212731>] dma_alloc_coherent+0x281/0x310 [<ffffffff805621c0>] hcd_buffer_alloc+0x50/0x90 [<ffffffff805547fd>] usb_buffer_alloc+0x2d/0x40 [<ffffffffa0056763>] uvc_alloc_urb_buffers+0x53/0xf0 [uvcvideo] [<ffffffffa0056958>] uvc_init_video+0x158/0x3e0 [uvcvideo] [<ffffffffa0056c17>] uvc_video_enable+0x37/0x80 [uvcvideo] [<ffffffffa0055853>] uvc_v4l2_do_ioctl+0x723/0x1260 [uvcvideo] [<ffffffff8026dd61>] ? trace_hardirqs_off_caller+0x21/0xc0 [<ffffffff8026dd61>] ? trace_hardirqs_off_caller+0x21/0xc0 [<ffffffffa0032c9f>] video_usercopy+0x19f/0x390 [videodev] [<ffffffffa0055130>] ? uvc_v4l2_do_ioctl+0x0/0x1260 [uvcvideo] [<ffffffff8026d0ce>] ? put_lock_stats+0xe/0x30 [<ffffffffa0054dad>] uvc_v4l2_ioctl+0x4d/0x80 [uvcvideo] [<ffffffffa0045083>] native_ioctl+0x83/0x90 [compat_ioctl32] [<ffffffffa004534e>] v4l_compat_ioctl32+0x2be/0x1da4 [compat_ioctl32] [<ffffffff806aad21>] ? do_page_fault+0x3d1/0xae0 [<ffffffff80270ccd>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff80270c59>] ? trace_hardirqs_on_caller+0x149/0x1b0 [<ffffffff80270ccd>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff80329afa>] compat_sys_ioctl+0x8a/0x3c0 [<ffffffff806a700d>] ? trace_hardirqs_off_thunk+0x3a/0x3c [<ffffffff8022f816>] sysenter_dispatch+0x7/0x2c [<ffffffff806a6fce>] ? trace_hardirqs_on_thunk+0x3a/0x3f Mem-Info: Node 0 DMA per-cpu: CPU 0: hi: 0, btch: 1 usd: 0 CPU 1: hi: 0, btch: 1 usd: 0 Node 0 DMA32 per-cpu: CPU 0: hi: 186, btch: 31 usd: 3 CPU 1: hi: 186, btch: 31 usd: 0 Node 0 Normal per-cpu: CPU 0: hi: 186, btch: 31 usd: 23 CPU 1: hi: 186, btch: 31 usd: 179 Active:78545 inactive:48683 dirty:31 writeback:0 unstable:2 free:830202 slab:17516 mapped:17473 pagetables:3496 bounce:0 Node 0 DMA free:36kB min:28kB low:32kB high:40kB active:0kB inactive:0kB present:15156kB pages_scanned:0 all_unreclaimable? no lowmem_reserve[]: 0 3207 3956 3956 Node 0 DMA32 free:3197192kB min:6512kB low:8140kB high:9768kB active:0kB inactive:0kB present:3284896kB pages_scanned:0 all_unreclaimable? no lowmem_reserve[]: 0 0 748 748 Node 0 Normal free:123580kB min:1516kB low:1892kB high:2272kB active:314180kB inactive:194732kB present:766464kB pages_scanned:0 all_unreclaimable? no lowmem_reserve[]: 0 0 0 0 Node 0 DMA: 1*4kB 0*8kB 0*16kB 1*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 36kB Node 0 DMA32: 4*4kB 3*8kB 2*16kB 3*32kB 4*64kB 5*128kB 3*256kB 5*512kB 4*1024kB 5*2048kB 776*4096kB = 3197224kB Node 0 Normal: 14*4kB 14*8kB 8*16kB 6*32kB 1*64kB 3*128kB 3*256kB 2*512kB 4*1024kB 1*2048kB 28*4096kB = 123560kB 64847 total pagecache pages 0 pages in swap cache Swap cache stats: add 0, delete 0, find 0/0 Free swap = 502752kB Total swap = 502752kB 1048576 pages RAM 52120 pages reserved 71967 pages shared 143004 pages non-shared --- [2] BUG: unable to handle kernel NULL pointer dereference at 00000000000002c8 IP: [<ffffffff8046c84c>] map_single+0x1c/0x280 PGD 10e54e067 PUD 10e595067 PMD 0 Oops: 0000 [1] PREEMPT SMP DEBUG_PAGEALLOC CPU 0 Modules linked in: kvm_intel kvm microcode uvcvideo compat_ioctl32 videodev v4l1_compat shpchp pci_hotplug Pid: 5895, comm: skype Not tainted 2.6.27-rc6-235c-debug #1 RIP: 0010:[<ffffffff8046c84c>] [<ffffffff8046c84c>] map_single+0x1c/0x280 RSP: 0018:ffff88010e78d988 EFLAGS: 00210296 RAX: 0000780000000000 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000005000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88010e78d9e8 R08: 0000000000000000 R09: 0000000000000001 R10: ffff88010e78d698 R11: 0000000000000001 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000005000 R15: ffff88012f1c9968 FS: 0000000000000000(0000) GS:ffffffff80a6cdc0(0063) knlGS:00000000f6355b90 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000000002c8 CR3: 000000010e57d000 CR4: 00000000000026e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process skype (pid: 5895, threadinfo ffff88010e78c000, task ffff88012b9cc460) Stack: 0000000200000000 0000000000005000 0000000000000000 0000000000000000 00000000000017b8 0000000000000000 ffff88010e78d9c8 0000000000000000 0000000000000002 0000000000000000 0000000000005000 ffff88012f1c9968 Call Trace: [<ffffffff8046cbb0>] swiotlb_map_single_attrs+0x60/0xf0 [<ffffffff8046cc4c>] swiotlb_map_single+0xc/0x10 [<ffffffff8046cdee>] swiotlb_alloc_coherent+0xfe/0x180 [<ffffffff80212731>] dma_alloc_coherent+0x281/0x310 [<ffffffff805621c0>] hcd_buffer_alloc+0x50/0x90 [<ffffffff805547fd>] usb_buffer_alloc+0x2d/0x40 [<ffffffffa0056763>] uvc_alloc_urb_buffers+0x53/0xf0 [uvcvideo] [<ffffffffa0056958>] uvc_init_video+0x158/0x3e0 [uvcvideo] [<ffffffffa0056c17>] uvc_video_enable+0x37/0x80 [uvcvideo] [<ffffffffa0055853>] uvc_v4l2_do_ioctl+0x723/0x1260 [uvcvideo] [<ffffffff8026dd61>] ? trace_hardirqs_off_caller+0x21/0xc0 [<ffffffff8026dd61>] ? trace_hardirqs_off_caller+0x21/0xc0 [<ffffffffa0032c9f>] video_usercopy+0x19f/0x390 [videodev] [<ffffffffa0055130>] ? uvc_v4l2_do_ioctl+0x0/0x1260 [uvcvideo] [<ffffffff8026d0ce>] ? put_lock_stats+0xe/0x30 [<ffffffffa0054dad>] uvc_v4l2_ioctl+0x4d/0x80 [uvcvideo] [<ffffffffa0045083>] native_ioctl+0x83/0x90 [compat_ioctl32] [<ffffffffa004534e>] v4l_compat_ioctl32+0x2be/0x1da4 [compat_ioctl32] [<ffffffff806aad21>] ? do_page_fault+0x3d1/0xae0 [<ffffffff80270ccd>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff80270c59>] ? trace_hardirqs_on_caller+0x149/0x1b0 [<ffffffff80270ccd>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff80329afa>] compat_sys_ioctl+0x8a/0x3c0 [<ffffffff806a700d>] ? trace_hardirqs_off_thunk+0x3a/0x3c [<ffffffff8022f816>] sysenter_dispatch+0x7/0x2c [<ffffffff806a6fce>] ? trace_hardirqs_on_thunk+0x3a/0x3f Code: 45 31 c0 48 89 e5 e8 a4 ff ff ff c9 c3 66 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 ec 38 48 89 75 b0 48 89 55 a8 89 4d a4 <48> 8b 87 c8 02 00 00 48 85 c0 0f 84 1c 02 00 00 48 8b 58 08 48 RIP [<ffffffff8046c84c>] map_single+0x1c/0x280 RSP <ffff88010e78d988> CR2: 00000000000002c8 ---[ end trace 5d15baeeb7025a0e ]--- --- [3] ffffffff8046c830 <map_single>: map_single(): /store/kernel/linux/lib/swiotlb.c:291 ffffffff8046c830: 55 push %rbp ffffffff8046c831: 48 89 e5 mov %rsp,%rbp ffffffff8046c834: 41 57 push %r15 ffffffff8046c836: 41 56 push %r14 ffffffff8046c838: 41 55 push %r13 ffffffff8046c83a: 41 54 push %r12 ffffffff8046c83c: 53 push %rbx ffffffff8046c83d: 48 83 ec 38 sub $0x38,%rsp ffffffff8046c841: 48 89 75 b0 mov %rsi,-0x50(%rbp) ffffffff8046c845: 48 89 55 a8 mov %rdx,-0x58(%rbp) ffffffff8046c849: 89 4d a4 mov %ecx,-0x5c(%rbp) dma_get_seg_boundary(): /store/kernel/linux/include/linux/dma-mapping.h:80 ffffffff8046c84c: 48 8b 87 c8 02 00 00 mov 0x2c8(%rdi),%rax <---- --- [4] Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
858 lines
24 KiB
C
858 lines
24 KiB
C
/*
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* Dynamic DMA mapping support.
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*
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* This implementation is a fallback for platforms that do not support
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* I/O TLBs (aka DMA address translation hardware).
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* Copyright (C) 2000 Asit Mallick <Asit.K.Mallick@intel.com>
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* Copyright (C) 2000 Goutham Rao <goutham.rao@intel.com>
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* Copyright (C) 2000, 2003 Hewlett-Packard Co
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* David Mosberger-Tang <davidm@hpl.hp.com>
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*
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* 03/05/07 davidm Switch from PCI-DMA to generic device DMA API.
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* 00/12/13 davidm Rename to swiotlb.c and add mark_clean() to avoid
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* unnecessary i-cache flushing.
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* 04/07/.. ak Better overflow handling. Assorted fixes.
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* 05/09/10 linville Add support for syncing ranges, support syncing for
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* DMA_BIDIRECTIONAL mappings, miscellaneous cleanup.
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*/
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#include <linux/cache.h>
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#include <linux/dma-mapping.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/spinlock.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/ctype.h>
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#include <asm/io.h>
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#include <asm/dma.h>
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#include <asm/scatterlist.h>
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#include <linux/init.h>
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#include <linux/bootmem.h>
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#include <linux/iommu-helper.h>
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#define OFFSET(val,align) ((unsigned long) \
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( (val) & ( (align) - 1)))
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#define SG_ENT_VIRT_ADDRESS(sg) (sg_virt((sg)))
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#define SG_ENT_PHYS_ADDRESS(sg) virt_to_bus(SG_ENT_VIRT_ADDRESS(sg))
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/*
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* Maximum allowable number of contiguous slabs to map,
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* must be a power of 2. What is the appropriate value ?
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* The complexity of {map,unmap}_single is linearly dependent on this value.
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*/
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#define IO_TLB_SEGSIZE 128
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/*
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* log of the size of each IO TLB slab. The number of slabs is command line
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* controllable.
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*/
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#define IO_TLB_SHIFT 11
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#define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
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/*
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* Minimum IO TLB size to bother booting with. Systems with mainly
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* 64bit capable cards will only lightly use the swiotlb. If we can't
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* allocate a contiguous 1MB, we're probably in trouble anyway.
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*/
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#define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
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/*
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* Enumeration for sync targets
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*/
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enum dma_sync_target {
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SYNC_FOR_CPU = 0,
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SYNC_FOR_DEVICE = 1,
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};
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int swiotlb_force;
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/*
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* Used to do a quick range check in swiotlb_unmap_single and
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* swiotlb_sync_single_*, to see if the memory was in fact allocated by this
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* API.
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*/
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static char *io_tlb_start, *io_tlb_end;
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/*
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* The number of IO TLB blocks (in groups of 64) betweeen io_tlb_start and
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* io_tlb_end. This is command line adjustable via setup_io_tlb_npages.
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*/
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static unsigned long io_tlb_nslabs;
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/*
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* When the IOMMU overflows we return a fallback buffer. This sets the size.
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*/
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static unsigned long io_tlb_overflow = 32*1024;
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void *io_tlb_overflow_buffer;
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/*
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* This is a free list describing the number of free entries available from
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* each index
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*/
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static unsigned int *io_tlb_list;
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static unsigned int io_tlb_index;
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/*
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* We need to save away the original address corresponding to a mapped entry
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* for the sync operations.
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*/
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static unsigned char **io_tlb_orig_addr;
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/*
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* Protect the above data structures in the map and unmap calls
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*/
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static DEFINE_SPINLOCK(io_tlb_lock);
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static int __init
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setup_io_tlb_npages(char *str)
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{
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if (isdigit(*str)) {
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io_tlb_nslabs = simple_strtoul(str, &str, 0);
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/* avoid tail segment of size < IO_TLB_SEGSIZE */
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io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
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}
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if (*str == ',')
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++str;
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if (!strcmp(str, "force"))
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swiotlb_force = 1;
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return 1;
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}
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__setup("swiotlb=", setup_io_tlb_npages);
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/* make io_tlb_overflow tunable too? */
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/*
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* Statically reserve bounce buffer space and initialize bounce buffer data
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* structures for the software IO TLB used to implement the DMA API.
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*/
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void __init
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swiotlb_init_with_default_size(size_t default_size)
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{
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unsigned long i, bytes;
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if (!io_tlb_nslabs) {
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io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
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io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
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}
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bytes = io_tlb_nslabs << IO_TLB_SHIFT;
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/*
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* Get IO TLB memory from the low pages
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*/
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io_tlb_start = alloc_bootmem_low_pages(bytes);
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if (!io_tlb_start)
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panic("Cannot allocate SWIOTLB buffer");
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io_tlb_end = io_tlb_start + bytes;
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/*
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* Allocate and initialize the free list array. This array is used
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* to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
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* between io_tlb_start and io_tlb_end.
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*/
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io_tlb_list = alloc_bootmem(io_tlb_nslabs * sizeof(int));
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for (i = 0; i < io_tlb_nslabs; i++)
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io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
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io_tlb_index = 0;
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io_tlb_orig_addr = alloc_bootmem(io_tlb_nslabs * sizeof(char *));
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/*
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* Get the overflow emergency buffer
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*/
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io_tlb_overflow_buffer = alloc_bootmem_low(io_tlb_overflow);
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if (!io_tlb_overflow_buffer)
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panic("Cannot allocate SWIOTLB overflow buffer!\n");
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printk(KERN_INFO "Placing software IO TLB between 0x%lx - 0x%lx\n",
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virt_to_bus(io_tlb_start), virt_to_bus(io_tlb_end));
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}
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void __init
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swiotlb_init(void)
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{
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swiotlb_init_with_default_size(64 * (1<<20)); /* default to 64MB */
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}
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/*
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* Systems with larger DMA zones (those that don't support ISA) can
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* initialize the swiotlb later using the slab allocator if needed.
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* This should be just like above, but with some error catching.
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*/
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int
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swiotlb_late_init_with_default_size(size_t default_size)
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{
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unsigned long i, bytes, req_nslabs = io_tlb_nslabs;
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unsigned int order;
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if (!io_tlb_nslabs) {
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io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
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io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
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}
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/*
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* Get IO TLB memory from the low pages
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*/
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order = get_order(io_tlb_nslabs << IO_TLB_SHIFT);
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io_tlb_nslabs = SLABS_PER_PAGE << order;
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bytes = io_tlb_nslabs << IO_TLB_SHIFT;
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while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
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io_tlb_start = (char *)__get_free_pages(GFP_DMA | __GFP_NOWARN,
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order);
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if (io_tlb_start)
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break;
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order--;
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}
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if (!io_tlb_start)
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goto cleanup1;
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if (order != get_order(bytes)) {
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printk(KERN_WARNING "Warning: only able to allocate %ld MB "
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"for software IO TLB\n", (PAGE_SIZE << order) >> 20);
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io_tlb_nslabs = SLABS_PER_PAGE << order;
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bytes = io_tlb_nslabs << IO_TLB_SHIFT;
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}
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io_tlb_end = io_tlb_start + bytes;
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memset(io_tlb_start, 0, bytes);
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/*
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* Allocate and initialize the free list array. This array is used
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* to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
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* between io_tlb_start and io_tlb_end.
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*/
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io_tlb_list = (unsigned int *)__get_free_pages(GFP_KERNEL,
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get_order(io_tlb_nslabs * sizeof(int)));
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if (!io_tlb_list)
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goto cleanup2;
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for (i = 0; i < io_tlb_nslabs; i++)
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io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
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io_tlb_index = 0;
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io_tlb_orig_addr = (unsigned char **)__get_free_pages(GFP_KERNEL,
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get_order(io_tlb_nslabs * sizeof(char *)));
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if (!io_tlb_orig_addr)
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goto cleanup3;
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memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(char *));
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/*
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* Get the overflow emergency buffer
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*/
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io_tlb_overflow_buffer = (void *)__get_free_pages(GFP_DMA,
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get_order(io_tlb_overflow));
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if (!io_tlb_overflow_buffer)
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goto cleanup4;
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printk(KERN_INFO "Placing %luMB software IO TLB between 0x%lx - "
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"0x%lx\n", bytes >> 20,
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virt_to_bus(io_tlb_start), virt_to_bus(io_tlb_end));
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return 0;
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cleanup4:
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free_pages((unsigned long)io_tlb_orig_addr, get_order(io_tlb_nslabs *
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sizeof(char *)));
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io_tlb_orig_addr = NULL;
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cleanup3:
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free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
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sizeof(int)));
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io_tlb_list = NULL;
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cleanup2:
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io_tlb_end = NULL;
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free_pages((unsigned long)io_tlb_start, order);
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io_tlb_start = NULL;
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cleanup1:
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io_tlb_nslabs = req_nslabs;
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return -ENOMEM;
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}
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static int
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address_needs_mapping(struct device *hwdev, dma_addr_t addr)
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{
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dma_addr_t mask = 0xffffffff;
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/* If the device has a mask, use it, otherwise default to 32 bits */
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if (hwdev && hwdev->dma_mask)
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mask = *hwdev->dma_mask;
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return (addr & ~mask) != 0;
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}
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/*
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* Allocates bounce buffer and returns its kernel virtual address.
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*/
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static void *
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map_single(struct device *hwdev, char *buffer, size_t size, int dir)
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{
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unsigned long flags;
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char *dma_addr;
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unsigned int nslots, stride, index, wrap;
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int i;
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unsigned long start_dma_addr;
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unsigned long mask;
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unsigned long offset_slots;
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unsigned long max_slots;
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|
mask = dma_get_seg_boundary(hwdev);
|
|
start_dma_addr = virt_to_bus(io_tlb_start) & mask;
|
|
|
|
offset_slots = ALIGN(start_dma_addr, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
|
|
max_slots = mask + 1
|
|
? ALIGN(mask + 1, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT
|
|
: 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
|
|
|
|
/*
|
|
* For mappings greater than a page, we limit the stride (and
|
|
* hence alignment) to a page size.
|
|
*/
|
|
nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
|
|
if (size > PAGE_SIZE)
|
|
stride = (1 << (PAGE_SHIFT - IO_TLB_SHIFT));
|
|
else
|
|
stride = 1;
|
|
|
|
BUG_ON(!nslots);
|
|
|
|
/*
|
|
* Find suitable number of IO TLB entries size that will fit this
|
|
* request and allocate a buffer from that IO TLB pool.
|
|
*/
|
|
spin_lock_irqsave(&io_tlb_lock, flags);
|
|
index = ALIGN(io_tlb_index, stride);
|
|
if (index >= io_tlb_nslabs)
|
|
index = 0;
|
|
wrap = index;
|
|
|
|
do {
|
|
while (iommu_is_span_boundary(index, nslots, offset_slots,
|
|
max_slots)) {
|
|
index += stride;
|
|
if (index >= io_tlb_nslabs)
|
|
index = 0;
|
|
if (index == wrap)
|
|
goto not_found;
|
|
}
|
|
|
|
/*
|
|
* If we find a slot that indicates we have 'nslots' number of
|
|
* contiguous buffers, we allocate the buffers from that slot
|
|
* and mark the entries as '0' indicating unavailable.
|
|
*/
|
|
if (io_tlb_list[index] >= nslots) {
|
|
int count = 0;
|
|
|
|
for (i = index; i < (int) (index + nslots); i++)
|
|
io_tlb_list[i] = 0;
|
|
for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE - 1) && io_tlb_list[i]; i--)
|
|
io_tlb_list[i] = ++count;
|
|
dma_addr = io_tlb_start + (index << IO_TLB_SHIFT);
|
|
|
|
/*
|
|
* Update the indices to avoid searching in the next
|
|
* round.
|
|
*/
|
|
io_tlb_index = ((index + nslots) < io_tlb_nslabs
|
|
? (index + nslots) : 0);
|
|
|
|
goto found;
|
|
}
|
|
index += stride;
|
|
if (index >= io_tlb_nslabs)
|
|
index = 0;
|
|
} while (index != wrap);
|
|
|
|
not_found:
|
|
spin_unlock_irqrestore(&io_tlb_lock, flags);
|
|
return NULL;
|
|
found:
|
|
spin_unlock_irqrestore(&io_tlb_lock, flags);
|
|
|
|
/*
|
|
* Save away the mapping from the original address to the DMA address.
|
|
* This is needed when we sync the memory. Then we sync the buffer if
|
|
* needed.
|
|
*/
|
|
for (i = 0; i < nslots; i++)
|
|
io_tlb_orig_addr[index+i] = buffer + (i << IO_TLB_SHIFT);
|
|
if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
|
|
memcpy(dma_addr, buffer, size);
|
|
|
|
return dma_addr;
|
|
}
|
|
|
|
/*
|
|
* dma_addr is the kernel virtual address of the bounce buffer to unmap.
|
|
*/
|
|
static void
|
|
unmap_single(struct device *hwdev, char *dma_addr, size_t size, int dir)
|
|
{
|
|
unsigned long flags;
|
|
int i, count, nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
|
|
int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
|
|
char *buffer = io_tlb_orig_addr[index];
|
|
|
|
/*
|
|
* First, sync the memory before unmapping the entry
|
|
*/
|
|
if (buffer && ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
|
|
/*
|
|
* bounce... copy the data back into the original buffer * and
|
|
* delete the bounce buffer.
|
|
*/
|
|
memcpy(buffer, dma_addr, size);
|
|
|
|
/*
|
|
* Return the buffer to the free list by setting the corresponding
|
|
* entries to indicate the number of contigous entries available.
|
|
* While returning the entries to the free list, we merge the entries
|
|
* with slots below and above the pool being returned.
|
|
*/
|
|
spin_lock_irqsave(&io_tlb_lock, flags);
|
|
{
|
|
count = ((index + nslots) < ALIGN(index + 1, IO_TLB_SEGSIZE) ?
|
|
io_tlb_list[index + nslots] : 0);
|
|
/*
|
|
* Step 1: return the slots to the free list, merging the
|
|
* slots with superceeding slots
|
|
*/
|
|
for (i = index + nslots - 1; i >= index; i--)
|
|
io_tlb_list[i] = ++count;
|
|
/*
|
|
* Step 2: merge the returned slots with the preceding slots,
|
|
* if available (non zero)
|
|
*/
|
|
for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE -1) && io_tlb_list[i]; i--)
|
|
io_tlb_list[i] = ++count;
|
|
}
|
|
spin_unlock_irqrestore(&io_tlb_lock, flags);
|
|
}
|
|
|
|
static void
|
|
sync_single(struct device *hwdev, char *dma_addr, size_t size,
|
|
int dir, int target)
|
|
{
|
|
int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
|
|
char *buffer = io_tlb_orig_addr[index];
|
|
|
|
buffer += ((unsigned long)dma_addr & ((1 << IO_TLB_SHIFT) - 1));
|
|
|
|
switch (target) {
|
|
case SYNC_FOR_CPU:
|
|
if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
|
|
memcpy(buffer, dma_addr, size);
|
|
else
|
|
BUG_ON(dir != DMA_TO_DEVICE);
|
|
break;
|
|
case SYNC_FOR_DEVICE:
|
|
if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))
|
|
memcpy(dma_addr, buffer, size);
|
|
else
|
|
BUG_ON(dir != DMA_FROM_DEVICE);
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
}
|
|
|
|
void *
|
|
swiotlb_alloc_coherent(struct device *hwdev, size_t size,
|
|
dma_addr_t *dma_handle, gfp_t flags)
|
|
{
|
|
dma_addr_t dev_addr;
|
|
void *ret;
|
|
int order = get_order(size);
|
|
|
|
/*
|
|
* XXX fix me: the DMA API should pass us an explicit DMA mask
|
|
* instead, or use ZONE_DMA32 (ia64 overloads ZONE_DMA to be a ~32
|
|
* bit range instead of a 16MB one).
|
|
*/
|
|
flags |= GFP_DMA;
|
|
|
|
ret = (void *)__get_free_pages(flags, order);
|
|
if (ret && address_needs_mapping(hwdev, virt_to_bus(ret))) {
|
|
/*
|
|
* The allocated memory isn't reachable by the device.
|
|
* Fall back on swiotlb_map_single().
|
|
*/
|
|
free_pages((unsigned long) ret, order);
|
|
ret = NULL;
|
|
}
|
|
if (!ret) {
|
|
/*
|
|
* We are either out of memory or the device can't DMA
|
|
* to GFP_DMA memory; fall back on
|
|
* swiotlb_map_single(), which will grab memory from
|
|
* the lowest available address range.
|
|
*/
|
|
dma_addr_t handle;
|
|
handle = swiotlb_map_single(hwdev, NULL, size, DMA_FROM_DEVICE);
|
|
if (swiotlb_dma_mapping_error(hwdev, handle))
|
|
return NULL;
|
|
|
|
ret = bus_to_virt(handle);
|
|
}
|
|
|
|
memset(ret, 0, size);
|
|
dev_addr = virt_to_bus(ret);
|
|
|
|
/* Confirm address can be DMA'd by device */
|
|
if (address_needs_mapping(hwdev, dev_addr)) {
|
|
printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
|
|
(unsigned long long)*hwdev->dma_mask,
|
|
(unsigned long long)dev_addr);
|
|
panic("swiotlb_alloc_coherent: allocated memory is out of "
|
|
"range for device");
|
|
}
|
|
*dma_handle = dev_addr;
|
|
return ret;
|
|
}
|
|
|
|
void
|
|
swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
|
|
dma_addr_t dma_handle)
|
|
{
|
|
WARN_ON(irqs_disabled());
|
|
if (!(vaddr >= (void *)io_tlb_start
|
|
&& vaddr < (void *)io_tlb_end))
|
|
free_pages((unsigned long) vaddr, get_order(size));
|
|
else
|
|
/* DMA_TO_DEVICE to avoid memcpy in unmap_single */
|
|
swiotlb_unmap_single (hwdev, dma_handle, size, DMA_TO_DEVICE);
|
|
}
|
|
|
|
static void
|
|
swiotlb_full(struct device *dev, size_t size, int dir, int do_panic)
|
|
{
|
|
/*
|
|
* Ran out of IOMMU space for this operation. This is very bad.
|
|
* Unfortunately the drivers cannot handle this operation properly.
|
|
* unless they check for dma_mapping_error (most don't)
|
|
* When the mapping is small enough return a static buffer to limit
|
|
* the damage, or panic when the transfer is too big.
|
|
*/
|
|
printk(KERN_ERR "DMA: Out of SW-IOMMU space for %zu bytes at "
|
|
"device %s\n", size, dev ? dev->bus_id : "?");
|
|
|
|
if (size > io_tlb_overflow && do_panic) {
|
|
if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)
|
|
panic("DMA: Memory would be corrupted\n");
|
|
if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
|
|
panic("DMA: Random memory would be DMAed\n");
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Map a single buffer of the indicated size for DMA in streaming mode. The
|
|
* physical address to use is returned.
|
|
*
|
|
* Once the device is given the dma address, the device owns this memory until
|
|
* either swiotlb_unmap_single or swiotlb_dma_sync_single is performed.
|
|
*/
|
|
dma_addr_t
|
|
swiotlb_map_single_attrs(struct device *hwdev, void *ptr, size_t size,
|
|
int dir, struct dma_attrs *attrs)
|
|
{
|
|
dma_addr_t dev_addr = virt_to_bus(ptr);
|
|
void *map;
|
|
|
|
BUG_ON(dir == DMA_NONE);
|
|
/*
|
|
* If the pointer passed in happens to be in the device's DMA window,
|
|
* we can safely return the device addr and not worry about bounce
|
|
* buffering it.
|
|
*/
|
|
if (!address_needs_mapping(hwdev, dev_addr) && !swiotlb_force)
|
|
return dev_addr;
|
|
|
|
/*
|
|
* Oh well, have to allocate and map a bounce buffer.
|
|
*/
|
|
map = map_single(hwdev, ptr, size, dir);
|
|
if (!map) {
|
|
swiotlb_full(hwdev, size, dir, 1);
|
|
map = io_tlb_overflow_buffer;
|
|
}
|
|
|
|
dev_addr = virt_to_bus(map);
|
|
|
|
/*
|
|
* Ensure that the address returned is DMA'ble
|
|
*/
|
|
if (address_needs_mapping(hwdev, dev_addr))
|
|
panic("map_single: bounce buffer is not DMA'ble");
|
|
|
|
return dev_addr;
|
|
}
|
|
EXPORT_SYMBOL(swiotlb_map_single_attrs);
|
|
|
|
dma_addr_t
|
|
swiotlb_map_single(struct device *hwdev, void *ptr, size_t size, int dir)
|
|
{
|
|
return swiotlb_map_single_attrs(hwdev, ptr, size, dir, NULL);
|
|
}
|
|
|
|
/*
|
|
* Unmap a single streaming mode DMA translation. The dma_addr and size must
|
|
* match what was provided for in a previous swiotlb_map_single call. All
|
|
* other usages are undefined.
|
|
*
|
|
* After this call, reads by the cpu to the buffer are guaranteed to see
|
|
* whatever the device wrote there.
|
|
*/
|
|
void
|
|
swiotlb_unmap_single_attrs(struct device *hwdev, dma_addr_t dev_addr,
|
|
size_t size, int dir, struct dma_attrs *attrs)
|
|
{
|
|
char *dma_addr = bus_to_virt(dev_addr);
|
|
|
|
BUG_ON(dir == DMA_NONE);
|
|
if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
|
|
unmap_single(hwdev, dma_addr, size, dir);
|
|
else if (dir == DMA_FROM_DEVICE)
|
|
dma_mark_clean(dma_addr, size);
|
|
}
|
|
EXPORT_SYMBOL(swiotlb_unmap_single_attrs);
|
|
|
|
void
|
|
swiotlb_unmap_single(struct device *hwdev, dma_addr_t dev_addr, size_t size,
|
|
int dir)
|
|
{
|
|
return swiotlb_unmap_single_attrs(hwdev, dev_addr, size, dir, NULL);
|
|
}
|
|
/*
|
|
* Make physical memory consistent for a single streaming mode DMA translation
|
|
* after a transfer.
|
|
*
|
|
* If you perform a swiotlb_map_single() but wish to interrogate the buffer
|
|
* using the cpu, yet do not wish to teardown the dma mapping, you must
|
|
* call this function before doing so. At the next point you give the dma
|
|
* address back to the card, you must first perform a
|
|
* swiotlb_dma_sync_for_device, and then the device again owns the buffer
|
|
*/
|
|
static void
|
|
swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
|
|
size_t size, int dir, int target)
|
|
{
|
|
char *dma_addr = bus_to_virt(dev_addr);
|
|
|
|
BUG_ON(dir == DMA_NONE);
|
|
if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
|
|
sync_single(hwdev, dma_addr, size, dir, target);
|
|
else if (dir == DMA_FROM_DEVICE)
|
|
dma_mark_clean(dma_addr, size);
|
|
}
|
|
|
|
void
|
|
swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
|
|
size_t size, int dir)
|
|
{
|
|
swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU);
|
|
}
|
|
|
|
void
|
|
swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
|
|
size_t size, int dir)
|
|
{
|
|
swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE);
|
|
}
|
|
|
|
/*
|
|
* Same as above, but for a sub-range of the mapping.
|
|
*/
|
|
static void
|
|
swiotlb_sync_single_range(struct device *hwdev, dma_addr_t dev_addr,
|
|
unsigned long offset, size_t size,
|
|
int dir, int target)
|
|
{
|
|
char *dma_addr = bus_to_virt(dev_addr) + offset;
|
|
|
|
BUG_ON(dir == DMA_NONE);
|
|
if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
|
|
sync_single(hwdev, dma_addr, size, dir, target);
|
|
else if (dir == DMA_FROM_DEVICE)
|
|
dma_mark_clean(dma_addr, size);
|
|
}
|
|
|
|
void
|
|
swiotlb_sync_single_range_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
|
|
unsigned long offset, size_t size, int dir)
|
|
{
|
|
swiotlb_sync_single_range(hwdev, dev_addr, offset, size, dir,
|
|
SYNC_FOR_CPU);
|
|
}
|
|
|
|
void
|
|
swiotlb_sync_single_range_for_device(struct device *hwdev, dma_addr_t dev_addr,
|
|
unsigned long offset, size_t size, int dir)
|
|
{
|
|
swiotlb_sync_single_range(hwdev, dev_addr, offset, size, dir,
|
|
SYNC_FOR_DEVICE);
|
|
}
|
|
|
|
void swiotlb_unmap_sg_attrs(struct device *, struct scatterlist *, int, int,
|
|
struct dma_attrs *);
|
|
/*
|
|
* Map a set of buffers described by scatterlist in streaming mode for DMA.
|
|
* This is the scatter-gather version of the above swiotlb_map_single
|
|
* interface. Here the scatter gather list elements are each tagged with the
|
|
* appropriate dma address and length. They are obtained via
|
|
* sg_dma_{address,length}(SG).
|
|
*
|
|
* NOTE: An implementation may be able to use a smaller number of
|
|
* DMA address/length pairs than there are SG table elements.
|
|
* (for example via virtual mapping capabilities)
|
|
* The routine returns the number of addr/length pairs actually
|
|
* used, at most nents.
|
|
*
|
|
* Device ownership issues as mentioned above for swiotlb_map_single are the
|
|
* same here.
|
|
*/
|
|
int
|
|
swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
|
|
int dir, struct dma_attrs *attrs)
|
|
{
|
|
struct scatterlist *sg;
|
|
void *addr;
|
|
dma_addr_t dev_addr;
|
|
int i;
|
|
|
|
BUG_ON(dir == DMA_NONE);
|
|
|
|
for_each_sg(sgl, sg, nelems, i) {
|
|
addr = SG_ENT_VIRT_ADDRESS(sg);
|
|
dev_addr = virt_to_bus(addr);
|
|
if (swiotlb_force || address_needs_mapping(hwdev, dev_addr)) {
|
|
void *map = map_single(hwdev, addr, sg->length, dir);
|
|
if (!map) {
|
|
/* Don't panic here, we expect map_sg users
|
|
to do proper error handling. */
|
|
swiotlb_full(hwdev, sg->length, dir, 0);
|
|
swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir,
|
|
attrs);
|
|
sgl[0].dma_length = 0;
|
|
return 0;
|
|
}
|
|
sg->dma_address = virt_to_bus(map);
|
|
} else
|
|
sg->dma_address = dev_addr;
|
|
sg->dma_length = sg->length;
|
|
}
|
|
return nelems;
|
|
}
|
|
EXPORT_SYMBOL(swiotlb_map_sg_attrs);
|
|
|
|
int
|
|
swiotlb_map_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
|
|
int dir)
|
|
{
|
|
return swiotlb_map_sg_attrs(hwdev, sgl, nelems, dir, NULL);
|
|
}
|
|
|
|
/*
|
|
* Unmap a set of streaming mode DMA translations. Again, cpu read rules
|
|
* concerning calls here are the same as for swiotlb_unmap_single() above.
|
|
*/
|
|
void
|
|
swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
|
|
int nelems, int dir, struct dma_attrs *attrs)
|
|
{
|
|
struct scatterlist *sg;
|
|
int i;
|
|
|
|
BUG_ON(dir == DMA_NONE);
|
|
|
|
for_each_sg(sgl, sg, nelems, i) {
|
|
if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))
|
|
unmap_single(hwdev, bus_to_virt(sg->dma_address),
|
|
sg->dma_length, dir);
|
|
else if (dir == DMA_FROM_DEVICE)
|
|
dma_mark_clean(SG_ENT_VIRT_ADDRESS(sg), sg->dma_length);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(swiotlb_unmap_sg_attrs);
|
|
|
|
void
|
|
swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
|
|
int dir)
|
|
{
|
|
return swiotlb_unmap_sg_attrs(hwdev, sgl, nelems, dir, NULL);
|
|
}
|
|
|
|
/*
|
|
* Make physical memory consistent for a set of streaming mode DMA translations
|
|
* after a transfer.
|
|
*
|
|
* The same as swiotlb_sync_single_* but for a scatter-gather list, same rules
|
|
* and usage.
|
|
*/
|
|
static void
|
|
swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl,
|
|
int nelems, int dir, int target)
|
|
{
|
|
struct scatterlist *sg;
|
|
int i;
|
|
|
|
BUG_ON(dir == DMA_NONE);
|
|
|
|
for_each_sg(sgl, sg, nelems, i) {
|
|
if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))
|
|
sync_single(hwdev, bus_to_virt(sg->dma_address),
|
|
sg->dma_length, dir, target);
|
|
else if (dir == DMA_FROM_DEVICE)
|
|
dma_mark_clean(SG_ENT_VIRT_ADDRESS(sg), sg->dma_length);
|
|
}
|
|
}
|
|
|
|
void
|
|
swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,
|
|
int nelems, int dir)
|
|
{
|
|
swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU);
|
|
}
|
|
|
|
void
|
|
swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
|
|
int nelems, int dir)
|
|
{
|
|
swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE);
|
|
}
|
|
|
|
int
|
|
swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
|
|
{
|
|
return (dma_addr == virt_to_bus(io_tlb_overflow_buffer));
|
|
}
|
|
|
|
/*
|
|
* Return whether the given device DMA address mask can be supported
|
|
* properly. For example, if your device can only drive the low 24-bits
|
|
* during bus mastering, then you would pass 0x00ffffff as the mask to
|
|
* this function.
|
|
*/
|
|
int
|
|
swiotlb_dma_supported(struct device *hwdev, u64 mask)
|
|
{
|
|
return virt_to_bus(io_tlb_end - 1) <= mask;
|
|
}
|
|
|
|
EXPORT_SYMBOL(swiotlb_map_single);
|
|
EXPORT_SYMBOL(swiotlb_unmap_single);
|
|
EXPORT_SYMBOL(swiotlb_map_sg);
|
|
EXPORT_SYMBOL(swiotlb_unmap_sg);
|
|
EXPORT_SYMBOL(swiotlb_sync_single_for_cpu);
|
|
EXPORT_SYMBOL(swiotlb_sync_single_for_device);
|
|
EXPORT_SYMBOL_GPL(swiotlb_sync_single_range_for_cpu);
|
|
EXPORT_SYMBOL_GPL(swiotlb_sync_single_range_for_device);
|
|
EXPORT_SYMBOL(swiotlb_sync_sg_for_cpu);
|
|
EXPORT_SYMBOL(swiotlb_sync_sg_for_device);
|
|
EXPORT_SYMBOL(swiotlb_dma_mapping_error);
|
|
EXPORT_SYMBOL(swiotlb_alloc_coherent);
|
|
EXPORT_SYMBOL(swiotlb_free_coherent);
|
|
EXPORT_SYMBOL(swiotlb_dma_supported);
|