Commit Graph

14 Commits

Author SHA1 Message Date
Andrey Smirnov 2cf2aa6a69 dma-mapping: fix false positivse warnings in dma_common_free_remap()
Commit 5cf4537975 ("dma-mapping: introduce a dma_common_find_pages
helper") changed invalid input check in dma_common_free_remap() from:

    if (!area || !area->flags != VM_DMA_COHERENT)

to

    if (!area || !area->flags != VM_DMA_COHERENT || !area->pages)

which seem to produce false positives for memory obtained via
dma_common_contiguous_remap()

This triggers the following warning message when doing "reboot" on ZII
VF610 Dev Board Rev B:

WARNING: CPU: 0 PID: 1 at kernel/dma/remap.c:112 dma_common_free_remap+0x88/0x8c
trying to free invalid coherent area: 9ef82980
Modules linked in:
CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 5.3.0-rc6-next-20190820 #119
Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree)
Backtrace:
[<8010d1ec>] (dump_backtrace) from [<8010d588>] (show_stack+0x20/0x24)
 r7:8015ed78 r6:00000009 r5:00000000 r4:9f4d9b14
[<8010d568>] (show_stack) from [<8077e3f0>] (dump_stack+0x24/0x28)
[<8077e3cc>] (dump_stack) from [<801197a0>] (__warn.part.3+0xcc/0xe4)
[<801196d4>] (__warn.part.3) from [<80119830>] (warn_slowpath_fmt+0x78/0x94)
 r6:00000070 r5:808e540c r4:81c03048
[<801197bc>] (warn_slowpath_fmt) from [<8015ed78>] (dma_common_free_remap+0x88/0x8c)
 r3:9ef82980 r2:808e53e0
 r7:00001000 r6:a0b1e000 r5:a0b1e000 r4:00001000
[<8015ecf0>] (dma_common_free_remap) from [<8010fa9c>] (remap_allocator_free+0x60/0x68)
 r5:81c03048 r4:9f4d9b78
[<8010fa3c>] (remap_allocator_free) from [<801100d0>] (__arm_dma_free.constprop.3+0xf8/0x148)
 r5:81c03048 r4:9ef82900
[<8010ffd8>] (__arm_dma_free.constprop.3) from [<80110144>] (arm_dma_free+0x24/0x2c)
 r5:9f563410 r4:80110120
[<80110120>] (arm_dma_free) from [<8015d80c>] (dma_free_attrs+0xa0/0xdc)
[<8015d76c>] (dma_free_attrs) from [<8020f3e4>] (dma_pool_destroy+0xc0/0x154)
 r8:9efa8860 r7:808f02f0 r6:808f02d0 r5:9ef82880 r4:9ef82780
[<8020f324>] (dma_pool_destroy) from [<805525d0>] (ehci_mem_cleanup+0x6c/0x150)
 r7:9f563410 r6:9efa8810 r5:00000000 r4:9efd0148
[<80552564>] (ehci_mem_cleanup) from [<80558e0c>] (ehci_stop+0xac/0xc0)
 r5:9efd0148 r4:9efd0000
[<80558d60>] (ehci_stop) from [<8053c4bc>] (usb_remove_hcd+0xf4/0x1b0)
 r7:9f563410 r6:9efd0074 r5:81c03048 r4:9efd0000
[<8053c3c8>] (usb_remove_hcd) from [<8056361c>] (host_stop+0x48/0xb8)
 r7:9f563410 r6:9efd0000 r5:9f5f4040 r4:9f5f5040
[<805635d4>] (host_stop) from [<80563d0c>] (ci_hdrc_host_destroy+0x34/0x38)
 r7:9f563410 r6:9f5f5040 r5:9efa8800 r4:9f5f4040
[<80563cd8>] (ci_hdrc_host_destroy) from [<8055ef18>] (ci_hdrc_remove+0x50/0x10c)
[<8055eec8>] (ci_hdrc_remove) from [<804a2ed8>] (platform_drv_remove+0x34/0x4c)
 r7:9f563410 r6:81c4f99c r5:9efa8810 r4:9efa8810
[<804a2ea4>] (platform_drv_remove) from [<804a18a8>] (device_release_driver_internal+0xec/0x19c)
 r5:00000000 r4:9efa8810
[<804a17bc>] (device_release_driver_internal) from [<804a1978>] (device_release_driver+0x20/0x24)
 r7:9f563410 r6:81c41ed0 r5:9efa8810 r4:9f4a1dac
[<804a1958>] (device_release_driver) from [<804a01b8>] (bus_remove_device+0xdc/0x108)
[<804a00dc>] (bus_remove_device) from [<8049c204>] (device_del+0x150/0x36c)
 r7:9f563410 r6:81c03048 r5:9efa8854 r4:9efa8810
[<8049c0b4>] (device_del) from [<804a3368>] (platform_device_del.part.2+0x20/0x84)
 r10:9f563414 r9:809177e0 r8:81cb07dc r7:81c78320 r6:9f563454 r5:9efa8800
 r4:9efa8800
[<804a3348>] (platform_device_del.part.2) from [<804a3420>] (platform_device_unregister+0x28/0x34)
 r5:9f563400 r4:9efa8800
[<804a33f8>] (platform_device_unregister) from [<8055dce0>] (ci_hdrc_remove_device+0x1c/0x30)
 r5:9f563400 r4:00000001
[<8055dcc4>] (ci_hdrc_remove_device) from [<805652ac>] (ci_hdrc_imx_remove+0x38/0x118)
 r7:81c78320 r6:9f563454 r5:9f563410 r4:9f541010
[<8056538c>] (ci_hdrc_imx_shutdown) from [<804a2970>] (platform_drv_shutdown+0x2c/0x30)
[<804a2944>] (platform_drv_shutdown) from [<8049e4fc>] (device_shutdown+0x158/0x1f0)
[<8049e3a4>] (device_shutdown) from [<8013ac80>] (kernel_restart_prepare+0x44/0x48)
 r10:00000058 r9:9f4d8000 r8:fee1dead r7:379ce700 r6:81c0b280 r5:81c03048
 r4:00000000
[<8013ac3c>] (kernel_restart_prepare) from [<8013ad14>] (kernel_restart+0x1c/0x60)
[<8013acf8>] (kernel_restart) from [<8013af84>] (__do_sys_reboot+0xe0/0x1d8)
 r5:81c03048 r4:00000000
[<8013aea4>] (__do_sys_reboot) from [<8013b0ec>] (sys_reboot+0x18/0x1c)
 r8:80101204 r7:00000058 r6:00000000 r5:00000000 r4:00000000
[<8013b0d4>] (sys_reboot) from [<80101000>] (ret_fast_syscall+0x0/0x54)
Exception stack(0x9f4d9fa8 to 0x9f4d9ff0)
9fa0:                   00000000 00000000 fee1dead 28121969 01234567 379ce700
9fc0: 00000000 00000000 00000000 00000058 00000000 00000000 00000000 00016d04
9fe0: 00028e0c 7ec87c64 000135ec 76c1f410

Restore original invalid input check in dma_common_free_remap() to
avoid this problem.

Fixes: 5cf4537975 ("dma-mapping: introduce a dma_common_find_pages helper")
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
[hch: just revert the offending hunk instead of creating a new helper]
Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-10-05 10:24:17 +02:00
Christoph Hellwig 5cf4537975 dma-mapping: introduce a dma_common_find_pages helper
A helper to find the backing page array based on a virtual address.
This also ensures we do the same vm_flags check everywhere instead
of slightly different or missing ones in a few places.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-09-04 11:13:20 +02:00
Christoph Hellwig 512317401f dma-mapping: always use VM_DMA_COHERENT for generic DMA remap
Currently the generic dma remap allocator gets a vm_flags passed by
the caller that is a little confusing.  We just introduced a generic
vmalloc-level flag to identify the dma coherent allocations, so use
that everywhere and remove the now pointless argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-09-04 11:13:20 +02:00
Christoph Hellwig 8e3a68fb55 dma-mapping: make dma_atomic_pool_init self-contained
The memory allocated for the atomic pool needs to have the same
mapping attributes that we use for remapping, so use
pgprot_dmacoherent instead of open coding it.  Also deduct a
suitable zone to allocate the memory from based on the presence
of the DMA zones.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-08-29 16:43:33 +02:00
Christoph Hellwig 33dcb37cef dma-mapping: fix page attributes for dma_mmap_*
All the way back to introducing dma_common_mmap we've defaulted to mark
the pages as uncached.  But this is wrong for DMA coherent devices.
Later on DMA_ATTR_WRITE_COMBINE also got incorrect treatment as that
flag is only treated special on the alloc side for non-coherent devices.

Introduce a new dma_pgprot helper that deals with the check for coherent
devices so that only the remapping cases ever reach arch_dma_mmap_pgprot
and we thus ensure no aliasing of page attributes happens, which makes
the powerpc version of arch_dma_mmap_pgprot obsolete and simplifies the
remaining ones.

Note that this means arch_dma_mmap_pgprot is a bit misnamed now, but
we'll phase it out soon.

Fixes: 64ccc9c033 ("common: dma-mapping: add support for generic dma_mmap_* calls")
Reported-by: Shawn Anastasio <shawn@anastas.io>
Reported-by: Gavin Li <git@thegavinli.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> # arm64
2019-08-10 19:52:45 +02:00
Christoph Hellwig d98849aff8 dma-direct: handle DMA_ATTR_NO_KERNEL_MAPPING in common code
DMA_ATTR_NO_KERNEL_MAPPING is generally implemented by allocating
normal cacheable pages or CMA memory, and then returning the page
pointer as the opaque handle.  Lift that code from the xtensa and
generic dma remapping implementations into the generic dma-direct
code so that we don't even call arch_dma_alloc for these allocations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-06-25 14:28:05 +02:00
Florian Fainelli 4b4b077cbd dma-remap: Avoid de-referencing NULL atomic_pool
With architectures allowing the kernel to be placed almost arbitrarily
in memory (e.g.: ARM64), it is possible to have the kernel resides at
physical addresses above 4GB, resulting in neither the default CMA area,
nor the atomic pool from successfully allocating. This does not prevent
specific peripherals from working though, one example is XHCI, which
still operates correctly.

Trouble comes when the XHCI driver gets suspended and resumed, since we
can now trigger the following NPD:

[   12.664170] usb usb1: root hub lost power or was reset
[   12.669387] usb usb2: root hub lost power or was reset
[   12.674662] Unable to handle kernel NULL pointer dereference at virtual address 00000008
[   12.682896] pgd = ffffffc1365a7000
[   12.686386] [00000008] *pgd=0000000136500003, *pud=0000000136500003, *pmd=0000000000000000
[   12.694897] Internal error: Oops: 96000006 [#1] SMP
[   12.699843] Modules linked in:
[   12.702980] CPU: 0 PID: 1499 Comm: pml Not tainted 4.9.135-1.13pre #51
[   12.709577] Hardware name: BCM97268DV (DT)
[   12.713736] task: ffffffc136bb6540 task.stack: ffffffc1366cc000
[   12.719740] PC is at addr_in_gen_pool+0x4/0x48
[   12.724253] LR is at __dma_free+0x64/0xbc
[   12.728325] pc : [<ffffff80083c0df8>] lr : [<ffffff80080979e0>] pstate: 60000145
[   12.735825] sp : ffffffc1366cf990
[   12.739196] x29: ffffffc1366cf990 x28: ffffffc1366cc000
[   12.744608] x27: 0000000000000000 x26: ffffffc13a8568c8
[   12.750020] x25: 0000000000000000 x24: ffffff80098f9000
[   12.755433] x23: 000000013a5ff000 x22: ffffff8009c57000
[   12.760844] x21: ffffffc13a856810 x20: 0000000000000000
[   12.766255] x19: 0000000000001000 x18: 000000000000000a
[   12.771667] x17: 0000007f917553e0 x16: 0000000000001002
[   12.777078] x15: 00000000000a36cb x14: ffffff80898feb77
[   12.782490] x13: ffffffffffffffff x12: 0000000000000030
[   12.787899] x11: 00000000fffffffe x10: ffffff80098feb7f
[   12.793311] x9 : 0000000005f5e0ff x8 : 65776f702074736f
[   12.798723] x7 : 6c2062756820746f x6 : ffffff80098febb1
[   12.804134] x5 : ffffff800809797c x4 : 0000000000000000
[   12.809545] x3 : 000000013a5ff000 x2 : 0000000000000fff
[   12.814955] x1 : ffffff8009c57000 x0 : 0000000000000000
[   12.820363]
[   12.821907] Process pml (pid: 1499, stack limit = 0xffffffc1366cc020)
[   12.828421] Stack: (0xffffffc1366cf990 to 0xffffffc1366d0000)
[   12.834240] f980:                                   ffffffc1366cf9e0 ffffff80086004d0
[   12.842186] f9a0: ffffffc13ab08238 0000000000000010 ffffff80097c2218 ffffffc13a856810
[   12.850131] f9c0: ffffff8009c57000 000000013a5ff000 0000000000000008 000000013a5ff000
[   12.858076] f9e0: ffffffc1366cfa50 ffffff80085f9250 ffffffc13ab08238 0000000000000004
[   12.866021] fa00: ffffffc13ab08000 ffffff80097b6000 ffffffc13ab08130 0000000000000001
[   12.873966] fa20: 0000000000000008 ffffffc13a8568c8 0000000000000000 ffffffc1366cc000
[   12.881911] fa40: ffffffc13ab08130 0000000000000001 ffffffc1366cfa90 ffffff80085e3de8
[   12.889856] fa60: ffffffc13ab08238 0000000000000000 ffffffc136b75b00 0000000000000000
[   12.897801] fa80: 0000000000000010 ffffff80089ccb92 ffffffc1366cfac0 ffffff80084ad040
[   12.905746] faa0: ffffffc13a856810 0000000000000000 ffffff80084ad004 ffffff80084b91a8
[   12.913691] fac0: ffffffc1366cfae0 ffffff80084b91b4 ffffffc13a856810 ffffff80080db5cc
[   12.921636] fae0: ffffffc1366cfb20 ffffff80084b96bc ffffffc13a856810 0000000000000010
[   12.929581] fb00: ffffffc13a856870 0000000000000000 ffffffc13a856810 ffffff800984d2b8
[   12.937526] fb20: ffffffc1366cfb50 ffffff80084baa70 ffffff8009932ad0 ffffff800984d260
[   12.945471] fb40: 0000000000000010 00000002eff0a065 ffffffc1366cfbb0 ffffff80084bafbc
[   12.953415] fb60: 0000000000000010 0000000000000003 ffffff80098fe000 0000000000000000
[   12.961360] fb80: ffffff80097b6000 ffffff80097b6dc8 ffffff80098c12b8 ffffff80098c12f8
[   12.969306] fba0: ffffff8008842000 ffffff80097b6dc8 ffffffc1366cfbd0 ffffff80080e0d88
[   12.977251] fbc0: 00000000fffffffb ffffff80080e10bc ffffffc1366cfc60 ffffff80080e16a8
[   12.985196] fbe0: 0000000000000000 0000000000000003 ffffff80097b6000 ffffff80098fe9f0
[   12.993140] fc00: ffffff80097d4000 ffffff8008983802 0000000000000123 0000000000000040
[   13.001085] fc20: ffffff8008842000 ffffffc1366cc000 ffffff80089803c2 00000000ffffffff
[   13.009029] fc40: 0000000000000000 0000000000000000 ffffffc1366cfc60 0000000000040987
[   13.016974] fc60: ffffffc1366cfcc0 ffffff80080dfd08 0000000000000003 0000000000000004
[   13.024919] fc80: 0000000000000003 ffffff80098fea08 ffffffc136577ec0 ffffff80089803c2
[   13.032864] fca0: 0000000000000123 0000000000000001 0000000500000002 0000000000040987
[   13.040809] fcc0: ffffffc1366cfd00 ffffff80083a89d4 0000000000000004 ffffffc136577ec0
[   13.048754] fce0: ffffffc136610cc0 ffffffffffffffea ffffffc1366cfeb0 ffffffc136610cd8
[   13.056700] fd00: ffffffc1366cfd10 ffffff800822a614 ffffffc1366cfd40 ffffff80082295d4
[   13.064645] fd20: 0000000000000004 ffffffc136577ec0 ffffffc136610cc0 0000000021670570
[   13.072590] fd40: ffffffc1366cfd80 ffffff80081b5d10 ffffff80097b6000 ffffffc13aae4200
[   13.080536] fd60: ffffffc1366cfeb0 0000000000000004 0000000021670570 0000000000000004
[   13.088481] fd80: ffffffc1366cfe30 ffffff80081b6b20 ffffffc13aae4200 0000000000000000
[   13.096427] fda0: 0000000000000004 0000000021670570 ffffffc1366cfeb0 ffffffc13a838200
[   13.104371] fdc0: 0000000000000000 000000000000000a ffffff80097b6000 0000000000040987
[   13.112316] fde0: ffffffc1366cfe20 ffffff80081b3af0 ffffffc13a838200 0000000000000000
[   13.120261] fe00: ffffffc1366cfe30 ffffff80081b6b0c ffffffc13aae4200 0000000000000000
[   13.128206] fe20: 0000000000000004 0000000000040987 ffffffc1366cfe70 ffffff80081b7dd8
[   13.136151] fe40: ffffff80097b6000 ffffffc13aae4200 ffffffc13aae4200 fffffffffffffff7
[   13.144096] fe60: 0000000021670570 ffffffc13a8c63c0 0000000000000000 ffffff8008083180
[   13.152042] fe80: ffffffffffffff1d 0000000021670570 ffffffffffffffff 0000007f917ad9b8
[   13.159986] fea0: 0000000020000000 0000000000000015 0000000000000000 0000000000040987
[   13.167930] fec0: 0000000000000001 0000000021670570 0000000000000004 0000000000000000
[   13.175874] fee0: 0000000000000888 0000440110000000 000000000000006d 0000000000000003
[   13.183819] ff00: 0000000000000040 ffffff80ffffffc8 0000000000000000 0000000000000020
[   13.191762] ff20: 0000000000000000 0000000000000000 0000000000000001 0000000000000000
[   13.199707] ff40: 0000000000000000 0000007f917553e0 0000000000000000 0000000000000004
[   13.207651] ff60: 0000000021670570 0000007f91835480 0000000000000004 0000007f91831638
[   13.215595] ff80: 0000000000000004 00000000004b0de0 00000000004b0000 0000000000000000
[   13.223539] ffa0: 0000000000000000 0000007fc92ac8c0 0000007f9175d178 0000007fc92ac8c0
[   13.231483] ffc0: 0000007f917ad9b8 0000000020000000 0000000000000001 0000000000000040
[   13.239427] ffe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[   13.247360] Call trace:
[   13.249866] Exception stack(0xffffffc1366cf7a0 to 0xffffffc1366cf8d0)
[   13.256386] f7a0: 0000000000001000 0000007fffffffff ffffffc1366cf990 ffffff80083c0df8
[   13.264331] f7c0: 0000000060000145 ffffff80089b5001 ffffffc13ab08130 0000000000000001
[   13.272275] f7e0: 0000000000000008 ffffffc13a8568c8 0000000000000000 0000000000000000
[   13.280220] f800: ffffffc1366cf960 ffffffc1366cf960 ffffffc1366cf930 00000000ffffffd8
[   13.288165] f820: ffffff8009931ac0 4554535953425553 4544006273753d4d 3831633d45434956
[   13.296110] f840: ffff003832313a39 ffffff800845926c ffffffc1366cf880 0000000000040987
[   13.304054] f860: 0000000000000000 ffffff8009c57000 0000000000000fff 000000013a5ff000
[   13.311999] f880: 0000000000000000 ffffff800809797c ffffff80098febb1 6c2062756820746f
[   13.319944] f8a0: 65776f702074736f 0000000005f5e0ff ffffff80098feb7f 00000000fffffffe
[   13.327884] f8c0: 0000000000000030 ffffffffffffffff
[   13.332835] [<ffffff80083c0df8>] addr_in_gen_pool+0x4/0x48
[   13.338398] [<ffffff80086004d0>] xhci_mem_cleanup+0xc8/0x51c
[   13.344137] [<ffffff80085f9250>] xhci_resume+0x308/0x65c
[   13.349524] [<ffffff80085e3de8>] xhci_brcm_resume+0x84/0x8c
[   13.355174] [<ffffff80084ad040>] platform_pm_resume+0x3c/0x64
[   13.360997] [<ffffff80084b91b4>] dpm_run_callback+0x5c/0x15c
[   13.366732] [<ffffff80084b96bc>] device_resume+0xc0/0x190
[   13.372205] [<ffffff80084baa70>] dpm_resume+0x144/0x2cc
[   13.377504] [<ffffff80084bafbc>] dpm_resume_end+0x20/0x34
[   13.382980] [<ffffff80080e0d88>] suspend_devices_and_enter+0x104/0x704
[   13.389585] [<ffffff80080e16a8>] pm_suspend+0x320/0x53c
[   13.394881] [<ffffff80080dfd08>] state_store+0xbc/0xe0
[   13.400094] [<ffffff80083a89d4>] kobj_attr_store+0x14/0x24
[   13.405655] [<ffffff800822a614>] sysfs_kf_write+0x60/0x70
[   13.411128] [<ffffff80082295d4>] kernfs_fop_write+0x130/0x194
[   13.416954] [<ffffff80081b5d10>] __vfs_write+0x60/0x150
[   13.422254] [<ffffff80081b6b20>] vfs_write+0xc8/0x164
[   13.427376] [<ffffff80081b7dd8>] SyS_write+0x70/0xc8
[   13.432412] [<ffffff8008083180>] el0_svc_naked+0x34/0x38
[   13.437800] Code: 92800173 97f6fb9e 17fffff5 d1000442 (f8408c03)
[   13.444033] ---[ end trace 2effe12f909ce205 ]---

The call path leading to this problem is xhci_mem_cleanup() ->
dma_free_coherent() -> dma_free_from_pool() -> addr_in_gen_pool. If the
atomic_pool is NULL, we can't possibly have the address in the atomic
pool anyway, so guard against that.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-06-14 14:30:21 +02:00
Christoph Hellwig 8270f3a11c dma-direct: fix DMA_ATTR_NO_KERNEL_MAPPING for remapped allocations
We need to return a dma_addr_t even if we don't have a kernel mapping.
Do so by consolidating the phys_to_dma call in a single place and jump
to it from all the branches that return successfully.

Fixes: bfd56cd605 ("dma-mapping: support highmem in the generic remap allocator")
Reported-by: Liviu Dudau <liviu@dudau.co.uk
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Liviu Dudau <liviu@dudau.co.uk>
2019-01-05 08:28:29 +01:00
Christoph Hellwig 20b105feda dma-mapping: remove a pointless memset in dma_atomic_pool_init
We already zero the memory after allocating it from the pool that
this function fills, and having the memset here in this form means
we can't support CMA highmem allocations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Russell King - ARM Linux <linux@armlinux.org.uk>
2018-12-13 21:05:20 +01:00
Marek Szyprowski a1da439cc0 dma-mapping: fix lack of DMA address assignment in generic remap allocator
Commit bfd56cd605 ("dma-mapping: support highmem in the generic remap
allocator") replaced dma_direct_alloc_pages() with __dma_direct_alloc_pages(),
which doesn't set dma_handle and zero allocated memory. Fix it by doing this
directly in the caller function.

Fixes: bfd56cd605 ("dma-mapping: support highmem in the generic remap allocator")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-12-05 05:49:10 -08:00
Christoph Hellwig e440e26a02 dma-remap: support DMA_ATTR_NO_KERNEL_MAPPING
Do not waste vmalloc space on allocations that do not require a mapping
into the kernel address space.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2018-12-01 18:07:14 +01:00
Christoph Hellwig bfd56cd605 dma-mapping: support highmem in the generic remap allocator
By using __dma_direct_alloc_pages we can deal entirely with struct page
instead of having to derive a kernel virtual address.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2018-12-01 18:07:14 +01:00
Christoph Hellwig 0c3b3171ce dma-mapping: move the arm64 noncoherent alloc/free support to common code
The arm64 codebase to implement coherent dma allocation for architectures
with non-coherent DMA is a good start for a generic implementation, given
that is uses the generic remap helpers, provides the atomic pool for
allocations that can't sleep and still is realtively simple and well
tested.  Move it to kernel/dma and allow architectures to opt into it
using a config symbol.  Architectures just need to provide a new
arch_dma_prep_coherent helper to writeback an invalidate the caches
for any memory that gets remapped for uncached access.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2018-12-01 18:07:11 +01:00
Christoph Hellwig f0edfea8ef dma-mapping: move the remap helpers to a separate file
The dma remap code only makes sense for not cache coherent architectures
(or possibly the corner case of highmem CMA allocations) and currently
is only used by arm, arm64, csky and xtensa.  Split it out into a
separate file with a separate Kconfig symbol, which gets the right
copyright notice given that this code was written by Laura Abbott
working for Code Aurora at that point.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2018-12-01 17:58:34 +01:00