/* * Scatter-Gather buffer * * Copyright (c) by Takashi Iwai * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ #include #include #include #include #include /* table entries are align to 32 */ #define SGBUF_TBL_ALIGN 32 #define sgbuf_align_table(tbl) ALIGN((tbl), SGBUF_TBL_ALIGN) int snd_free_sgbuf_pages(struct snd_dma_buffer *dmab) { struct snd_sg_buf *sgbuf = dmab->private_data; struct snd_dma_buffer tmpb; int i; if (! sgbuf) return -EINVAL; vunmap(dmab->area); dmab->area = NULL; tmpb.dev.type = SNDRV_DMA_TYPE_DEV; tmpb.dev.dev = sgbuf->dev; for (i = 0; i < sgbuf->pages; i++) { if (!(sgbuf->table[i].addr & ~PAGE_MASK)) continue; /* continuous pages */ tmpb.area = sgbuf->table[i].buf; tmpb.addr = sgbuf->table[i].addr & PAGE_MASK; tmpb.bytes = (sgbuf->table[i].addr & ~PAGE_MASK) << PAGE_SHIFT; snd_dma_free_pages(&tmpb); } kfree(sgbuf->table); kfree(sgbuf->page_table); kfree(sgbuf); dmab->private_data = NULL; return 0; } #define MAX_ALLOC_PAGES 32 void *snd_malloc_sgbuf_pages(struct device *device, size_t size, struct snd_dma_buffer *dmab, size_t *res_size) { struct snd_sg_buf *sgbuf; unsigned int i, pages, chunk, maxpages; struct snd_dma_buffer tmpb; struct snd_sg_page *table; struct page **pgtable; dmab->area = NULL; dmab->addr = 0; dmab->private_data = sgbuf = kzalloc(sizeof(*sgbuf), GFP_KERNEL); if (! sgbuf) return NULL; sgbuf->dev = device; pages = snd_sgbuf_aligned_pages(size); sgbuf->tblsize = sgbuf_align_table(pages); table = kcalloc(sgbuf->tblsize, sizeof(*table), GFP_KERNEL); if (!table) goto _failed; sgbuf->table = table; pgtable = kcalloc(sgbuf->tblsize, sizeof(*pgtable), GFP_KERNEL); if (!pgtable) goto _failed; sgbuf->page_table = pgtable; /* allocate pages */ maxpages = MAX_ALLOC_PAGES; while (pages > 0) { chunk = pages; /* don't be too eager to take a huge chunk */ if (chunk > maxpages) chunk = maxpages; chunk <<= PAGE_SHIFT; if (snd_dma_alloc_pages_fallback(SNDRV_DMA_TYPE_DEV, device, chunk, &tmpb) < 0) { if (!sgbuf->pages) goto _failed; if (!res_size) goto _failed; size = sgbuf->pages * PAGE_SIZE; break; } chunk = tmpb.bytes >> PAGE_SHIFT; for (i = 0; i < chunk; i++) { table->buf = tmpb.area; table->addr = tmpb.addr; if (!i) table->addr |= chunk; /* mark head */ table++; *pgtable++ = virt_to_page(tmpb.area); tmpb.area += PAGE_SIZE; tmpb.addr += PAGE_SIZE; } sgbuf->pages += chunk; pages -= chunk; if (chunk < maxpages) maxpages = chunk; } sgbuf->size = size; dmab->area = vmap(sgbuf->page_table, sgbuf->pages, VM_MAP, PAGE_KERNEL); if (! dmab->area) goto _failed; if (res_size) *res_size = sgbuf->size; return dmab->area; _failed: snd_free_sgbuf_pages(dmab); /* free the table */ return NULL; } /* * compute the max chunk size with continuous pages on sg-buffer */ unsigned int snd_sgbuf_get_chunk_size(struct snd_dma_buffer *dmab, unsigned int ofs, unsigned int size) { struct snd_sg_buf *sg = dmab->private_data; unsigned int start, end, pg; start = ofs >> PAGE_SHIFT; end = (ofs + size - 1) >> PAGE_SHIFT; /* check page continuity */ pg = sg->table[start].addr >> PAGE_SHIFT; for (;;) { start++; if (start > end) break; pg++; if ((sg->table[start].addr >> PAGE_SHIFT) != pg) return (start << PAGE_SHIFT) - ofs; } /* ok, all on continuous pages */ return size; } EXPORT_SYMBOL(snd_sgbuf_get_chunk_size); ue='10'>10space:mode:
authorArd Biesheuvel <ard.biesheuvel@linaro.org>2017-02-01 17:45:02 +0000
committerIngo Molnar <mingo@kernel.org>2017-02-01 21:17:49 +0100
commitc8f325a59cfc718d13a50fbc746ed9b415c25e92 (patch)
treed53fbdac9d0781e39a13b2ac6b2bd258cf3b4140 /tools/testing/selftests/media_tests/video_device_test.c
parentbf29bddf0417a4783da3b24e8c9e017ac649326f (diff)
efi/fdt: Avoid FDT manipulation after ExitBootServices()
Some AArch64 UEFI implementations disable the MMU in ExitBootServices(), after which unaligned accesses to RAM are no longer supported. Commit: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") fixed an issue in the memory map handling of the stub FDT code, but inadvertently created an issue with such firmware, by moving some of the FDT manipulation to after the invocation of ExitBootServices(). Given that the stub's libfdt implementation uses the ordinary, accelerated string functions, which rely on hardware handling of unaligned accesses, manipulating the FDT with the MMU off may result in alignment faults. So fix the situation by moving the update_fdt_memmap() call into the callback function invoked by efi_exit_boot_services() right before it calls the ExitBootServices() UEFI service (which is arguably a better place for it anyway) Note that disabling the MMU in ExitBootServices() is not compliant with the UEFI spec, and carries great risk due to the fact that switching from cached to uncached memory accesses halfway through compiler generated code (i.e., involving a stack) can never be done in a way that is architecturally safe. Fixes: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Riku Voipio <riku.voipio@linaro.org> Cc: <stable@vger.kernel.org> Cc: mark.rutland@arm.com Cc: linux-efi@vger.kernel.org Cc: matt@codeblueprint.co.uk Cc: leif.lindholm@linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1485971102-23330-2-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/testing/selftests/media_tests/video_device_test.c')