/* * Copyright (C) 2000 Takashi Iwai * * Generic memory management routines for soundcard memory allocation * * 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 #include MODULE_AUTHOR("Takashi Iwai"); MODULE_DESCRIPTION("Generic memory management routines for soundcard memory allocation"); MODULE_LICENSE("GPL"); #define get_memblk(p) list_entry(p, struct snd_util_memblk, list) /* * create a new memory manager */ struct snd_util_memhdr * snd_util_memhdr_new(int memsize) { struct snd_util_memhdr *hdr; hdr = kzalloc(sizeof(*hdr), GFP_KERNEL); if (hdr == NULL) return NULL; hdr->size = memsize; mutex_init(&hdr->block_mutex); INIT_LIST_HEAD(&hdr->block); return hdr; } /* * free a memory manager */ void snd_util_memhdr_free(struct snd_util_memhdr *hdr) { struct list_head *p; if (!hdr) return; /* release all blocks */ while ((p = hdr->block.next) != &hdr->block) { list_del(p); kfree(get_memblk(p)); } kfree(hdr); } /* * allocate a memory block (without mutex) */ struct snd_util_memblk * __snd_util_mem_alloc(struct snd_util_memhdr *hdr, int size) { struct snd_util_memblk *blk; unsigned int units, prev_offset; struct list_head *p; if (snd_BUG_ON(!hdr || size <= 0)) return NULL; /* word alignment */ units = size; if (units & 1) units++; if (units > hdr->size) return NULL; /* look for empty block */ prev_offset = 0; list_for_each(p, &hdr->block) { blk = get_memblk(p); if (blk->offset - prev_offset >= units) goto __found; prev_offset = blk->offset + blk->size; } if (hdr->size - prev_offset < units) return NULL; __found: return __snd_util_memblk_new(hdr, units, p->prev); } /* * create a new memory block with the given size * the block is linked next to prev */ struct snd_util_memblk * __snd_util_memblk_new(struct snd_util_memhdr *hdr, unsigned int units, struct list_head *prev) { struct snd_util_memblk *blk; blk = kmalloc(sizeof(struct snd_util_memblk) + hdr->block_extra_size, GFP_KERNEL); if (blk == NULL) return NULL; if (prev == &hdr->block) blk->offset = 0; else { struct snd_util_memblk *p = get_memblk(prev); blk->offset = p->offset + p->size; } blk->size = units; list_add(&blk->list, prev); hdr->nblocks++; hdr->used += units; return blk; } /* * allocate a memory block (with mutex) */ struct snd_util_memblk * snd_util_mem_alloc(struct snd_util_memhdr *hdr, int size) { struct snd_util_memblk *blk; mutex_lock(&hdr->block_mutex); blk = __snd_util_mem_alloc(hdr, size); mutex_unlock(&hdr->block_mutex); return blk; } /* * remove the block from linked-list and free resource * (without mutex) */ void __snd_util_mem_free(struct snd_util_memhdr *hdr, struct snd_util_memblk *blk) { list_del(&blk->list); hdr->nblocks--; hdr->used -= blk->size; kfree(blk); } /* * free a memory block (with mutex) */ int snd_util_mem_free(struct snd_util_memhdr *hdr, struct snd_util_memblk *blk) { if (snd_BUG_ON(!hdr || !blk)) return -EINVAL; mutex_lock(&hdr->block_mutex); __snd_util_mem_free(hdr, blk); mutex_unlock(&hdr->block_mutex); return 0; } /* * return available memory size */ int snd_util_mem_avail(struct snd_util_memhdr *hdr) { unsigned int size; mutex_lock(&hdr->block_mutex); size = hdr->size - hdr->used; mutex_unlock(&hdr->block_mutex); return size; } EXPORT_SYMBOL(snd_util_memhdr_new); EXPORT_SYMBOL(snd_util_memhdr_free); EXPORT_SYMBOL(snd_util_mem_alloc); EXPORT_SYMBOL(snd_util_mem_free); EXPORT_SYMBOL(snd_util_mem_avail); EXPORT_SYMBOL(__snd_util_mem_alloc); EXPORT_SYMBOL(__snd_util_mem_free); EXPORT_SYMBOL(__snd_util_memblk_new); /* * INIT part */ static int __init alsa_util_mem_init(void) { return 0; } static void __exit alsa_util_mem_exit(void) { } module_init(alsa_util_mem_init) module_exit(alsa_util_mem_exit) class='commit-info'> 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 /net/rds 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 'net/rds')