/* * helpers for managing a buffer for many packets * * Copyright (c) Clemens Ladisch * Licensed under the terms of the GNU General Public License, version 2. */ #include #include #include #include "packets-buffer.h" /** * iso_packets_buffer_init - allocates the memory for packets * @b: the buffer structure to initialize * @unit: the device at the other end of the stream * @count: the number of packets * @packet_size: the (maximum) size of a packet, in bytes * @direction: %DMA_TO_DEVICE or %DMA_FROM_DEVICE */ int iso_packets_buffer_init(struct iso_packets_buffer *b, struct fw_unit *unit, unsigned int count, unsigned int packet_size, enum dma_data_direction direction) { unsigned int packets_per_page, pages; unsigned int i, page_index, offset_in_page; void *p; int err; b->packets = kmalloc(count * sizeof(*b->packets), GFP_KERNEL); if (!b->packets) { err = -ENOMEM; goto error; } packet_size = L1_CACHE_ALIGN(packet_size); packets_per_page = PAGE_SIZE / packet_size; if (WARN_ON(!packets_per_page)) { err = -EINVAL; goto error; } pages = DIV_ROUND_UP(count, packets_per_page); err = fw_iso_buffer_init(&b->iso_buffer, fw_parent_device(unit)->card, pages, direction); if (err < 0) goto err_packets; for (i = 0; i < count; ++i) { page_index = i / packets_per_page; p = page_address(b->iso_buffer.pages[page_index]); offset_in_page = (i % packets_per_page) * packet_size; b->packets[i].buffer = p + offset_in_page; b->packets[i].offset = page_index * PAGE_SIZE + offset_in_page; } return 0; err_packets: kfree(b->packets); error: return err; } EXPORT_SYMBOL(iso_packets_buffer_init); /** * iso_packets_buffer_destroy - frees packet buffer resources * @b: the buffer structure to free * @unit: the device at the other end of the stream */ void iso_packets_buffer_destroy(struct iso_packets_buffer *b, struct fw_unit *unit) { fw_iso_buffer_destroy(&b->iso_buffer, fw_parent_device(unit)->card); kfree(b->packets); } EXPORT_SYMBOL(iso_packets_buffer_destroy); ound/pci?h=nds-private-remove&id=f598f82e204ec0b17797caaf1b0311c52d43fb9a'>diff
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authorColy Li <colyli@suse.de>2017-01-24 15:18:46 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-24 16:26:14 -0800
commitf598f82e204ec0b17797caaf1b0311c52d43fb9a (patch)
tree20e0109db50c168a36df14af76b484eaf9b71836 /sound/pci
parent4180c4c170a5a33b9987b314d248a9d572d89ab0 (diff)
romfs: use different way to generate fsid for BLOCK or MTD
Commit 8a59f5d25265 ("fs/romfs: return f_fsid for statfs(2)") generates a 64bit id from sb->s_bdev->bd_dev. This is only correct when romfs is defined with CONFIG_ROMFS_ON_BLOCK. If romfs is only defined with CONFIG_ROMFS_ON_MTD, sb->s_bdev is NULL, referencing sb->s_bdev->bd_dev will triger an oops. Richard Weinberger points out that when CONFIG_ROMFS_BACKED_BY_BOTH=y, both CONFIG_ROMFS_ON_BLOCK and CONFIG_ROMFS_ON_MTD are defined. Therefore when calling huge_encode_dev() to generate a 64bit id, I use the follow order to choose parameter, - CONFIG_ROMFS_ON_BLOCK defined use sb->s_bdev->bd_dev - CONFIG_ROMFS_ON_BLOCK undefined and CONFIG_ROMFS_ON_MTD defined use sb->s_dev when, - both CONFIG_ROMFS_ON_BLOCK and CONFIG_ROMFS_ON_MTD undefined leave id as 0 When CONFIG_ROMFS_ON_MTD is defined and sb->s_mtd is not NULL, sb->s_dev is set to a device ID generated by MTD_BLOCK_MAJOR and mtd index, otherwise sb->s_dev is 0. This is a try-best effort to generate a uniq file system ID, if all the above conditions are not meet, f_fsid of this romfs instance will be 0. Generally only one romfs can be built on single MTD block device, this method is enough to identify multiple romfs instances in a computer. Link: http://lkml.kernel.org/r/1482928596-115155-1-git-send-email-colyli@suse.de Signed-off-by: Coly Li <colyli@suse.de> Reported-by: Nong Li <nongli1031@gmail.com> Tested-by: Nong Li <nongli1031@gmail.com> Cc: Richard Weinberger <richard.weinberger@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'sound/pci')