diff options
author | Christoph Hellwig <hch@lst.de> | 2022-04-19 10:35:29 +0300 |
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committer | Christoph Hellwig <hch@lst.de> | 2022-07-07 19:18:56 +0300 |
commit | e3217540c2710f42a2388fe7896f0f28695c00b2 (patch) | |
tree | d27914e888b63e668bba904d8ab0e306ea709bf9 /arch/arm/common | |
parent | 9ba26f5cecd86c85551a5120529c2f548099100f (diff) | |
download | linux-e3217540c2710f42a2388fe7896f0f28695c00b2.tar.xz |
ARM/dma-mapping: remove dmabounce
Remove the now unused dmabounce code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/arm/common')
-rw-r--r-- | arch/arm/common/Kconfig | 4 | ||||
-rw-r--r-- | arch/arm/common/Makefile | 1 | ||||
-rw-r--r-- | arch/arm/common/dmabounce.c | 582 |
3 files changed, 0 insertions, 587 deletions
diff --git a/arch/arm/common/Kconfig b/arch/arm/common/Kconfig index bc158fd227e1..d2fdb1796f48 100644 --- a/arch/arm/common/Kconfig +++ b/arch/arm/common/Kconfig @@ -3,10 +3,6 @@ config SA1111 bool select ZONE_DMA if ARCH_SA1100 -config DMABOUNCE - bool - select ZONE_DMA - config KRAIT_L2_ACCESSORS bool diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile index 8cd574be94cf..7bae8cbaafe7 100644 --- a/arch/arm/common/Makefile +++ b/arch/arm/common/Makefile @@ -6,7 +6,6 @@ obj-y += firmware.o obj-$(CONFIG_SA1111) += sa1111.o -obj-$(CONFIG_DMABOUNCE) += dmabounce.o obj-$(CONFIG_KRAIT_L2_ACCESSORS) += krait-l2-accessors.o obj-$(CONFIG_SHARP_LOCOMO) += locomo.o obj-$(CONFIG_SHARP_PARAM) += sharpsl_param.o diff --git a/arch/arm/common/dmabounce.c b/arch/arm/common/dmabounce.c deleted file mode 100644 index 7996c04393d5..000000000000 --- a/arch/arm/common/dmabounce.c +++ /dev/null @@ -1,582 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * arch/arm/common/dmabounce.c - * - * Special dma_{map/unmap/dma_sync}_* routines for systems that have - * limited DMA windows. These functions utilize bounce buffers to - * copy data to/from buffers located outside the DMA region. This - * only works for systems in which DMA memory is at the bottom of - * RAM, the remainder of memory is at the top and the DMA memory - * can be marked as ZONE_DMA. Anything beyond that such as discontiguous - * DMA windows will require custom implementations that reserve memory - * areas at early bootup. - * - * Original version by Brad Parker (brad@heeltoe.com) - * Re-written by Christopher Hoover <ch@murgatroid.com> - * Made generic by Deepak Saxena <dsaxena@plexity.net> - * - * Copyright (C) 2002 Hewlett Packard Company. - * Copyright (C) 2004 MontaVista Software, Inc. - */ - -#include <linux/module.h> -#include <linux/init.h> -#include <linux/slab.h> -#include <linux/page-flags.h> -#include <linux/device.h> -#include <linux/dma-direct.h> -#include <linux/dma-map-ops.h> -#include <linux/dmapool.h> -#include <linux/list.h> -#include <linux/scatterlist.h> - -#include <asm/cacheflush.h> -#include <asm/dma-iommu.h> - -#undef STATS - -#ifdef STATS -#define DO_STATS(X) do { X ; } while (0) -#else -#define DO_STATS(X) do { } while (0) -#endif - -/* ************************************************** */ - -struct safe_buffer { - struct list_head node; - - /* original request */ - void *ptr; - size_t size; - int direction; - - /* safe buffer info */ - struct dmabounce_pool *pool; - void *safe; - dma_addr_t safe_dma_addr; -}; - -struct dmabounce_pool { - unsigned long size; - struct dma_pool *pool; -#ifdef STATS - unsigned long allocs; -#endif -}; - -struct dmabounce_device_info { - struct device *dev; - struct list_head safe_buffers; -#ifdef STATS - unsigned long total_allocs; - unsigned long map_op_count; - unsigned long bounce_count; - int attr_res; -#endif - struct dmabounce_pool small; - struct dmabounce_pool large; - - rwlock_t lock; - - int (*needs_bounce)(struct device *, dma_addr_t, size_t); -}; - -#ifdef STATS -static ssize_t dmabounce_show(struct device *dev, struct device_attribute *attr, - char *buf) -{ - struct dmabounce_device_info *device_info = dev->archdata.dmabounce; - return sprintf(buf, "%lu %lu %lu %lu %lu %lu\n", - device_info->small.allocs, - device_info->large.allocs, - device_info->total_allocs - device_info->small.allocs - - device_info->large.allocs, - device_info->total_allocs, - device_info->map_op_count, - device_info->bounce_count); -} - -static DEVICE_ATTR(dmabounce_stats, 0400, dmabounce_show, NULL); -#endif - - -/* allocate a 'safe' buffer and keep track of it */ -static inline struct safe_buffer * -alloc_safe_buffer(struct dmabounce_device_info *device_info, void *ptr, - size_t size, enum dma_data_direction dir) -{ - struct safe_buffer *buf; - struct dmabounce_pool *pool; - struct device *dev = device_info->dev; - unsigned long flags; - - dev_dbg(dev, "%s(ptr=%p, size=%d, dir=%d)\n", - __func__, ptr, size, dir); - - if (size <= device_info->small.size) { - pool = &device_info->small; - } else if (size <= device_info->large.size) { - pool = &device_info->large; - } else { - pool = NULL; - } - - buf = kmalloc(sizeof(struct safe_buffer), GFP_ATOMIC); - if (buf == NULL) { - dev_warn(dev, "%s: kmalloc failed\n", __func__); - return NULL; - } - - buf->ptr = ptr; - buf->size = size; - buf->direction = dir; - buf->pool = pool; - - if (pool) { - buf->safe = dma_pool_alloc(pool->pool, GFP_ATOMIC, - &buf->safe_dma_addr); - } else { - buf->safe = dma_alloc_coherent(dev, size, &buf->safe_dma_addr, - GFP_ATOMIC); - } - - if (buf->safe == NULL) { - dev_warn(dev, - "%s: could not alloc dma memory (size=%d)\n", - __func__, size); - kfree(buf); - return NULL; - } - -#ifdef STATS - if (pool) - pool->allocs++; - device_info->total_allocs++; -#endif - - write_lock_irqsave(&device_info->lock, flags); - list_add(&buf->node, &device_info->safe_buffers); - write_unlock_irqrestore(&device_info->lock, flags); - - return buf; -} - -/* determine if a buffer is from our "safe" pool */ -static inline struct safe_buffer * -find_safe_buffer(struct dmabounce_device_info *device_info, dma_addr_t safe_dma_addr) -{ - struct safe_buffer *b, *rb = NULL; - unsigned long flags; - - read_lock_irqsave(&device_info->lock, flags); - - list_for_each_entry(b, &device_info->safe_buffers, node) - if (b->safe_dma_addr <= safe_dma_addr && - b->safe_dma_addr + b->size > safe_dma_addr) { - rb = b; - break; - } - - read_unlock_irqrestore(&device_info->lock, flags); - return rb; -} - -static inline void -free_safe_buffer(struct dmabounce_device_info *device_info, struct safe_buffer *buf) -{ - unsigned long flags; - - dev_dbg(device_info->dev, "%s(buf=%p)\n", __func__, buf); - - write_lock_irqsave(&device_info->lock, flags); - - list_del(&buf->node); - - write_unlock_irqrestore(&device_info->lock, flags); - - if (buf->pool) - dma_pool_free(buf->pool->pool, buf->safe, buf->safe_dma_addr); - else - dma_free_coherent(device_info->dev, buf->size, buf->safe, - buf->safe_dma_addr); - - kfree(buf); -} - -/* ************************************************** */ - -static struct safe_buffer *find_safe_buffer_dev(struct device *dev, - dma_addr_t dma_addr, const char *where) -{ - if (!dev || !dev->archdata.dmabounce) - return NULL; - if (dma_mapping_error(dev, dma_addr)) { - dev_err(dev, "Trying to %s invalid mapping\n", where); - return NULL; - } - return find_safe_buffer(dev->archdata.dmabounce, dma_addr); -} - -static int needs_bounce(struct device *dev, dma_addr_t dma_addr, size_t size) -{ - if (!dev || !dev->archdata.dmabounce) - return 0; - - if (dev->dma_mask) { - unsigned long limit, mask = *dev->dma_mask; - - limit = (mask + 1) & ~mask; - if (limit && size > limit) { - dev_err(dev, "DMA mapping too big (requested %#x " - "mask %#Lx)\n", size, *dev->dma_mask); - return -E2BIG; - } - - /* Figure out if we need to bounce from the DMA mask. */ - if ((dma_addr | (dma_addr + size - 1)) & ~mask) - return 1; - } - - return !!dev->archdata.dmabounce->needs_bounce(dev, dma_addr, size); -} - -static inline dma_addr_t map_single(struct device *dev, void *ptr, size_t size, - enum dma_data_direction dir, - unsigned long attrs) -{ - struct dmabounce_device_info *device_info = dev->archdata.dmabounce; - struct safe_buffer *buf; - - if (device_info) - DO_STATS ( device_info->map_op_count++ ); - - buf = alloc_safe_buffer(device_info, ptr, size, dir); - if (buf == NULL) { - dev_err(dev, "%s: unable to map unsafe buffer %p!\n", - __func__, ptr); - return DMA_MAPPING_ERROR; - } - - dev_dbg(dev, "%s: unsafe buffer %p (dma=%#x) mapped to %p (dma=%#x)\n", - __func__, buf->ptr, virt_to_dma(dev, buf->ptr), - buf->safe, buf->safe_dma_addr); - - if ((dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL) && - !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) { - dev_dbg(dev, "%s: copy unsafe %p to safe %p, size %d\n", - __func__, ptr, buf->safe, size); - memcpy(buf->safe, ptr, size); - } - - return buf->safe_dma_addr; -} - -static inline void unmap_single(struct device *dev, struct safe_buffer *buf, - size_t size, enum dma_data_direction dir, - unsigned long attrs) -{ - BUG_ON(buf->size != size); - BUG_ON(buf->direction != dir); - - dev_dbg(dev, "%s: unsafe buffer %p (dma=%#x) mapped to %p (dma=%#x)\n", - __func__, buf->ptr, virt_to_dma(dev, buf->ptr), - buf->safe, buf->safe_dma_addr); - - DO_STATS(dev->archdata.dmabounce->bounce_count++); - - if ((dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL) && - !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) { - void *ptr = buf->ptr; - - dev_dbg(dev, "%s: copy back safe %p to unsafe %p size %d\n", - __func__, buf->safe, ptr, size); - memcpy(ptr, buf->safe, size); - - /* - * Since we may have written to a page cache page, - * we need to ensure that the data will be coherent - * with user mappings. - */ - __cpuc_flush_dcache_area(ptr, size); - } - free_safe_buffer(dev->archdata.dmabounce, buf); -} - -/* ************************************************** */ - -/* - * see if a buffer address is in an 'unsafe' range. if it is - * allocate a 'safe' buffer and copy the unsafe buffer into it. - * substitute the safe buffer for the unsafe one. - * (basically move the buffer from an unsafe area to a safe one) - */ -static dma_addr_t dmabounce_map_page(struct device *dev, struct page *page, - unsigned long offset, size_t size, enum dma_data_direction dir, - unsigned long attrs) -{ - dma_addr_t dma_addr; - int ret; - - dev_dbg(dev, "%s(page=%p,off=%#lx,size=%zx,dir=%x)\n", - __func__, page, offset, size, dir); - - dma_addr = pfn_to_dma(dev, page_to_pfn(page)) + offset; - - ret = needs_bounce(dev, dma_addr, size); - if (ret < 0) - return DMA_MAPPING_ERROR; - - if (ret == 0) { - arm_dma_ops.sync_single_for_device(dev, dma_addr, size, dir); - return dma_addr; - } - - if (PageHighMem(page)) { - dev_err(dev, "DMA buffer bouncing of HIGHMEM pages is not supported\n"); - return DMA_MAPPING_ERROR; - } - - return map_single(dev, page_address(page) + offset, size, dir, attrs); -} - -/* - * see if a mapped address was really a "safe" buffer and if so, copy - * the data from the safe buffer back to the unsafe buffer and free up - * the safe buffer. (basically return things back to the way they - * should be) - */ -static void dmabounce_unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size, - enum dma_data_direction dir, unsigned long attrs) -{ - struct safe_buffer *buf; - - dev_dbg(dev, "%s(dma=%#x,size=%d,dir=%x)\n", - __func__, dma_addr, size, dir); - - buf = find_safe_buffer_dev(dev, dma_addr, __func__); - if (!buf) { - arm_dma_ops.sync_single_for_cpu(dev, dma_addr, size, dir); - return; - } - - unmap_single(dev, buf, size, dir, attrs); -} - -static int __dmabounce_sync_for_cpu(struct device *dev, dma_addr_t addr, - size_t sz, enum dma_data_direction dir) -{ - struct safe_buffer *buf; - unsigned long off; - - dev_dbg(dev, "%s(dma=%#x,sz=%zx,dir=%x)\n", - __func__, addr, sz, dir); - - buf = find_safe_buffer_dev(dev, addr, __func__); - if (!buf) - return 1; - - off = addr - buf->safe_dma_addr; - - BUG_ON(buf->direction != dir); - - dev_dbg(dev, "%s: unsafe buffer %p (dma=%#x off=%#lx) mapped to %p (dma=%#x)\n", - __func__, buf->ptr, virt_to_dma(dev, buf->ptr), off, - buf->safe, buf->safe_dma_addr); - - DO_STATS(dev->archdata.dmabounce->bounce_count++); - - if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL) { - dev_dbg(dev, "%s: copy back safe %p to unsafe %p size %d\n", - __func__, buf->safe + off, buf->ptr + off, sz); - memcpy(buf->ptr + off, buf->safe + off, sz); - } - return 0; -} - -static void dmabounce_sync_for_cpu(struct device *dev, - dma_addr_t handle, size_t size, enum dma_data_direction dir) -{ - if (!__dmabounce_sync_for_cpu(dev, handle, size, dir)) - return; - - arm_dma_ops.sync_single_for_cpu(dev, handle, size, dir); -} - -static int __dmabounce_sync_for_device(struct device *dev, dma_addr_t addr, - size_t sz, enum dma_data_direction dir) -{ - struct safe_buffer *buf; - unsigned long off; - - dev_dbg(dev, "%s(dma=%#x,sz=%zx,dir=%x)\n", - __func__, addr, sz, dir); - - buf = find_safe_buffer_dev(dev, addr, __func__); - if (!buf) - return 1; - - off = addr - buf->safe_dma_addr; - - BUG_ON(buf->direction != dir); - - dev_dbg(dev, "%s: unsafe buffer %p (dma=%#x off=%#lx) mapped to %p (dma=%#x)\n", - __func__, buf->ptr, virt_to_dma(dev, buf->ptr), off, - buf->safe, buf->safe_dma_addr); - - DO_STATS(dev->archdata.dmabounce->bounce_count++); - - if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL) { - dev_dbg(dev, "%s: copy out unsafe %p to safe %p, size %d\n", - __func__,buf->ptr + off, buf->safe + off, sz); - memcpy(buf->safe + off, buf->ptr + off, sz); - } - return 0; -} - -static void dmabounce_sync_for_device(struct device *dev, - dma_addr_t handle, size_t size, enum dma_data_direction dir) -{ - if (!__dmabounce_sync_for_device(dev, handle, size, dir)) - return; - - arm_dma_ops.sync_single_for_device(dev, handle, size, dir); -} - -static int dmabounce_dma_supported(struct device *dev, u64 dma_mask) -{ - if (dev->archdata.dmabounce) - return 0; - - return arm_dma_ops.dma_supported(dev, dma_mask); -} - -static const struct dma_map_ops dmabounce_ops = { - .alloc = arm_dma_alloc, - .free = arm_dma_free, - .mmap = arm_dma_mmap, - .get_sgtable = arm_dma_get_sgtable, - .map_page = dmabounce_map_page, - .unmap_page = dmabounce_unmap_page, - .sync_single_for_cpu = dmabounce_sync_for_cpu, - .sync_single_for_device = dmabounce_sync_for_device, - .map_sg = arm_dma_map_sg, - .unmap_sg = arm_dma_unmap_sg, - .sync_sg_for_cpu = arm_dma_sync_sg_for_cpu, - .sync_sg_for_device = arm_dma_sync_sg_for_device, - .dma_supported = dmabounce_dma_supported, -}; - -static int dmabounce_init_pool(struct dmabounce_pool *pool, struct device *dev, - const char *name, unsigned long size) -{ - pool->size = size; - DO_STATS(pool->allocs = 0); - pool->pool = dma_pool_create(name, dev, size, - 0 /* byte alignment */, - 0 /* no page-crossing issues */); - - return pool->pool ? 0 : -ENOMEM; -} - -int dmabounce_register_dev(struct device *dev, unsigned long small_buffer_size, - unsigned long large_buffer_size, - int (*needs_bounce_fn)(struct device *, dma_addr_t, size_t)) -{ - struct dmabounce_device_info *device_info; - int ret; - - device_info = kmalloc(sizeof(struct dmabounce_device_info), GFP_ATOMIC); - if (!device_info) { - dev_err(dev, - "Could not allocated dmabounce_device_info\n"); - return -ENOMEM; - } - - ret = dmabounce_init_pool(&device_info->small, dev, - "small_dmabounce_pool", small_buffer_size); - if (ret) { - dev_err(dev, - "dmabounce: could not allocate DMA pool for %ld byte objects\n", - small_buffer_size); - goto err_free; - } - - if (large_buffer_size) { - ret = dmabounce_init_pool(&device_info->large, dev, - "large_dmabounce_pool", - large_buffer_size); - if (ret) { - dev_err(dev, - "dmabounce: could not allocate DMA pool for %ld byte objects\n", - large_buffer_size); - goto err_destroy; - } - } - - device_info->dev = dev; - INIT_LIST_HEAD(&device_info->safe_buffers); - rwlock_init(&device_info->lock); - device_info->needs_bounce = needs_bounce_fn; - -#ifdef STATS - device_info->total_allocs = 0; - device_info->map_op_count = 0; - device_info->bounce_count = 0; - device_info->attr_res = device_create_file(dev, &dev_attr_dmabounce_stats); -#endif - - dev->archdata.dmabounce = device_info; - set_dma_ops(dev, &dmabounce_ops); - - dev_info(dev, "dmabounce: registered device\n"); - - return 0; - - err_destroy: - dma_pool_destroy(device_info->small.pool); - err_free: - kfree(device_info); - return ret; -} -EXPORT_SYMBOL(dmabounce_register_dev); - -void dmabounce_unregister_dev(struct device *dev) -{ - struct dmabounce_device_info *device_info = dev->archdata.dmabounce; - - dev->archdata.dmabounce = NULL; - set_dma_ops(dev, NULL); - - if (!device_info) { - dev_warn(dev, - "Never registered with dmabounce but attempting" - "to unregister!\n"); - return; - } - - if (!list_empty(&device_info->safe_buffers)) { - dev_err(dev, - "Removing from dmabounce with pending buffers!\n"); - BUG(); - } - - if (device_info->small.pool) - dma_pool_destroy(device_info->small.pool); - if (device_info->large.pool) - dma_pool_destroy(device_info->large.pool); - -#ifdef STATS - if (device_info->attr_res == 0) - device_remove_file(dev, &dev_attr_dmabounce_stats); -#endif - - kfree(device_info); - - dev_info(dev, "dmabounce: device unregistered\n"); -} -EXPORT_SYMBOL(dmabounce_unregister_dev); - -MODULE_AUTHOR("Christopher Hoover <ch@hpl.hp.com>, Deepak Saxena <dsaxena@plexity.net>"); -MODULE_DESCRIPTION("Special dma_{map/unmap/dma_sync}_* routines for systems with limited DMA windows"); -MODULE_LICENSE("GPL"); |