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Subject[PATCH 02/10] ARM/dma-mapping: remove dmabounce
Date
Remove the now unused dmabounce code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
---
arch/arm/common/Kconfig | 4 -
arch/arm/common/Makefile | 1 -
arch/arm/common/dmabounce.c | 582 -----------------------------
arch/arm/include/asm/device.h | 3 -
arch/arm/include/asm/dma-mapping.h | 29 --
5 files changed, 619 deletions(-)
delete mode 100644 arch/arm/common/dmabounce.c

diff --git a/arch/arm/common/Kconfig b/arch/arm/common/Kconfig
index bc158fd227e12..d2fdb1796f488 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 8cd574be94cfe..7bae8cbaafe78 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 7996c04393d50..0000000000000
--- 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");
diff --git a/arch/arm/include/asm/device.h b/arch/arm/include/asm/device.h
index be666f58bf7ae..8754c0f5fc904 100644
--- a/arch/arm/include/asm/device.h
+++ b/arch/arm/include/asm/device.h
@@ -6,9 +6,6 @@
#define ASMARM_DEVICE_H

struct dev_archdata {
-#ifdef CONFIG_DMABOUNCE
- struct dmabounce_device_info *dmabounce;
-#endif
#ifdef CONFIG_ARM_DMA_USE_IOMMU
struct dma_iommu_mapping *mapping;
#endif
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index 77082246a5e12..1e015a7ad86aa 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -80,35 +80,6 @@ extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
*
*/

-/**
- * dmabounce_register_dev
- *
- * @dev: valid struct device pointer
- * @small_buf_size: size of buffers to use with small buffer pool
- * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
- * @needs_bounce_fn: called to determine whether buffer needs bouncing
- *
- * This function should be called by low-level platform code to register
- * a device as requireing DMA buffer bouncing. The function will allocate
- * appropriate DMA pools for the device.
- */
-extern int dmabounce_register_dev(struct device *, unsigned long,
- unsigned long, int (*)(struct device *, dma_addr_t, size_t));
-
-/**
- * dmabounce_unregister_dev
- *
- * @dev: valid struct device pointer
- *
- * This function should be called by low-level platform code when device
- * that was previously registered with dmabounce_register_dev is removed
- * from the system.
- *
- */
-extern void dmabounce_unregister_dev(struct device *);
-
-
-
/*
* The scatter list versions of the above methods.
*/
--
2.30.2
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