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-rw-r--r--drivers/staging/comedi/comedi_buf.c99
-rw-r--r--drivers/staging/comedi/comedi_fops.c38
-rw-r--r--drivers/staging/comedi/comedi_internal.h3
-rw-r--r--drivers/staging/comedi/comedidev.h14
-rw-r--r--drivers/staging/comedi/drivers/mite.c2
5 files changed, 99 insertions, 57 deletions
diff --git a/drivers/staging/comedi/comedi_buf.c b/drivers/staging/comedi/comedi_buf.c
index 4e26bd7fc84f..924fce977985 100644
--- a/drivers/staging/comedi/comedi_buf.c
+++ b/drivers/staging/comedi/comedi_buf.c
@@ -16,6 +16,7 @@
*/
#include <linux/vmalloc.h>
+#include <linux/slab.h>
#include "comedidev.h"
#include "comedi_internal.h"
@@ -26,31 +27,21 @@
#define COMEDI_PAGE_PROTECTION PAGE_KERNEL
#endif
-static void __comedi_buf_free(struct comedi_device *dev,
- struct comedi_subdevice *s,
- unsigned n_pages)
+static void comedi_buf_map_kref_release(struct kref *kref)
{
- struct comedi_async *async = s->async;
+ struct comedi_buf_map *bm =
+ container_of(kref, struct comedi_buf_map, refcount);
struct comedi_buf_page *buf;
- unsigned i;
-
- if (async->prealloc_buf) {
- vunmap(async->prealloc_buf);
- async->prealloc_buf = NULL;
- async->prealloc_bufsz = 0;
- }
+ unsigned int i;
- if (!async->buf_page_list)
- return;
-
- for (i = 0; i < n_pages; ++i) {
- buf = &async->buf_page_list[i];
- if (buf->virt_addr) {
+ if (bm->page_list) {
+ for (i = 0; i < bm->n_pages; i++) {
+ buf = &bm->page_list[i];
clear_bit(PG_reserved,
&(virt_to_page(buf->virt_addr)->flags));
- if (s->async_dma_dir != DMA_NONE) {
+ if (bm->dma_dir != DMA_NONE) {
#ifdef CONFIG_HAS_DMA
- dma_free_coherent(dev->hw_dev,
+ dma_free_coherent(bm->dma_hw_dev,
PAGE_SIZE,
buf->virt_addr,
buf->dma_addr);
@@ -59,10 +50,26 @@ static void __comedi_buf_free(struct comedi_device *dev,
free_page((unsigned long)buf->virt_addr);
}
}
+ vfree(bm->page_list);
}
- vfree(async->buf_page_list);
- async->buf_page_list = NULL;
- async->n_buf_pages = 0;
+ if (bm->dma_dir != DMA_NONE)
+ put_device(bm->dma_hw_dev);
+ kfree(bm);
+}
+
+static void __comedi_buf_free(struct comedi_device *dev,
+ struct comedi_subdevice *s)
+{
+ struct comedi_async *async = s->async;
+
+ if (async->prealloc_buf) {
+ vunmap(async->prealloc_buf);
+ async->prealloc_buf = NULL;
+ async->prealloc_bufsz = 0;
+ }
+
+ comedi_buf_map_put(async->buf_map);
+ async->buf_map = NULL;
}
static void __comedi_buf_alloc(struct comedi_device *dev,
@@ -71,6 +78,7 @@ static void __comedi_buf_alloc(struct comedi_device *dev,
{
struct comedi_async *async = s->async;
struct page **pages = NULL;
+ struct comedi_buf_map *bm;
struct comedi_buf_page *buf;
unsigned i;
@@ -80,18 +88,29 @@ static void __comedi_buf_alloc(struct comedi_device *dev,
return;
}
- async->buf_page_list = vzalloc(sizeof(*buf) * n_pages);
- if (async->buf_page_list)
+ bm = kzalloc(sizeof(*async->buf_map), GFP_KERNEL);
+ if (!bm)
+ return;
+
+ async->buf_map = bm;
+ kref_init(&bm->refcount);
+ bm->dma_dir = s->async_dma_dir;
+ if (bm->dma_dir != DMA_NONE)
+ /* Need ref to hardware device to free buffer later. */
+ bm->dma_hw_dev = get_device(dev->hw_dev);
+
+ bm->page_list = vzalloc(sizeof(*buf) * n_pages);
+ if (bm->page_list)
pages = vmalloc(sizeof(struct page *) * n_pages);
if (!pages)
return;
for (i = 0; i < n_pages; i++) {
- buf = &async->buf_page_list[i];
- if (s->async_dma_dir != DMA_NONE)
+ buf = &bm->page_list[i];
+ if (bm->dma_dir != DMA_NONE)
#ifdef CONFIG_HAS_DMA
- buf->virt_addr = dma_alloc_coherent(dev->hw_dev,
+ buf->virt_addr = dma_alloc_coherent(bm->dma_hw_dev,
PAGE_SIZE,
&buf->dma_addr,
GFP_KERNEL |
@@ -108,6 +127,7 @@ static void __comedi_buf_alloc(struct comedi_device *dev,
pages[i] = virt_to_page(buf->virt_addr);
}
+ bm->n_pages = i;
/* vmap the prealloc_buf if all the pages were allocated */
if (i == n_pages)
@@ -117,6 +137,26 @@ static void __comedi_buf_alloc(struct comedi_device *dev,
vfree(pages);
}
+void comedi_buf_map_get(struct comedi_buf_map *bm)
+{
+ if (bm)
+ kref_get(&bm->refcount);
+}
+
+int comedi_buf_map_put(struct comedi_buf_map *bm)
+{
+ if (bm)
+ return kref_put(&bm->refcount, comedi_buf_map_kref_release);
+ return 1;
+}
+
+bool comedi_buf_is_mmapped(struct comedi_async *async)
+{
+ struct comedi_buf_map *bm = async->buf_map;
+
+ return bm && (atomic_read(&bm->refcount.refcount) > 1);
+}
+
int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
unsigned long new_size)
{
@@ -130,7 +170,7 @@ int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
return 0;
/* deallocate old buffer */
- __comedi_buf_free(dev, s, async->n_buf_pages);
+ __comedi_buf_free(dev, s);
/* allocate new buffer */
if (new_size) {
@@ -140,10 +180,9 @@ int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
if (!async->prealloc_buf) {
/* allocation failed */
- __comedi_buf_free(dev, s, n_pages);
+ __comedi_buf_free(dev, s);
return -ENOMEM;
}
- async->n_buf_pages = n_pages;
}
async->prealloc_bufsz = new_size;
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index 8cb9d956e8f2..58f2b27144ca 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -264,7 +264,7 @@ static int resize_async_buffer(struct comedi_device *dev,
DPRINTK("subdevice is busy, cannot resize buffer\n");
return -EBUSY;
}
- if (async->mmap_count) {
+ if (comedi_buf_is_mmapped(async)) {
DPRINTK("subdevice is mmapped, cannot resize buffer\n");
return -EBUSY;
}
@@ -647,7 +647,7 @@ static int is_device_busy(struct comedi_device *dev)
s = &dev->subdevices[i];
if (s->busy)
return 1;
- if (s->async && s->async->mmap_count)
+ if (s->async && comedi_buf_is_mmapped(s->async))
return 1;
}
@@ -1899,28 +1899,18 @@ done:
static void comedi_vm_open(struct vm_area_struct *area)
{
- struct comedi_async *async;
- struct comedi_device *dev;
+ struct comedi_buf_map *bm;
- async = area->vm_private_data;
- dev = async->subdevice->device;
-
- mutex_lock(&dev->mutex);
- async->mmap_count++;
- mutex_unlock(&dev->mutex);
+ bm = area->vm_private_data;
+ comedi_buf_map_get(bm);
}
static void comedi_vm_close(struct vm_area_struct *area)
{
- struct comedi_async *async;
- struct comedi_device *dev;
+ struct comedi_buf_map *bm;
- async = area->vm_private_data;
- dev = async->subdevice->device;
-
- mutex_lock(&dev->mutex);
- async->mmap_count--;
- mutex_unlock(&dev->mutex);
+ bm = area->vm_private_data;
+ comedi_buf_map_put(bm);
}
static struct vm_operations_struct comedi_vm_ops = {
@@ -1934,6 +1924,7 @@ static int comedi_mmap(struct file *file, struct vm_area_struct *vma)
struct comedi_device *dev = file->private_data;
struct comedi_subdevice *s;
struct comedi_async *async;
+ struct comedi_buf_map *bm;
unsigned long start = vma->vm_start;
unsigned long size;
int n_pages;
@@ -1980,8 +1971,13 @@ static int comedi_mmap(struct file *file, struct vm_area_struct *vma)
}
n_pages = size >> PAGE_SHIFT;
+ bm = async->buf_map;
+ if (!bm || n_pages > bm->n_pages) {
+ retval = -EINVAL;
+ goto done;
+ }
for (i = 0; i < n_pages; ++i) {
- struct comedi_buf_page *buf = &async->buf_page_list[i];
+ struct comedi_buf_page *buf = &bm->page_list[i];
if (remap_pfn_range(vma, start,
page_to_pfn(virt_to_page(buf->virt_addr)),
@@ -1993,9 +1989,9 @@ static int comedi_mmap(struct file *file, struct vm_area_struct *vma)
}
vma->vm_ops = &comedi_vm_ops;
- vma->vm_private_data = async;
+ vma->vm_private_data = bm;
- async->mmap_count++;
+ vma->vm_ops->open(vma);
retval = 0;
done:
diff --git a/drivers/staging/comedi/comedi_internal.h b/drivers/staging/comedi/comedi_internal.h
index 151693b11383..9a746570f161 100644
--- a/drivers/staging/comedi/comedi_internal.h
+++ b/drivers/staging/comedi/comedi_internal.h
@@ -16,6 +16,9 @@ void comedi_free_subdevice_minor(struct comedi_subdevice *s);
int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
unsigned long new_size);
void comedi_buf_reset(struct comedi_async *async);
+bool comedi_buf_is_mmapped(struct comedi_async *async);
+void comedi_buf_map_get(struct comedi_buf_map *bm);
+int comedi_buf_map_put(struct comedi_buf_map *bm);
unsigned int comedi_buf_write_n_allocated(struct comedi_async *async);
void comedi_device_cancel_all(struct comedi_device *dev);
diff --git a/drivers/staging/comedi/comedidev.h b/drivers/staging/comedi/comedidev.h
index 4e7cd1443be6..a7b8937aa4a3 100644
--- a/drivers/staging/comedi/comedidev.h
+++ b/drivers/staging/comedi/comedidev.h
@@ -104,18 +104,22 @@ struct comedi_buf_page {
dma_addr_t dma_addr;
};
+struct comedi_buf_map {
+ struct device *dma_hw_dev;
+ struct comedi_buf_page *page_list;
+ unsigned int n_pages;
+ enum dma_data_direction dma_dir;
+ struct kref refcount;
+};
+
struct comedi_async {
struct comedi_subdevice *subdevice;
void *prealloc_buf; /* pre-allocated buffer */
unsigned int prealloc_bufsz; /* buffer size, in bytes */
- /* virtual and dma address of each page */
- struct comedi_buf_page *buf_page_list;
- unsigned n_buf_pages; /* num elements in buf_page_list */
+ struct comedi_buf_map *buf_map; /* map of buffer pages */
unsigned int max_bufsize; /* maximum buffer size, bytes */
- /* current number of mmaps of prealloc_buf */
- unsigned int mmap_count;
/* byte count for writer (write completed) */
unsigned int buf_write_count;
diff --git a/drivers/staging/comedi/drivers/mite.c b/drivers/staging/comedi/drivers/mite.c
index 35cb4ace7970..1a2191699351 100644
--- a/drivers/staging/comedi/drivers/mite.c
+++ b/drivers/staging/comedi/drivers/mite.c
@@ -345,7 +345,7 @@ int mite_buf_change(struct mite_dma_descriptor_ring *ring,
for (i = 0; i < n_links; i++) {
ring->descriptors[i].count = cpu_to_le32(PAGE_SIZE);
ring->descriptors[i].addr =
- cpu_to_le32(async->buf_page_list[i].dma_addr);
+ cpu_to_le32(async->buf_map->page_list[i].dma_addr);
ring->descriptors[i].next =
cpu_to_le32(ring->descriptors_dma_addr + (i +
1) *
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-06-25 13:00:14 +0200