The function comedi_buf_alloc() first frees any allocated buffer then,
optionally, allocates a new buffer.
Factor out the new buffer allocation to a new function. This allows
reducing the indent level of the code and makes comedi_buf_alloc()
a bit cleaner.
Cleanup the factored out code to make it a bit more concise.
Use a local variable for the current comedi_buf_page being allocated.
This cleans up the ugly line breaks and makes the code a bit cleaner.
Also, move the #ifdef'ery for the page protection determination out of
the vmap() call.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbobbi@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/comedi_buf.c | 96 ++++++++++++++++++++-----------------
1 file changed, 51 insertions(+), 45 deletions(-)
diff --git a/drivers/staging/comedi/comedi_buf.c b/drivers/staging/comedi/comedi_buf.c
index 37656d9..cab496b 100644
--- a/drivers/staging/comedi/comedi_buf.c
+++ b/drivers/staging/comedi/comedi_buf.c
@@ -22,6 +22,12 @@
#include "comedidev.h"
#include "comedi_internal.h"
+#ifdef PAGE_KERNEL_NOCACHE
+#define COMEDI_PAGE_PROTECTION PAGE_KERNEL_NOCACHE
+#else
+#define COMEDI_PAGE_PROTECTION PAGE_KERNEL
+#endif
+
static void comedi_buf_free_page_list(struct comedi_device *dev,
struct comedi_subdevice *s,
unsigned n_pages)
@@ -50,6 +56,48 @@ static void comedi_buf_free_page_list(struct comedi_device *dev,
async->n_buf_pages = 0;
}
+static void __comedi_buf_alloc(struct comedi_device *dev,
+ struct comedi_subdevice *s,
+ unsigned n_pages)
+{
+ struct comedi_async *async = s->async;
+ struct page **pages = NULL;
+ struct comedi_buf_page *buf;
+ unsigned i;
+
+ async->buf_page_list = vzalloc(sizeof(*buf) * n_pages);
+ if (async->buf_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->virt_addr = dma_alloc_coherent(dev->hw_dev,
+ PAGE_SIZE,
+ &buf->dma_addr,
+ GFP_KERNEL |
+ __GFP_COMP);
+ else
+ buf->virt_addr = (void *)get_zeroed_page(GFP_KERNEL);
+ if (!buf->virt_addr)
+ break;
+
+ set_bit(PG_reserved, &(virt_to_page(buf->virt_addr)->flags));
+
+ pages[i] = virt_to_page(buf->virt_addr);
+ }
+
+ /* vmap the prealloc_buf if all the pages were allocated */
+ if (i == n_pages)
+ async->prealloc_buf = vmap(pages, n_pages, VM_MAP,
+ COMEDI_PAGE_PROTECTION);
+
+ vfree(pages);
+}
+
int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
unsigned long new_size)
{
@@ -73,53 +121,11 @@ int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
/* allocate new buffer */
if (new_size) {
- unsigned i = 0;
unsigned n_pages = new_size >> PAGE_SHIFT;
- struct page **pages = NULL;
-
- async->buf_page_list =
- vzalloc(sizeof(struct comedi_buf_page) * n_pages);
- if (async->buf_page_list)
- pages = vmalloc(sizeof(struct page *) * n_pages);
-
- if (pages) {
- for (i = 0; i < n_pages; i++) {
- if (s->async_dma_dir != DMA_NONE) {
- async->buf_page_list[i].virt_addr =
- dma_alloc_coherent(dev->hw_dev,
- PAGE_SIZE,
- &async->
- buf_page_list
- [i].dma_addr,
- GFP_KERNEL |
- __GFP_COMP);
- } else {
- async->buf_page_list[i].virt_addr =
- (void *)
- get_zeroed_page(GFP_KERNEL);
- }
- if (async->buf_page_list[i].virt_addr == NULL)
- break;
-
- set_bit(PG_reserved,
- &(virt_to_page(async->buf_page_list[i].
- virt_addr)->flags));
- pages[i] = virt_to_page(async->buf_page_list[i].
- virt_addr);
- }
- }
- if (i == n_pages) {
- async->prealloc_buf =
-#ifdef PAGE_KERNEL_NOCACHE
- vmap(pages, n_pages, VM_MAP, PAGE_KERNEL_NOCACHE);
-#else
- vmap(pages, n_pages, VM_MAP, PAGE_KERNEL);
-#endif
- }
- vfree(pages);
- if (async->prealloc_buf == NULL) {
- /* Some allocation failed above. */
+ __comedi_buf_alloc(dev, s, n_pages);
+ if (!async->prealloc_buf) {
+ /* Allocation failed */
if (async->buf_page_list)
comedi_buf_free_page_list(dev, s, n_pages);
return -ENOMEM;
--
1.8.0
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