Instead of using low level cache manipulation API,
use the standard DMA API. This is achieved by adding
a proc_begin_dma function that takes a generic
dma_data_direction, and then implementing proc_flush_memory
and proc_invalidate_memory by means of proc_begin_dma
in the following manner:
* flush calls proc_begin_dma with DMA_BIDIRECTIONAL
* Invalidate calls proc_begin_dma with DMA_FROM_DEVICE
proc_begin_dma builds a scatter gatter list using the
page information that was kept during proc_map,
and feed it to the standard dma_map_sg API.
Note that now users cannot manipulate the cache state of any random
address; if the buffer is not part of a previous memory mapping of that
application, the request is denied.
Signed-off-by: Ohad Ben-Cohen <ohad@xxxxxxxxxx>
---
If you want, you can also reach me at < ohadb at ti dot com >.
arch/arm/plat-omap/include/dspbridge/drv.h | 13 +++
drivers/dsp/bridge/rmgr/proc.c | 119 +++++++++++++++++++++-------
2 files changed, 104 insertions(+), 28 deletions(-)
diff --git a/arch/arm/plat-omap/include/dspbridge/drv.h b/arch/arm/plat-omap/include/dspbridge/drv.h
index b1312aa..3186935 100644
--- a/arch/arm/plat-omap/include/dspbridge/drv.h
+++ b/arch/arm/plat-omap/include/dspbridge/drv.h
@@ -84,6 +84,18 @@ struct node_res_object {
struct node_res_object *next;
};
+/* used to cache dma mapping information */
+struct bridge_dma_map_info {
+ /* direction of DMA in action, or DMA_NONE */
+ enum dma_data_direction dir;
+ /* number of elements requested by us */
+ int num_pages;
+ /* number of elements returned from dma_map_sg */
+ int sg_num;
+ /* list of buffers used in this DMA action */
+ struct scatterlist *sg;
+};
+
/* Used for DMM mapped memory accounting */
struct dmm_map_object {
struct list_head link;
@@ -92,6 +104,7 @@ struct dmm_map_object {
u32 size;
u32 num_usr_pgs;
struct page **pages;
+ struct bridge_dma_map_info dma_info;
};
/* Used for DMM reserved memory accounting */
diff --git a/drivers/dsp/bridge/rmgr/proc.c b/drivers/dsp/bridge/rmgr/proc.c
index 6628483..2710a11 100644
--- a/drivers/dsp/bridge/rmgr/proc.c
+++ b/drivers/dsp/bridge/rmgr/proc.c
@@ -17,6 +17,8 @@
*/
/* ------------------------------------ Host OS */
+#include <linux/dma-mapping.h>
+#include <linux/scatterlist.h>
#include <dspbridge/host_os.h>
/* ----------------------------------- DSP/BIOS Bridge */
@@ -74,6 +76,8 @@
#define RBUF 0x4000 /* Input buffer */
#define WBUF 0x8000 /* Output Buffer */
+extern struct device *bridge;
+
/* ----------------------------------- Globals */
/* The proc_object structure. */
@@ -177,6 +181,7 @@ static void remove_mapping_information(struct process_context *pr_ctxt,
if (match_exact_map_obj(map_obj, dsp_addr, size)) {
pr_debug("%s: match, deleting map info\n", __func__);
list_del(&map_obj->link);
+ kfree(map_obj->dma_info.sg);
kfree(map_obj->pages);
kfree(map_obj);
goto out;
@@ -606,49 +611,108 @@ dsp_status proc_enum_nodes(void *hprocessor, void **node_tab,
}
/* Cache operation against kernel address instead of users */
-static int memory_sync_page(struct dmm_map_object *map_obj,
- unsigned long start, ssize_t len, enum dsp_flushtype ftype)
+static int build_dma_sg(struct dmm_map_object *map_obj, unsigned long start,
+ ssize_t len, int pg_i)
{
struct page *page;
- void *kaddr;
unsigned long offset;
ssize_t rest;
- int pg_i;
-
- pg_i = find_first_page_in_cache(map_obj, start);
- if (pg_i < 0) {
- pr_err("%s: failed to find first page in cache\n", __func__);
- return -EINVAL;
- }
+ int ret = 0, i = 0;
+ struct scatterlist *sg = map_obj->dma_info.sg;
while (len) {
page = get_mapping_page(map_obj, pg_i);
if (!page) {
pr_err("%s: no page for %08lx\n", __func__, start);
- return -EINVAL;
+ ret = -EINVAL;
+ goto out;
} else if (IS_ERR(page)) {
pr_err("%s: err page for %08lx(%lu)\n", __func__, start,
PTR_ERR(page));
- return PTR_ERR(page);
+ ret = PTR_ERR(page);
+ goto out;
}
offset = start & ~PAGE_MASK;
- kaddr = kmap(page) + offset;
rest = min_t(ssize_t, PAGE_SIZE - offset, len);
- mem_flush_cache(kaddr, rest, ftype);
- kunmap(page);
+ sg_set_page(&sg[i], page, rest, offset);
+
len -= rest;
start += rest;
- pg_i++;
+ pg_i++, i++;
}
+ if (i != map_obj->dma_info.num_pages) {
+ pr_err("%s: bad number of sg iterations\n", __func__);
+ ret = -EFAULT;
+ goto out;
+ }
+
+out:
+ return ret;
+}
+
+/* Cache operation against kernel address instead of users */
+static int memory_give_ownership(struct dmm_map_object *map_obj,
+ unsigned long start, ssize_t len, enum dma_data_direction dir)
+{
+ int pg_i, ret, sg_num;
+ struct scatterlist *sg;
+ unsigned long first_data_page = start >> PAGE_SHIFT;
+ unsigned long last_data_page = ((u32)(start + len - 1) >> PAGE_SHIFT);
+ /* calculating the number of pages this area spans */
+ unsigned long num_pages = last_data_page - first_data_page + 1;
+
+ pg_i = find_first_page_in_cache(map_obj, start);
+ if (pg_i < 0) {
+ pr_err("%s: failed to find first page in cache\n", __func__);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ sg = kcalloc(num_pages, sizeof(*sg), GFP_KERNEL);
+ if (!sg) {
+ pr_err("%s: kcalloc failed\n", __func__);
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ sg_init_table(sg, num_pages);
+
+ /* cleanup a previous sg allocation */
+ /* this may happen if application doesn't signal for e/o DMA */
+ kfree(map_obj->dma_info.sg);
+
+ map_obj->dma_info.sg = sg;
+ map_obj->dma_info.dir = dir;
+ map_obj->dma_info.num_pages = num_pages;
+
+ ret = build_dma_sg(map_obj, start, len, pg_i);
+ if (ret)
+ goto kfree_sg;
+
+ sg_num = dma_map_sg(bridge, sg, num_pages, dir);
+ if (sg_num < 1) {
+ pr_err("%s: dma_map_sg failed: %d\n", __func__, sg_num);
+ ret = -EFAULT;
+ goto kfree_sg;
+ }
+
+ pr_debug("%s: dma_map_sg mapped %d elements\n", __func__, sg_num);
+ map_obj->dma_info.sg_num = sg_num;
+
return 0;
+
+kfree_sg:
+ kfree(sg);
+ map_obj->dma_info.sg = NULL;
+out:
+ return ret;
}
-static dsp_status proc_memory_sync(void *hprocessor, void *pmpu_addr,
- u32 ul_size, u32 ul_flags,
- enum dsp_flushtype FlushMemType)
+static int proc_begin_dma(void *hprocessor, void *pmpu_addr, u32 ul_size,
+ enum dma_data_direction dir)
{
/* Keep STATUS here for future additions to this function */
dsp_status status = DSP_SOK;
@@ -664,7 +728,7 @@ static dsp_status proc_memory_sync(void *hprocessor, void *pmpu_addr,
pr_debug("%s: addr 0x%x, size 0x%x, type %d\n", __func__,
(u32)pmpu_addr,
- ul_size, ul_flags);
+ ul_size, dir);
/* find requested memory are in cached mapping information */
map_obj = find_containing_mapping(pr_ctxt, (u32) pmpu_addr, ul_size);
@@ -673,7 +737,8 @@ static dsp_status proc_memory_sync(void *hprocessor, void *pmpu_addr,
status = -EFAULT;
goto err_out;
}
- if (memory_sync_page(map_obj, (u32) pmpu_addr, ul_size, ul_flags)) {
+
+ if (memory_give_ownership(map_obj, (u32) pmpu_addr, ul_size, dir)) {
pr_err("%s: InValid address parameters %p %x\n",
__func__, pmpu_addr, ul_size);
status = -EFAULT;
@@ -692,10 +757,9 @@ err_out:
dsp_status proc_flush_memory(void *hprocessor, void *pmpu_addr,
u32 ul_size, u32 ul_flags)
{
- enum dsp_flushtype mtype = PROC_WRITEBACK_INVALIDATE_MEM;
+ enum dma_data_direction dir = DMA_BIDIRECTIONAL;
- return proc_memory_sync(hprocessor, pmpu_addr, ul_size, ul_flags,
- mtype);
+ return proc_begin_dma(hprocessor, pmpu_addr, ul_size, dir);
}
/*
@@ -703,12 +767,11 @@ dsp_status proc_flush_memory(void *hprocessor, void *pmpu_addr,
* Purpose:
* Invalidates the memory specified
*/
-dsp_status proc_invalidate_memory(void *hprocessor, void *pmpu_addr,
- u32 ul_size)
+dsp_status proc_invalidate_memory(void *hprocessor, void *pmpu_addr, u32 size)
{
- enum dsp_flushtype mtype = PROC_INVALIDATE_MEM;
+ enum dma_data_direction dir = DMA_FROM_DEVICE;
- return proc_memory_sync(hprocessor, pmpu_addr, ul_size, 0, mtype);
+ return proc_begin_dma(hprocessor, pmpu_addr, size, dir);
}
/*
--
1.7.0.4
--
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