Instead of using low level cache manipulation API,
use the standard DMA API. This changes the concept
of the dspbridge cache API a little, hence the naming changes:
* Flush marks the beginning of a DMA transfer from the MPU
to the DSP.
* Invalidate marks the beginning of a DMA transfer from the DSP
to the MPU.
Both of these actions eventually build 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 <o...@wizery.com>
---
If you want, you can also reach me at < ohadb at ti dot com >.
arch/arm/plat-omap/include/dspbridge/_dcd.h | 4 +-
arch/arm/plat-omap/include/dspbridge/proc.h | 4 +-
arch/arm/plat-omap/include/dspbridge/wcdioctl.h | 4 +-
drivers/dsp/bridge/pmgr/wcd.c | 12 +-
drivers/dsp/bridge/rmgr/proc.c | 152 ++++++++++++++++++-----
5 files changed, 134 insertions(+), 42 deletions(-)
diff --git a/arch/arm/plat-omap/include/dspbridge/_dcd.h
b/arch/arm/plat-omap/include/dspbridge/_dcd.h
index 1350feb..0af4a31 100644
--- a/arch/arm/plat-omap/include/dspbridge/_dcd.h
+++ b/arch/arm/plat-omap/include/dspbridge/_dcd.h
@@ -110,9 +110,9 @@ extern u32 procwrap_reserve_memory(union Trapped_Args
*args, void *pr_ctxt);
extern u32 procwrap_un_reserve_memory(union Trapped_Args *args, void *pr_ctxt);
extern u32 procwrap_map(union Trapped_Args *args, void *pr_ctxt);
extern u32 procwrap_un_map(union Trapped_Args *args, void *pr_ctxt);
-extern u32 procwrap_flush_memory(union Trapped_Args *args, void *pr_ctxt);
+extern u32 procwrap_begin_dma_to_dsp(union Trapped_Args *args, void *pr_ctxt);
extern u32 procwrap_stop(union Trapped_Args *args, void *pr_ctxt);
-extern u32 procwrap_invalidate_memory(union Trapped_Args *args, void *pr_ctxt);
+extern u32 procwrap_begin_dma_from_dsp(union Trapped_Args *args, void
*pr_ctxt);
/* NODE wrapper functions */
extern u32 nodewrap_allocate(union Trapped_Args *args, void *pr_ctxt);
diff --git a/arch/arm/plat-omap/include/dspbridge/proc.h
b/arch/arm/plat-omap/include/dspbridge/proc.h
index 0707739..f8450a6 100644
--- a/arch/arm/plat-omap/include/dspbridge/proc.h
+++ b/arch/arm/plat-omap/include/dspbridge/proc.h
@@ -472,7 +472,7 @@ extern dsp_status proc_stop(void *hprocessor);
* Details:
* All the arguments are currently ignored.
*/
-extern dsp_status proc_flush_memory(void *hprocessor,
+extern dsp_status proc_begin_dma_to_dsp(void *hprocessor,
void *pmpu_addr, u32 ul_size, u32 ul_flags);
/*
@@ -493,7 +493,7 @@ extern dsp_status proc_flush_memory(void *hprocessor,
* Details:
* All the arguments are currently ignored.
*/
-extern dsp_status proc_invalidate_memory(void *hprocessor,
+extern dsp_status proc_begin_dma_from_dsp(void *hprocessor,
void *pmpu_addr, u32 ul_size);
/*
diff --git a/arch/arm/plat-omap/include/dspbridge/wcdioctl.h
b/arch/arm/plat-omap/include/dspbridge/wcdioctl.h
index b6a4dda..aba2078 100644
--- a/arch/arm/plat-omap/include/dspbridge/wcdioctl.h
+++ b/arch/arm/plat-omap/include/dspbridge/wcdioctl.h
@@ -452,9 +452,9 @@ union Trapped_Args {
#define PROC_UNRSVMEM _IOW(DB, DB_IOC(DB_PROC, 11), unsigned long)
#define PROC_MAPMEM _IOWR(DB, DB_IOC(DB_PROC, 12), unsigned long)
#define PROC_UNMAPMEM _IOR(DB, DB_IOC(DB_PROC, 13), unsigned long)
-#define PROC_FLUSHMEMORY _IOW(DB, DB_IOC(DB_PROC, 14), unsigned long)
+#define PROC_BEGINDMATODSP _IOW(DB, DB_IOC(DB_PROC, 14), unsigned long)
#define PROC_STOP _IOWR(DB, DB_IOC(DB_PROC, 15), unsigned long)
-#define PROC_INVALIDATEMEMORY _IOW(DB, DB_IOC(DB_PROC, 16), unsigned long)
+#define PROC_BEGINDMAFROMDSP _IOW(DB, DB_IOC(DB_PROC, 16), unsigned long)
/* NODE Module */
#define NODE_ALLOCATE _IOWR(DB, DB_IOC(DB_NODE, 0), unsigned long)
diff --git a/drivers/dsp/bridge/pmgr/wcd.c b/drivers/dsp/bridge/pmgr/wcd.c
index 15a05a6..89243f1 100644
--- a/drivers/dsp/bridge/pmgr/wcd.c
+++ b/drivers/dsp/bridge/pmgr/wcd.c
@@ -111,9 +111,9 @@ static struct wcd_cmd proc_cmd[] = {
{procwrap_un_reserve_memory}, /* PROC_UNRSVMEM */
{procwrap_map}, /* PROC_MAPMEM */
{procwrap_un_map}, /* PROC_UNMAPMEM */
- {procwrap_flush_memory}, /* PROC_FLUSHMEMORY */
+ {procwrap_begin_dma_to_dsp}, /* PROC_BEGINDMATODSP */
{procwrap_stop}, /* PROC_STOP */
- {procwrap_invalidate_memory}, /* PROC_INVALIDATEMEMORY */
+ {procwrap_begin_dma_from_dsp}, /* PROC_BEGINDMAFROMDSP */
};
/* NODE wrapper functions */
@@ -680,7 +680,7 @@ u32 procwrap_enum_node_info(union Trapped_Args *args, void
*pr_ctxt)
/*
* ======== procwrap_flush_memory ========
*/
-u32 procwrap_flush_memory(union Trapped_Args *args, void *pr_ctxt)
+u32 procwrap_begin_dma_to_dsp(union Trapped_Args *args, void *pr_ctxt)
{
dsp_status status;
@@ -688,7 +688,7 @@ u32 procwrap_flush_memory(union Trapped_Args *args, void
*pr_ctxt)
PROC_WRITEBACK_INVALIDATE_MEM)
return DSP_EINVALIDARG;
- status = proc_flush_memory(args->args_proc_flushmemory.hprocessor,
+ status = proc_begin_dma_to_dsp(args->args_proc_flushmemory.hprocessor,
args->args_proc_flushmemory.pmpu_addr,
args->args_proc_flushmemory.ul_size,
args->args_proc_flushmemory.ul_flags);
@@ -698,12 +698,12 @@ u32 procwrap_flush_memory(union Trapped_Args *args, void
*pr_ctxt)
/*
* ======== procwrap_invalidate_memory ========
*/
-u32 procwrap_invalidate_memory(union Trapped_Args *args, void *pr_ctxt)
+u32 procwrap_begin_dma_from_dsp(union Trapped_Args *args, void *pr_ctxt)
{
dsp_status status;
status =
- proc_invalidate_memory(args->args_proc_invalidatememory.hprocessor,
+ proc_begin_dma_from_dsp(args->args_proc_invalidatememory.hprocessor,
args->args_proc_invalidatememory.pmpu_addr,
args->args_proc_invalidatememory.ul_size);
return status;
diff --git a/drivers/dsp/bridge/rmgr/proc.c b/drivers/dsp/bridge/rmgr/proc.c
index bbc7e0f..8a76681 100644
--- a/drivers/dsp/bridge/rmgr/proc.c
+++ b/drivers/dsp/bridge/rmgr/proc.c
@@ -18,6 +18,8 @@
/* ------------------------------------ Host OS */
#include <linux/list.h>
+#include <linux/dma-mapping.h>
+#include <linux/scatterlist.h>
#include <linux/spinlock.h>
#include <dspbridge/host_os.h>
@@ -80,6 +82,7 @@
#define WBUF 0x8000 /* Output Buffer */
extern char *iva_img;
+extern struct device *bridge;
/* ----------------------------------- Globals */
@@ -110,6 +113,18 @@ struct proc_object {
spinlock_t maps_lock;
};
+/* 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 to cache memory mapping information */
struct memory_map_info {
struct list_head node;
@@ -118,6 +133,7 @@ struct memory_map_info {
u32 dsp_addr;
u32 size;
u32 num_usr_pgs;
+ struct bridge_dma_map_info dma_info;
};
static u32 refs;
@@ -130,7 +146,23 @@ static s32 get_envp_count(char **envp);
static char **prepend_envp(char **new_envp, char **envp, s32 envp_elems,
s32 cnew_envp, char *szVar);
-/* remember mapping information */
+/* Mapping and Page info caching
+ *
+ * The map_info mechanism is built to remember the (struct page *)
+ * pointers of all pages per a specific memory mapping of a specific
+ * process.
+ * Whenever a memory area is mapped, get_user_pages is used to pin the
+ * relevant pages in memory. As a result of running get_user_pages,
+ * we get the pointers to the page structures, which we now keep in
+ * the memory_map_info struct.
+ * Then, any time the user (the MM application) intends to begin
+ * a DMA (Direct Memory Access) operation to/from the remote processor,
+ * we use this cached page information to build a scatter gatter list
+ * which is given to the standard DMA API (which takes care of low
+ * level cache manipulation).
+ * Currently a simple linked list is used to cache the memory mapping
+ * info per process. This can be further optimized if needed.
+ */
static struct memory_map_info *add_mapping_info(struct proc_object *pr_obj,
u32 mpu_addr, u32 dsp_addr, u32 size)
{
@@ -197,6 +229,7 @@ static void remove_mapping_information(struct proc_object
*pr_obj,
if (match_exact_map_info(map_info, dsp_addr, size)) {
pr_debug("%s: match, deleting map info\n", __func__);
list_del(&map_info->node);
+ kfree(map_info->dma_info.sg);
kfree(map_info->pages);
kfree(map_info);
goto out;
@@ -625,50 +658,109 @@ dsp_status proc_enum_nodes(void *hprocessor, void
**node_tab,
return status;
}
-/* Cache operation against kernel address instead of users */
-static int memory_sync_page(struct memory_map_info *map_info,
- unsigned long start, ssize_t len, enum dsp_flushtype ftype)
+static int build_dma_sg(struct memory_map_info *map_info, 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_info, 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_info->dma_info.sg;
while (len) {
page = get_mapping_page(map_info, 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_info->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_release_ownership(struct memory_map_info *map_info,
+ 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_info, 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_info->dma_info.sg);
+
+ map_info->dma_info.sg = sg;
+ map_info->dma_info.dir = dir;
+ map_info->dma_info.num_pages = num_pages;
+
+ ret = build_dma_sg(map_info, 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_info->dma_info.sg_num = sg_num;
+
return 0;
+
+kfree_sg:
+ kfree(sg);
+ map_info->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 ftype)
+static dsp_status proc_begin_dma(void *hprocessor, void *pmpu_addr,
+ u32 ul_size, u32 ul_flags,
+ enum dma_data_direction dir)
{
/* Keep STATUS here for future additions to this function */
dsp_status status = DSP_SOK;
@@ -684,7 +776,7 @@ 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, ftype);
+ ul_size, dir);
/* find requested memory are in cached mapping information */
map_info = find_containing_mapping(p_proc_object, (u32) pmpu_addr,
@@ -695,7 +787,8 @@ static dsp_status proc_memory_sync(void *hprocessor, void
*pmpu_addr,
goto err_out;
}
- if (memory_sync_page(map_info, (u32) pmpu_addr, ul_size, ftype)) {
+ if (memory_release_ownership(map_info, (u32) pmpu_addr, ul_size,
+ dir)) {
pr_err("%s: InValid address parameters %p %x\n",
__func__, pmpu_addr, ul_size);
status = DSP_EHANDLE;
@@ -710,13 +803,12 @@ err_out:
* Purpose:
* Flush cache
*/
-dsp_status proc_flush_memory(void *hprocessor, void *pmpu_addr,
+dsp_status proc_begin_dma_to_dsp(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, ul_flags, dir);
}
/*
@@ -724,12 +816,12 @@ 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,
+dsp_status proc_begin_dma_from_dsp(void *hprocessor, void *pmpu_addr,
u32 ul_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, ul_size, 0, dir);
}
/*
--
1.6.3.3
--
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