Improve handling of the command buffer in goldfish_sync
32 command is not enough and just changing
the buffer size will consume too much stack.
Bug: 229140548
Test: presubmit
Change-Id: I6396f7523c0a84ecdc2382da164872fb4091d0e6
diff --git a/goldfish_drivers/goldfish_sync.c b/goldfish_drivers/goldfish_sync.c
index cb9b8e9..4aabedd 100644
--- a/goldfish_drivers/goldfish_sync.c
+++ b/goldfish_drivers/goldfish_sync.c
@@ -133,7 +133,8 @@
SYNC_REG_INIT = 0x18,
};
-#define GOLDFISH_SYNC_MAX_CMDS 32
+#define GOLDFISH_SYNC_MAX_CMDS 256
+#define GOLDFISH_SYNC_MAX_CMDS_STACK 32
/* The driver state: */
struct goldfish_sync_state {
@@ -152,8 +153,9 @@
/* Buffer holding commands issued from host. */
struct goldfish_sync_hostcmd to_do[GOLDFISH_SYNC_MAX_CMDS];
- u32 to_do_end;
- /* Protects to_do and to_do_end */
+ u16 to_do_begin;
+ u16 to_do_end;
+ /* Protects the to_do fields */
spinlock_t to_do_lock;
/* Buffers for the reading or writing
@@ -402,13 +404,29 @@
u32 time_arg,
u64 hostcmd_handle)
{
- const unsigned to_do_end = sync_state->to_do_end;
+ unsigned to_do_end = sync_state->to_do_end;
+ struct goldfish_sync_hostcmd *to_do = sync_state->to_do;
struct goldfish_sync_hostcmd *to_add;
- if (to_do_end >= GOLDFISH_SYNC_MAX_CMDS)
- return false;
+ if (to_do_end >= GOLDFISH_SYNC_MAX_CMDS) {
+ const unsigned to_do_begin = sync_state->to_do_begin;
+ const unsigned to_do_size = to_do_end - to_do_begin;
- to_add = &sync_state->to_do[to_do_end];
+ /*
+ * this memmove should not run often if
+ * goldfish_sync_work_item_fn grabs commands faster than they
+ * arrive.
+ */
+ memmove(&to_do[0], &to_do[to_do_begin],
+ sizeof(*to_do) * to_do_size);
+ to_do_end = to_do_size;
+ sync_state->to_do_begin = 0;
+
+ if (to_do_end >= GOLDFISH_SYNC_MAX_CMDS)
+ return false;
+ }
+
+ to_add = &to_do[to_do_end];
to_add->cmd = cmd;
to_add->handle = handle;
@@ -543,22 +561,37 @@
*/
static u32 __must_check
goldfish_sync_grab_commands(struct goldfish_sync_state *sync_state,
- struct goldfish_sync_hostcmd *dst)
+ struct goldfish_sync_hostcmd *dst,
+ const u32 dst_size)
{
- u32 to_do_end;
- u32 i;
+ u32 result;
+ unsigned to_do_begin;
+ unsigned to_do_end;
+ unsigned to_do_size;
+ struct goldfish_sync_hostcmd *to_do;
unsigned long irq_flags;
spin_lock_irqsave(&sync_state->to_do_lock, irq_flags);
+ to_do = sync_state->to_do;
+ to_do_begin = sync_state->to_do_begin;
to_do_end = sync_state->to_do_end;
- for (i = 0; i < to_do_end; i++)
- dst[i] = sync_state->to_do[i];
- sync_state->to_do_end = 0;
+ to_do_size = to_do_end - to_do_begin;
+
+ if (to_do_size > dst_size) {
+ memcpy(dst, &to_do[to_do_begin], sizeof(*to_do) * dst_size);
+ sync_state->to_do_begin = to_do_begin + dst_size;
+ result = dst_size;
+ } else {
+ memcpy(dst, &to_do[to_do_begin], sizeof(*to_do) * to_do_size);
+ sync_state->to_do_begin = 0;
+ sync_state->to_do_end = 0;
+ result = to_do_size;
+ }
spin_unlock_irqrestore(&sync_state->to_do_lock, irq_flags);
- return to_do_end;
+ return result;
}
void goldfish_sync_run_hostcmd(struct goldfish_sync_state *sync_state,
@@ -619,16 +652,22 @@
struct goldfish_sync_state *sync_state =
container_of(input, struct goldfish_sync_state, work_item);
- struct goldfish_sync_hostcmd to_run[GOLDFISH_SYNC_MAX_CMDS];
- u32 to_do_end;
- u32 i;
+ struct goldfish_sync_hostcmd to_run[GOLDFISH_SYNC_MAX_CMDS_STACK];
mutex_lock(&sync_state->mutex_lock);
- to_do_end = goldfish_sync_grab_commands(sync_state, to_run);
+ while (true) {
+ u32 i;
+ u32 to_do_end =
+ goldfish_sync_grab_commands(sync_state, to_run,
+ ARRAY_SIZE(to_run));
- for (i = 0; i < to_do_end; i++)
- goldfish_sync_run_hostcmd(sync_state, &to_run[i]);
+ for (i = 0; i < to_do_end; i++)
+ goldfish_sync_run_hostcmd(sync_state, &to_run[i]);
+
+ if (to_do_end < ARRAY_SIZE(to_run))
+ break;
+ }
mutex_unlock(&sync_state->mutex_lock);
}
