@@ -26,6 +26,7 @@
#include <linux/arm_ffa.h>
#include <linux/bitfield.h>
#include <linux/cpuhotplug.h>
+#include <linux/delay.h>
#include <linux/device.h>
#include <linux/hashtable.h>
#include <linux/interrupt.h>
@@ -397,6 +398,18 @@ static int ffa_id_get(u16 *vm_id)
return 0;
}
+static inline void ffa_msg_send_wait_for_completion(ffa_value_t *ret)
+{
+ while (ret->a0 == FFA_INTERRUPT || ret->a0 == FFA_YIELD) {
+ if (ret->a0 == FFA_YIELD)
+ fsleep(1000);
+
+ invoke_ffa_fn((ffa_value_t){
+ .a0 = FFA_RUN, .a1 = ret->a1,
+ }, ret);
+ }
+}
+
static int ffa_msg_send_direct_req(u16 src_id, u16 dst_id, bool mode_32bit,
struct ffa_send_direct_data *data)
{
@@ -417,10 +430,7 @@ static int ffa_msg_send_direct_req(u16 src_id, u16 dst_id, bool mode_32bit,
.a6 = data->data3, .a7 = data->data4,
}, &ret);
- while (ret.a0 == FFA_INTERRUPT)
- invoke_ffa_fn((ffa_value_t){
- .a0 = FFA_RUN, .a1 = ret.a1,
- }, &ret);
+ ffa_msg_send_wait_for_completion(&ret);
if (ret.a0 == FFA_ERROR)
return ffa_to_linux_errno((int)ret.a2);
@@ -482,10 +492,7 @@ static int ffa_msg_send_direct_req2(u16 src_id, u16 dst_id, const uuid_t *uuid,
invoke_ffa_fn(args, &ret);
- while (ret.a0 == FFA_INTERRUPT)
- invoke_ffa_fn((ffa_value_t){
- .a0 = FFA_RUN, .a1 = ret.a1,
- }, &ret);
+ ffa_msg_send_wait_for_completion(&ret);
if (ret.a0 == FFA_ERROR)
return ffa_to_linux_errno((int)ret.a2);
Successful completion of both direct messaging function can be indicated through an invocation of FFA_YIELD or GGA_INTERRUPT by the callee. FFA_INTERRUPT indicates that the direct request was interrupted and must be resumed through the FFA_RUN interface which is already done in the driver. FFA_YIELD indicates that the receiver endpoint has transitioned to the blocked runtime state and must be resumed through the FFA_RUN interface. However, the way receiver endpoint gets unblocked is implementation defined. So, the driver just sleeps for 1 - 2ms and issues FFA_RUN. It can return to the caller with FFA_YIELD is the receiver endpoint is still blocked. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> --- drivers/firmware/arm_ffa/driver.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-)