firmware: arm_ffa: Implement the FFA_RUN interface

FFA_RUN is used by a scheduler to allocate CPU cycles to a target
endpoint execution context specified in the target information parameter.

If the endpoint execution context is in the waiting/blocked state, it
transitions to the running state.

Expose the ability to call FFA_RUN in order to give any partition in the
system cpu cycles to perform IMPDEF functionality.

Link: https://lore.kernel.org/r/20231005-ffa_v1-1_notif-v4-4-cddd3237809c@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c
index 20f8f4ca8e89b0d7ce1c37fb392c33e5fc53c19b..82e54d231074651f11a9d4dcce30f74d8d2ea15a 100644 (file)
--- a/drivers/firmware/arm_ffa/driver.c
+++ b/drivers/firmware/arm_ffa/driver.c
@@ -616,6 +616,23 @@ static int ffa_notification_bind_common(u16 dst_id, u64 bitmap,
        return 0;
 }
 
+static int ffa_run(struct ffa_device *dev, u16 vcpu)
+{
+       ffa_value_t ret;
+       u32 target = dev->vm_id << 16 | vcpu;
+
+       invoke_ffa_fn((ffa_value_t){ .a0 = FFA_RUN, .a1 = target, }, &ret);
+
+       while (ret.a0 == FFA_INTERRUPT)
+               invoke_ffa_fn((ffa_value_t){ .a0 = FFA_RUN, .a1 = ret.a1, },
+                             &ret);
+
+       if (ret.a0 == FFA_ERROR)
+               return ffa_to_linux_errno((int)ret.a2);
+
+       return 0;
+}
+
 static void ffa_set_up_mem_ops_native_flag(void)
 {
        if (!ffa_features(FFA_FN_NATIVE(MEM_LEND), 0, NULL, NULL) ||
@@ -700,10 +717,15 @@ static const struct ffa_mem_ops ffa_drv_mem_ops = {
        .memory_lend = ffa_memory_lend,
 };
 
+static const struct ffa_cpu_ops ffa_drv_cpu_ops = {
+       .run = ffa_run,
+};
+
 static const struct ffa_ops ffa_drv_ops = {
        .info_ops = &ffa_drv_info_ops,
        .msg_ops = &ffa_drv_msg_ops,
        .mem_ops = &ffa_drv_mem_ops,
+       .cpu_ops = &ffa_drv_cpu_ops,
 };
 
 void ffa_device_match_uuid(struct ffa_device *ffa_dev, const uuid_t *uuid)

diff --git a/include/linux/arm_ffa.h b/include/linux/arm_ffa.h
index 2ea1717a08251422e3bf8b1caa5fa3c109d5e509..12fd134bf6700ccb3ed38b053a642b8cbe9f1bea 100644 (file)
--- a/include/linux/arm_ffa.h
+++ b/include/linux/arm_ffa.h
@@ -387,10 +387,15 @@ struct ffa_mem_ops {
        int (*memory_lend)(struct ffa_mem_ops_args *args);
 };
 
+struct ffa_cpu_ops {
+       int (*run)(struct ffa_device *dev, u16 vcpu);
+};
+
 struct ffa_ops {
        const struct ffa_info_ops *info_ops;
        const struct ffa_msg_ops *msg_ops;
        const struct ffa_mem_ops *mem_ops;
+       const struct ffa_cpu_ops *cpu_ops;
 };
 
 #endif /* _LINUX_ARM_FFA_H */