[PATCH RFT 07/12] firmware: arm_ffa: Implement the NOTIFICATION_INFO_GET interface

From: Sudeep Holla
Date: Thu Aug 03 2023 - 15:02:51 EST


The receiver’s scheduler uses the FFA_NOTIFICATION_INFO_GET interface
to retrieve the list of endpoints that have pending notifications and
must be run. A notification could be signaled by a sender in the secure
world to a VM. The Hypervisor needs to determine which VM and vCPU
(in case a per-vCPU notification is signaled) has a pending notification
in this scenario. It must obtain this information through an invocation
of the FFA_NOTIFICATION_INFO_GET.

Add the implementation of the NOTIFICATION_INFO_GET interface
and prepare to use this to handle the schedule receiver interrupt.
Implementation of handling notifications will be added later.

Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
---
drivers/firmware/arm_ffa/driver.c | 70 +++++++++++++++++++++++++++++++++++++++
1 file changed, 70 insertions(+)

diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c
index 6cad91ee57eb..77ca9753e3f0 100644
--- a/drivers/firmware/arm_ffa/driver.c
+++ b/drivers/firmware/arm_ffa/driver.c
@@ -590,6 +590,13 @@ static int ffa_notification_bitmap_destroy(void)
(FIELD_PREP(RECEIVER_VCPU_MASK, (vcpu_r)) | \
FIELD_PREP(RECEIVER_ID_MASK, (r)))

+#define NOTIFICATION_INFO_GET_MORE_PEND_MASK BIT(0)
+#define NOTIFICATION_INFO_GET_ID_COUNT GENMASK(11, 7)
+#define ID_LIST_MASK_64 GENMASK(51, 12)
+#define ID_LIST_MASK_32 GENMASK(31, 12)
+#define MAX_IDS_64 20
+#define MAX_IDS_32 10
+
static int ffa_notification_bind_common(u16 dst_id, u64 bitmap,
u32 flags, bool is_bind)
{
@@ -661,6 +668,69 @@ static int ffa_notification_get(u32 flags, struct ffa_notify_bitmaps *notify)
return 0;
}

+static void __do_sched_recv_cb(u16 partition_id, u16 vcpu, bool is_per_vcpu)
+{
+ pr_err("Callback for partition 0x%x failed.\n", partition_id);
+}
+
+static void ffa_notification_info_get(bool is_64b)
+{
+ int idx, list, max_ids, lists_cnt, ids_processed, ids_count[MAX_IDS_64];
+ ffa_value_t ret;
+ u64 id_list;
+
+ do {
+ invoke_ffa_fn((ffa_value_t){
+ .a0 = FFA_FN_NATIVE(NOTIFICATION_INFO_GET),
+ }, &ret);
+
+ if (ret.a0 != FFA_FN_NATIVE(SUCCESS)) {
+ if (ret.a2 != FFA_RET_NO_DATA)
+ pr_err("Notification Info fetch failed: 0x%lx (0x%lx)",
+ ret.a0, ret.a2);
+ return;
+ }
+
+ ids_processed = 0;
+ lists_cnt = FIELD_GET(NOTIFICATION_INFO_GET_ID_COUNT, ret.a2);
+ if (is_64b) {
+ max_ids = MAX_IDS_64;
+ id_list = FIELD_GET(ID_LIST_MASK_64, ret.a2);
+ } else {
+ max_ids = MAX_IDS_32;
+ id_list = FIELD_GET(ID_LIST_MASK_32, ret.a2);
+ }
+
+ for (idx = 0; idx < lists_cnt; idx++, id_list >>= 2)
+ ids_count[idx] = (id_list & 0x3) + 1;
+
+ /* Process IDs */
+ for (list = 0; list < lists_cnt; list++) {
+ u16 vcpu_id, part_id, *packed_id_list = (u16 *)&ret.a3;
+
+ if (ids_processed >= max_ids - 1)
+ break;
+
+ part_id = packed_id_list[++ids_processed];
+
+ if (!ids_count[list]) { /* Global Notification */
+ __do_sched_recv_cb(part_id, 0, false);
+ continue;
+ }
+
+ /* Per vCPU Notification */
+ for (idx = 0; idx < ids_count[list]; idx++) {
+ if (ids_processed >= max_ids - 1)
+ break;
+
+ vcpu_id = packed_id_list[++ids_processed];
+
+ __do_sched_recv_cb(part_id, vcpu_id, true);
+ }
+ }
+ } while (ret.a2 & NOTIFICATION_INFO_GET_MORE_PEND_MASK);
+}
+
static int ffa_run(struct ffa_device *dev, u16 vcpu)
{
ffa_value_t ret;

--
2.41.0