FF-A v1.1 adds support to discovery the UUIDs of the partitions that was
missing in v1.0 and which the driver workarounds by using UUIDs supplied
by the ffa_drivers.

Add the v1.1 get_partition_info support and disable the workaround if
the detected FF-A version is greater than v1.0.

Signed-off-by: Sudeep Holla <redacted>
---
 drivers/firmware/arm_ffa/driver.c | 42 +++++++++++++++++++++++++------
 include/linux/arm_ffa.h           |  1 +
 2 files changed, 35 insertions(+), 8 deletions(-)

diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c
index 2532e0f16cc9..dd6ab2f81580 100644
--- a/drivers/firmware/arm_ffa/driver.c
+++ b/drivers/firmware/arm_ffa/driver.c

@@ -264,18 +264,24 @@ static int ffa_rxtx_unmap(u16 vm_id)
        return 0;
 }

+#define PARTITION_INFO_GET_RETURN_COUNT_ONLY   BIT(0)
+
 /* buffer must be sizeof(struct ffa_partition_info) * num_partitions */
 static int
 __ffa_partition_info_get(u32 uuid0, u32 uuid1, u32 uuid2, u32 uuid3,
                         struct ffa_partition_info *buffer, int num_partitions)
 {
-       int count;
+       int idx, count, flags = 0, size;
        ffa_value_t partition_info;

+       if (!buffer || !num_partitions) /* Just get the count for now */
+               flags = PARTITION_INFO_GET_RETURN_COUNT_ONLY;
+
        mutex_lock(&drv_info->rx_lock);
        invoke_ffa_fn((ffa_value_t){
                      .a0 = FFA_PARTITION_INFO_GET,
                      .a1 = uuid0, .a2 = uuid1, .a3 = uuid2, .a4 = uuid3,
+                     .a5 = flags,
                      }, &partition_info);

        if (partition_info.a0 == FFA_ERROR) {

@@ -285,8 +291,18 @@ __ffa_partition_info_get(u32 uuid0, u32 uuid1, u32 uuid2, u32 uuid3,

        count = partition_info.a2;

+       if (drv_info->version > FFA_VERSION_1_0) {
+               size = partition_info.a3;
+               if (size > sizeof(*buffer))
+                       size = sizeof(*buffer);

+       } else {
+               size = 8; /* FFA_VERSION_1_0 lacks size in the response */
+       }
+
        if (buffer && count <= num_partitions)
-               memcpy(buffer, drv_info->rx_buffer, sizeof(*buffer) * count);
+               for (idx = 0; idx < count; idx++)
+                       memcpy(buffer + idx, drv_info->rx_buffer + idx * size,
+                              size);

        ffa_rx_release();

@@ -681,6 +697,14 @@ void ffa_device_match_uuid(struct ffa_device *ffa_dev, const uuid_t *uuid)
        int count, idx;
        struct ffa_partition_info *pbuf, *tpbuf;

+       /*
+        * FF-A v1.1 provides UUID for each partition as part of the discovery
+        * API, the discovered UUID must be populated in the device's UUID and
+        * there is no need to copy the same from the driver table.
+        */
+       if (drv_info->version > FFA_VERSION_1_0)
+               return;
+
        count = ffa_partition_probe(uuid, &pbuf);
        if (count <= 0)
                return;

@@ -694,6 +718,7 @@ void ffa_device_match_uuid(struct ffa_device *ffa_dev, const uuid_t *uuid)
 static void ffa_setup_partitions(void)
 {
        int count, idx;
+       uuid_t uuid;
        struct ffa_device *ffa_dev;
        struct ffa_partition_info *pbuf, *tpbuf;

@@ -704,14 +729,15 @@ static void ffa_setup_partitions(void)
        }

        for (idx = 0, tpbuf = pbuf; idx < count; idx++, tpbuf++) {
-               /* Note that the &uuid_null parameter will require
+               import_uuid(&uuid, (u8 *)tpbuf->uuid);
+
+               /* Note that if the UUID will be uuid_null, that will require
                 * ffa_device_match() to find the UUID of this partition id
-                * with help of ffa_device_match_uuid(). Once the FF-A spec
-                * is updated to provide correct UUID here for each partition
-                * as part of the discovery API, we need to pass the
-                * discovered UUID here instead.
+                * with help of ffa_device_match_uuid(). FF-A v1.1 and above
+                * provides UUID here for each partition as part of the
+                * discovery API and the same is passed.
                 */
-               ffa_dev = ffa_device_register(&uuid_null, tpbuf->id, &ffa_ops);
+               ffa_dev = ffa_device_register(&uuid, tpbuf->id, &ffa_ops);
                if (!ffa_dev) {
                        pr_err("%s: failed to register partition ID 0x%x\n",
                               __func__, tpbuf->id);

diff --git a/include/linux/arm_ffa.h b/include/linux/arm_ffa.h
index 4c4b06783035..09567ffd1f49 100644
--- a/include/linux/arm_ffa.h
+++ b/include/linux/arm_ffa.h

@@ -107,6 +107,7 @@ struct ffa_partition_info {
 /* partition can send and receive indirect messages. */
 #define FFA_PARTITION_INDIRECT_MSG     BIT(2)
        u32 properties;
+       u32 uuid[4];
 };

 /* For use with FFA_MSG_SEND_DIRECT_{REQ,RESP} which pass data via registers */
--

2.37.3