Re: [PATCH v2 08/10] firmware: arm_ffa: Add v1.1 get_partition_info support

On Fri, Sep 2, 2022 at 2:40 PM Sudeep Holla sudeep.holla@arm.com wrote:

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 sudeep.holla@arm.com

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);
  

Below when calculating the address in the source buffer with "drv_info->rx_buffer + idx * size" you should use the size from partition_info.a3 even if it's larger than sizeof(*buffer). The amount of bytes to copy looks correct though. Does that make sense?

Cheers, Jens

•   } 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