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

On Wed, Sep 07, 2022 at 10:38:05AM +0200, Jens Wiklander wrote:

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?

Good spot, I missed to see that. It makes complete sense. I will fix it.