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authorSudeep Holla <sudeep.holla@arm.com>2023-05-03 14:12:52 +0100
committerSudeep Holla <sudeep.holla@arm.com>2023-05-08 20:40:46 +0100
commit111a833dc5cbef3d05b2a796a7e23cb7f6ff2192 (patch)
tree6acc96f8f5e34b7e97f74848ac3bfe793371dd1e /drivers/firmware/arm_ffa
parent19b8766459c41c6f318f8a548cc1c66dffd18363 (diff)
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firmware: arm_ffa: Set reserved/MBZ fields to zero in the memory descriptors
The transmit buffers allocated by the driver can be used to transmit data by any messages/commands needing the buffer. However, it is not guaranteed to have been zero-ed before every new transmission and hence it will just contain residual value from the previous transmission. There are several reserved fields in the memory descriptors that must be zero(MBZ). The receiver can reject the transmission if any such MBZ fields are non-zero. While we can set the whole page to zero, it is not optimal as most of the fields get initialised to the value required for the current transmission. So, just set the reserved/MBZ fields to zero in the memory descriptors explicitly to honour the requirement and keep the receiver happy. Fixes: cc2195fe536c ("firmware: arm_ffa: Add support for MEM_* interfaces") Reported-by: Marc Bonnici <marc.bonnici@arm.com> Link: https://lore.kernel.org/r/20230503131252.12585-1-sudeep.holla@arm.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Diffstat (limited to 'drivers/firmware/arm_ffa')
-rw-r--r--drivers/firmware/arm_ffa/driver.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c
index 4aced2e5b772..e23409138667 100644
--- a/drivers/firmware/arm_ffa/driver.c
+++ b/drivers/firmware/arm_ffa/driver.c
@@ -421,12 +421,17 @@ ffa_setup_and_transmit(u32 func_id, void *buffer, u32 max_fragsize,
ep_mem_access->receiver = args->attrs[idx].receiver;
ep_mem_access->attrs = args->attrs[idx].attrs;
ep_mem_access->composite_off = COMPOSITE_OFFSET(args->nattrs);
+ ep_mem_access->flag = 0;
+ ep_mem_access->reserved = 0;
}
+ mem_region->reserved_0 = 0;
+ mem_region->reserved_1 = 0;
mem_region->ep_count = args->nattrs;
composite = buffer + COMPOSITE_OFFSET(args->nattrs);
composite->total_pg_cnt = ffa_get_num_pages_sg(args->sg);
composite->addr_range_cnt = num_entries;
+ composite->reserved = 0;
length = COMPOSITE_CONSTITUENTS_OFFSET(args->nattrs, num_entries);
frag_len = COMPOSITE_CONSTITUENTS_OFFSET(args->nattrs, 0);
@@ -461,6 +466,7 @@ ffa_setup_and_transmit(u32 func_id, void *buffer, u32 max_fragsize,
constituents->address = sg_phys(args->sg);
constituents->pg_cnt = args->sg->length / FFA_PAGE_SIZE;
+ constituents->reserved = 0;
constituents++;
frag_len += sizeof(struct ffa_mem_region_addr_range);
} while ((args->sg = sg_next(args->sg)));