Commit 987756f6 authored Apr 26, 2022 by Marc Bonnici Committed by Sudeep Holla Apr 27, 2022

firmware: arm_ffa: Fix handling of fragmented memory descriptors

Fix the handling of MEM_FRAG_TX/RX SMCs when the full memory descriptor
does not fit in a single innovation of a memory sharing request.

The current implementation expects a FFA_MEM_SHARE/FFA_MEM_LEND
call to always receive a FFA_SUCCESS response, however in the
case where a full descriptor does not fit inside the partitions
TX buffer, the call can instead complete with a FFA_MEM_FRAG_RX SMC
to request the next part of the descriptor to be transmitted.

Similarly a FFA_MEM_FRAG_TX call currently only expects
FFA_MEM_FRAG_RX as a response, however once the full descriptor
has been transmitted the FFA_SUCCESS ABI will be used to indicate
successful transmission.

Update the existing code to match the expected behaviour.

Link: https://lore.kernel.org/r/20220426121219.1801601-1-marc.bonnici@arm.com


Signed-off-by: Marc Bonnici <marc.bonnici@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

parent 31231092

drivers/firmware/arm_ffa/driver.c

+13 −7

Original line number	Diff line number	Diff line
		@@ -398,11 +398,15 @@ static int ffa_mem_first_frag(u32 func_id, phys_addr_t buf, u32 buf_sz,
		if (ret.a0 == FFA_ERROR)
		return ffa_to_linux_errno((int)ret.a2);

		if (ret.a0 != FFA_SUCCESS)
		return -EOPNOTSUPP;

		if (ret.a0 == FFA_SUCCESS) {
		if (handle)
		*handle = PACK_HANDLE(ret.a2, ret.a3);
		} else if (ret.a0 == FFA_MEM_FRAG_RX) {
		if (handle)
		*handle = PACK_HANDLE(ret.a1, ret.a2);
		} else {
		return -EOPNOTSUPP;
		}

		return frag_len;
		}
		@@ -426,10 +430,12 @@ static int ffa_mem_next_frag(u64 handle, u32 frag_len)
		if (ret.a0 == FFA_ERROR)
		return ffa_to_linux_errno((int)ret.a2);

		if (ret.a0 != FFA_MEM_FRAG_RX)
		return -EOPNOTSUPP;

		if (ret.a0 == FFA_MEM_FRAG_RX)
		return ret.a3;
		else if (ret.a0 == FFA_SUCCESS)
		return 0;

		return -EOPNOTSUPP;
		}

		static int