net: ipa: introduce ipa_mem_find()

Introduce a new function that abstracts finding information about a
region in IPA-local memory, given its memory region ID.  For now it
simply uses the region ID as an index into the IPA memory array.
If the region is not defined, ipa_mem_find() returns a null pointer.

Update all code that accesses the ipa->mem[] array directly to use
ipa_mem_find() instead.  The return value must be checked for null
when optional memory regions are sought.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 3 deletions

diff --git a/drivers/net/ipa/ipa_cmd.c b/drivers/net/ipa/ipa_cmd.c
index 3e5f10d3c131..af44ca41189e 100644
--- a/drivers/net/ipa/ipa_cmd.c
+++ b/drivers/net/ipa/ipa_cmd.c
@@ -218,7 +218,7 @@ static bool ipa_cmd_header_valid(struct ipa *ipa)
 	/* The header memory area contains both the modem and AP header
 	 * regions.  The modem portion defines the address of the region.
 	 */
-	mem = &ipa->mem[IPA_MEM_MODEM_HEADER];
+	mem = ipa_mem_find(ipa, IPA_MEM_MODEM_HEADER);
 	offset = mem->offset;
 	size = mem->size;
 
@@ -231,8 +231,10 @@ static bool ipa_cmd_header_valid(struct ipa *ipa)
 		return false;
 	}
 
-	/* Add the size of the AP portion to the combined size */
-	size += ipa->mem[IPA_MEM_AP_HEADER].size;
+	/* Add the size of the AP portion (if defined) to the combined size */
+	mem = ipa_mem_find(ipa, IPA_MEM_AP_HEADER);
+	if (mem)
+		size += mem->size;
 
 	/* Make sure the combined size fits in the IPA command */
 	if (size > size_max) {