net: ipa: define IPA_MEM_END_MARKER

Define a new pseudo memory region identifer that specifies the
offset at the end of IPA resident memory.  Use it instead of
IPA_MEM_UC_EVENT_RING in places where the size of that region was
defined to be 0.

The size of the IPA_MEM_END_MARKER pseudo region must be zero.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ipa/ipa_data-v4.11.c

@@ -325,7 +325,7 @@ static const struct ipa_mem ipa_mem_local_data[] = {
 		.size		= 0x100c,
 		.canary_count	= 2,
 	},
-	[IPA_MEM_UC_EVENT_RING] = {
+	[IPA_MEM_END_MARKER] = {
 		.offset		= 0x3000,
 		.size		= 0x0000,
 		.canary_count	= 1,

drivers/net/ipa/ipa_data-v4.2.c

@@ -304,7 +304,7 @@ static const struct ipa_mem ipa_mem_local_data[] = {
 		.size		= 0x140c,
 		.canary_count	= 0,
 	},
-	[IPA_MEM_UC_EVENT_RING] = {
+	[IPA_MEM_END_MARKER] = {
 		.offset		= 0x2000,
 		.size		= 0,
 		.canary_count	= 1,

drivers/net/ipa/ipa_mem.c

@@ -120,6 +120,8 @@ static bool ipa_mem_valid(struct ipa *ipa, enum ipa_mem_id mem_id)
 	else if (mem->offset + mem->size > ipa->mem_size)
 		dev_err(dev, "region %u ends beyond memory limit (0x%08x)\n",
 			mem_id, ipa->mem_size);
+	else if (mem_id == IPA_MEM_END_MARKER && mem->size)
+		dev_err(dev, "non-zero end marker region size\n");
 	else
 		return true;
 

drivers/net/ipa/ipa_mem.h

@@ -70,6 +70,7 @@ enum ipa_mem_id {
 	IPA_MEM_STATS_DROP,		/* 0 canaries (IPA v4.0 and above) */
 	IPA_MEM_MODEM,			/* 0/2 canaries */
 	IPA_MEM_UC_EVENT_RING,		/* 1 canary */
+	IPA_MEM_END_MARKER,		/* 1 canary (not a real region) */
 	IPA_MEM_COUNT,			/* Number of regions (not an index) */
 };