[PATCH net-next 2/4] net: ipa: determine route table size from memory region

[Alex Elder <elder@linaro.org>]

Currently we assume that any routing table contains a fixed number
of entries.  The number of entries in a routing table can actually
vary, depending only on the size of the IPA-local memory region used
to hold the table.

Stop assuming that a routing table has exactly 15 entries.  Instead,
determine the number of entries in a routing table by dividing its
memory region size by the size of an entry.

The number of entries is computed early, when ipa_table_mem_valid()
is called by ipa_table_init().

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/ipa_cmd.c   | 17 ++++++++---------
 drivers/net/ipa/ipa_table.c | 14 +++++---------
 drivers/net/ipa/ipa_table.h |  3 ---
 3 files changed, 13 insertions(+), 21 deletions(-)

diff --git a/drivers/net/ipa/ipa_cmd.c b/drivers/net/ipa/ipa_cmd.c
index de2cd86aa9e28..08e3f395a9453 100644
--- a/drivers/net/ipa/ipa_cmd.c
+++ b/drivers/net/ipa/ipa_cmd.c
@@ -145,18 +145,15 @@ union ipa_cmd_payload {
 
 static void ipa_cmd_validate_build(void)
 {
-	/* The sizes of a filter and route tables need to fit into fields
-	 * in the ipa_cmd_hw_ip_fltrt_init structure.  Although hashed tables
+	/* The size of a filter table needs to fit into fields in the
+	 * ipa_cmd_hw_ip_fltrt_init structure.  Although hashed tables
 	 * might not be used, non-hashed and hashed tables have the same
 	 * maximum size.  IPv4 and IPv6 filter tables have the same number
-	 * of entries, as and IPv4 and IPv6 route tables have the same number
 	 * of entries.
 	 */
-#define TABLE_SIZE	(TABLE_COUNT_MAX * sizeof(__le64))
-#define TABLE_COUNT_MAX	max_t(u32, IPA_ROUTE_COUNT_MAX, IPA_FILTER_COUNT_MAX)
+#define TABLE_SIZE	(IPA_FILTER_COUNT_MAX * sizeof(__le64))
 	BUILD_BUG_ON(TABLE_SIZE > field_max(IP_FLTRT_FLAGS_HASH_SIZE_FMASK));
 	BUILD_BUG_ON(TABLE_SIZE > field_max(IP_FLTRT_FLAGS_NHASH_SIZE_FMASK));
-#undef TABLE_COUNT_MAX
 #undef TABLE_SIZE
 
 	/* Hashed and non-hashed fields are assumed to be the same size */
@@ -178,12 +175,14 @@ bool ipa_cmd_table_init_valid(struct ipa *ipa, const struct ipa_mem *mem,
 	u32 size_max = field_max(IP_FLTRT_FLAGS_NHASH_SIZE_FMASK);
 	const char *table = route ? "route" : "filter";
 	struct device *dev = &ipa->pdev->dev;
+	u32 size;
+
+	size = route ? ipa->route_count * sizeof(__le64) : mem->size;
 
 	/* Size must fit in the immediate command field that holds it */
-	if (mem->size > size_max) {
+	if (size > size_max) {
 		dev_err(dev, "%s table region size too large\n", table);
-		dev_err(dev, "    (0x%04x > 0x%04x)\n",
-			mem->size, size_max);
+		dev_err(dev, "    (0x%04x > 0x%04x)\n", size, size_max);
 
 		return false;
 	}
diff --git a/drivers/net/ipa/ipa_table.c b/drivers/net/ipa/ipa_table.c
index 0815c8967e914..23d3f081ac8e1 100644
--- a/drivers/net/ipa/ipa_table.c
+++ b/drivers/net/ipa/ipa_table.c
@@ -130,12 +130,8 @@ static void ipa_table_validate_build(void)
 	 */
 	BUILD_BUG_ON(IPA_ZERO_RULE_SIZE != sizeof(__le64));
 
-	/* Impose a practical limit on the number of routes */
-	BUILD_BUG_ON(IPA_ROUTE_COUNT_MAX > 32);
 	/* The modem must be allotted at least one route table entry */
 	BUILD_BUG_ON(!IPA_ROUTE_MODEM_COUNT);
-	/* AP must too, but we can't use more than what is available */
-	BUILD_BUG_ON(IPA_ROUTE_MODEM_COUNT >= IPA_ROUTE_COUNT_MAX);
 }
 
 static const struct ipa_mem *
@@ -593,18 +589,18 @@ bool ipa_table_mem_valid(struct ipa *ipa, bool modem_route_count)
 	if (mem_ipv4->size != mem_ipv6->size)
 		return false;
 
-	/* Record the number of routing table entries */
+	/* Compute the number of entries, and for routing tables, record it */
+	count = mem_ipv4->size / sizeof(__le64);
+	if (count < 2)
+		return false;
 	if (!filter)
-		ipa->route_count = IPA_ROUTE_COUNT_MAX;
+		ipa->route_count = count;
 
 	/* Table offset and size must fit in TABLE_INIT command fields */
 	if (!ipa_cmd_table_init_valid(ipa, mem_ipv4, !filter))
 		return false;
 
 	/* Make sure the regions are big enough */
-	count = mem_ipv4->size / sizeof(__le64);
-	if (count < 2)
-		return false;
 	if (filter) {
 		/* Filter tables must able to hold the endpoint bitmap plus
 		 * an entry for each endpoint that supports filtering
diff --git a/drivers/net/ipa/ipa_table.h b/drivers/net/ipa/ipa_table.h
index 65d96debd3917..31363292dc1db 100644
--- a/drivers/net/ipa/ipa_table.h
+++ b/drivers/net/ipa/ipa_table.h
@@ -16,9 +16,6 @@ struct ipa;
 /* The number of route table entries allotted to the modem */
 #define IPA_ROUTE_MODEM_COUNT	8
 
-/* The maximum number of route table entries (IPv4, IPv6; hashed or not) */
-#define IPA_ROUTE_COUNT_MAX	15
-
 /**
  * ipa_filter_map_valid() - Validate a filter table endpoint bitmap
  * @ipa:	IPA pointer
-- 
2.34.1