net: ipa: fix assumptions about DMA address size

[ Upstream commit d2fd2311de909a7f4e99b4bd11a19e6b671d6a6b ]

Some build time checks in ipa_table_validate_build() assume that a
DMA address is 64 bits wide.  That is more restrictive than it has
to be.  A route or filter table is 64 bits wide no matter what the
size of a DMA address is on the AP.  The code actually uses a
pointer to __le64 to access table entries, and a fixed constant
IPA_TABLE_ENTRY_SIZE to describe the size of those entries.

Loosen up two checks so they still verify some requirements, but
such that they do not assume the size of a DMA address is 64 bits.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: cf412ec33325 ("net: ipa: properly limit modem routing table use")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ipa/ipa_table.c b/drivers/net/ipa/ipa_table.c
index 0747866d60abcf5ff24f2a3d51f637f3d13141c6..f26cb9d706dac9c89c49adaed20dc9c0b6fa651b 100644 (file)
--- a/drivers/net/ipa/ipa_table.c
+++ b/drivers/net/ipa/ipa_table.c
@@ -126,13 +126,15 @@ static void ipa_table_validate_build(void)
         */
        BUILD_BUG_ON(ARCH_DMA_MINALIGN % IPA_TABLE_ALIGN);
 
-       /* Filter and route tables contain DMA addresses that refer to
-        * filter or route rules.  We use a fixed constant to represent
-        * the size of either type of table entry.  Code in ipa_table_init()
-        * uses a pointer to __le64 to initialize table entriews.
+       /* Filter and route tables contain DMA addresses that refer
+        * to filter or route rules.  But the size of a table entry
+        * is 64 bits regardless of what the size of an AP DMA address
+        * is.  A fixed constant defines the size of an entry, and
+        * code in ipa_table_init() uses a pointer to __le64 to
+        * initialize tables.
         */
-       BUILD_BUG_ON(IPA_TABLE_ENTRY_SIZE != sizeof(dma_addr_t));
-       BUILD_BUG_ON(sizeof(dma_addr_t) != sizeof(__le64));
+       BUILD_BUG_ON(sizeof(dma_addr_t) > IPA_TABLE_ENTRY_SIZE);
+       BUILD_BUG_ON(sizeof(__le64) != IPA_TABLE_ENTRY_SIZE);
 
        /* A "zero rule" is used to represent no filtering or no routing.
         * It is a 64-bit block of zeroed memory.  Code in ipa_table_init()