This is a note to let you know that I've just added the patch titled
net: ipa: fix assumptions about DMA address size
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-ipa-fix-assumptions-about-dma-address-size.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 6ca9d847aa1e418f45b8b76728d2db179f5717b3
Author: Alex Elder <elder@xxxxxxxxxx>
Date: Thu Mar 18 13:59:27 2021 -0500
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@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Stable-dep-of: cf412ec33325 ("net: ipa: properly limit modem routing table use")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ipa/ipa_table.c b/drivers/net/ipa/ipa_table.c
index 0747866d60ab..f26cb9d706da 100644
--- 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()
