From d2fd2311de909a7f4e99b4bd11a19e6b671d6a6b Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Thu, 18 Mar 2021 13:59:27 -0500 Subject: [PATCH] net: ipa: fix assumptions about DMA address size 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 Signed-off-by: David S. Miller --- drivers/net/ipa/ipa_table.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/net/ipa/ipa_table.c b/drivers/net/ipa/ipa_table.c index 7450e27..dd07fe9 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() -- 2.7.4