diff mbox series

[net-next,2/7] net: ipa: zero unused portions of filter table memory

Message ID 20211124202511.862588-3-elder@linaro.org (mailing list archive)
State Accepted
Commit dc901505fd9820e2428dabb38f5c700d195ce2d3
Delegated to: Netdev Maintainers
Headers show
Series net: ipa: small collected improvements | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers success CCed 4 of 4 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 75 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Alex Elder Nov. 24, 2021, 8:25 p.m. UTC
Not all filter table entries are used.  Only certain endpoints
support filtering, and the table begins with a bitmap indicating
which endpoints use the "slots" that follow for filter rules.

Currently, unused filter table entries are not initialized.
Instead, zero-fill the entire unused portion of the filter table
memory regions, to make it more obvious that memory is unused (and
not subsequently modified).

This is not strictly necessary, but the result is reassuring when
looking at filter table memory.

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/ipa_table.c | 48 +++++++++++++++++++++++++++++++------
 1 file changed, 41 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ipa/ipa_table.c b/drivers/net/ipa/ipa_table.c
index 1da334f54944a..2f5a58bfc529a 100644
--- a/drivers/net/ipa/ipa_table.c
+++ b/drivers/net/ipa/ipa_table.c
@@ -419,21 +419,26 @@  static void ipa_table_init_add(struct gsi_trans *trans, bool filter,
 	const struct ipa_mem *mem = ipa_mem_find(ipa, mem_id);
 	dma_addr_t hash_addr;
 	dma_addr_t addr;
+	u32 zero_offset;
 	u16 hash_count;
+	u32 zero_size;
 	u16 hash_size;
 	u16 count;
 	u16 size;
 
-	/* The number of filtering endpoints determines number of entries
-	 * in the filter table.  The hashed and non-hashed filter table
-	 * will have the same number of entries.  The size of the route
-	 * table region determines the number of entries it has.
-	 */
+	/* Compute the number of table entries to initialize */
 	if (filter) {
-		/* Include one extra "slot" to hold the filter map itself */
+		/* The number of filtering endpoints determines number of
+		 * entries in the filter table; we also add one more "slot"
+		 * to hold the bitmap itself.  The size of the hashed filter
+		 * table is either the same as the non-hashed one, or zero.
+		 */
 		count = 1 + hweight32(ipa->filter_map);
 		hash_count = hash_mem->size ? count : 0;
 	} else {
+		/* The size of a route table region determines the number
+		 * of entries it has.
+		 */
 		count = mem->size / sizeof(__le64);
 		hash_count = hash_mem->size / sizeof(__le64);
 	}
@@ -445,13 +450,42 @@  static void ipa_table_init_add(struct gsi_trans *trans, bool filter,
 
 	ipa_cmd_table_init_add(trans, opcode, size, mem->offset, addr,
 			       hash_size, hash_mem->offset, hash_addr);
+	if (!filter)
+		return;
+
+	/* Zero the unused space in the filter table */
+	zero_offset = mem->offset + size;
+	zero_size = mem->size - size;
+	ipa_cmd_dma_shared_mem_add(trans, zero_offset, zero_size,
+				   ipa->zero_addr, true);
+	if (!hash_size)
+		return;
+
+	/* Zero the unused space in the hashed filter table */
+	zero_offset = hash_mem->offset + hash_size;
+	zero_size = hash_mem->size - hash_size;
+	ipa_cmd_dma_shared_mem_add(trans, zero_offset, zero_size,
+				   ipa->zero_addr, true);
 }
 
 int ipa_table_setup(struct ipa *ipa)
 {
 	struct gsi_trans *trans;
 
-	trans = ipa_cmd_trans_alloc(ipa, 4);
+	/* We will need at most 8 TREs:
+	 * - IPv4:
+	 *     - One for route table initialization (non-hashed and hashed)
+	 *     - One for filter table initialization (non-hashed and hashed)
+	 *     - One to zero unused entries in the non-hashed filter table
+	 *     - One to zero unused entries in the hashed filter table
+	 * - IPv6:
+	 *     - One for route table initialization (non-hashed and hashed)
+	 *     - One for filter table initialization (non-hashed and hashed)
+	 *     - One to zero unused entries in the non-hashed filter table
+	 *     - One to zero unused entries in the hashed filter table
+	 * All platforms support at least 8 TREs in a transaction.
+	 */
+	trans = ipa_cmd_trans_alloc(ipa, 8);
 	if (!trans) {
 		dev_err(&ipa->pdev->dev, "no transaction for table setup\n");
 		return -EBUSY;