diff mbox series

[net-next,06/13] can: mcp251xfd: ring: prepare support for runtime configurable RX/TX ring parameters

Message ID 20220313085138.507062-7-mkl@pengutronix.de (mailing list archive)
State Accepted
Commit 0a1f2e6502a1ea55db78ae1baaba4b6f0c0c3b53
Delegated to: Netdev Maintainers
Headers show
Series [net-next,01/13] can: vxcan: vxcan_xmit(): use kfree_skb() instead of kfree() to free skb | 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 Pull request is its own 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 warning 3 maintainers not CCed: thomas.kopp@microchip.com wg@grandegger.com mani@kernel.org
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, 56 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Marc Kleine-Budde March 13, 2022, 8:51 a.m. UTC 
This patch prepares the driver for runtime configurable RX and TX ring
parameters. The actual runtime config support will be added in the
next patch.

Link: https://lore.kernel.org/20220313083640.501791-6-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 .../net/can/spi/mcp251xfd/mcp251xfd-ring.c    | 26 ++++++++-----------
 drivers/net/can/spi/mcp251xfd/mcp251xfd.h     |  2 ++
 2 files changed, 13 insertions(+), 15 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-ring.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-ring.c
index e540c97b4160..0e78941601bf 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-ring.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-ring.c
@@ -289,9 +289,9 @@  int mcp251xfd_ring_alloc(struct mcp251xfd_priv *priv)
 {
 	struct mcp251xfd_tx_ring *tx_ring;
 	struct mcp251xfd_rx_ring *rx_ring;
-	int tef_obj_size, tx_obj_size, rx_obj_size;
-	int tx_obj_num;
-	int ram_free, i;
+	u8 tef_obj_size, tx_obj_size, rx_obj_size;
+	u8 tx_obj_num;
+	u8 rem, i;
 
 	tef_obj_size = sizeof(struct mcp251xfd_hw_tef_obj);
 	if (mcp251xfd_is_fd_mode(priv)) {
@@ -310,17 +310,14 @@  int mcp251xfd_ring_alloc(struct mcp251xfd_priv *priv)
 	tx_ring->obj_num = tx_obj_num;
 	tx_ring->obj_size = tx_obj_size;
 
-	ram_free = MCP251XFD_RAM_SIZE - tx_obj_num *
-		(tef_obj_size + tx_obj_size);
+	rem = (MCP251XFD_RAM_SIZE - tx_obj_num *
+	       (tef_obj_size + tx_obj_size)) / rx_obj_size;
+	for (i = 0; i < ARRAY_SIZE(priv->rx) && rem; i++) {
+		u8 rx_obj_num;
 
-	for (i = 0;
-	     i < ARRAY_SIZE(priv->rx) && ram_free >= rx_obj_size;
-	     i++) {
-		int rx_obj_num;
-
-		rx_obj_num = ram_free / rx_obj_size;
-		rx_obj_num = min(1 << (fls(rx_obj_num) - 1),
-				 MCP251XFD_RX_OBJ_NUM_MAX);
+		rx_obj_num = min_t(u8, rounddown_pow_of_two(rem),
+				   MCP251XFD_FIFO_DEPTH);
+		rem -= rx_obj_num;
 
 		priv->rx_obj_num += rx_obj_num;
 
@@ -330,11 +327,10 @@  int mcp251xfd_ring_alloc(struct mcp251xfd_priv *priv)
 			mcp251xfd_ring_free(priv);
 			return -ENOMEM;
 		}
+
 		rx_ring->obj_num = rx_obj_num;
 		rx_ring->obj_size = rx_obj_size;
 		priv->rx[i] = rx_ring;
-
-		ram_free -= rx_ring->obj_num * rx_ring->obj_size;
 	}
 	priv->rx_ring_num = i;
 
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd.h b/drivers/net/can/spi/mcp251xfd/mcp251xfd.h
index 5c7a672464b1..bd7a9999b5e3 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd.h
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd.h
@@ -415,6 +415,8 @@  static_assert(MCP251XFD_TIMESTAMP_WORK_DELAY_SEC <
 #define MCP251XFD_FIFO_RX_NUM_MAX 1U
 #define MCP251XFD_FIFO_TX_NUM 1U
 
+#define MCP251XFD_FIFO_DEPTH 32U
+
 static_assert(MCP251XFD_FIFO_TEF_NUM == 1U);
 static_assert(MCP251XFD_FIFO_TEF_NUM == MCP251XFD_FIFO_TX_NUM);
 static_assert(MCP251XFD_FIFO_RX_NUM_MAX <= 4U);