* [PATCH net-next v2 0/4] net: lan966x: Add support for FDMA
@ 2022-03-18 20:47 Horatiu Vultur
2022-03-18 20:47 ` [PATCH net-next v2 1/4] net: lan966x: Add registers that are used " Horatiu Vultur
` (4 more replies)
0 siblings, 5 replies; 10+ messages in thread
From: Horatiu Vultur @ 2022-03-18 20:47 UTC (permalink / raw)
To: linux-kernel, netdev; +Cc: davem, kuba, michael, UNGLinuxDriver, Horatiu Vultur
Currently when injecting or extracting a frame from CPU, the frame
is given to the HW each word at a time. There is another way to
inject/extract frames from CPU using FDMA(Frame Direct Memory Access).
In this way the entire frame is given to the HW. This improves both
RX and TX bitrate.
v1->v2:
- fix typo in commit message in last patch
- remove first patch as the changes are already there
- make sure that there is space in skb to put the FCS
- move skb_tx_timestamp closer to the handover of the frame to the HW
Horatiu Vultur (4):
net: lan966x: Add registers that are used for FDMA.
net: lan966x: Expose functions that are needed by FDMA
net: lan966x: Add FDMA functionality
net: lan966x: Update FDMA to change MTU.
.../net/ethernet/microchip/lan966x/Makefile | 2 +-
.../ethernet/microchip/lan966x/lan966x_fdma.c | 775 ++++++++++++++++++
.../ethernet/microchip/lan966x/lan966x_main.c | 44 +-
.../ethernet/microchip/lan966x/lan966x_main.h | 120 +++
.../ethernet/microchip/lan966x/lan966x_port.c | 3 +
.../ethernet/microchip/lan966x/lan966x_regs.h | 106 +++
6 files changed, 1038 insertions(+), 12 deletions(-)
create mode 100644 drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
--
2.33.0
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH net-next v2 1/4] net: lan966x: Add registers that are used for FDMA.
2022-03-18 20:47 [PATCH net-next v2 0/4] net: lan966x: Add support for FDMA Horatiu Vultur
@ 2022-03-18 20:47 ` Horatiu Vultur
2022-03-18 20:47 ` [PATCH net-next v2 2/4] net: lan966x: Expose functions that are needed by FDMA Horatiu Vultur
` (3 subsequent siblings)
4 siblings, 0 replies; 10+ messages in thread
From: Horatiu Vultur @ 2022-03-18 20:47 UTC (permalink / raw)
To: linux-kernel, netdev; +Cc: davem, kuba, michael, UNGLinuxDriver, Horatiu Vultur
Add the registers that are used to configure the FDMA.
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
.../ethernet/microchip/lan966x/lan966x_main.c | 1 +
.../ethernet/microchip/lan966x/lan966x_regs.h | 106 ++++++++++++++++++
2 files changed, 107 insertions(+)
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
index e1bcb28039dc..4240db708886 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
@@ -43,6 +43,7 @@ struct lan966x_main_io_resource {
static const struct lan966x_main_io_resource lan966x_main_iomap[] = {
{ TARGET_CPU, 0xc0000, 0 }, /* 0xe00c0000 */
+ { TARGET_FDMA, 0xc0400, 0 }, /* 0xe00c0400 */
{ TARGET_ORG, 0, 1 }, /* 0xe2000000 */
{ TARGET_GCB, 0x4000, 1 }, /* 0xe2004000 */
{ TARGET_QS, 0x8000, 1 }, /* 0xe2008000 */
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_regs.h b/drivers/net/ethernet/microchip/lan966x/lan966x_regs.h
index 0c0b3e173d53..2f59285bef29 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_regs.h
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_regs.h
@@ -17,6 +17,7 @@ enum lan966x_target {
TARGET_CHIP_TOP = 5,
TARGET_CPU = 6,
TARGET_DEV = 13,
+ TARGET_FDMA = 21,
TARGET_GCB = 27,
TARGET_ORG = 36,
TARGET_PTP = 41,
@@ -578,6 +579,111 @@ enum lan966x_target {
#define DEV_PCS1G_STICKY_LINK_DOWN_STICKY_GET(x)\
FIELD_GET(DEV_PCS1G_STICKY_LINK_DOWN_STICKY, x)
+/* FDMA:FDMA:FDMA_CH_ACTIVATE */
+#define FDMA_CH_ACTIVATE __REG(TARGET_FDMA, 0, 1, 8, 0, 1, 428, 0, 0, 1, 4)
+
+#define FDMA_CH_ACTIVATE_CH_ACTIVATE GENMASK(7, 0)
+#define FDMA_CH_ACTIVATE_CH_ACTIVATE_SET(x)\
+ FIELD_PREP(FDMA_CH_ACTIVATE_CH_ACTIVATE, x)
+#define FDMA_CH_ACTIVATE_CH_ACTIVATE_GET(x)\
+ FIELD_GET(FDMA_CH_ACTIVATE_CH_ACTIVATE, x)
+
+/* FDMA:FDMA:FDMA_CH_RELOAD */
+#define FDMA_CH_RELOAD __REG(TARGET_FDMA, 0, 1, 8, 0, 1, 428, 4, 0, 1, 4)
+
+#define FDMA_CH_RELOAD_CH_RELOAD GENMASK(7, 0)
+#define FDMA_CH_RELOAD_CH_RELOAD_SET(x)\
+ FIELD_PREP(FDMA_CH_RELOAD_CH_RELOAD, x)
+#define FDMA_CH_RELOAD_CH_RELOAD_GET(x)\
+ FIELD_GET(FDMA_CH_RELOAD_CH_RELOAD, x)
+
+/* FDMA:FDMA:FDMA_CH_DISABLE */
+#define FDMA_CH_DISABLE __REG(TARGET_FDMA, 0, 1, 8, 0, 1, 428, 8, 0, 1, 4)
+
+#define FDMA_CH_DISABLE_CH_DISABLE GENMASK(7, 0)
+#define FDMA_CH_DISABLE_CH_DISABLE_SET(x)\
+ FIELD_PREP(FDMA_CH_DISABLE_CH_DISABLE, x)
+#define FDMA_CH_DISABLE_CH_DISABLE_GET(x)\
+ FIELD_GET(FDMA_CH_DISABLE_CH_DISABLE, x)
+
+/* FDMA:FDMA:FDMA_CH_DB_DISCARD */
+#define FDMA_CH_DB_DISCARD __REG(TARGET_FDMA, 0, 1, 8, 0, 1, 428, 16, 0, 1, 4)
+
+#define FDMA_CH_DB_DISCARD_DB_DISCARD GENMASK(7, 0)
+#define FDMA_CH_DB_DISCARD_DB_DISCARD_SET(x)\
+ FIELD_PREP(FDMA_CH_DB_DISCARD_DB_DISCARD, x)
+#define FDMA_CH_DB_DISCARD_DB_DISCARD_GET(x)\
+ FIELD_GET(FDMA_CH_DB_DISCARD_DB_DISCARD, x)
+
+/* FDMA:FDMA:FDMA_DCB_LLP */
+#define FDMA_DCB_LLP(r) __REG(TARGET_FDMA, 0, 1, 8, 0, 1, 428, 52, r, 8, 4)
+
+/* FDMA:FDMA:FDMA_DCB_LLP1 */
+#define FDMA_DCB_LLP1(r) __REG(TARGET_FDMA, 0, 1, 8, 0, 1, 428, 84, r, 8, 4)
+
+/* FDMA:FDMA:FDMA_CH_ACTIVE */
+#define FDMA_CH_ACTIVE __REG(TARGET_FDMA, 0, 1, 8, 0, 1, 428, 180, 0, 1, 4)
+
+/* FDMA:FDMA:FDMA_CH_CFG */
+#define FDMA_CH_CFG(r) __REG(TARGET_FDMA, 0, 1, 8, 0, 1, 428, 224, r, 8, 4)
+
+#define FDMA_CH_CFG_CH_INTR_DB_EOF_ONLY BIT(4)
+#define FDMA_CH_CFG_CH_INTR_DB_EOF_ONLY_SET(x)\
+ FIELD_PREP(FDMA_CH_CFG_CH_INTR_DB_EOF_ONLY, x)
+#define FDMA_CH_CFG_CH_INTR_DB_EOF_ONLY_GET(x)\
+ FIELD_GET(FDMA_CH_CFG_CH_INTR_DB_EOF_ONLY, x)
+
+#define FDMA_CH_CFG_CH_INJ_PORT BIT(3)
+#define FDMA_CH_CFG_CH_INJ_PORT_SET(x)\
+ FIELD_PREP(FDMA_CH_CFG_CH_INJ_PORT, x)
+#define FDMA_CH_CFG_CH_INJ_PORT_GET(x)\
+ FIELD_GET(FDMA_CH_CFG_CH_INJ_PORT, x)
+
+#define FDMA_CH_CFG_CH_DCB_DB_CNT GENMASK(2, 1)
+#define FDMA_CH_CFG_CH_DCB_DB_CNT_SET(x)\
+ FIELD_PREP(FDMA_CH_CFG_CH_DCB_DB_CNT, x)
+#define FDMA_CH_CFG_CH_DCB_DB_CNT_GET(x)\
+ FIELD_GET(FDMA_CH_CFG_CH_DCB_DB_CNT, x)
+
+#define FDMA_CH_CFG_CH_MEM BIT(0)
+#define FDMA_CH_CFG_CH_MEM_SET(x)\
+ FIELD_PREP(FDMA_CH_CFG_CH_MEM, x)
+#define FDMA_CH_CFG_CH_MEM_GET(x)\
+ FIELD_GET(FDMA_CH_CFG_CH_MEM, x)
+
+/* FDMA:FDMA:FDMA_PORT_CTRL */
+#define FDMA_PORT_CTRL(r) __REG(TARGET_FDMA, 0, 1, 8, 0, 1, 428, 376, r, 2, 4)
+
+#define FDMA_PORT_CTRL_INJ_STOP BIT(4)
+#define FDMA_PORT_CTRL_INJ_STOP_SET(x)\
+ FIELD_PREP(FDMA_PORT_CTRL_INJ_STOP, x)
+#define FDMA_PORT_CTRL_INJ_STOP_GET(x)\
+ FIELD_GET(FDMA_PORT_CTRL_INJ_STOP, x)
+
+#define FDMA_PORT_CTRL_XTR_STOP BIT(2)
+#define FDMA_PORT_CTRL_XTR_STOP_SET(x)\
+ FIELD_PREP(FDMA_PORT_CTRL_XTR_STOP, x)
+#define FDMA_PORT_CTRL_XTR_STOP_GET(x)\
+ FIELD_GET(FDMA_PORT_CTRL_XTR_STOP, x)
+
+/* FDMA:FDMA:FDMA_INTR_DB */
+#define FDMA_INTR_DB __REG(TARGET_FDMA, 0, 1, 8, 0, 1, 428, 392, 0, 1, 4)
+
+/* FDMA:FDMA:FDMA_INTR_DB_ENA */
+#define FDMA_INTR_DB_ENA __REG(TARGET_FDMA, 0, 1, 8, 0, 1, 428, 396, 0, 1, 4)
+
+#define FDMA_INTR_DB_ENA_INTR_DB_ENA GENMASK(7, 0)
+#define FDMA_INTR_DB_ENA_INTR_DB_ENA_SET(x)\
+ FIELD_PREP(FDMA_INTR_DB_ENA_INTR_DB_ENA, x)
+#define FDMA_INTR_DB_ENA_INTR_DB_ENA_GET(x)\
+ FIELD_GET(FDMA_INTR_DB_ENA_INTR_DB_ENA, x)
+
+/* FDMA:FDMA:FDMA_INTR_ERR */
+#define FDMA_INTR_ERR __REG(TARGET_FDMA, 0, 1, 8, 0, 1, 428, 400, 0, 1, 4)
+
+/* FDMA:FDMA:FDMA_ERRORS */
+#define FDMA_ERRORS __REG(TARGET_FDMA, 0, 1, 8, 0, 1, 428, 412, 0, 1, 4)
+
/* PTP:PTP_CFG:PTP_DOM_CFG */
#define PTP_DOM_CFG __REG(TARGET_PTP, 0, 1, 512, 0, 1, 16, 12, 0, 1, 4)
--
2.33.0
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH net-next v2 2/4] net: lan966x: Expose functions that are needed by FDMA
2022-03-18 20:47 [PATCH net-next v2 0/4] net: lan966x: Add support for FDMA Horatiu Vultur
2022-03-18 20:47 ` [PATCH net-next v2 1/4] net: lan966x: Add registers that are used " Horatiu Vultur
@ 2022-03-18 20:47 ` Horatiu Vultur
2022-03-18 20:47 ` [PATCH net-next v2 3/4] net: lan966x: Add FDMA functionality Horatiu Vultur
` (2 subsequent siblings)
4 siblings, 0 replies; 10+ messages in thread
From: Horatiu Vultur @ 2022-03-18 20:47 UTC (permalink / raw)
To: linux-kernel, netdev; +Cc: davem, kuba, michael, UNGLinuxDriver, Horatiu Vultur
Expose the following functions 'lan966x_hw_offload',
'lan966x_ifh_get_src_port' and 'lan966x_ifh_get_timestamp' in
lan966x_main.h so they can be accessed by FDMA.
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
drivers/net/ethernet/microchip/lan966x/lan966x_main.c | 10 +++-------
drivers/net/ethernet/microchip/lan966x/lan966x_main.h | 8 ++++++++
2 files changed, 11 insertions(+), 7 deletions(-)
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
index 4240db708886..2c82f847ae6d 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
@@ -24,9 +24,6 @@
#define XTR_NOT_READY 0x07000080U
#define XTR_VALID_BYTES(x) (4 - (((x) >> 24) & 3))
-#define READL_SLEEP_US 10
-#define READL_TIMEOUT_US 100000000
-
#define IO_RANGES 2
static const struct of_device_id lan966x_match[] = {
@@ -430,8 +427,7 @@ bool lan966x_netdevice_check(const struct net_device *dev)
return dev->netdev_ops == &lan966x_port_netdev_ops;
}
-static bool lan966x_hw_offload(struct lan966x *lan966x, u32 port,
- struct sk_buff *skb)
+bool lan966x_hw_offload(struct lan966x *lan966x, u32 port, struct sk_buff *skb)
{
u32 val;
@@ -512,7 +508,7 @@ static int lan966x_rx_frame_word(struct lan966x *lan966x, u8 grp, u32 *rval)
}
}
-static void lan966x_ifh_get_src_port(void *ifh, u64 *src_port)
+void lan966x_ifh_get_src_port(void *ifh, u64 *src_port)
{
packing(ifh, src_port, IFH_POS_SRCPORT + IFH_WID_SRCPORT - 1,
IFH_POS_SRCPORT, IFH_LEN * 4, UNPACK, 0);
@@ -524,7 +520,7 @@ static void lan966x_ifh_get_len(void *ifh, u64 *len)
IFH_POS_LEN, IFH_LEN * 4, UNPACK, 0);
}
-static void lan966x_ifh_get_timestamp(void *ifh, u64 *timestamp)
+void lan966x_ifh_get_timestamp(void *ifh, u64 *timestamp)
{
packing(ifh, timestamp, IFH_POS_TIMESTAMP + IFH_WID_TIMESTAMP - 1,
IFH_POS_TIMESTAMP, IFH_LEN * 4, UNPACK, 0);
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
index ae282da1da74..b692c612f235 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
@@ -17,6 +17,9 @@
#define TABLE_UPDATE_SLEEP_US 10
#define TABLE_UPDATE_TIMEOUT_US 100000
+#define READL_SLEEP_US 10
+#define READL_TIMEOUT_US 100000000
+
#define LAN966X_BUFFER_CELL_SZ 64
#define LAN966X_BUFFER_MEMORY (160 * 1024)
#define LAN966X_BUFFER_MIN_SZ 60
@@ -195,6 +198,11 @@ bool lan966x_netdevice_check(const struct net_device *dev);
void lan966x_register_notifier_blocks(void);
void lan966x_unregister_notifier_blocks(void);
+bool lan966x_hw_offload(struct lan966x *lan966x, u32 port, struct sk_buff *skb);
+
+void lan966x_ifh_get_src_port(void *ifh, u64 *src_port);
+void lan966x_ifh_get_timestamp(void *ifh, u64 *timestamp);
+
void lan966x_stats_get(struct net_device *dev,
struct rtnl_link_stats64 *stats);
int lan966x_stats_init(struct lan966x *lan966x);
--
2.33.0
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH net-next v2 3/4] net: lan966x: Add FDMA functionality
2022-03-18 20:47 [PATCH net-next v2 0/4] net: lan966x: Add support for FDMA Horatiu Vultur
2022-03-18 20:47 ` [PATCH net-next v2 1/4] net: lan966x: Add registers that are used " Horatiu Vultur
2022-03-18 20:47 ` [PATCH net-next v2 2/4] net: lan966x: Expose functions that are needed by FDMA Horatiu Vultur
@ 2022-03-18 20:47 ` Horatiu Vultur
2022-03-22 6:01 ` Jakub Kicinski
2022-03-18 20:47 ` [PATCH net-next v2 4/4] net: lan966x: Update FDMA to change MTU Horatiu Vultur
2022-03-18 20:55 ` [PATCH net-next v2 0/4] net: lan966x: Add support for FDMA Michael Walle
4 siblings, 1 reply; 10+ messages in thread
From: Horatiu Vultur @ 2022-03-18 20:47 UTC (permalink / raw)
To: linux-kernel, netdev; +Cc: davem, kuba, michael, UNGLinuxDriver, Horatiu Vultur
Ethernet frames can be extracted or injected to or from the device's
DDR memory. There is one channel for injection and one channel for
extraction. Each of these channels contain a linked list of DCBs which
contains DB. The DCB for injection contains only 1 DB and the DCB for
extraction contains 3 DBs. Each DB contains a frame. Everytime when a
frame is received or transmitted an interrupt is generated.
It is not possible to use both the FDMA and the manual
injection/extraction of the frames. Therefore the FDMA has priority over
the manual because of better performance values.
FDMA:
[ 5] 0.00-10.01 sec 456 MBytes 382 Mbits/sec 0 sender
[ 5] 0.00-10.05 sec 315 MBytes 263 Mbits/sec receiver
Manual:
[ 5] 0.00-10.02 sec 94.0 MBytes 78.7 Mbits/sec 0 sender
[ 5] 0.00-10.01 sec 118 MBytes 98.6 Mbits/sec receiver
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
.../net/ethernet/microchip/lan966x/Makefile | 2 +-
.../ethernet/microchip/lan966x/lan966x_fdma.c | 680 ++++++++++++++++++
.../ethernet/microchip/lan966x/lan966x_main.c | 31 +-
.../ethernet/microchip/lan966x/lan966x_main.h | 111 +++
.../ethernet/microchip/lan966x/lan966x_port.c | 3 +
5 files changed, 823 insertions(+), 4 deletions(-)
create mode 100644 drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
diff --git a/drivers/net/ethernet/microchip/lan966x/Makefile b/drivers/net/ethernet/microchip/lan966x/Makefile
index a9ffc719aa0e..fd2e0ebb2427 100644
--- a/drivers/net/ethernet/microchip/lan966x/Makefile
+++ b/drivers/net/ethernet/microchip/lan966x/Makefile
@@ -8,4 +8,4 @@ obj-$(CONFIG_LAN966X_SWITCH) += lan966x-switch.o
lan966x-switch-objs := lan966x_main.o lan966x_phylink.o lan966x_port.o \
lan966x_mac.o lan966x_ethtool.o lan966x_switchdev.o \
lan966x_vlan.o lan966x_fdb.o lan966x_mdb.o \
- lan966x_ptp.o
+ lan966x_ptp.o lan966x_fdma.o
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
new file mode 100644
index 000000000000..c3266d07302d
--- /dev/null
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
@@ -0,0 +1,680 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include "lan966x_main.h"
+
+static int lan966x_fdma_channel_active(struct lan966x *lan966x)
+{
+ return lan_rd(lan966x, FDMA_CH_ACTIVE);
+}
+
+static struct sk_buff *lan966x_fdma_rx_alloc_skb(struct lan966x_rx *rx,
+ struct lan966x_db *db)
+{
+ struct lan966x *lan966x = rx->lan966x;
+ struct sk_buff *skb;
+ dma_addr_t dma_addr;
+ struct page *page;
+ void *buff_addr;
+
+ page = dev_alloc_pages(rx->page_order);
+ if (unlikely(!page))
+ return NULL;
+
+ dma_addr = dma_map_page(lan966x->dev, page, 0,
+ PAGE_SIZE << rx->page_order,
+ DMA_FROM_DEVICE);
+ if (unlikely(dma_mapping_error(lan966x->dev, dma_addr))) {
+ __free_pages(page, rx->page_order);
+ return NULL;
+ }
+
+ buff_addr = page_address(page);
+ skb = build_skb(buff_addr, PAGE_SIZE << rx->page_order);
+
+ if (unlikely(!skb)) {
+ dev_err_ratelimited(lan966x->dev,
+ "build_skb failed !\n");
+ dma_unmap_single(lan966x->dev, dma_addr,
+ PAGE_SIZE << rx->page_order,
+ DMA_FROM_DEVICE);
+ __free_pages(page, rx->page_order);
+ return NULL;
+ }
+
+ db->dataptr = dma_addr;
+ return skb;
+}
+
+static void lan966x_fdma_rx_free_skbs(struct lan966x_rx *rx)
+{
+ struct lan966x *lan966x = rx->lan966x;
+ struct lan966x_rx_dcb *dcb;
+ struct lan966x_db *db;
+ int i, j;
+
+ for (i = 0; i < FDMA_DCB_MAX; ++i) {
+ dcb = &rx->dcbs[i];
+
+ for (j = 0; j < FDMA_RX_DCB_MAX_DBS; ++j) {
+ db = &dcb->db[j];
+ dma_unmap_single(lan966x->dev,
+ (dma_addr_t)db->dataptr,
+ PAGE_SIZE << rx->page_order,
+ DMA_FROM_DEVICE);
+ kfree_skb(rx->skb[i][j]);
+ }
+ }
+}
+
+static void lan966x_fdma_rx_add_dcb(struct lan966x_rx *rx,
+ struct lan966x_rx_dcb *dcb,
+ u64 nextptr)
+{
+ struct lan966x_db *db;
+ int i;
+
+ for (i = 0; i < FDMA_RX_DCB_MAX_DBS; ++i) {
+ db = &dcb->db[i];
+ db->status = FDMA_DCB_STATUS_INTR;
+ }
+
+ dcb->nextptr = FDMA_DCB_INVALID_DATA;
+ dcb->info = FDMA_DCB_INFO_DATAL(PAGE_SIZE << rx->page_order);
+
+ rx->last_entry->nextptr = nextptr;
+ rx->last_entry = dcb;
+}
+
+static int lan966x_fdma_rx_alloc(struct lan966x_rx *rx)
+{
+ struct lan966x *lan966x = rx->lan966x;
+ struct lan966x_rx_dcb *dcb;
+ struct lan966x_db *db;
+ struct sk_buff *skb;
+ int i, j;
+ int size;
+
+ /* calculate how many pages are needed to allocate the dcbs */
+ size = sizeof(struct lan966x_rx_dcb) * FDMA_DCB_MAX;
+ size = ALIGN(size, PAGE_SIZE);
+
+ rx->dcbs = dma_alloc_coherent(lan966x->dev, size, &rx->dma, GFP_ATOMIC);
+ rx->last_entry = rx->dcbs;
+ rx->db_index = 0;
+ rx->dcb_index = 0;
+
+ /* Now for each dcb allocate the dbs */
+ for (i = 0; i < FDMA_DCB_MAX; ++i) {
+ dcb = &rx->dcbs[i];
+ dcb->info = 0;
+
+ /* For each db allocate a skb and map skb data pointer to the DB
+ * dataptr. In this way when the frame is received the skb->data
+ * will contain the frame, so it is not needed any memcpy
+ */
+ for (j = 0; j < FDMA_RX_DCB_MAX_DBS; ++j) {
+ db = &dcb->db[j];
+ skb = lan966x_fdma_rx_alloc_skb(rx, db);
+ if (!skb)
+ return -ENOMEM;
+
+ db->status = 0;
+ rx->skb[i][j] = skb;
+ }
+
+ lan966x_fdma_rx_add_dcb(rx, dcb, rx->dma + sizeof(*dcb) * i);
+ }
+
+ return 0;
+}
+
+static void lan966x_fdma_rx_free(struct lan966x_rx *rx)
+{
+ struct lan966x *lan966x = rx->lan966x;
+ u32 size;
+
+ /* Now it is possible to do the cleanup of dcb */
+ size = sizeof(struct lan966x_tx_dcb) * FDMA_DCB_MAX;
+ size = ALIGN(size, PAGE_SIZE);
+ dma_free_coherent(lan966x->dev, size, rx->dcbs, rx->dma);
+}
+
+static void lan966x_fdma_rx_start(struct lan966x_rx *rx)
+{
+ struct lan966x *lan966x = rx->lan966x;
+ u32 mask;
+
+ /* When activating a channel, first is required to write the first DCB
+ * address and then to activate it
+ */
+ lan_wr(((u64)rx->dma) & GENMASK(31, 0), lan966x,
+ FDMA_DCB_LLP(rx->channel_id));
+ lan_wr(((u64)rx->dma) >> 32, lan966x, FDMA_DCB_LLP1(rx->channel_id));
+
+ lan_wr(FDMA_CH_CFG_CH_DCB_DB_CNT_SET(FDMA_RX_DCB_MAX_DBS) |
+ FDMA_CH_CFG_CH_INTR_DB_EOF_ONLY_SET(1) |
+ FDMA_CH_CFG_CH_INJ_PORT_SET(0) |
+ FDMA_CH_CFG_CH_MEM_SET(1),
+ lan966x, FDMA_CH_CFG(rx->channel_id));
+
+ /* Start fdma */
+ lan_rmw(FDMA_PORT_CTRL_XTR_STOP_SET(0),
+ FDMA_PORT_CTRL_XTR_STOP,
+ lan966x, FDMA_PORT_CTRL(0));
+
+ /* Enable interrupts */
+ mask = lan_rd(lan966x, FDMA_INTR_DB_ENA);
+ mask = FDMA_INTR_DB_ENA_INTR_DB_ENA_GET(mask);
+ mask |= BIT(rx->channel_id);
+ lan_rmw(FDMA_INTR_DB_ENA_INTR_DB_ENA_SET(mask),
+ FDMA_INTR_DB_ENA_INTR_DB_ENA,
+ lan966x, FDMA_INTR_DB_ENA);
+
+ /* Activate the channel */
+ lan_rmw(FDMA_CH_ACTIVATE_CH_ACTIVATE_SET(BIT(rx->channel_id)),
+ FDMA_CH_ACTIVATE_CH_ACTIVATE,
+ lan966x, FDMA_CH_ACTIVATE);
+}
+
+static void lan966x_fdma_rx_disable(struct lan966x_rx *rx)
+{
+ struct lan966x *lan966x = rx->lan966x;
+ u32 val;
+
+ /* Disable the channel */
+ lan_rmw(FDMA_CH_DISABLE_CH_DISABLE_SET(BIT(rx->channel_id)),
+ FDMA_CH_DISABLE_CH_DISABLE,
+ lan966x, FDMA_CH_DISABLE);
+
+ readx_poll_timeout_atomic(lan966x_fdma_channel_active, lan966x,
+ val, !(val & BIT(rx->channel_id)),
+ READL_SLEEP_US, READL_TIMEOUT_US);
+
+ lan_rmw(FDMA_CH_DB_DISCARD_DB_DISCARD_SET(BIT(rx->channel_id)),
+ FDMA_CH_DB_DISCARD_DB_DISCARD,
+ lan966x, FDMA_CH_DB_DISCARD);
+}
+
+static void lan966x_fdma_rx_reload(struct lan966x_rx *rx)
+{
+ struct lan966x *lan966x = rx->lan966x;
+
+ lan_rmw(FDMA_CH_RELOAD_CH_RELOAD_SET(BIT(rx->channel_id)),
+ FDMA_CH_RELOAD_CH_RELOAD,
+ lan966x, FDMA_CH_RELOAD);
+}
+
+static void lan966x_fdma_tx_add_dcb(struct lan966x_tx *tx,
+ struct lan966x_tx_dcb *dcb)
+{
+ dcb->nextptr = FDMA_DCB_INVALID_DATA;
+ dcb->info = 0;
+}
+
+static int lan966x_fdma_tx_alloc(struct lan966x_tx *tx)
+{
+ struct lan966x *lan966x = tx->lan966x;
+ struct lan966x_tx_dcb *dcb;
+ struct lan966x_db *db;
+ int size;
+ int i, j;
+
+ tx->dcbs_buf = kcalloc(FDMA_DCB_MAX, sizeof(struct lan966x_tx_dcb_buf),
+ GFP_ATOMIC);
+ if (!tx->dcbs_buf)
+ return -ENOMEM;
+
+ /* calculate how many pages are needed to allocate the dcbs */
+ size = sizeof(struct lan966x_tx_dcb) * FDMA_DCB_MAX;
+ size = ALIGN(size, PAGE_SIZE);
+ tx->dcbs = dma_alloc_coherent(lan966x->dev, size, &tx->dma, GFP_ATOMIC);
+
+ /* Now for each dcb allocate the db */
+ for (i = 0; i < FDMA_DCB_MAX; ++i) {
+ dcb = &tx->dcbs[i];
+
+ for (j = 0; j < FDMA_TX_DCB_MAX_DBS; ++j) {
+ db = &dcb->db[j];
+ db->dataptr = 0;
+ db->status = 0;
+ }
+
+ lan966x_fdma_tx_add_dcb(tx, dcb);
+ }
+
+ return 0;
+}
+
+static void lan966x_fdma_tx_free(struct lan966x_tx *tx)
+{
+ struct lan966x *lan966x = tx->lan966x;
+ int size;
+
+ kfree(tx->dcbs_buf);
+
+ size = sizeof(struct lan966x_tx_dcb) * FDMA_DCB_MAX;
+ size = ALIGN(size, PAGE_SIZE);
+ dma_free_coherent(lan966x->dev, size, tx->dcbs, tx->dma);
+}
+
+static void lan966x_fdma_tx_activate(struct lan966x_tx *tx)
+{
+ struct lan966x *lan966x = tx->lan966x;
+ u32 mask;
+
+ /* When activating a channel, first is required to write the first DCB
+ * address and then to activate it
+ */
+ lan_wr(((u64)tx->dma) & GENMASK(31, 0), lan966x,
+ FDMA_DCB_LLP(tx->channel_id));
+ lan_wr(((u64)tx->dma) >> 32, lan966x, FDMA_DCB_LLP1(tx->channel_id));
+
+ lan_wr(FDMA_CH_CFG_CH_DCB_DB_CNT_SET(FDMA_TX_DCB_MAX_DBS) |
+ FDMA_CH_CFG_CH_INTR_DB_EOF_ONLY_SET(1) |
+ FDMA_CH_CFG_CH_INJ_PORT_SET(0) |
+ FDMA_CH_CFG_CH_MEM_SET(1),
+ lan966x, FDMA_CH_CFG(tx->channel_id));
+
+ /* Start fdma */
+ lan_rmw(FDMA_PORT_CTRL_INJ_STOP_SET(0),
+ FDMA_PORT_CTRL_INJ_STOP,
+ lan966x, FDMA_PORT_CTRL(0));
+
+ /* Enable interrupts */
+ mask = lan_rd(lan966x, FDMA_INTR_DB_ENA);
+ mask = FDMA_INTR_DB_ENA_INTR_DB_ENA_GET(mask);
+ mask |= BIT(tx->channel_id);
+ lan_rmw(FDMA_INTR_DB_ENA_INTR_DB_ENA_SET(mask),
+ FDMA_INTR_DB_ENA_INTR_DB_ENA,
+ lan966x, FDMA_INTR_DB_ENA);
+
+ /* Activate the channel */
+ lan_rmw(FDMA_CH_ACTIVATE_CH_ACTIVATE_SET(BIT(tx->channel_id)),
+ FDMA_CH_ACTIVATE_CH_ACTIVATE,
+ lan966x, FDMA_CH_ACTIVATE);
+}
+
+static void lan966x_fdma_tx_disable(struct lan966x_tx *tx)
+{
+ struct lan966x *lan966x = tx->lan966x;
+ u32 val;
+
+ /* Disable the channel */
+ lan_rmw(FDMA_CH_DISABLE_CH_DISABLE_SET(BIT(tx->channel_id)),
+ FDMA_CH_DISABLE_CH_DISABLE,
+ lan966x, FDMA_CH_DISABLE);
+
+ readx_poll_timeout_atomic(lan966x_fdma_channel_active, lan966x,
+ val, !(val & BIT(tx->channel_id)),
+ READL_SLEEP_US, READL_TIMEOUT_US);
+
+ lan_rmw(FDMA_CH_DB_DISCARD_DB_DISCARD_SET(BIT(tx->channel_id)),
+ FDMA_CH_DB_DISCARD_DB_DISCARD,
+ lan966x, FDMA_CH_DB_DISCARD);
+
+ tx->activated = false;
+}
+
+static void lan966x_fdma_tx_reload(struct lan966x_tx *tx)
+{
+ struct lan966x *lan966x = tx->lan966x;
+
+ /* Write the registers to reload the channel */
+ lan_rmw(FDMA_CH_RELOAD_CH_RELOAD_SET(BIT(tx->channel_id)),
+ FDMA_CH_RELOAD_CH_RELOAD,
+ lan966x, FDMA_CH_RELOAD);
+}
+
+static void lan966x_fdma_wakeup_netdev(struct lan966x *lan966x)
+{
+ struct lan966x_port *port;
+ int i;
+
+ for (i = 0; i < lan966x->num_phys_ports; ++i) {
+ port = lan966x->ports[i];
+ if (!port)
+ continue;
+
+ if (netif_queue_stopped(port->dev))
+ netif_wake_queue(port->dev);
+ }
+}
+
+static void lan966x_fdma_tx_clear_buf(struct lan966x *lan966x, int weight)
+{
+ struct lan966x_tx *tx = &lan966x->tx;
+ struct lan966x_tx_dcb_buf *dcb_buf;
+ struct lan966x_db *db;
+ unsigned long flags;
+ bool clear = false;
+ int i;
+
+ spin_lock_irqsave(&lan966x->tx_lock, flags);
+ for (i = 0; i < FDMA_DCB_MAX; ++i) {
+ dcb_buf = &tx->dcbs_buf[i];
+
+ if (!dcb_buf->used)
+ continue;
+
+ db = &tx->dcbs[i].db[0];
+ if (!(db->status & FDMA_DCB_STATUS_DONE))
+ continue;
+
+ dcb_buf->used = false;
+ dma_unmap_single(lan966x->dev,
+ dcb_buf->dma_addr,
+ dcb_buf->skb->len,
+ DMA_TO_DEVICE);
+ if (!dcb_buf->ptp)
+ dev_kfree_skb_any(dcb_buf->skb);
+
+ clear = true;
+ }
+ spin_unlock_irqrestore(&lan966x->tx_lock, flags);
+
+ if (clear)
+ lan966x_fdma_wakeup_netdev(lan966x);
+}
+
+static struct sk_buff *lan966x_fdma_rx_get_frame(struct lan966x_rx *rx)
+{
+ struct lan966x *lan966x = rx->lan966x;
+ u64 src_port, timestamp;
+ struct sk_buff *new_skb;
+ struct lan966x_db *db;
+ struct sk_buff *skb;
+
+ /* Check if there is any data */
+ db = &rx->dcbs[rx->dcb_index].db[rx->db_index];
+ if (unlikely(!(db->status & FDMA_DCB_STATUS_DONE)))
+ return NULL;
+
+ /* Get the received frame and unmap it */
+ skb = rx->skb[rx->dcb_index][rx->db_index];
+ dma_unmap_single(lan966x->dev, (dma_addr_t)db->dataptr,
+ FDMA_DCB_STATUS_BLOCKL(db->status),
+ DMA_FROM_DEVICE);
+
+ /* Allocate a new skb and map it */
+ new_skb = lan966x_fdma_rx_alloc_skb(rx, db);
+ if (unlikely(!new_skb))
+ return NULL;
+
+ rx->skb[rx->dcb_index][rx->db_index] = new_skb;
+
+ skb_put(skb, FDMA_DCB_STATUS_BLOCKL(db->status));
+
+ lan966x_ifh_get_src_port(skb->data, &src_port);
+ lan966x_ifh_get_timestamp(skb->data, ×tamp);
+
+ WARN_ON(src_port >= lan966x->num_phys_ports);
+
+ skb->dev = lan966x->ports[src_port]->dev;
+ skb_pull(skb, IFH_LEN * sizeof(u32));
+
+ if (likely(!(skb->dev->features & NETIF_F_RXFCS)))
+ skb_trim(skb, skb->len - ETH_FCS_LEN);
+
+ lan966x_ptp_rxtstamp(lan966x, skb, timestamp);
+ skb->protocol = eth_type_trans(skb, skb->dev);
+
+ if (lan966x->bridge_mask & BIT(src_port)) {
+ skb->offload_fwd_mark = 1;
+
+ skb_reset_network_header(skb);
+ if (!lan966x_hw_offload(lan966x, src_port, skb))
+ skb->offload_fwd_mark = 0;
+ }
+
+ skb->dev->stats.rx_bytes += skb->len;
+ skb->dev->stats.rx_packets++;
+
+ return skb;
+}
+
+static int lan966x_fdma_napi_poll(struct napi_struct *napi, int weight)
+{
+ struct lan966x *lan966x = container_of(napi, struct lan966x, napi);
+ struct lan966x_rx *rx = &lan966x->rx;
+ struct list_head rx_list;
+ int counter = 0;
+
+ lan966x_fdma_tx_clear_buf(lan966x, weight);
+
+ INIT_LIST_HEAD(&rx_list);
+
+ while (counter < weight) {
+ struct lan966x_rx_dcb *old_dcb;
+ struct sk_buff *skb;
+ u64 nextptr;
+
+ skb = lan966x_fdma_rx_get_frame(rx);
+ if (!skb)
+ break;
+ list_add_tail(&skb->list, &rx_list);
+
+ rx->db_index++;
+ counter++;
+
+ /* Check if the DCB can be reused */
+ if (rx->db_index != FDMA_RX_DCB_MAX_DBS)
+ continue;
+
+ /* Now the DCB can be reused, just advance the dcb_index
+ * pointer and set the nextptr in the DCB
+ */
+ rx->db_index = 0;
+
+ old_dcb = &rx->dcbs[rx->dcb_index];
+ rx->dcb_index++;
+ rx->dcb_index &= FDMA_DCB_MAX - 1;
+
+ nextptr = rx->dma + ((unsigned long)old_dcb -
+ (unsigned long)rx->dcbs);
+ lan966x_fdma_rx_add_dcb(rx, old_dcb, nextptr);
+ lan966x_fdma_rx_reload(rx);
+ }
+
+ if (counter < weight) {
+ napi_complete_done(napi, counter);
+ lan_wr(0xff, lan966x, FDMA_INTR_DB_ENA);
+ }
+
+ netif_receive_skb_list(&rx_list);
+
+ return counter;
+}
+
+irqreturn_t lan966x_fdma_irq_handler(int irq, void *args)
+{
+ struct lan966x *lan966x = args;
+ u32 db, err, err_type;
+
+ db = lan_rd(lan966x, FDMA_INTR_DB);
+ err = lan_rd(lan966x, FDMA_INTR_ERR);
+
+ if (db) {
+ lan_wr(0, lan966x, FDMA_INTR_DB_ENA);
+ lan_wr(db, lan966x, FDMA_INTR_DB);
+
+ napi_schedule(&lan966x->napi);
+ }
+
+ if (err) {
+ err_type = lan_rd(lan966x, FDMA_ERRORS);
+
+ WARN(1, "Unexpected error: %d, error_type: %d\n", err, err_type);
+
+ lan_wr(err, lan966x, FDMA_INTR_ERR);
+ lan_wr(err_type, lan966x, FDMA_ERRORS);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int lan966x_fdma_get_next_dcb(struct lan966x_tx *tx)
+{
+ struct lan966x_tx_dcb_buf *dcb_buf;
+ int i;
+
+ for (i = 0; i < FDMA_DCB_MAX; ++i) {
+ dcb_buf = &tx->dcbs_buf[i];
+ if (!dcb_buf->used && i != tx->last_in_use)
+ return i;
+ }
+
+ return -1;
+}
+
+int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev)
+{
+ struct lan966x_port *port = netdev_priv(dev);
+ struct lan966x *lan966x = port->lan966x;
+ struct lan966x_tx_dcb_buf *next_dcb_buf;
+ struct lan966x_tx_dcb *next_dcb, *dcb;
+ struct lan966x_tx *tx = &lan966x->tx;
+ struct lan966x_db *next_db;
+ int needed_headroom;
+ int needed_tailroom;
+ dma_addr_t dma_addr;
+ int next_to_use;
+ int err;
+
+ /* Get next index */
+ next_to_use = lan966x_fdma_get_next_dcb(tx);
+ if (next_to_use < 0) {
+ netif_stop_queue(dev);
+ err = NETDEV_TX_BUSY;
+ goto out;
+ }
+
+ if (skb_put_padto(skb, ETH_ZLEN)) {
+ dev->stats.tx_dropped++;
+ err = NETDEV_TX_OK;
+ goto out;
+ }
+
+ /* skb processing */
+ needed_headroom = max_t(int, IFH_LEN * sizeof(u32) - skb_headroom(skb), 0);
+ needed_tailroom = max_t(int, ETH_FCS_LEN - skb_tailroom(skb), 0);
+ if (needed_headroom || needed_tailroom) {
+ err = pskb_expand_head(skb, needed_headroom, needed_tailroom,
+ GFP_ATOMIC);
+ if (unlikely(err)) {
+ dev->stats.tx_dropped++;
+ err = NETDEV_TX_OK;
+ goto release;
+ }
+ }
+
+ skb_push(skb, IFH_LEN * sizeof(u32));
+ memcpy(skb->data, ifh, IFH_LEN * sizeof(u32));
+ skb_put(skb, 4);
+
+ dma_addr = dma_map_single(lan966x->dev, skb->data, skb->len,
+ DMA_TO_DEVICE);
+ if (dma_mapping_error(lan966x->dev, dma_addr)) {
+ dev->stats.tx_dropped++;
+ err = NETDEV_TX_OK;
+ goto release;
+ }
+
+ /* Setup next dcb */
+ next_dcb = &tx->dcbs[next_to_use];
+ next_dcb->nextptr = FDMA_DCB_INVALID_DATA;
+
+ next_db = &next_dcb->db[0];
+ next_db->dataptr = dma_addr;
+ next_db->status = FDMA_DCB_STATUS_SOF |
+ FDMA_DCB_STATUS_EOF |
+ FDMA_DCB_STATUS_INTR |
+ FDMA_DCB_STATUS_BLOCKO(0) |
+ FDMA_DCB_STATUS_BLOCKL(skb->len);
+
+ /* Fill up the buffer */
+ next_dcb_buf = &tx->dcbs_buf[next_to_use];
+ next_dcb_buf->skb = skb;
+ next_dcb_buf->dma_addr = dma_addr;
+ next_dcb_buf->used = true;
+ next_dcb_buf->ptp = false;
+
+ if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
+ LAN966X_SKB_CB(skb)->rew_op == IFH_REW_OP_TWO_STEP_PTP)
+ next_dcb_buf->ptp = true;
+
+ skb_tx_timestamp(skb);
+ if (likely(lan966x->tx.activated)) {
+ /* Connect current dcb to the next db */
+ dcb = &tx->dcbs[tx->last_in_use];
+ dcb->nextptr = tx->dma + (next_to_use *
+ sizeof(struct lan966x_tx_dcb));
+
+ lan966x_fdma_tx_reload(tx);
+ } else {
+ /* Because it is first time, then just activate */
+ lan966x->tx.activated = true;
+ lan966x_fdma_tx_activate(tx);
+ }
+
+ /* Move to next dcb because this last in use */
+ tx->last_in_use = next_to_use;
+
+ dev->stats.tx_packets++;
+ dev->stats.tx_bytes += skb->len;
+
+ return NETDEV_TX_OK;
+
+out:
+ return err;
+
+release:
+ if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
+ LAN966X_SKB_CB(skb)->rew_op == IFH_REW_OP_TWO_STEP_PTP)
+ lan966x_ptp_txtstamp_release(port, skb);
+
+ dev_kfree_skb_any(skb);
+ return err;
+}
+
+void lan966x_fdma_netdev_init(struct lan966x *lan966x, struct net_device *dev)
+{
+ if (lan966x->fdma_ndev)
+ return;
+
+ lan966x->fdma_ndev = dev;
+ netif_napi_add(dev, &lan966x->napi, lan966x_fdma_napi_poll,
+ FDMA_WEIGHT);
+ napi_enable(&lan966x->napi);
+}
+
+void lan966x_fdma_netdev_deinit(struct lan966x *lan966x, struct net_device *dev)
+{
+ if (lan966x->fdma_ndev == dev) {
+ netif_napi_del(&lan966x->napi);
+ lan966x->fdma_ndev = NULL;
+ }
+}
+
+void lan966x_fdma_init(struct lan966x *lan966x)
+{
+ lan966x->rx.lan966x = lan966x;
+ lan966x->rx.channel_id = FDMA_XTR_CHANNEL;
+ lan966x->tx.lan966x = lan966x;
+ lan966x->tx.channel_id = FDMA_INJ_CHANNEL;
+ lan966x->tx.last_in_use = -1;
+
+ lan966x_fdma_rx_alloc(&lan966x->rx);
+ lan966x_fdma_tx_alloc(&lan966x->tx);
+
+ lan966x_fdma_rx_start(&lan966x->rx);
+}
+
+void lan966x_fdma_deinit(struct lan966x *lan966x)
+{
+ lan966x_fdma_rx_disable(&lan966x->rx);
+ lan966x_fdma_tx_disable(&lan966x->tx);
+
+ lan966x_fdma_rx_free_skbs(&lan966x->rx);
+ lan966x_fdma_rx_free(&lan966x->rx);
+ lan966x_fdma_tx_free(&lan966x->tx);
+}
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
index 2c82f847ae6d..6cb9fffc3058 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
@@ -341,7 +341,10 @@ static int lan966x_port_xmit(struct sk_buff *skb, struct net_device *dev)
}
spin_lock(&lan966x->tx_lock);
- err = lan966x_port_ifh_xmit(skb, ifh, dev);
+ if (port->lan966x->fdma)
+ err = lan966x_fdma_xmit(skb, ifh, dev);
+ else
+ err = lan966x_port_ifh_xmit(skb, ifh, dev);
spin_unlock(&lan966x->tx_lock);
return err;
@@ -640,6 +643,9 @@ static void lan966x_cleanup_ports(struct lan966x *lan966x)
if (port->dev)
unregister_netdev(port->dev);
+ if (lan966x->fdma && lan966x->fdma_ndev == port->dev)
+ lan966x_fdma_netdev_deinit(lan966x, port->dev);
+
if (port->phylink) {
rtnl_lock();
lan966x_port_stop(port->dev);
@@ -659,6 +665,11 @@ static void lan966x_cleanup_ports(struct lan966x *lan966x)
disable_irq(lan966x->ana_irq);
lan966x->ana_irq = -ENXIO;
}
+
+ if (lan966x->fdma_irq) {
+ disable_irq(lan966x->fdma_irq);
+ lan966x->fdma_irq = -ENXIO;
+ }
}
static int lan966x_probe_port(struct lan966x *lan966x, u32 p,
@@ -787,12 +798,12 @@ static void lan966x_init(struct lan966x *lan966x)
/* Do byte-swap and expect status after last data word
* Extraction: Mode: manual extraction) | Byte_swap
*/
- lan_wr(QS_XTR_GRP_CFG_MODE_SET(1) |
+ lan_wr(QS_XTR_GRP_CFG_MODE_SET(lan966x->fdma ? 2 : 1) |
QS_XTR_GRP_CFG_BYTE_SWAP_SET(1),
lan966x, QS_XTR_GRP_CFG(0));
/* Injection: Mode: manual injection | Byte_swap */
- lan_wr(QS_INJ_GRP_CFG_MODE_SET(1) |
+ lan_wr(QS_INJ_GRP_CFG_MODE_SET(lan966x->fdma ? 2 : 1) |
QS_INJ_GRP_CFG_BYTE_SWAP_SET(1),
lan966x, QS_INJ_GRP_CFG(0));
@@ -1014,6 +1025,17 @@ static int lan966x_probe(struct platform_device *pdev)
lan966x->ptp = 1;
}
+ lan966x->fdma_irq = platform_get_irq_byname(pdev, "fdma");
+ if (lan966x->fdma_irq > 0) {
+ err = devm_request_threaded_irq(&pdev->dev, lan966x->fdma_irq, NULL,
+ lan966x_fdma_irq_handler, IRQF_ONESHOT,
+ "fdma irq", lan966x);
+ if (err)
+ return dev_err_probe(&pdev->dev, err, "Unable to use fdma irq");
+
+ lan966x->fdma = true;
+ }
+
/* init switch */
lan966x_init(lan966x);
lan966x_stats_init(lan966x);
@@ -1043,6 +1065,8 @@ static int lan966x_probe(struct platform_device *pdev)
lan966x_port_init(lan966x->ports[p]);
}
+ lan966x_fdma_init(lan966x);
+
lan966x_mdb_init(lan966x);
err = lan966x_fdb_init(lan966x);
if (err)
@@ -1073,6 +1097,7 @@ static int lan966x_remove(struct platform_device *pdev)
{
struct lan966x *lan966x = platform_get_drvdata(pdev);
+ lan966x_fdma_deinit(lan966x);
lan966x_cleanup_ports(lan966x);
cancel_delayed_work_sync(&lan966x->stats_work);
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
index b692c612f235..bfa7feea2b56 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
@@ -61,6 +61,23 @@
#define IFH_REW_OP_ONE_STEP_PTP 0x3
#define IFH_REW_OP_TWO_STEP_PTP 0x4
+#define FDMA_RX_DCB_MAX_DBS 3
+#define FDMA_TX_DCB_MAX_DBS 1
+#define FDMA_DCB_INFO_DATAL(x) ((x) & GENMASK(15, 0))
+
+#define FDMA_DCB_STATUS_BLOCKL(x) ((x) & GENMASK(15, 0))
+#define FDMA_DCB_STATUS_SOF BIT(16)
+#define FDMA_DCB_STATUS_EOF BIT(17)
+#define FDMA_DCB_STATUS_INTR BIT(18)
+#define FDMA_DCB_STATUS_DONE BIT(19)
+#define FDMA_DCB_STATUS_BLOCKO(x) (((x) << 20) & GENMASK(31, 20))
+#define FDMA_DCB_INVALID_DATA 0x1
+
+#define FDMA_XTR_CHANNEL 6
+#define FDMA_INJ_CHANNEL 0
+#define FDMA_DCB_MAX 512
+#define FDMA_WEIGHT 64
+
/* MAC table entry types.
* ENTRYTYPE_NORMAL is subject to aging.
* ENTRYTYPE_LOCKED is not subject to aging.
@@ -76,6 +93,85 @@ enum macaccess_entry_type {
struct lan966x_port;
+struct lan966x_db {
+ u64 dataptr;
+ u64 status;
+};
+
+struct lan966x_rx_dcb {
+ u64 nextptr;
+ u64 info;
+ struct lan966x_db db[FDMA_RX_DCB_MAX_DBS];
+};
+
+struct lan966x_tx_dcb {
+ u64 nextptr;
+ u64 info;
+ struct lan966x_db db[FDMA_TX_DCB_MAX_DBS];
+};
+
+struct lan966x_rx {
+ struct lan966x *lan966x;
+
+ /* Pointer to the array of hardware dcbs. */
+ struct lan966x_rx_dcb *dcbs;
+
+ /* Pointer to the last address in the dcbs. */
+ struct lan966x_rx_dcb *last_entry;
+
+ /* For each DB, there is a skb, and the skb data pointer is mapped in
+ * the DB. Once a frame is received the skb is given to the upper layers
+ * and a new skb is added to the db.
+ */
+ struct sk_buff *skb[FDMA_DCB_MAX][FDMA_RX_DCB_MAX_DBS];
+
+ /* Represents the db_index, it can have a value between 0 and
+ * FDMA_RX_DCB_MAX_DBS, once it reaches the value of FDMA_RX_DCB_MAX_DBS
+ * it means that the DCB can be reused.
+ */
+ int db_index;
+
+ /* Represents the index in the dcbs. It has a value between 0 and
+ * FDMA_DCB_MAX
+ */
+ int dcb_index;
+
+ /* Represents the dma address to the dcbs array */
+ dma_addr_t dma;
+
+ /* Represents the page order that is used to allocate the pages for the
+ * RX buffers. This value is calculated based on max MTU of the devices.
+ */
+ u8 page_order;
+
+ u8 channel_id;
+};
+
+struct lan966x_tx_dcb_buf {
+ struct sk_buff *skb;
+ dma_addr_t dma_addr;
+ bool used;
+ bool ptp;
+};
+
+struct lan966x_tx {
+ struct lan966x *lan966x;
+
+ /* Pointer to the dcb list */
+ struct lan966x_tx_dcb *dcbs;
+ u16 last_in_use;
+
+ /* Represents the DMA address to the first entry of the dcb entries. */
+ dma_addr_t dma;
+
+ /* Array of dcbs that are given to the HW */
+ struct lan966x_tx_dcb_buf *dcbs_buf;
+
+ u8 channel_id;
+
+ bool activated;
+};
+
struct lan966x_stat_layout {
u32 offset;
char name[ETH_GSTRING_LEN];
@@ -137,6 +233,7 @@ struct lan966x {
int xtr_irq;
int ana_irq;
int ptp_irq;
+ int fdma_irq;
/* worqueue for fdb */
struct workqueue_struct *fdb_work;
@@ -153,6 +250,13 @@ struct lan966x {
spinlock_t ptp_ts_id_lock; /* lock for ts_id */
struct mutex ptp_lock; /* lock for ptp interface state */
u16 ptp_skbs;
+
+ /* fdma */
+ bool fdma;
+ struct net_device *fdma_ndev;
+ struct lan966x_rx rx;
+ struct lan966x_tx tx;
+ struct napi_struct napi;
};
struct lan966x_port_config {
@@ -292,6 +396,13 @@ void lan966x_ptp_txtstamp_release(struct lan966x_port *port,
struct sk_buff *skb);
irqreturn_t lan966x_ptp_irq_handler(int irq, void *args);
+int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev);
+void lan966x_fdma_netdev_init(struct lan966x *lan966x, struct net_device *dev);
+void lan966x_fdma_netdev_deinit(struct lan966x *lan966x, struct net_device *dev);
+void lan966x_fdma_init(struct lan966x *lan966x);
+void lan966x_fdma_deinit(struct lan966x *lan966x);
+irqreturn_t lan966x_fdma_irq_handler(int irq, void *args);
+
static inline void __iomem *lan_addr(void __iomem *base[],
int id, int tinst, int tcnt,
int gbase, int ginst,
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_port.c b/drivers/net/ethernet/microchip/lan966x/lan966x_port.c
index 237555845a52..f141644e4372 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_port.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_port.c
@@ -393,6 +393,9 @@ void lan966x_port_init(struct lan966x_port *port)
lan966x_port_config_down(port);
+ if (lan966x->fdma)
+ lan966x_fdma_netdev_init(lan966x, port->dev);
+
if (config->portmode != PHY_INTERFACE_MODE_QSGMII)
return;
--
2.33.0
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH net-next v2 4/4] net: lan966x: Update FDMA to change MTU.
2022-03-18 20:47 [PATCH net-next v2 0/4] net: lan966x: Add support for FDMA Horatiu Vultur
` (2 preceding siblings ...)
2022-03-18 20:47 ` [PATCH net-next v2 3/4] net: lan966x: Add FDMA functionality Horatiu Vultur
@ 2022-03-18 20:47 ` Horatiu Vultur
2022-03-18 20:55 ` [PATCH net-next v2 0/4] net: lan966x: Add support for FDMA Michael Walle
4 siblings, 0 replies; 10+ messages in thread
From: Horatiu Vultur @ 2022-03-18 20:47 UTC (permalink / raw)
To: linux-kernel, netdev; +Cc: davem, kuba, michael, UNGLinuxDriver, Horatiu Vultur
When changing the MTU, it is required to change also the size of the
DBs. In case those frames will arrive to CPU.
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
.../ethernet/microchip/lan966x/lan966x_fdma.c | 95 +++++++++++++++++++
.../ethernet/microchip/lan966x/lan966x_main.c | 2 +-
.../ethernet/microchip/lan966x/lan966x_main.h | 1 +
3 files changed, 97 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
index c3266d07302d..f3245dd713f4 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
@@ -636,6 +636,101 @@ int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev)
return err;
}
+static int lan966x_fdma_get_max_mtu(struct lan966x *lan966x)
+{
+ int max_mtu = 0;
+ int i;
+
+ for (i = 0; i < lan966x->num_phys_ports; ++i) {
+ int mtu;
+
+ if (!lan966x->ports[i])
+ continue;
+
+ mtu = lan966x->ports[i]->dev->mtu;
+ if (mtu > max_mtu)
+ max_mtu = mtu;
+ }
+
+ return max_mtu;
+}
+
+static int lan966x_qsys_sw_status(struct lan966x *lan966x)
+{
+ return lan_rd(lan966x, QSYS_SW_STATUS(CPU_PORT));
+}
+
+static void lan966x_fdma_reload(struct lan966x *lan966x, int new_mtu)
+{
+ void *rx_dcb, *tx_dcb, *tx_dcb_buf;
+ dma_addr_t rx_dma, tx_dma;
+ unsigned long flags;
+ u32 size;
+
+ /* Store these for later to free them */
+ rx_dma = lan966x->rx.dma;
+ tx_dma = lan966x->tx.dma;
+ rx_dcb = lan966x->rx.dcbs;
+ tx_dcb = lan966x->tx.dcbs;
+ tx_dcb_buf = lan966x->tx.dcbs_buf;
+
+ lan966x_fdma_rx_disable(&lan966x->rx);
+ lan966x_fdma_rx_free_skbs(&lan966x->rx);
+ lan966x->rx.page_order = round_up(new_mtu, PAGE_SIZE) / PAGE_SIZE - 1;
+ lan966x_fdma_rx_alloc(&lan966x->rx);
+ lan966x_fdma_rx_start(&lan966x->rx);
+
+ spin_lock_irqsave(&lan966x->tx_lock, flags);
+ lan966x_fdma_tx_disable(&lan966x->tx);
+ lan966x_fdma_tx_alloc(&lan966x->tx);
+ spin_unlock_irqrestore(&lan966x->tx_lock, flags);
+
+ /* Now it is possible to clean */
+ size = sizeof(struct lan966x_tx_dcb) * FDMA_DCB_MAX;
+ size = ALIGN(size, PAGE_SIZE);
+ dma_free_coherent(lan966x->dev, size, tx_dcb, tx_dma);
+
+ kfree(tx_dcb_buf);
+
+ size = sizeof(struct lan966x_rx_dcb) * FDMA_DCB_MAX;
+ size = ALIGN(size, PAGE_SIZE);
+ dma_free_coherent(lan966x->dev, size, rx_dcb, rx_dma);
+}
+
+int lan966x_fdma_change_mtu(struct lan966x *lan966x)
+{
+ int max_mtu;
+ u32 val;
+
+ max_mtu = lan966x_fdma_get_max_mtu(lan966x);
+ if (round_up(max_mtu, PAGE_SIZE) / PAGE_SIZE - 1 ==
+ lan966x->rx.page_order)
+ return 0;
+
+ /* Disable the CPU port */
+ lan_rmw(QSYS_SW_PORT_MODE_PORT_ENA_SET(0),
+ QSYS_SW_PORT_MODE_PORT_ENA,
+ lan966x, QSYS_SW_PORT_MODE(CPU_PORT));
+
+ /* Flush the CPU queues */
+ readx_poll_timeout(lan966x_qsys_sw_status, lan966x,
+ val, !(QSYS_SW_STATUS_EQ_AVAIL_GET(val)),
+ READL_SLEEP_US, READL_TIMEOUT_US);
+
+ /* Add a sleep in case there are frames between the queues and the CPU
+ * port
+ */
+ usleep_range(1000, 2000);
+
+ lan966x_fdma_reload(lan966x, max_mtu);
+
+ /* Enable back the CPU port */
+ lan_rmw(QSYS_SW_PORT_MODE_PORT_ENA_SET(1),
+ QSYS_SW_PORT_MODE_PORT_ENA,
+ lan966x, QSYS_SW_PORT_MODE(CPU_PORT));
+ return 0;
+}
+
void lan966x_fdma_netdev_init(struct lan966x *lan966x, struct net_device *dev)
{
if (lan966x->fdma_ndev)
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
index 6cb9fffc3058..a78fee5471e7 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
@@ -359,7 +359,7 @@ static int lan966x_port_change_mtu(struct net_device *dev, int new_mtu)
lan966x, DEV_MAC_MAXLEN_CFG(port->chip_port));
dev->mtu = new_mtu;
- return 0;
+ return !lan966x->fdma ? 0 : lan966x_fdma_change_mtu(lan966x);
}
static int lan966x_mc_unsync(struct net_device *dev, const unsigned char *addr)
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
index bfa7feea2b56..fa4016f2b5d4 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
@@ -397,6 +397,7 @@ void lan966x_ptp_txtstamp_release(struct lan966x_port *port,
irqreturn_t lan966x_ptp_irq_handler(int irq, void *args);
int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev);
+int lan966x_fdma_change_mtu(struct lan966x *lan966x);
void lan966x_fdma_netdev_init(struct lan966x *lan966x, struct net_device *dev);
void lan966x_fdma_netdev_deinit(struct lan966x *lan966x, struct net_device *dev);
void lan966x_fdma_init(struct lan966x *lan966x);
--
2.33.0
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH net-next v2 0/4] net: lan966x: Add support for FDMA
2022-03-18 20:47 [PATCH net-next v2 0/4] net: lan966x: Add support for FDMA Horatiu Vultur
` (3 preceding siblings ...)
2022-03-18 20:47 ` [PATCH net-next v2 4/4] net: lan966x: Update FDMA to change MTU Horatiu Vultur
@ 2022-03-18 20:55 ` Michael Walle
4 siblings, 0 replies; 10+ messages in thread
From: Michael Walle @ 2022-03-18 20:55 UTC (permalink / raw)
To: Horatiu Vultur; +Cc: linux-kernel, netdev, davem, kuba, UNGLinuxDriver
Am 2022-03-18 21:47, schrieb Horatiu Vultur:
> Currently when injecting or extracting a frame from CPU, the frame
> is given to the HW each word at a time. There is another way to
> inject/extract frames from CPU using FDMA(Frame Direct Memory Access).
> In this way the entire frame is given to the HW. This improves both
> RX and TX bitrate.
>
> v1->v2:
> - fix typo in commit message in last patch
> - remove first patch as the changes are already there
> - make sure that there is space in skb to put the FCS
> - move skb_tx_timestamp closer to the handover of the frame to the HW
>
> Horatiu Vultur (4):
> net: lan966x: Add registers that are used for FDMA.
> net: lan966x: Expose functions that are needed by FDMA
> net: lan966x: Add FDMA functionality
> net: lan966x: Update FDMA to change MTU.
>
> .../net/ethernet/microchip/lan966x/Makefile | 2 +-
> .../ethernet/microchip/lan966x/lan966x_fdma.c | 775 ++++++++++++++++++
> .../ethernet/microchip/lan966x/lan966x_main.c | 44 +-
> .../ethernet/microchip/lan966x/lan966x_main.h | 120 +++
> .../ethernet/microchip/lan966x/lan966x_port.c | 3 +
> .../ethernet/microchip/lan966x/lan966x_regs.h | 106 +++
> 6 files changed, 1038 insertions(+), 12 deletions(-)
> create mode 100644
> drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
Tested-by: Michael Walle <michael@walle.cc>
Thanks,
-michael
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH net-next v2 3/4] net: lan966x: Add FDMA functionality
2022-03-18 20:47 ` [PATCH net-next v2 3/4] net: lan966x: Add FDMA functionality Horatiu Vultur
@ 2022-03-22 6:01 ` Jakub Kicinski
2022-03-22 21:04 ` Horatiu Vultur
0 siblings, 1 reply; 10+ messages in thread
From: Jakub Kicinski @ 2022-03-22 6:01 UTC (permalink / raw)
To: Horatiu Vultur; +Cc: linux-kernel, netdev, davem, michael, UNGLinuxDriver
On Fri, 18 Mar 2022 21:47:49 +0100 Horatiu Vultur wrote:
> Ethernet frames can be extracted or injected to or from the device's
> DDR memory. There is one channel for injection and one channel for
> extraction. Each of these channels contain a linked list of DCBs which
> contains DB. The DCB for injection contains only 1 DB and the DCB for
> extraction contains 3 DBs. Each DB contains a frame. Everytime when a
> frame is received or transmitted an interrupt is generated.
>
> It is not possible to use both the FDMA and the manual
> injection/extraction of the frames. Therefore the FDMA has priority over
> the manual because of better performance values.
> +static struct sk_buff *lan966x_fdma_rx_alloc_skb(struct lan966x_rx *rx,
> + struct lan966x_db *db)
> +{
> + struct lan966x *lan966x = rx->lan966x;
> + struct sk_buff *skb;
> + dma_addr_t dma_addr;
> + struct page *page;
> + void *buff_addr;
> +
> + page = dev_alloc_pages(rx->page_order);
> + if (unlikely(!page))
> + return NULL;
> +
> + dma_addr = dma_map_page(lan966x->dev, page, 0,
> + PAGE_SIZE << rx->page_order,
> + DMA_FROM_DEVICE);
> + if (unlikely(dma_mapping_error(lan966x->dev, dma_addr))) {
> + __free_pages(page, rx->page_order);
> + return NULL;
> + }
> +
> + buff_addr = page_address(page);
> + skb = build_skb(buff_addr, PAGE_SIZE << rx->page_order);
> +
spurious new line
> + if (unlikely(!skb)) {
> + dev_err_ratelimited(lan966x->dev,
> + "build_skb failed !\n");
a statistic for that would be better than prints
kernel will already do some printing if it goes oom
> + dma_unmap_single(lan966x->dev, dma_addr,
> + PAGE_SIZE << rx->page_order,
> + DMA_FROM_DEVICE);
why unmap_single if you used map_page for mapping?
> + __free_pages(page, rx->page_order);
> + return NULL;
please move the error handling to the end of the function and use goto
to jump into the right spot
> + }
> +
> + db->dataptr = dma_addr;
> + return skb;
> +}
> +static int lan966x_fdma_rx_alloc(struct lan966x_rx *rx)
> +{
> + struct lan966x *lan966x = rx->lan966x;
> + struct lan966x_rx_dcb *dcb;
> + struct lan966x_db *db;
> + struct sk_buff *skb;
> + int i, j;
> + int size;
> +
> + /* calculate how many pages are needed to allocate the dcbs */
> + size = sizeof(struct lan966x_rx_dcb) * FDMA_DCB_MAX;
> + size = ALIGN(size, PAGE_SIZE);
> +
> + rx->dcbs = dma_alloc_coherent(lan966x->dev, size, &rx->dma, GFP_ATOMIC);
Why ATOMIC? This seems to be called from the probe path.
Error checking missing.
> + rx->last_entry = rx->dcbs;
> + rx->db_index = 0;
> + rx->dcb_index = 0;
> +static void lan966x_fdma_rx_start(struct lan966x_rx *rx)
> +{
> + struct lan966x *lan966x = rx->lan966x;
> + u32 mask;
> +
> + /* When activating a channel, first is required to write the first DCB
> + * address and then to activate it
> + */
> + lan_wr(((u64)rx->dma) & GENMASK(31, 0), lan966x,
lower_32_bits()
> + FDMA_DCB_LLP(rx->channel_id));
> + lan_wr(((u64)rx->dma) >> 32, lan966x, FDMA_DCB_LLP1(rx->channel_id));
upper_32_bits()
> + lan_wr(FDMA_CH_CFG_CH_DCB_DB_CNT_SET(FDMA_RX_DCB_MAX_DBS) |
> + FDMA_CH_CFG_CH_INTR_DB_EOF_ONLY_SET(1) |
> + FDMA_CH_CFG_CH_INJ_PORT_SET(0) |
> + FDMA_CH_CFG_CH_MEM_SET(1),
> + lan966x, FDMA_CH_CFG(rx->channel_id));
> +static int lan966x_fdma_tx_alloc(struct lan966x_tx *tx)
> +{
> + struct lan966x *lan966x = tx->lan966x;
> + struct lan966x_tx_dcb *dcb;
> + struct lan966x_db *db;
> + int size;
> + int i, j;
> +
> + tx->dcbs_buf = kcalloc(FDMA_DCB_MAX, sizeof(struct lan966x_tx_dcb_buf),
> + GFP_ATOMIC);
> + if (!tx->dcbs_buf)
> + return -ENOMEM;
> +
> + /* calculate how many pages are needed to allocate the dcbs */
> + size = sizeof(struct lan966x_tx_dcb) * FDMA_DCB_MAX;
> + size = ALIGN(size, PAGE_SIZE);
> + tx->dcbs = dma_alloc_coherent(lan966x->dev, size, &tx->dma, GFP_ATOMIC);
same comments re: atomic and error checking as on rx
> + /* Now for each dcb allocate the db */
> + for (i = 0; i < FDMA_DCB_MAX; ++i) {
> + dcb = &tx->dcbs[i];
> +
> + for (j = 0; j < FDMA_TX_DCB_MAX_DBS; ++j) {
> + db = &dcb->db[j];
> + db->dataptr = 0;
> + db->status = 0;
> + }
> +
> + lan966x_fdma_tx_add_dcb(tx, dcb);
> + }
> +
> + return 0;
> +}
> +static struct sk_buff *lan966x_fdma_rx_get_frame(struct lan966x_rx *rx)
> +{
> + struct lan966x *lan966x = rx->lan966x;
> + u64 src_port, timestamp;
> + struct sk_buff *new_skb;
> + struct lan966x_db *db;
> + struct sk_buff *skb;
> +
> + /* Check if there is any data */
> + db = &rx->dcbs[rx->dcb_index].db[rx->db_index];
> + if (unlikely(!(db->status & FDMA_DCB_STATUS_DONE)))
> + return NULL;
> +
> + /* Get the received frame and unmap it */
> + skb = rx->skb[rx->dcb_index][rx->db_index];
> + dma_unmap_single(lan966x->dev, (dma_addr_t)db->dataptr,
> + FDMA_DCB_STATUS_BLOCKL(db->status),
> + DMA_FROM_DEVICE);
> +
> + /* Allocate a new skb and map it */
> + new_skb = lan966x_fdma_rx_alloc_skb(rx, db);
> + if (unlikely(!new_skb))
> + return NULL;
So how is memory pressure handled, exactly? Looks like it's handled
the same as if the ring was empty, so the IRQ is going to get re-raise
immediately, or never raised again?
> + rx->skb[rx->dcb_index][rx->db_index] = new_skb;
> +
> + skb_put(skb, FDMA_DCB_STATUS_BLOCKL(db->status));
> +
> + lan966x_ifh_get_src_port(skb->data, &src_port);
> + lan966x_ifh_get_timestamp(skb->data, ×tamp);
> +
> + WARN_ON(src_port >= lan966x->num_phys_ports);
> +
> + skb->dev = lan966x->ports[src_port]->dev;
> + skb_pull(skb, IFH_LEN * sizeof(u32));
> +
> + if (likely(!(skb->dev->features & NETIF_F_RXFCS)))
> + skb_trim(skb, skb->len - ETH_FCS_LEN);
> +
> + lan966x_ptp_rxtstamp(lan966x, skb, timestamp);
> + skb->protocol = eth_type_trans(skb, skb->dev);
> +
> + if (lan966x->bridge_mask & BIT(src_port)) {
> + skb->offload_fwd_mark = 1;
> +
> + skb_reset_network_header(skb);
> + if (!lan966x_hw_offload(lan966x, src_port, skb))
> + skb->offload_fwd_mark = 0;
> + }
> +
> + skb->dev->stats.rx_bytes += skb->len;
> + skb->dev->stats.rx_packets++;
> +
> + return skb;
> +}
> +
> +static int lan966x_fdma_napi_poll(struct napi_struct *napi, int weight)
> +{
> + struct lan966x *lan966x = container_of(napi, struct lan966x, napi);
> + struct lan966x_rx *rx = &lan966x->rx;
> + struct list_head rx_list;
> + int counter = 0;
> +
> + lan966x_fdma_tx_clear_buf(lan966x, weight);
> +
> + INIT_LIST_HEAD(&rx_list);
> +
> + while (counter < weight) {
> + struct lan966x_rx_dcb *old_dcb;
> + struct sk_buff *skb;
> + u64 nextptr;
> +
> + skb = lan966x_fdma_rx_get_frame(rx);
> + if (!skb)
> + break;
> + list_add_tail(&skb->list, &rx_list);
> +
> + rx->db_index++;
> + counter++;
> +
> + /* Check if the DCB can be reused */
> + if (rx->db_index != FDMA_RX_DCB_MAX_DBS)
> + continue;
> +
> + /* Now the DCB can be reused, just advance the dcb_index
> + * pointer and set the nextptr in the DCB
> + */
> + rx->db_index = 0;
> +
> + old_dcb = &rx->dcbs[rx->dcb_index];
> + rx->dcb_index++;
> + rx->dcb_index &= FDMA_DCB_MAX - 1;
> +
> + nextptr = rx->dma + ((unsigned long)old_dcb -
> + (unsigned long)rx->dcbs);
> + lan966x_fdma_rx_add_dcb(rx, old_dcb, nextptr);
> + lan966x_fdma_rx_reload(rx);
> + }
> +
> + if (counter < weight) {
> + napi_complete_done(napi, counter);
You should check the return value of napi_complete_done().
busy polling or something else may want the IRQ to stay
disabled.
> + lan_wr(0xff, lan966x, FDMA_INTR_DB_ENA);
> + }
> +
> + netif_receive_skb_list(&rx_list);
Why not GRO?
> + return counter;
> +}
> +
> +irqreturn_t lan966x_fdma_irq_handler(int irq, void *args)
> +{
> + struct lan966x *lan966x = args;
> + u32 db, err, err_type;
> +
> + db = lan_rd(lan966x, FDMA_INTR_DB);
> + err = lan_rd(lan966x, FDMA_INTR_ERR);
Hm, IIUC you request a threaded IRQ for this. Why?
The register accesses can't sleep because you poke
them from napi_poll as well...
> + if (db) {
> + lan_wr(0, lan966x, FDMA_INTR_DB_ENA);
> + lan_wr(db, lan966x, FDMA_INTR_DB);
> +
> + napi_schedule(&lan966x->napi);
> + }
> +
> + if (err) {
> + err_type = lan_rd(lan966x, FDMA_ERRORS);
> +
> + WARN(1, "Unexpected error: %d, error_type: %d\n", err, err_type);
> +
> + lan_wr(err, lan966x, FDMA_INTR_ERR);
> + lan_wr(err_type, lan966x, FDMA_ERRORS);
> + }
> +
> + return IRQ_HANDLED;
> +}
> +int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev)
> +{
> + struct lan966x_port *port = netdev_priv(dev);
> + struct lan966x *lan966x = port->lan966x;
> + struct lan966x_tx_dcb_buf *next_dcb_buf;
> + struct lan966x_tx_dcb *next_dcb, *dcb;
> + struct lan966x_tx *tx = &lan966x->tx;
> + struct lan966x_db *next_db;
> + int needed_headroom;
> + int needed_tailroom;
> + dma_addr_t dma_addr;
> + int next_to_use;
> + int err;
> +
> + /* Get next index */
> + next_to_use = lan966x_fdma_get_next_dcb(tx);
> + if (next_to_use < 0) {
> + netif_stop_queue(dev);
> + err = NETDEV_TX_BUSY;
> + goto out;
> + }
> +
> + if (skb_put_padto(skb, ETH_ZLEN)) {
> + dev->stats.tx_dropped++;
It's preferred not to use the old dev->stats, but I guess you already
do so :( This is under some locks, right? No chance for another queue
or port to try to touch those stats at the same time?
> + err = NETDEV_TX_OK;
> + goto out;
> + }
> +
> + /* skb processing */
> + needed_headroom = max_t(int, IFH_LEN * sizeof(u32) - skb_headroom(skb), 0);
> + needed_tailroom = max_t(int, ETH_FCS_LEN - skb_tailroom(skb), 0);
> + if (needed_headroom || needed_tailroom) {
> + err = pskb_expand_head(skb, needed_headroom, needed_tailroom,
> + GFP_ATOMIC);
> + if (unlikely(err)) {
> + dev->stats.tx_dropped++;
> + err = NETDEV_TX_OK;
> + goto release;
> + }
> + }
You need to skb_cow_head() even if you don't need to grow the headroom
or tailroom.
> + skb_push(skb, IFH_LEN * sizeof(u32));
> + memcpy(skb->data, ifh, IFH_LEN * sizeof(u32));
> + skb_put(skb, 4);
> +
> + dma_addr = dma_map_single(lan966x->dev, skb->data, skb->len,
> + DMA_TO_DEVICE);
> + if (dma_mapping_error(lan966x->dev, dma_addr)) {
> + dev->stats.tx_dropped++;
> + err = NETDEV_TX_OK;
> + goto release;
> + }
> +
> + /* Setup next dcb */
> + next_dcb = &tx->dcbs[next_to_use];
> + next_dcb->nextptr = FDMA_DCB_INVALID_DATA;
> +
> + next_db = &next_dcb->db[0];
> + next_db->dataptr = dma_addr;
> + next_db->status = FDMA_DCB_STATUS_SOF |
> + FDMA_DCB_STATUS_EOF |
> + FDMA_DCB_STATUS_INTR |
> + FDMA_DCB_STATUS_BLOCKO(0) |
> + FDMA_DCB_STATUS_BLOCKL(skb->len);
> +
> + /* Fill up the buffer */
> + next_dcb_buf = &tx->dcbs_buf[next_to_use];
> + next_dcb_buf->skb = skb;
> + next_dcb_buf->dma_addr = dma_addr;
> + next_dcb_buf->used = true;
> + next_dcb_buf->ptp = false;
> +
> + if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
> + LAN966X_SKB_CB(skb)->rew_op == IFH_REW_OP_TWO_STEP_PTP)
> + next_dcb_buf->ptp = true;
> +
> + skb_tx_timestamp(skb);
> + if (likely(lan966x->tx.activated)) {
> + /* Connect current dcb to the next db */
> + dcb = &tx->dcbs[tx->last_in_use];
> + dcb->nextptr = tx->dma + (next_to_use *
> + sizeof(struct lan966x_tx_dcb));
> +
> + lan966x_fdma_tx_reload(tx);
> + } else {
> + /* Because it is first time, then just activate */
> + lan966x->tx.activated = true;
> + lan966x_fdma_tx_activate(tx);
> + }
> +
> + /* Move to next dcb because this last in use */
> + tx->last_in_use = next_to_use;
> +
> + dev->stats.tx_packets++;
> + dev->stats.tx_bytes += skb->len;
I think it's best practice to increase the stats when processing
completions, you're not sure at this point whether the skb will
actually get transmitted. Also normally skb could be freed by the
IRQ handler as soon as its given to HW, but I think you have a lock
so no risk of UAF on the skb->len access?
> + return NETDEV_TX_OK;
> +
> +out:
> + return err;
> +
> +release:
> + if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
> + LAN966X_SKB_CB(skb)->rew_op == IFH_REW_OP_TWO_STEP_PTP)
> + lan966x_ptp_txtstamp_release(port, skb);
> +
> + dev_kfree_skb_any(skb);
> + return err;
I think you're better off returning BUSY directly then you can forgo
setting err and always return TX_OK.
> +void lan966x_fdma_init(struct lan966x *lan966x)
> +{
> + lan966x->rx.lan966x = lan966x;
> + lan966x->rx.channel_id = FDMA_XTR_CHANNEL;
> + lan966x->tx.lan966x = lan966x;
> + lan966x->tx.channel_id = FDMA_INJ_CHANNEL;
> + lan966x->tx.last_in_use = -1;
> +
> + lan966x_fdma_rx_alloc(&lan966x->rx);
> + lan966x_fdma_tx_alloc(&lan966x->tx);
> +
> + lan966x_fdma_rx_start(&lan966x->rx);
Not checking for any errors here is highly suspicious
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH net-next v2 3/4] net: lan966x: Add FDMA functionality
2022-03-22 6:01 ` Jakub Kicinski
@ 2022-03-22 21:04 ` Horatiu Vultur
2022-03-22 22:25 ` Jakub Kicinski
0 siblings, 1 reply; 10+ messages in thread
From: Horatiu Vultur @ 2022-03-22 21:04 UTC (permalink / raw)
To: Jakub Kicinski; +Cc: linux-kernel, netdev, davem, michael, UNGLinuxDriver
The 03/21/2022 23:01, Jakub Kicinski wrote:
Hi Jakub,
Thanks for the review.
Please see bellow my comments.
>
> On Fri, 18 Mar 2022 21:47:49 +0100 Horatiu Vultur wrote:
> > Ethernet frames can be extracted or injected to or from the device's
> > DDR memory. There is one channel for injection and one channel for
> > extraction. Each of these channels contain a linked list of DCBs which
> > contains DB. The DCB for injection contains only 1 DB and the DCB for
> > extraction contains 3 DBs. Each DB contains a frame. Everytime when a
> > frame is received or transmitted an interrupt is generated.
> >
> > It is not possible to use both the FDMA and the manual
> > injection/extraction of the frames. Therefore the FDMA has priority over
> > the manual because of better performance values.
>
>
> > +static struct sk_buff *lan966x_fdma_rx_alloc_skb(struct lan966x_rx *rx,
> > + struct lan966x_db *db)
> > +{
> > + struct lan966x *lan966x = rx->lan966x;
> > + struct sk_buff *skb;
> > + dma_addr_t dma_addr;
> > + struct page *page;
> > + void *buff_addr;
> > +
> > + page = dev_alloc_pages(rx->page_order);
> > + if (unlikely(!page))
> > + return NULL;
> > +
> > + dma_addr = dma_map_page(lan966x->dev, page, 0,
> > + PAGE_SIZE << rx->page_order,
> > + DMA_FROM_DEVICE);
> > + if (unlikely(dma_mapping_error(lan966x->dev, dma_addr))) {
> > + __free_pages(page, rx->page_order);
> > + return NULL;
> > + }
> > +
> > + buff_addr = page_address(page);
> > + skb = build_skb(buff_addr, PAGE_SIZE << rx->page_order);
> > +
>
> spurious new line
>
> > + if (unlikely(!skb)) {
> > + dev_err_ratelimited(lan966x->dev,
> > + "build_skb failed !\n");
>
> a statistic for that would be better than prints
> kernel will already do some printing if it goes oom
>
> > + dma_unmap_single(lan966x->dev, dma_addr,
> > + PAGE_SIZE << rx->page_order,
> > + DMA_FROM_DEVICE);
>
> why unmap_single if you used map_page for mapping?
That is a mistake. I will fix in the next version.
>
> > + __free_pages(page, rx->page_order);
> > + return NULL;
>
> please move the error handling to the end of the function and use goto
> to jump into the right spot
>
> > + }
> > +
> > + db->dataptr = dma_addr;
> > + return skb;
> > +}
>
> > +static int lan966x_fdma_rx_alloc(struct lan966x_rx *rx)
> > +{
> > + struct lan966x *lan966x = rx->lan966x;
> > + struct lan966x_rx_dcb *dcb;
> > + struct lan966x_db *db;
> > + struct sk_buff *skb;
> > + int i, j;
> > + int size;
> > +
> > + /* calculate how many pages are needed to allocate the dcbs */
> > + size = sizeof(struct lan966x_rx_dcb) * FDMA_DCB_MAX;
> > + size = ALIGN(size, PAGE_SIZE);
> > +
> > + rx->dcbs = dma_alloc_coherent(lan966x->dev, size, &rx->dma, GFP_ATOMIC);
>
> Why ATOMIC? This seems to be called from the probe path.
> Error checking missing.
The ATOMIC is a mistake for rx.
>
> > + rx->last_entry = rx->dcbs;
> > + rx->db_index = 0;
> > + rx->dcb_index = 0;
>
> > +static void lan966x_fdma_rx_start(struct lan966x_rx *rx)
> > +{
> > + struct lan966x *lan966x = rx->lan966x;
> > + u32 mask;
> > +
> > + /* When activating a channel, first is required to write the first DCB
> > + * address and then to activate it
> > + */
> > + lan_wr(((u64)rx->dma) & GENMASK(31, 0), lan966x,
>
> lower_32_bits()
>
> > + FDMA_DCB_LLP(rx->channel_id));
> > + lan_wr(((u64)rx->dma) >> 32, lan966x, FDMA_DCB_LLP1(rx->channel_id));
>
> upper_32_bits()
>
> > + lan_wr(FDMA_CH_CFG_CH_DCB_DB_CNT_SET(FDMA_RX_DCB_MAX_DBS) |
> > + FDMA_CH_CFG_CH_INTR_DB_EOF_ONLY_SET(1) |
> > + FDMA_CH_CFG_CH_INJ_PORT_SET(0) |
> > + FDMA_CH_CFG_CH_MEM_SET(1),
> > + lan966x, FDMA_CH_CFG(rx->channel_id));
>
> > +static int lan966x_fdma_tx_alloc(struct lan966x_tx *tx)
> > +{
> > + struct lan966x *lan966x = tx->lan966x;
> > + struct lan966x_tx_dcb *dcb;
> > + struct lan966x_db *db;
> > + int size;
> > + int i, j;
> > +
> > + tx->dcbs_buf = kcalloc(FDMA_DCB_MAX, sizeof(struct lan966x_tx_dcb_buf),
> > + GFP_ATOMIC);
> > + if (!tx->dcbs_buf)
> > + return -ENOMEM;
> > +
> > + /* calculate how many pages are needed to allocate the dcbs */
> > + size = sizeof(struct lan966x_tx_dcb) * FDMA_DCB_MAX;
> > + size = ALIGN(size, PAGE_SIZE);
> > + tx->dcbs = dma_alloc_coherent(lan966x->dev, size, &tx->dma, GFP_ATOMIC);
>
> same comments re: atomic and error checking as on rx
Here the ATOMIC is required because in patch 4, when changing the MTU,
we take a spin lock.
>
> > + /* Now for each dcb allocate the db */
> > + for (i = 0; i < FDMA_DCB_MAX; ++i) {
> > + dcb = &tx->dcbs[i];
> > +
> > + for (j = 0; j < FDMA_TX_DCB_MAX_DBS; ++j) {
> > + db = &dcb->db[j];
> > + db->dataptr = 0;
> > + db->status = 0;
> > + }
> > +
> > + lan966x_fdma_tx_add_dcb(tx, dcb);
> > + }
> > +
> > + return 0;
> > +}
>
> > +static struct sk_buff *lan966x_fdma_rx_get_frame(struct lan966x_rx *rx)
> > +{
> > + struct lan966x *lan966x = rx->lan966x;
> > + u64 src_port, timestamp;
> > + struct sk_buff *new_skb;
> > + struct lan966x_db *db;
> > + struct sk_buff *skb;
> > +
> > + /* Check if there is any data */
> > + db = &rx->dcbs[rx->dcb_index].db[rx->db_index];
> > + if (unlikely(!(db->status & FDMA_DCB_STATUS_DONE)))
> > + return NULL;
> > +
> > + /* Get the received frame and unmap it */
> > + skb = rx->skb[rx->dcb_index][rx->db_index];
> > + dma_unmap_single(lan966x->dev, (dma_addr_t)db->dataptr,
> > + FDMA_DCB_STATUS_BLOCKL(db->status),
> > + DMA_FROM_DEVICE);
> > +
> > + /* Allocate a new skb and map it */
> > + new_skb = lan966x_fdma_rx_alloc_skb(rx, db);
> > + if (unlikely(!new_skb))
> > + return NULL;
>
> So how is memory pressure handled, exactly? Looks like it's handled
> the same as if the ring was empty, so the IRQ is going to get re-raise
> immediately, or never raised again?
That is correct, the IRQ is going to get re-raised.
But I am not sure that this is correct approach. Do you have any
suggestions how it should be?
>
> > + rx->skb[rx->dcb_index][rx->db_index] = new_skb;
> > +
> > + skb_put(skb, FDMA_DCB_STATUS_BLOCKL(db->status));
> > +
> > + lan966x_ifh_get_src_port(skb->data, &src_port);
> > + lan966x_ifh_get_timestamp(skb->data, ×tamp);
> > +
> > + WARN_ON(src_port >= lan966x->num_phys_ports);
> > +
> > + skb->dev = lan966x->ports[src_port]->dev;
> > + skb_pull(skb, IFH_LEN * sizeof(u32));
> > +
> > + if (likely(!(skb->dev->features & NETIF_F_RXFCS)))
> > + skb_trim(skb, skb->len - ETH_FCS_LEN);
> > +
> > + lan966x_ptp_rxtstamp(lan966x, skb, timestamp);
> > + skb->protocol = eth_type_trans(skb, skb->dev);
> > +
> > + if (lan966x->bridge_mask & BIT(src_port)) {
> > + skb->offload_fwd_mark = 1;
> > +
> > + skb_reset_network_header(skb);
> > + if (!lan966x_hw_offload(lan966x, src_port, skb))
> > + skb->offload_fwd_mark = 0;
> > + }
> > +
> > + skb->dev->stats.rx_bytes += skb->len;
> > + skb->dev->stats.rx_packets++;
> > +
> > + return skb;
> > +}
> > +
> > +static int lan966x_fdma_napi_poll(struct napi_struct *napi, int weight)
> > +{
> > + struct lan966x *lan966x = container_of(napi, struct lan966x, napi);
> > + struct lan966x_rx *rx = &lan966x->rx;
> > + struct list_head rx_list;
> > + int counter = 0;
> > +
> > + lan966x_fdma_tx_clear_buf(lan966x, weight);
> > +
> > + INIT_LIST_HEAD(&rx_list);
> > +
> > + while (counter < weight) {
> > + struct lan966x_rx_dcb *old_dcb;
> > + struct sk_buff *skb;
> > + u64 nextptr;
> > +
> > + skb = lan966x_fdma_rx_get_frame(rx);
> > + if (!skb)
> > + break;
> > + list_add_tail(&skb->list, &rx_list);
> > +
> > + rx->db_index++;
> > + counter++;
> > +
> > + /* Check if the DCB can be reused */
> > + if (rx->db_index != FDMA_RX_DCB_MAX_DBS)
> > + continue;
> > +
> > + /* Now the DCB can be reused, just advance the dcb_index
> > + * pointer and set the nextptr in the DCB
> > + */
> > + rx->db_index = 0;
> > +
> > + old_dcb = &rx->dcbs[rx->dcb_index];
> > + rx->dcb_index++;
> > + rx->dcb_index &= FDMA_DCB_MAX - 1;
> > +
> > + nextptr = rx->dma + ((unsigned long)old_dcb -
> > + (unsigned long)rx->dcbs);
> > + lan966x_fdma_rx_add_dcb(rx, old_dcb, nextptr);
> > + lan966x_fdma_rx_reload(rx);
> > + }
> > +
> > + if (counter < weight) {
> > + napi_complete_done(napi, counter);
>
> You should check the return value of napi_complete_done().
> busy polling or something else may want the IRQ to stay
> disabled.
>
> > + lan_wr(0xff, lan966x, FDMA_INTR_DB_ENA);
> > + }
> > +
> > + netif_receive_skb_list(&rx_list);
>
> Why not GRO?
No reason, I have just looked at other drivers what they are doing.
I will update this.
>
> > + return counter;
> > +}
> > +
> > +irqreturn_t lan966x_fdma_irq_handler(int irq, void *args)
> > +{
> > + struct lan966x *lan966x = args;
> > + u32 db, err, err_type;
> > +
> > + db = lan_rd(lan966x, FDMA_INTR_DB);
> > + err = lan_rd(lan966x, FDMA_INTR_ERR);
>
> Hm, IIUC you request a threaded IRQ for this. Why?
> The register accesses can't sleep because you poke
> them from napi_poll as well...
Good point. What about the WARN?
>
> > + if (db) {
> > + lan_wr(0, lan966x, FDMA_INTR_DB_ENA);
> > + lan_wr(db, lan966x, FDMA_INTR_DB);
> > +
> > + napi_schedule(&lan966x->napi);
> > + }
> > +
> > + if (err) {
> > + err_type = lan_rd(lan966x, FDMA_ERRORS);
> > +
> > + WARN(1, "Unexpected error: %d, error_type: %d\n", err, err_type);
> > +
> > + lan_wr(err, lan966x, FDMA_INTR_ERR);
> > + lan_wr(err_type, lan966x, FDMA_ERRORS);
> > + }
> > +
> > + return IRQ_HANDLED;
> > +}
>
> > +int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev)
> > +{
> > + struct lan966x_port *port = netdev_priv(dev);
> > + struct lan966x *lan966x = port->lan966x;
> > + struct lan966x_tx_dcb_buf *next_dcb_buf;
> > + struct lan966x_tx_dcb *next_dcb, *dcb;
> > + struct lan966x_tx *tx = &lan966x->tx;
> > + struct lan966x_db *next_db;
> > + int needed_headroom;
> > + int needed_tailroom;
> > + dma_addr_t dma_addr;
> > + int next_to_use;
> > + int err;
> > +
> > + /* Get next index */
> > + next_to_use = lan966x_fdma_get_next_dcb(tx);
> > + if (next_to_use < 0) {
> > + netif_stop_queue(dev);
> > + err = NETDEV_TX_BUSY;
> > + goto out;
> > + }
> > +
> > + if (skb_put_padto(skb, ETH_ZLEN)) {
> > + dev->stats.tx_dropped++;
>
> It's preferred not to use the old dev->stats, but I guess you already
> do so :( This is under some locks, right? No chance for another queue
> or port to try to touch those stats at the same time?
What is the preffered way of doing it?
Yes, it is under a lock.
>
> > + err = NETDEV_TX_OK;
> > + goto out;
> > + }
> > +
> > + /* skb processing */
> > + needed_headroom = max_t(int, IFH_LEN * sizeof(u32) - skb_headroom(skb), 0);
> > + needed_tailroom = max_t(int, ETH_FCS_LEN - skb_tailroom(skb), 0);
> > + if (needed_headroom || needed_tailroom) {
> > + err = pskb_expand_head(skb, needed_headroom, needed_tailroom,
> > + GFP_ATOMIC);
> > + if (unlikely(err)) {
> > + dev->stats.tx_dropped++;
> > + err = NETDEV_TX_OK;
> > + goto release;
> > + }
> > + }
>
> You need to skb_cow_head() even if you don't need to grow the headroom
> or tailroom.
>
> > + skb_push(skb, IFH_LEN * sizeof(u32));
> > + memcpy(skb->data, ifh, IFH_LEN * sizeof(u32));
> > + skb_put(skb, 4);
> > +
> > + dma_addr = dma_map_single(lan966x->dev, skb->data, skb->len,
> > + DMA_TO_DEVICE);
> > + if (dma_mapping_error(lan966x->dev, dma_addr)) {
> > + dev->stats.tx_dropped++;
> > + err = NETDEV_TX_OK;
> > + goto release;
> > + }
> > +
> > + /* Setup next dcb */
> > + next_dcb = &tx->dcbs[next_to_use];
> > + next_dcb->nextptr = FDMA_DCB_INVALID_DATA;
> > +
> > + next_db = &next_dcb->db[0];
> > + next_db->dataptr = dma_addr;
> > + next_db->status = FDMA_DCB_STATUS_SOF |
> > + FDMA_DCB_STATUS_EOF |
> > + FDMA_DCB_STATUS_INTR |
> > + FDMA_DCB_STATUS_BLOCKO(0) |
> > + FDMA_DCB_STATUS_BLOCKL(skb->len);
> > +
> > + /* Fill up the buffer */
> > + next_dcb_buf = &tx->dcbs_buf[next_to_use];
> > + next_dcb_buf->skb = skb;
> > + next_dcb_buf->dma_addr = dma_addr;
> > + next_dcb_buf->used = true;
> > + next_dcb_buf->ptp = false;
> > +
> > + if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
> > + LAN966X_SKB_CB(skb)->rew_op == IFH_REW_OP_TWO_STEP_PTP)
> > + next_dcb_buf->ptp = true;
> > +
> > + skb_tx_timestamp(skb);
> > + if (likely(lan966x->tx.activated)) {
> > + /* Connect current dcb to the next db */
> > + dcb = &tx->dcbs[tx->last_in_use];
> > + dcb->nextptr = tx->dma + (next_to_use *
> > + sizeof(struct lan966x_tx_dcb));
> > +
> > + lan966x_fdma_tx_reload(tx);
> > + } else {
> > + /* Because it is first time, then just activate */
> > + lan966x->tx.activated = true;
> > + lan966x_fdma_tx_activate(tx);
> > + }
> > +
> > + /* Move to next dcb because this last in use */
> > + tx->last_in_use = next_to_use;
> > +
> > + dev->stats.tx_packets++;
> > + dev->stats.tx_bytes += skb->len;
>
> I think it's best practice to increase the stats when processing
> completions, you're not sure at this point whether the skb will
> actually get transmitted. Also normally skb could be freed by the
> IRQ handler as soon as its given to HW, but I think you have a lock
> so no risk of UAF on the skb->len access?
Yes, that is correct. I will update this in the IRQ handler.
>
> > + return NETDEV_TX_OK;
> > +
> > +out:
> > + return err;
> > +
> > +release:
> > + if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
> > + LAN966X_SKB_CB(skb)->rew_op == IFH_REW_OP_TWO_STEP_PTP)
> > + lan966x_ptp_txtstamp_release(port, skb);
> > +
> > + dev_kfree_skb_any(skb);
> > + return err;
>
> I think you're better off returning BUSY directly then you can forgo
> setting err and always return TX_OK.
>
> > +void lan966x_fdma_init(struct lan966x *lan966x)
> > +{
> > + lan966x->rx.lan966x = lan966x;
> > + lan966x->rx.channel_id = FDMA_XTR_CHANNEL;
> > + lan966x->tx.lan966x = lan966x;
> > + lan966x->tx.channel_id = FDMA_INJ_CHANNEL;
> > + lan966x->tx.last_in_use = -1;
> > +
> > + lan966x_fdma_rx_alloc(&lan966x->rx);
> > + lan966x_fdma_tx_alloc(&lan966x->tx);
> > +
> > + lan966x_fdma_rx_start(&lan966x->rx);
>
> Not checking for any errors here is highly suspicious
--
/Horatiu
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH net-next v2 3/4] net: lan966x: Add FDMA functionality
2022-03-22 21:04 ` Horatiu Vultur
@ 2022-03-22 22:25 ` Jakub Kicinski
2022-03-23 7:19 ` Horatiu Vultur
0 siblings, 1 reply; 10+ messages in thread
From: Jakub Kicinski @ 2022-03-22 22:25 UTC (permalink / raw)
To: Horatiu Vultur; +Cc: linux-kernel, netdev, davem, michael, UNGLinuxDriver
On Tue, 22 Mar 2022 22:04:02 +0100 Horatiu Vultur wrote:
> > > +static struct sk_buff *lan966x_fdma_rx_get_frame(struct lan966x_rx *rx)
> > > +{
> > > + struct lan966x *lan966x = rx->lan966x;
> > > + u64 src_port, timestamp;
> > > + struct sk_buff *new_skb;
> > > + struct lan966x_db *db;
> > > + struct sk_buff *skb;
> > > +
> > > + /* Check if there is any data */
> > > + db = &rx->dcbs[rx->dcb_index].db[rx->db_index];
> > > + if (unlikely(!(db->status & FDMA_DCB_STATUS_DONE)))
> > > + return NULL;
> > > +
> > > + /* Get the received frame and unmap it */
> > > + skb = rx->skb[rx->dcb_index][rx->db_index];
> > > + dma_unmap_single(lan966x->dev, (dma_addr_t)db->dataptr,
> > > + FDMA_DCB_STATUS_BLOCKL(db->status),
> > > + DMA_FROM_DEVICE);
> > > +
> > > + /* Allocate a new skb and map it */
> > > + new_skb = lan966x_fdma_rx_alloc_skb(rx, db);
> > > + if (unlikely(!new_skb))
> > > + return NULL;
> >
> > So how is memory pressure handled, exactly? Looks like it's handled
> > the same as if the ring was empty, so the IRQ is going to get re-raise
> > immediately, or never raised again?
>
> That is correct, the IRQ is going to get re-raised.
> But I am not sure that this is correct approach. Do you have any
> suggestions how it should be?
In my experience it's better to let the ring drain and have a service
task kick in some form of refill. Usually when machine is out of memory
last thing it needs is getting stormed by network IRQs. Some form of
back off would be good, at least?
> > > + return counter;
> > > +}
> > > +
> > > +irqreturn_t lan966x_fdma_irq_handler(int irq, void *args)
> > > +{
> > > + struct lan966x *lan966x = args;
> > > + u32 db, err, err_type;
> > > +
> > > + db = lan_rd(lan966x, FDMA_INTR_DB);
> > > + err = lan_rd(lan966x, FDMA_INTR_ERR);
> >
> > Hm, IIUC you request a threaded IRQ for this. Why?
> > The register accesses can't sleep because you poke
> > them from napi_poll as well...
>
> Good point. What about the WARN?
which one? Did something generate a warning without the threaded IRQ?
> > > +int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev)
> > > +{
> > > + struct lan966x_port *port = netdev_priv(dev);
> > > + struct lan966x *lan966x = port->lan966x;
> > > + struct lan966x_tx_dcb_buf *next_dcb_buf;
> > > + struct lan966x_tx_dcb *next_dcb, *dcb;
> > > + struct lan966x_tx *tx = &lan966x->tx;
> > > + struct lan966x_db *next_db;
> > > + int needed_headroom;
> > > + int needed_tailroom;
> > > + dma_addr_t dma_addr;
> > > + int next_to_use;
> > > + int err;
> > > +
> > > + /* Get next index */
> > > + next_to_use = lan966x_fdma_get_next_dcb(tx);
> > > + if (next_to_use < 0) {
> > > + netif_stop_queue(dev);
> > > + err = NETDEV_TX_BUSY;
> > > + goto out;
> > > + }
> > > +
> > > + if (skb_put_padto(skb, ETH_ZLEN)) {
> > > + dev->stats.tx_dropped++;
> >
> > It's preferred not to use the old dev->stats, but I guess you already
> > do so :( This is under some locks, right? No chance for another queue
> > or port to try to touch those stats at the same time?
>
> What is the preffered way of doing it?
> Yes, it is under a lock.
Drivers can put counters they need in their own structures and then
implement ndo_get_stats64 to copy it to the expected format.
If you have locks and there's no risk of races - I guess it's fine.
Unlikely we'll ever convert all the drivers, anyway.
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH net-next v2 3/4] net: lan966x: Add FDMA functionality
2022-03-22 22:25 ` Jakub Kicinski
@ 2022-03-23 7:19 ` Horatiu Vultur
0 siblings, 0 replies; 10+ messages in thread
From: Horatiu Vultur @ 2022-03-23 7:19 UTC (permalink / raw)
To: Jakub Kicinski; +Cc: linux-kernel, netdev, davem, michael, UNGLinuxDriver
The 03/22/2022 15:25, Jakub Kicinski wrote:
> On Tue, 22 Mar 2022 22:04:02 +0100 Horatiu Vultur wrote:
> > > > +static struct sk_buff *lan966x_fdma_rx_get_frame(struct lan966x_rx *rx)
> > > > +{
> > > > + struct lan966x *lan966x = rx->lan966x;
> > > > + u64 src_port, timestamp;
> > > > + struct sk_buff *new_skb;
> > > > + struct lan966x_db *db;
> > > > + struct sk_buff *skb;
> > > > +
> > > > + /* Check if there is any data */
> > > > + db = &rx->dcbs[rx->dcb_index].db[rx->db_index];
> > > > + if (unlikely(!(db->status & FDMA_DCB_STATUS_DONE)))
> > > > + return NULL;
> > > > +
> > > > + /* Get the received frame and unmap it */
> > > > + skb = rx->skb[rx->dcb_index][rx->db_index];
> > > > + dma_unmap_single(lan966x->dev, (dma_addr_t)db->dataptr,
> > > > + FDMA_DCB_STATUS_BLOCKL(db->status),
> > > > + DMA_FROM_DEVICE);
> > > > +
> > > > + /* Allocate a new skb and map it */
> > > > + new_skb = lan966x_fdma_rx_alloc_skb(rx, db);
> > > > + if (unlikely(!new_skb))
> > > > + return NULL;
> > >
> > > So how is memory pressure handled, exactly? Looks like it's handled
> > > the same as if the ring was empty, so the IRQ is going to get re-raise
> > > immediately, or never raised again?
> >
> > That is correct, the IRQ is going to get re-raised.
> > But I am not sure that this is correct approach. Do you have any
> > suggestions how it should be?
>
> In my experience it's better to let the ring drain and have a service
> task kick in some form of refill. Usually when machine is out of memory
> last thing it needs is getting stormed by network IRQs. Some form of
> back off would be good, at least?
OK. I will try to implement something like this in the next version.
>
> > > > + return counter;
> > > > +}
> > > > +
> > > > +irqreturn_t lan966x_fdma_irq_handler(int irq, void *args)
> > > > +{
> > > > + struct lan966x *lan966x = args;
> > > > + u32 db, err, err_type;
> > > > +
> > > > + db = lan_rd(lan966x, FDMA_INTR_DB);
> > > > + err = lan_rd(lan966x, FDMA_INTR_ERR);
> > >
> > > Hm, IIUC you request a threaded IRQ for this. Why?
> > > The register accesses can't sleep because you poke
> > > them from napi_poll as well...
> >
> > Good point. What about the WARN?
>
> which one? Did something generate a warning without the threaded IRQ?
Ah.. no. I was talking about the WARN in case err is set.
---
if (err) {
err_type = lan_rd(lan966x, FDMA_ERRORS);
WARN(1, "Unexpected error: %d, error_type: %d\n", err, err_type);
...
}
---
But that is fine. So I will change to non threaded irq.
>
> > > > +int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev)
> > > > +{
> > > > + struct lan966x_port *port = netdev_priv(dev);
> > > > + struct lan966x *lan966x = port->lan966x;
> > > > + struct lan966x_tx_dcb_buf *next_dcb_buf;
> > > > + struct lan966x_tx_dcb *next_dcb, *dcb;
> > > > + struct lan966x_tx *tx = &lan966x->tx;
> > > > + struct lan966x_db *next_db;
> > > > + int needed_headroom;
> > > > + int needed_tailroom;
> > > > + dma_addr_t dma_addr;
> > > > + int next_to_use;
> > > > + int err;
> > > > +
> > > > + /* Get next index */
> > > > + next_to_use = lan966x_fdma_get_next_dcb(tx);
> > > > + if (next_to_use < 0) {
> > > > + netif_stop_queue(dev);
> > > > + err = NETDEV_TX_BUSY;
> > > > + goto out;
> > > > + }
> > > > +
> > > > + if (skb_put_padto(skb, ETH_ZLEN)) {
> > > > + dev->stats.tx_dropped++;
> > >
> > > It's preferred not to use the old dev->stats, but I guess you already
> > > do so :( This is under some locks, right? No chance for another queue
> > > or port to try to touch those stats at the same time?
> >
> > What is the preffered way of doing it?
> > Yes, it is under a lock.
>
> Drivers can put counters they need in their own structures and then
> implement ndo_get_stats64 to copy it to the expected format.
> If you have locks and there's no risk of races - I guess it's fine.
> Unlikely we'll ever convert all the drivers, anyway.
OK, now I see.
I can create a different patch for this because then I should update the
statistics when injecting frames the other way(when writing each
word of the frame to HW).
--
/Horatiu
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2022-03-23 7:17 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-03-18 20:47 [PATCH net-next v2 0/4] net: lan966x: Add support for FDMA Horatiu Vultur
2022-03-18 20:47 ` [PATCH net-next v2 1/4] net: lan966x: Add registers that are used " Horatiu Vultur
2022-03-18 20:47 ` [PATCH net-next v2 2/4] net: lan966x: Expose functions that are needed by FDMA Horatiu Vultur
2022-03-18 20:47 ` [PATCH net-next v2 3/4] net: lan966x: Add FDMA functionality Horatiu Vultur
2022-03-22 6:01 ` Jakub Kicinski
2022-03-22 21:04 ` Horatiu Vultur
2022-03-22 22:25 ` Jakub Kicinski
2022-03-23 7:19 ` Horatiu Vultur
2022-03-18 20:47 ` [PATCH net-next v2 4/4] net: lan966x: Update FDMA to change MTU Horatiu Vultur
2022-03-18 20:55 ` [PATCH net-next v2 0/4] net: lan966x: Add support for FDMA Michael Walle
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