[PATCH AUTOSEL 6.8 09/68] wifi: rtw89: pci: validate RX tag for RXQ and RPQ

From: Sasha Levin
Date: Fri Mar 29 2024 - 08:30:07 EST

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From: Ping-Ke Shih <pkshih@xxxxxxxxxxx>

[ Upstream commit 0bc7d1d4e63cf31ff1b4396b0e2f0e3c76828d26 ]

PCI RX ring is a kind of read/write index ring, and DMA and ring index are
asynchronous, so suddenly driver gets newer index ahead before DMA. To
resolve this rare situation, we use a RX tag as helpers to make sure DMA
is done.

The RX tag is a 13-bit value, and range is from 1 ~ 0x1FFF, but 0 isn't
used so should be skipped.

Only enable this validation to coming WiFi 7 chips, because existing
chips use different design and don't really meet this situation.

Add missed rx_ring_eq_is_full for 8851BE by the way.

Signed-off-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxx>
Link: https://msgid.link/20240121071826.10159-4-pkshih@xxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/wireless/realtek/rtw89/pci.c | 60 +++++++++++++++++--
drivers/net/wireless/realtek/rtw89/pci.h | 4 +-
.../net/wireless/realtek/rtw89/rtw8851be.c | 2 +
.../net/wireless/realtek/rtw89/rtw8852ae.c | 1 +
.../net/wireless/realtek/rtw89/rtw8852be.c | 1 +
.../net/wireless/realtek/rtw89/rtw8852ce.c | 1 +
.../net/wireless/realtek/rtw89/rtw8922ae.c | 1 +
7 files changed, 63 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtw89/pci.c b/drivers/net/wireless/realtek/rtw89/pci.c
index 769f1ce62ebcc..cb03474f81552 100644
--- a/drivers/net/wireless/realtek/rtw89/pci.c
+++ b/drivers/net/wireless/realtek/rtw89/pci.c
@@ -155,8 +155,8 @@ static void rtw89_pci_sync_skb_for_device(struct rtw89_dev *rtwdev,
DMA_FROM_DEVICE);
}

-static int rtw89_pci_rxbd_info_update(struct rtw89_dev *rtwdev,
- struct sk_buff *skb)
+static void rtw89_pci_rxbd_info_update(struct rtw89_dev *rtwdev,
+ struct sk_buff *skb)
{
struct rtw89_pci_rxbd_info *rxbd_info;
struct rtw89_pci_rx_info *rx_info = RTW89_PCI_RX_SKB_CB(skb);
@@ -166,10 +166,58 @@ static int rtw89_pci_rxbd_info_update(struct rtw89_dev *rtwdev,
rx_info->ls = le32_get_bits(rxbd_info->dword, RTW89_PCI_RXBD_LS);
rx_info->len = le32_get_bits(rxbd_info->dword, RTW89_PCI_RXBD_WRITE_SIZE);
rx_info->tag = le32_get_bits(rxbd_info->dword, RTW89_PCI_RXBD_TAG);
+}
+
+static int rtw89_pci_validate_rx_tag(struct rtw89_dev *rtwdev,
+ struct rtw89_pci_rx_ring *rx_ring,
+ struct sk_buff *skb)
+{
+ struct rtw89_pci_rx_info *rx_info = RTW89_PCI_RX_SKB_CB(skb);
+ const struct rtw89_pci_info *info = rtwdev->pci_info;
+ u32 target_rx_tag;
+
+ if (!info->check_rx_tag)
+ return 0;
+
+ /* valid range is 1 ~ 0x1FFF */
+ if (rx_ring->target_rx_tag == 0)
+ target_rx_tag = 1;
+ else
+ target_rx_tag = rx_ring->target_rx_tag;
+
+ if (rx_info->tag != target_rx_tag) {
+ rtw89_debug(rtwdev, RTW89_DBG_UNEXP, "mismatch RX tag 0x%x 0x%x\n",
+ rx_info->tag, target_rx_tag);
+ return -EAGAIN;
+ }

return 0;
}

+static
+int rtw89_pci_sync_skb_for_device_and_validate_rx_info(struct rtw89_dev *rtwdev,
+ struct rtw89_pci_rx_ring *rx_ring,
+ struct sk_buff *skb)
+{
+ struct rtw89_pci_rx_info *rx_info = RTW89_PCI_RX_SKB_CB(skb);
+ int rx_tag_retry = 100;
+ int ret;
+
+ do {
+ rtw89_pci_sync_skb_for_cpu(rtwdev, skb);
+ rtw89_pci_rxbd_info_update(rtwdev, skb);
+
+ ret = rtw89_pci_validate_rx_tag(rtwdev, rx_ring, skb);
+ if (ret != -EAGAIN)
+ break;
+ } while (rx_tag_retry--);
+
+ /* update target rx_tag for next RX */
+ rx_ring->target_rx_tag = rx_info->tag + 1;
+
+ return ret;
+}
+
static void rtw89_pci_ctrl_txdma_ch_pcie(struct rtw89_dev *rtwdev, bool enable)
{
const struct rtw89_pci_info *info = rtwdev->pci_info;
@@ -259,9 +307,8 @@ static u32 rtw89_pci_rxbd_deliver_skbs(struct rtw89_dev *rtwdev,

skb_idx = rtw89_pci_get_rx_skb_idx(rtwdev, bd_ring);
skb = rx_ring->buf[skb_idx];
- rtw89_pci_sync_skb_for_cpu(rtwdev, skb);

- ret = rtw89_pci_rxbd_info_update(rtwdev, skb);
+ ret = rtw89_pci_sync_skb_for_device_and_validate_rx_info(rtwdev, rx_ring, skb);
if (ret) {
rtw89_err(rtwdev, "failed to update %d RXBD info: %d\n",
bd_ring->wp, ret);
@@ -549,9 +596,8 @@ static u32 rtw89_pci_release_tx_skbs(struct rtw89_dev *rtwdev,

skb_idx = rtw89_pci_get_rx_skb_idx(rtwdev, bd_ring);
skb = rx_ring->buf[skb_idx];
- rtw89_pci_sync_skb_for_cpu(rtwdev, skb);

- ret = rtw89_pci_rxbd_info_update(rtwdev, skb);
+ ret = rtw89_pci_sync_skb_for_device_and_validate_rx_info(rtwdev, rx_ring, skb);
if (ret) {
rtw89_err(rtwdev, "failed to update %d RXBD info: %d\n",
bd_ring->wp, ret);
@@ -1550,6 +1596,7 @@ static void rtw89_pci_reset_trx_rings(struct rtw89_dev *rtwdev)
bd_ring->rp = 0;
rx_ring->diliver_skb = NULL;
rx_ring->diliver_desc.ready = false;
+ rx_ring->target_rx_tag = 0;

rtw89_write16(rtwdev, addr_num, bd_ring->len);
rtw89_write32(rtwdev, addr_desa_l, bd_ring->dma);
@@ -3148,6 +3195,7 @@ static int rtw89_pci_alloc_rx_ring(struct rtw89_dev *rtwdev,
rx_ring->buf_sz = buf_sz;
rx_ring->diliver_skb = NULL;
rx_ring->diliver_desc.ready = false;
+ rx_ring->target_rx_tag = 0;

for (i = 0; i < len; i++) {
skb = dev_alloc_skb(buf_sz);
diff --git a/drivers/net/wireless/realtek/rtw89/pci.h b/drivers/net/wireless/realtek/rtw89/pci.h
index ca5de77fee90a..83a36358504f4 100644
--- a/drivers/net/wireless/realtek/rtw89/pci.h
+++ b/drivers/net/wireless/realtek/rtw89/pci.h
@@ -1234,6 +1234,7 @@ struct rtw89_pci_info {
enum mac_ax_pcie_func_ctrl io_rcy_en;
enum mac_ax_io_rcy_tmr io_rcy_tmr;
bool rx_ring_eq_is_full;
+ bool check_rx_tag;

u32 init_cfg_reg;
u32 txhci_en_bit;
@@ -1276,7 +1277,7 @@ struct rtw89_pci_tx_data {

struct rtw89_pci_rx_info {
dma_addr_t dma;
- u32 fs:1, ls:1, tag:11, len:14;
+ u32 fs:1, ls:1, tag:13, len:14;
};

#define RTW89_PCI_TXBD_OPTION_LS BIT(14)
@@ -1405,6 +1406,7 @@ struct rtw89_pci_rx_ring {
u32 buf_sz;
struct sk_buff *diliver_skb;
struct rtw89_rx_desc_info diliver_desc;
+ u32 target_rx_tag:13;
};

struct rtw89_pci_isrs {
diff --git a/drivers/net/wireless/realtek/rtw89/rtw8851be.c b/drivers/net/wireless/realtek/rtw89/rtw8851be.c
index ade69bd30fc86..ca1374a717272 100644
--- a/drivers/net/wireless/realtek/rtw89/rtw8851be.c
+++ b/drivers/net/wireless/realtek/rtw89/rtw8851be.c
@@ -25,6 +25,8 @@ static const struct rtw89_pci_info rtw8851b_pci_info = {
.autok_en = MAC_AX_PCIE_DISABLE,
.io_rcy_en = MAC_AX_PCIE_DISABLE,
.io_rcy_tmr = MAC_AX_IO_RCY_ANA_TMR_6MS,
+ .rx_ring_eq_is_full = false,
+ .check_rx_tag = false,

.init_cfg_reg = R_AX_PCIE_INIT_CFG1,
.txhci_en_bit = B_AX_TXHCI_EN,
diff --git a/drivers/net/wireless/realtek/rtw89/rtw8852ae.c b/drivers/net/wireless/realtek/rtw89/rtw8852ae.c
index f1e890bde0499..7c6ffedb77e27 100644
--- a/drivers/net/wireless/realtek/rtw89/rtw8852ae.c
+++ b/drivers/net/wireless/realtek/rtw89/rtw8852ae.c
@@ -26,6 +26,7 @@ static const struct rtw89_pci_info rtw8852a_pci_info = {
.io_rcy_en = MAC_AX_PCIE_DISABLE,
.io_rcy_tmr = MAC_AX_IO_RCY_ANA_TMR_6MS,
.rx_ring_eq_is_full = false,
+ .check_rx_tag = false,

.init_cfg_reg = R_AX_PCIE_INIT_CFG1,
.txhci_en_bit = B_AX_TXHCI_EN,
diff --git a/drivers/net/wireless/realtek/rtw89/rtw8852be.c b/drivers/net/wireless/realtek/rtw89/rtw8852be.c
index 920b20bbcfb73..ed71364e6437b 100644
--- a/drivers/net/wireless/realtek/rtw89/rtw8852be.c
+++ b/drivers/net/wireless/realtek/rtw89/rtw8852be.c
@@ -26,6 +26,7 @@ static const struct rtw89_pci_info rtw8852b_pci_info = {
.io_rcy_en = MAC_AX_PCIE_DISABLE,
.io_rcy_tmr = MAC_AX_IO_RCY_ANA_TMR_6MS,
.rx_ring_eq_is_full = false,
+ .check_rx_tag = false,

.init_cfg_reg = R_AX_PCIE_INIT_CFG1,
.txhci_en_bit = B_AX_TXHCI_EN,
diff --git a/drivers/net/wireless/realtek/rtw89/rtw8852ce.c b/drivers/net/wireless/realtek/rtw89/rtw8852ce.c
index 4592de3dbd942..583ea673a4f54 100644
--- a/drivers/net/wireless/realtek/rtw89/rtw8852ce.c
+++ b/drivers/net/wireless/realtek/rtw89/rtw8852ce.c
@@ -35,6 +35,7 @@ static const struct rtw89_pci_info rtw8852c_pci_info = {
.io_rcy_en = MAC_AX_PCIE_ENABLE,
.io_rcy_tmr = MAC_AX_IO_RCY_ANA_TMR_6MS,
.rx_ring_eq_is_full = false,
+ .check_rx_tag = false,

.init_cfg_reg = R_AX_HAXI_INIT_CFG1,
.txhci_en_bit = B_AX_TXHCI_EN_V1,
diff --git a/drivers/net/wireless/realtek/rtw89/rtw8922ae.c b/drivers/net/wireless/realtek/rtw89/rtw8922ae.c
index 7b3d98d2c402c..9f46fb1661055 100644
--- a/drivers/net/wireless/realtek/rtw89/rtw8922ae.c
+++ b/drivers/net/wireless/realtek/rtw89/rtw8922ae.c
@@ -26,6 +26,7 @@ static const struct rtw89_pci_info rtw8922a_pci_info = {
.io_rcy_en = MAC_AX_PCIE_ENABLE,
.io_rcy_tmr = MAC_AX_IO_RCY_ANA_TMR_DEF,
.rx_ring_eq_is_full = true,
+ .check_rx_tag = true,

.init_cfg_reg = R_BE_HAXI_INIT_CFG1,
.txhci_en_bit = B_BE_TXDMA_EN,
--
2.43.0

Next message: Sasha Levin: "[PATCH AUTOSEL 6.8 10/68] wifi: rtw89: pci: enlarge RX DMA buffer to consider size of RX descriptor"
Previous message: Sasha Levin: "[PATCH AUTOSEL 6.8 08/68] net: phy: phy_device: Prevent nullptr exceptions on ISR"
In reply to: Sasha Levin: "[PATCH AUTOSEL 6.8 08/68] net: phy: phy_device: Prevent nullptr exceptions on ISR"
Next in thread: Sasha Levin: "[PATCH AUTOSEL 6.8 10/68] wifi: rtw89: pci: enlarge RX DMA buffer to consider size of RX descriptor"
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