Commit 0bc7d1d4 authored by Ping-Ke Shih's avatar Ping-Ke Shih Committed by Kalle Valo
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wifi: rtw89: pci: validate RX tag for RXQ and RPQ 



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: default avatarPing-Ke Shih <pkshih@realtek.com>
Signed-off-by: default avatarKalle Valo <kvalo@kernel.org>
Link: https://msgid.link/20240121071826.10159-4-pkshih@realtek.com
parent 26cdaee4

drivers/net/wireless/realtek/rtw89/pci.c

+54 −6
Original line number Diff line number Diff line
@@ -155,7 +155,7 @@ 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,

static void rtw89_pci_rxbd_info_update(struct rtw89_dev *rtwdev,

				       struct sk_buff *skb)

{

	struct rtw89_pci_rxbd_info *rxbd_info;
@@ -166,8 +166,56 @@ 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)
@@ -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);
@@ -3213,6 +3260,7 @@ 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);

drivers/net/wireless/realtek/rtw89/pci.h

+3 −1
Original line number Diff line number Diff line
@@ -1235,6 +1235,7 @@ 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;
@@ -1277,7 +1278,7 @@ 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)
@@ -1406,6 +1407,7 @@ 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 {

drivers/net/wireless/realtek/rtw89/rtw8851be.c

+2 −0
Original line number Diff line number Diff line
@@ -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,

drivers/net/wireless/realtek/rtw89/rtw8852ae.c

+1 −0
Original line number Diff line number Diff line
@@ -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,

drivers/net/wireless/realtek/rtw89/rtw8852be.c

+1 −0
Original line number Diff line number Diff line
@@ -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,