[PATCH v6] sun4i-emac.c: add dma support

conleylee@foxmail.com posted 1 patch 4 years, 6 months ago
drivers/net/ethernet/allwinner/sun4i-emac.c | 200 ++++++++++++++++++++
1 file changed, 200 insertions(+)
[PATCH v6] sun4i-emac.c: add dma support
Posted by conleylee@foxmail.com 4 years, 6 months ago
From: Conley Lee <conleylee@foxmail.com>

Thanks for your review. Here is the new version for this patch.

This patch adds support for the emac rx dma present on sun4i. The emac
is able to move packets from rx fifo to RAM by using dma.

Change since v4.
  - rename sbk field to skb
  - rename alloc_emac_dma_req to emac_alloc_dma_req
  - using kzalloc(..., GPF_ATOMIC) in interrupt context to avoid
    sleeping
  - retry by using emac_inblk_32bit when emac_dma_inblk_32bit fails
  - fix some code style issues 

Change since v5.
  - fix some code style issue

Signed-off-by: Conley Lee <conleylee@foxmail.com>
---
 drivers/net/ethernet/allwinner/sun4i-emac.c | 200 ++++++++++++++++++++
 1 file changed, 200 insertions(+)

diff --git a/drivers/net/ethernet/allwinner/sun4i-emac.c b/drivers/net/ethernet/allwinner/sun4i-emac.c
index cccf8a3ead5e..964227e342ee 100644
--- a/drivers/net/ethernet/allwinner/sun4i-emac.c
+++ b/drivers/net/ethernet/allwinner/sun4i-emac.c
@@ -29,6 +29,7 @@
 #include <linux/platform_device.h>
 #include <linux/phy.h>
 #include <linux/soc/sunxi/sunxi_sram.h>
+#include <linux/dmaengine.h>
 
 #include "sun4i-emac.h"
 
@@ -86,6 +87,16 @@ struct emac_board_info {
 	unsigned int		duplex;
 
 	phy_interface_t		phy_interface;
+	struct dma_chan	*rx_chan;
+	phys_addr_t emac_rx_fifo;
+};
+
+struct emac_dma_req {
+	struct emac_board_info *db;
+	struct dma_async_tx_descriptor *desc;
+	struct sk_buff *skb;
+	dma_addr_t rxbuf;
+	int count;
 };
 
 static void emac_update_speed(struct net_device *dev)
@@ -205,6 +216,117 @@ static void emac_inblk_32bit(void __iomem *reg, void *data, int count)
 	readsl(reg, data, round_up(count, 4) / 4);
 }
 
+static struct emac_dma_req *
+emac_alloc_dma_req(struct emac_board_info *db,
+		   struct dma_async_tx_descriptor *desc, struct sk_buff *skb,
+		   dma_addr_t rxbuf, int count)
+{
+	struct emac_dma_req *req;
+
+	req = kzalloc(sizeof(struct emac_dma_req), GFP_ATOMIC);
+	if (!req)
+		return NULL;
+
+	req->db = db;
+	req->desc = desc;
+	req->skb = skb;
+	req->rxbuf = rxbuf;
+	req->count = count;
+	return req;
+}
+
+static void emac_free_dma_req(struct emac_dma_req *req)
+{
+	kfree(req);
+}
+
+static void emac_dma_done_callback(void *arg)
+{
+	struct emac_dma_req *req = arg;
+	struct emac_board_info *db = req->db;
+	struct sk_buff *skb = req->skb;
+	struct net_device *dev = db->ndev;
+	int rxlen = req->count;
+	u32 reg_val;
+
+	dma_unmap_single(db->dev, req->rxbuf, rxlen, DMA_FROM_DEVICE);
+
+	skb->protocol = eth_type_trans(skb, dev);
+	netif_rx(skb);
+	dev->stats.rx_bytes += rxlen;
+	/* Pass to upper layer */
+	dev->stats.rx_packets++;
+
+	/* re enable cpu receive */
+	reg_val = readl(db->membase + EMAC_RX_CTL_REG);
+	reg_val &= ~EMAC_RX_CTL_DMA_EN;
+	writel(reg_val, db->membase + EMAC_RX_CTL_REG);
+
+	/* re enable interrupt */
+	reg_val = readl(db->membase + EMAC_INT_CTL_REG);
+	reg_val |= (0x01 << 8);
+	writel(reg_val, db->membase + EMAC_INT_CTL_REG);
+
+	db->emacrx_completed_flag = 1;
+	emac_free_dma_req(req);
+}
+
+static int emac_dma_inblk_32bit(struct emac_board_info *db,
+		struct sk_buff *skb, void *rdptr, int count)
+{
+	struct dma_async_tx_descriptor *desc;
+	dma_cookie_t cookie;
+	dma_addr_t rxbuf;
+	struct emac_dma_req *req;
+	int ret = 0;
+
+	rxbuf = dma_map_single(db->dev, rdptr, count, DMA_FROM_DEVICE);
+	ret = dma_mapping_error(db->dev, rxbuf);
+	if (ret) {
+		dev_err(db->dev, "dma mapping error.\n");
+		return ret;
+	}
+
+	desc = dmaengine_prep_slave_single(db->rx_chan, rxbuf, count,
+					   DMA_DEV_TO_MEM,
+					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc) {
+		dev_err(db->dev, "prepare slave single failed\n");
+		ret = -ENOMEM;
+		goto prepare_err;
+	}
+
+	req = emac_alloc_dma_req(db, desc, skb, rxbuf, count);
+	if (!req) {
+		dev_err(db->dev, "alloc emac dma req error.\n");
+		ret = -ENOMEM;
+		goto alloc_req_err;
+	}
+
+	desc->callback_param = req;
+	desc->callback = emac_dma_done_callback;
+
+	cookie = dmaengine_submit(desc);
+	ret = dma_submit_error(cookie);
+	if (ret) {
+		dev_err(db->dev, "dma submit error.\n");
+		goto submit_err;
+	}
+
+	dma_async_issue_pending(db->rx_chan);
+	return ret;
+
+submit_err:
+	emac_free_dma_req(req);
+
+alloc_req_err:
+	dmaengine_desc_free(desc);
+
+prepare_err:
+	dma_unmap_single(db->dev, rxbuf, count, DMA_FROM_DEVICE);
+	return ret;
+}
+
 /* ethtool ops */
 static void emac_get_drvinfo(struct net_device *dev,
 			      struct ethtool_drvinfo *info)
@@ -605,6 +727,19 @@ static void emac_rx(struct net_device *dev)
 			if (netif_msg_rx_status(db))
 				dev_dbg(db->dev, "RxLen %x\n", rxlen);
 
+			if (rxlen >= dev->mtu && db->rx_chan) {
+				reg_val = readl(db->membase + EMAC_RX_CTL_REG);
+				reg_val |= EMAC_RX_CTL_DMA_EN;
+				writel(reg_val, db->membase + EMAC_RX_CTL_REG);
+				if (!emac_dma_inblk_32bit(db, skb, rdptr, rxlen))
+					break;
+
+				/* re enable cpu receive. then try to receive by emac_inblk_32bit */
+				reg_val = readl(db->membase + EMAC_RX_CTL_REG);
+				reg_val &= ~EMAC_RX_CTL_DMA_EN;
+				writel(reg_val, db->membase + EMAC_RX_CTL_REG);
+			}
+
 			emac_inblk_32bit(db->membase + EMAC_RX_IO_DATA_REG,
 					rdptr, rxlen);
 			dev->stats.rx_bytes += rxlen;
@@ -659,7 +794,12 @@ static irqreturn_t emac_interrupt(int irq, void *dev_id)
 		reg_val = readl(db->membase + EMAC_INT_CTL_REG);
 		reg_val |= (0xf << 0) | (0x01 << 8);
 		writel(reg_val, db->membase + EMAC_INT_CTL_REG);
+	} else {
+		reg_val = readl(db->membase + EMAC_INT_CTL_REG);
+		reg_val |= (0xf << 0);
+		writel(reg_val, db->membase + EMAC_INT_CTL_REG);
 	}
+
 	spin_unlock(&db->lock);
 
 	return IRQ_HANDLED;
@@ -764,6 +904,58 @@ static const struct net_device_ops emac_netdev_ops = {
 #endif
 };
 
+static int emac_configure_dma(struct emac_board_info *db)
+{
+	struct platform_device *pdev = db->pdev;
+	struct net_device *ndev = db->ndev;
+	struct dma_slave_config conf = {};
+	struct resource *regs;
+	int err = 0;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs) {
+		netdev_err(ndev, "get io resource from device failed.\n");
+		err = -ENOMEM;
+		goto out_clear_chan;
+	}
+
+	netdev_info(ndev, "get io resource from device: 0x%x, size = %u\n",
+		    regs->start, resource_size(regs));
+	db->emac_rx_fifo = regs->start + EMAC_RX_IO_DATA_REG;
+
+	db->rx_chan = dma_request_chan(&pdev->dev, "rx");
+	if (IS_ERR(db->rx_chan)) {
+		netdev_err(ndev,
+			   "failed to request dma channel. dma is disabled\n");
+		err = PTR_ERR(db->rx_chan);
+		goto out_clear_chan;
+	}
+
+	conf.direction = DMA_DEV_TO_MEM;
+	conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	conf.src_addr = db->emac_rx_fifo;
+	conf.dst_maxburst = 4;
+	conf.src_maxburst = 4;
+	conf.device_fc = false;
+
+	err = dmaengine_slave_config(db->rx_chan, &conf);
+	if (err) {
+		netdev_err(ndev, "config dma slave failed\n");
+		err = -EINVAL;
+		goto out_slave_configure_err;
+	}
+
+	return err;
+
+out_slave_configure_err:
+	dma_release_channel(db->rx_chan);
+
+out_clear_chan:
+	db->rx_chan = NULL;
+	return err;
+}
+
 /* Search EMAC board, allocate space and register it
  */
 static int emac_probe(struct platform_device *pdev)
@@ -806,6 +998,9 @@ static int emac_probe(struct platform_device *pdev)
 		goto out_iounmap;
 	}
 
+	if (emac_configure_dma(db))
+		netdev_info(ndev, "configure dma failed. disable dma.\n");
+
 	db->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(db->clk)) {
 		ret = PTR_ERR(db->clk);
@@ -888,6 +1083,11 @@ static int emac_remove(struct platform_device *pdev)
 	struct net_device *ndev = platform_get_drvdata(pdev);
 	struct emac_board_info *db = netdev_priv(ndev);
 
+	if (db->rx_chan) {
+		dmaengine_terminate_all(db->rx_chan);
+		dma_release_channel(db->rx_chan);
+	}
+
 	unregister_netdev(ndev);
 	sunxi_sram_release(&pdev->dev);
 	clk_disable_unprepare(db->clk);
-- 
2.31.1

Re: [PATCH v6] sun4i-emac.c: add dma support
Posted by patchwork-bot+netdevbpf@kernel.org 4 years, 6 months ago
Hello:

This patch was applied to netdev/net-next.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Wed, 29 Dec 2021 09:43:51 +0800 you wrote:
> From: Conley Lee <conleylee@foxmail.com>
> 
> Thanks for your review. Here is the new version for this patch.
> 
> This patch adds support for the emac rx dma present on sun4i. The emac
> is able to move packets from rx fifo to RAM by using dma.
> 
> [...]

Here is the summary with links:
  - [v6] sun4i-emac.c: add dma support
    https://git.kernel.org/netdev/net-next/c/47869e82c8b8

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html


Re: [PATCH v6] sun4i-emac.c: add dma support
Posted by Corentin Labbe 4 years, 1 month ago
Le Thu, Dec 30, 2021 at 02:00:11AM +0000, patchwork-bot+netdevbpf@kernel.org a écrit :
> Hello:
> 
> This patch was applied to netdev/net-next.git (master)
> by Jakub Kicinski <kuba@kernel.org>:
> 
> On Wed, 29 Dec 2021 09:43:51 +0800 you wrote:
> > From: Conley Lee <conleylee@foxmail.com>
> > 
> > Thanks for your review. Here is the new version for this patch.
> > 
> > This patch adds support for the emac rx dma present on sun4i. The emac
> > is able to move packets from rx fifo to RAM by using dma.
> > 
> > [...]
> 
> Here is the summary with links:
>   - [v6] sun4i-emac.c: add dma support
>     https://git.kernel.org/netdev/net-next/c/47869e82c8b8
> 
> You are awesome, thank you!
> -- 
> Deet-doot-dot, I am a bot.
> https://korg.docs.kernel.org/patchwork/pwbot.html
> 

Hello

Any news on patch which enable sun4i-emac DMA in DT ?

Regards
Re: [PATCH v6] sun4i-emac.c: add dma support
Posted by Jakub Kicinski 4 years, 1 month ago
On Mon, 30 May 2022 06:51:14 +0200 Corentin Labbe wrote:
> Any news on patch which enable sun4i-emac DMA in DT ?

Who are you directing this question to and where's that patch posted?
Re: [PATCH v6] sun4i-emac.c: add dma support
Posted by Corentin Labbe 4 years, 1 month ago
Le Mon, May 30, 2022 at 11:48:19AM -0700, Jakub Kicinski a écrit :
> On Mon, 30 May 2022 06:51:14 +0200 Corentin Labbe wrote:
> > Any news on patch which enable sun4i-emac DMA in DT ?
> 
> Who are you directing this question to and where's that patch posted?

I am sorry, I fail to set the right "to:"
My question was for Conley Lee.

This serie was applied but the DT part was never posted.
So sun4i-emac can handle DMA but is not enabled at all.

The DT patch is easy, so without answer, I will send it.

Regards
Re: [PATCH v6] sun4i-emac.c: add dma support
Posted by Kees Cook 4 years, 5 months ago
On Wed, Dec 29, 2021 at 09:43:51AM +0800, conleylee@foxmail.com wrote:
> From: Conley Lee <conleylee@foxmail.com>
>
> Thanks for your review. Here is the new version for this patch.
>
> This patch adds support for the emac rx dma present on sun4i. The emac
> is able to move packets from rx fifo to RAM by using dma.
>
> Change since v4.
>   - rename sbk field to skb
>   - rename alloc_emac_dma_req to emac_alloc_dma_req
>   - using kzalloc(..., GPF_ATOMIC) in interrupt context to avoid
>     sleeping
>   - retry by using emac_inblk_32bit when emac_dma_inblk_32bit fails
>   - fix some code style issues
>
> Change since v5.
>   - fix some code style issue
>
> Signed-off-by: Conley Lee <conleylee@foxmail.com>
> ---
>  drivers/net/ethernet/allwinner/sun4i-emac.c | 200 ++++++++++++++++++++
>  1 file changed, 200 insertions(+)

This is causing build failures:

$ make CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 allmodconfig
$ make CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 -j... -k -s
drivers/net/ethernet/allwinner/sun4i-emac.c: In function 'emac_configure_dma':
drivers/net/ethernet/allwinner/sun4i-emac.c:922:60: error: format '%x' expects argument of type 'unsigned int', but argument 3 has type 'resource_size_t' {aka 'long long unsigned int'} [-Werror=format=]
  922 |         netdev_info(ndev, "get io resource from device: 0x%x, size = %u\n",
      |                                                           ~^
      |                                                            |                                      |                                                            unsigned int
      |                                                           %llx
  923 |                     regs->start, resource_size(regs));
      |                     ~~~~~~~~~~~
      |                         |
      |                         resource_size_t {aka long long unsigned int}
drivers/net/ethernet/allwinner/sun4i-emac.c:922:71: error: format '%u' expects argument of type 'unsigned int', but argument 4 has type 'resource_size_t' {aka 'long long unsigned int'} [-Werror=format=]
  922 |         netdev_info(ndev, "get io resource from device: 0x%x, size = %u\n",
      |                                                                      ~^
      |                                                                       |
      |                                                                       unsigned int
      |                                                                      %llu
  923 |                     regs->start, resource_size(regs));
      |                                  ~~~~~~~~~~~~~~~~~~~
      |                                  |
      |                                  resource_size_t {aka long long unsigned int}


--
Kees Cook
Re: [PATCH v6] sun4i-emac.c: add dma support
Posted by Jakub Kicinski 4 years, 5 months ago
On Fri, 7 Jan 2022 15:34:18 -0800 Kees Cook wrote:
> On Wed, Dec 29, 2021 at 09:43:51AM +0800, conleylee@foxmail.com wrote:
> > From: Conley Lee <conleylee@foxmail.com>
> >
> > Thanks for your review. Here is the new version for this patch.
> >
> > This patch adds support for the emac rx dma present on sun4i. The emac
> > is able to move packets from rx fifo to RAM by using dma.
> >
> > Change since v4.
> >   - rename sbk field to skb
> >   - rename alloc_emac_dma_req to emac_alloc_dma_req
> >   - using kzalloc(..., GPF_ATOMIC) in interrupt context to avoid
> >     sleeping
> >   - retry by using emac_inblk_32bit when emac_dma_inblk_32bit fails
> >   - fix some code style issues
> >
> > Change since v5.
> >   - fix some code style issue
> >
> > Signed-off-by: Conley Lee <conleylee@foxmail.com>
>
> This is causing build failures:
> 
> $ make CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 allmodconfig
> $ make CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 -j... -k -s
> drivers/net/ethernet/allwinner/sun4i-emac.c: In function 'emac_configure_dma':
> drivers/net/ethernet/allwinner/sun4i-emac.c:922:60: error: format '%x' expects argument of type 'unsigned int', but argument 3 has type 'resource_size_t' {aka 'long long unsigned int'} [-Werror=format=]
>   922 |         netdev_info(ndev, "get io resource from device: 0x%x, size = %u\n",
>       |                                                           ~^
>       |                                                            |                                      |                                                            unsigned int
>       |                                                           %llx
>   923 |                     regs->start, resource_size(regs));
>       |                     ~~~~~~~~~~~
>       |                         |
>       |                         resource_size_t {aka long long unsigned int}
> drivers/net/ethernet/allwinner/sun4i-emac.c:922:71: error: format '%u' expects argument of type 'unsigned int', but argument 4 has type 'resource_size_t' {aka 'long long unsigned int'} [-Werror=format=]
>   922 |         netdev_info(ndev, "get io resource from device: 0x%x, size = %u\n",
>       |                                                                      ~^
>       |                                                                       |
>       |                                                                       unsigned int
>       |                                                                      %llu
>   923 |                     regs->start, resource_size(regs));
>       |                                  ~~~~~~~~~~~~~~~~~~~
>       |                                  |
>       |                                  resource_size_t {aka long long unsigned int}
> 

Ugh, I saw this and somehow it didn't enter my brain that it's new.
%pa right? Let me test that and send a fix before we close net-next..