net:enetc: allocate CBD ring data memory using DMA coherent methods

To replace the dma_map_single() stream DMA mapping with DMA coherent
method dma_alloc_coherent() which is more simple.

dma_map_single() found by Tim Gardner not proper. Suggested by Claudiu
Manoil and Jakub Kicinski to use dma_alloc_coherent(). Discussion at:

https://lore.kernel.org/netdev/AM9PR04MB8397F300DECD3C44D2EBD07796BD9@AM9PR04MB8397.eurprd04.prod.outlook.com/t/

Fixes: 888ae5a3952ba ("net: enetc: add tc flower psfp offload driver")
cc: Claudiu Manoil <claudiu.manoil@nxp.com>
Reported-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Po Liu <po.liu@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/freescale/enetc/enetc_qos.c b/drivers/net/ethernet/freescale/enetc/enetc_qos.c
index 3555c12..d3d7172 100644 (file)
--- a/drivers/net/ethernet/freescale/enetc/enetc_qos.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_qos.c
@@ -45,6 +45,7 @@ void enetc_sched_speed_set(struct enetc_ndev_priv *priv, int speed)
                      | pspeed);
 }
 
+#define ENETC_QOS_ALIGN        64
 static int enetc_setup_taprio(struct net_device *ndev,
                              struct tc_taprio_qopt_offload *admin_conf)
 {
@@ -52,10 +53,11 @@ static int enetc_setup_taprio(struct net_device *ndev,
        struct enetc_cbd cbd = {.cmd = 0};
        struct tgs_gcl_conf *gcl_config;
        struct tgs_gcl_data *gcl_data;
+       dma_addr_t dma, dma_align;
        struct gce *gce;
-       dma_addr_t dma;
        u16 data_size;
        u16 gcl_len;
+       void *tmp;
        u32 tge;
        int err;
        int i;
@@ -82,9 +84,16 @@ static int enetc_setup_taprio(struct net_device *ndev,
        gcl_config = &cbd.gcl_conf;
 
        data_size = struct_size(gcl_data, entry, gcl_len);
-       gcl_data = kzalloc(data_size, __GFP_DMA | GFP_KERNEL);
-       if (!gcl_data)
+       tmp = dma_alloc_coherent(&priv->si->pdev->dev,
+                                data_size + ENETC_QOS_ALIGN,
+                                &dma, GFP_KERNEL);
+       if (!tmp) {
+               dev_err(&priv->si->pdev->dev,
+                       "DMA mapping of taprio gate list failed!\n");
                return -ENOMEM;
+       }
+       dma_align = ALIGN(dma, ENETC_QOS_ALIGN);
+       gcl_data = (struct tgs_gcl_data *)PTR_ALIGN(tmp, ENETC_QOS_ALIGN);
 
        gce = (struct gce *)(gcl_data + 1);
 
@@ -110,16 +119,8 @@ static int enetc_setup_taprio(struct net_device *ndev,
        cbd.length = cpu_to_le16(data_size);
        cbd.status_flags = 0;
 
-       dma = dma_map_single(&priv->si->pdev->dev, gcl_data,
-                            data_size, DMA_TO_DEVICE);
-       if (dma_mapping_error(&priv->si->pdev->dev, dma)) {
-               netdev_err(priv->si->ndev, "DMA mapping failed!\n");
-               kfree(gcl_data);
-               return -ENOMEM;
-       }
-
-       cbd.addr[0] = cpu_to_le32(lower_32_bits(dma));
-       cbd.addr[1] = cpu_to_le32(upper_32_bits(dma));
+       cbd.addr[0] = cpu_to_le32(lower_32_bits(dma_align));
+       cbd.addr[1] = cpu_to_le32(upper_32_bits(dma_align));
        cbd.cls = BDCR_CMD_PORT_GCL;
        cbd.status_flags = 0;
 
@@ -132,8 +133,8 @@ static int enetc_setup_taprio(struct net_device *ndev,
                         ENETC_QBV_PTGCR_OFFSET,
                         tge & (~ENETC_QBV_TGE));
 
-       dma_unmap_single(&priv->si->pdev->dev, dma, data_size, DMA_TO_DEVICE);
-       kfree(gcl_data);
+       dma_free_coherent(&priv->si->pdev->dev, data_size + ENETC_QOS_ALIGN,
+                         tmp, dma);
 
        return err;
 }
@@ -463,8 +464,9 @@ static int enetc_streamid_hw_set(struct enetc_ndev_priv *priv,
        struct enetc_cbd cbd = {.cmd = 0};
        struct streamid_data *si_data;
        struct streamid_conf *si_conf;
+       dma_addr_t dma, dma_align;
        u16 data_size;
-       dma_addr_t dma;
+       void *tmp;
        int port;
        int err;
 
@@ -485,21 +487,20 @@ static int enetc_streamid_hw_set(struct enetc_ndev_priv *priv,
        cbd.status_flags = 0;
 
        data_size = sizeof(struct streamid_data);
-       si_data = kzalloc(data_size, __GFP_DMA | GFP_KERNEL);
-       if (!si_data)
+       tmp = dma_alloc_coherent(&priv->si->pdev->dev,
+                                data_size + ENETC_QOS_ALIGN,
+                                &dma, GFP_KERNEL);
+       if (!tmp) {
+               dev_err(&priv->si->pdev->dev,
+                       "DMA mapping of stream identify failed!\n");
                return -ENOMEM;
-       cbd.length = cpu_to_le16(data_size);
-
-       dma = dma_map_single(&priv->si->pdev->dev, si_data,
-                            data_size, DMA_FROM_DEVICE);
-       if (dma_mapping_error(&priv->si->pdev->dev, dma)) {
-               netdev_err(priv->si->ndev, "DMA mapping failed!\n");
-               err = -ENOMEM;
-               goto out;
        }
+       dma_align = ALIGN(dma, ENETC_QOS_ALIGN);
+       si_data = (struct streamid_data *)PTR_ALIGN(tmp, ENETC_QOS_ALIGN);
 
-       cbd.addr[0] = cpu_to_le32(lower_32_bits(dma));
-       cbd.addr[1] = cpu_to_le32(upper_32_bits(dma));
+       cbd.length = cpu_to_le16(data_size);
+       cbd.addr[0] = cpu_to_le32(lower_32_bits(dma_align));
+       cbd.addr[1] = cpu_to_le32(upper_32_bits(dma_align));
        eth_broadcast_addr(si_data->dmac);
        si_data->vid_vidm_tg = (ENETC_CBDR_SID_VID_MASK
                               + ((0x3 << 14) | ENETC_CBDR_SID_VIDM));
@@ -539,8 +540,8 @@ static int enetc_streamid_hw_set(struct enetc_ndev_priv *priv,
 
        cbd.length = cpu_to_le16(data_size);
 
-       cbd.addr[0] = cpu_to_le32(lower_32_bits(dma));
-       cbd.addr[1] = cpu_to_le32(upper_32_bits(dma));
+       cbd.addr[0] = cpu_to_le32(lower_32_bits(dma_align));
+       cbd.addr[1] = cpu_to_le32(upper_32_bits(dma_align));
 
        /* VIDM default to be 1.
         * VID Match. If set (b1) then the VID must match, otherwise
@@ -561,10 +562,8 @@ static int enetc_streamid_hw_set(struct enetc_ndev_priv *priv,
 
        err = enetc_send_cmd(priv->si, &cbd);
 out:
-       if (!dma_mapping_error(&priv->si->pdev->dev, dma))
-               dma_unmap_single(&priv->si->pdev->dev, dma, data_size, DMA_FROM_DEVICE);
-
-       kfree(si_data);
+       dma_free_coherent(&priv->si->pdev->dev, data_size + ENETC_QOS_ALIGN,
+                         tmp, dma);
 
        return err;
 }
@@ -633,8 +632,9 @@ static int enetc_streamcounter_hw_get(struct enetc_ndev_priv *priv,
 {
        struct enetc_cbd cbd = { .cmd = 2 };
        struct sfi_counter_data *data_buf;
-       dma_addr_t dma;
+       dma_addr_t dma, dma_align;
        u16 data_size;
+       void *tmp;
        int err;
 
        cbd.index = cpu_to_le16((u16)index);
@@ -643,19 +643,19 @@ static int enetc_streamcounter_hw_get(struct enetc_ndev_priv *priv,
        cbd.status_flags = 0;
 
        data_size = sizeof(struct sfi_counter_data);
-       data_buf = kzalloc(data_size, __GFP_DMA | GFP_KERNEL);
-       if (!data_buf)
+       tmp = dma_alloc_coherent(&priv->si->pdev->dev,
+                                data_size + ENETC_QOS_ALIGN,
+                                &dma, GFP_KERNEL);
+       if (!tmp) {
+               dev_err(&priv->si->pdev->dev,
+                       "DMA mapping of stream counter failed!\n");
                return -ENOMEM;
-
-       dma = dma_map_single(&priv->si->pdev->dev, data_buf,
-                            data_size, DMA_FROM_DEVICE);
-       if (dma_mapping_error(&priv->si->pdev->dev, dma)) {
-               netdev_err(priv->si->ndev, "DMA mapping failed!\n");
-               err = -ENOMEM;
-               goto exit;
        }
-       cbd.addr[0] = cpu_to_le32(lower_32_bits(dma));
-       cbd.addr[1] = cpu_to_le32(upper_32_bits(dma));
+       dma_align = ALIGN(dma, ENETC_QOS_ALIGN);
+       data_buf = (struct sfi_counter_data *)PTR_ALIGN(tmp, ENETC_QOS_ALIGN);
+
+       cbd.addr[0] = cpu_to_le32(lower_32_bits(dma_align));
+       cbd.addr[1] = cpu_to_le32(upper_32_bits(dma_align));
 
        cbd.length = cpu_to_le16(data_size);
 
@@ -684,7 +684,9 @@ static int enetc_streamcounter_hw_get(struct enetc_ndev_priv *priv,
                                data_buf->flow_meter_dropl;
 
 exit:
-       kfree(data_buf);
+       dma_free_coherent(&priv->si->pdev->dev, data_size + ENETC_QOS_ALIGN,
+                         tmp, dma);
+
        return err;
 }
 
@@ -723,9 +725,10 @@ static int enetc_streamgate_hw_set(struct enetc_ndev_priv *priv,
        struct sgcl_conf *sgcl_config;
        struct sgcl_data *sgcl_data;
        struct sgce *sgce;
-       dma_addr_t dma;
+       dma_addr_t dma, dma_align;
        u16 data_size;
        int err, i;
+       void *tmp;
        u64 now;
 
        cbd.index = cpu_to_le16(sgi->index);
@@ -772,24 +775,20 @@ static int enetc_streamgate_hw_set(struct enetc_ndev_priv *priv,
        sgcl_config->acl_len = (sgi->num_entries - 1) & 0x3;
 
        data_size = struct_size(sgcl_data, sgcl, sgi->num_entries);
-
-       sgcl_data = kzalloc(data_size, __GFP_DMA | GFP_KERNEL);
-       if (!sgcl_data)
-               return -ENOMEM;
-
-       cbd.length = cpu_to_le16(data_size);
-
-       dma = dma_map_single(&priv->si->pdev->dev,
-                            sgcl_data, data_size,
-                            DMA_FROM_DEVICE);
-       if (dma_mapping_error(&priv->si->pdev->dev, dma)) {
-               netdev_err(priv->si->ndev, "DMA mapping failed!\n");
-               kfree(sgcl_data);
+       tmp = dma_alloc_coherent(&priv->si->pdev->dev,
+                                data_size + ENETC_QOS_ALIGN,
+                                &dma, GFP_KERNEL);
+       if (!tmp) {
+               dev_err(&priv->si->pdev->dev,
+                       "DMA mapping of stream counter failed!\n");
                return -ENOMEM;
        }
+       dma_align = ALIGN(dma, ENETC_QOS_ALIGN);
+       sgcl_data = (struct sgcl_data *)PTR_ALIGN(tmp, ENETC_QOS_ALIGN);
 
-       cbd.addr[0] = cpu_to_le32(lower_32_bits(dma));
-       cbd.addr[1] = cpu_to_le32(upper_32_bits(dma));
+       cbd.length = cpu_to_le16(data_size);
+       cbd.addr[0] = cpu_to_le32(lower_32_bits(dma_align));
+       cbd.addr[1] = cpu_to_le32(upper_32_bits(dma_align));
 
        sgce = &sgcl_data->sgcl[0];
 
@@ -844,7 +843,8 @@ static int enetc_streamgate_hw_set(struct enetc_ndev_priv *priv,
        err = enetc_send_cmd(priv->si, &cbd);
 
 exit:
-       kfree(sgcl_data);
+       dma_free_coherent(&priv->si->pdev->dev, data_size + ENETC_QOS_ALIGN,
+                         tmp, dma);
 
        return err;
 }