[PATCH v4 07/14] dmaengine: dw-edma-pcie: Add capability match data

[Koichiro Den <den@valinux.co.jp>]

Move device-specific capability parsing behind per-device match data.

The existing probe path mixes two decisions: which static template a PCI
ID uses, and which device-specific capability parser adjusts that
template. Split those decisions so device-specific discovery can be
added through match data instead of adding more vendor checks to
dw_edma_pcie_probe().

No functional change is intended for the existing Synopsys EDDA and
AMD (Xilinx) MDB/CPM6 matches. They still copy the same static template
data and run the same capability parsing logic before BAR mapping. The
AMD (Xilinx) MDB/CPM6 entries also keep using endpoint memory physical
addresses for descriptor windows through a new match-data flag.

Suggested-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Koichiro Den <den@valinux.co.jp>
---
Changes in v4:
  - No changes.

 drivers/dma/dw-edma/dw-edma-pcie.c | 139 ++++++++++++++++++++---------
 1 file changed, 96 insertions(+), 43 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-pcie.c b/drivers/dma/dw-edma/dw-edma-pcie.c
index 8ecf67828a52..22e3efa6b365 100644
--- a/drivers/dma/dw-edma/dw-edma-pcie.c
+++ b/drivers/dma/dw-edma/dw-edma-pcie.c
@@ -76,6 +76,19 @@ struct dw_edma_pcie_data {
 	bool				cfg_non_ll;
 };
 
+struct dw_edma_pcie_match_data {
+	const struct dw_edma_pcie_data *data;
+	/*
+	 * Mandatory callback. It may leave @pdata unchanged when the static
+	 * template already describes the device.
+	 */
+	int (*parse_caps)(struct pci_dev *pdev,
+			  struct dw_edma_pcie_data *pdata);
+	unsigned long flags;
+};
+
+#define DW_EDMA_PCIE_F_DEVMEM_PHYS_OFF	BIT(0)
+
 static const struct dw_edma_pcie_data snps_edda_data = {
 	/* eDMA registers location */
 	.rg.bar				= BAR_0,
@@ -310,24 +323,70 @@ static void dw_edma_pcie_get_xilinx_dma_data(struct pci_dev *pdev,
 	pdata->devmem_phys_off = off;
 }
 
+static int
+dw_edma_pcie_parse_synopsys_caps(struct pci_dev *pdev,
+				 struct dw_edma_pcie_data *pdata)
+{
+	dw_edma_pcie_get_synopsys_dma_data(pdev, pdata);
+
+	return 0;
+}
+
+static int
+dw_edma_pcie_parse_xilinx_caps(struct pci_dev *pdev,
+			       struct dw_edma_pcie_data *pdata)
+{
+	dw_edma_pcie_get_xilinx_dma_data(pdev, pdata);
+
+	/*
+	 * There is no valid address found for the LL memory space on the
+	 * device side. In the absence of LL base address use the non-LL mode or
+	 * simple mode supported by the HDMA IP.
+	 */
+	if (pdata->devmem_phys_off == DW_PCIE_XILINX_MDB_INVALID_ADDR) {
+		pdata->cfg_non_ll = true;
+		return 0;
+	}
+
+	/*
+	 * Configure the channel LL and data blocks if number of channels
+	 * enabled in VSEC capability are more than the channels configured in
+	 * xilinx_mdb_data.
+	 */
+	dw_edma_set_chan_region_offset(pdata, BAR_2, 0,
+				       DW_PCIE_XILINX_MDB_LL_OFF_GAP,
+				       DW_PCIE_XILINX_MDB_LL_SIZE,
+				       DW_PCIE_XILINX_MDB_DT_OFF_GAP,
+				       DW_PCIE_XILINX_MDB_DT_SIZE);
+
+	return 0;
+}
+
 static u64 dw_edma_get_phys_addr(struct pci_dev *pdev,
+				 const struct dw_edma_pcie_match_data *match,
 				 struct dw_edma_pcie_data *pdata,
 				 enum pci_barno bar)
 {
-	if (pdev->vendor == PCI_VENDOR_ID_XILINX)
+	if (match->flags & DW_EDMA_PCIE_F_DEVMEM_PHYS_OFF)
 		return pdata->devmem_phys_off;
+
 	return pci_bus_address(pdev, bar);
 }
 
 static int dw_edma_pcie_probe(struct pci_dev *pdev,
 			      const struct pci_device_id *pid)
 {
-	struct dw_edma_pcie_data *pdata = (void *)pid->driver_data;
+	const struct dw_edma_pcie_match_data *match = (void *)pid->driver_data;
+	const struct dw_edma_pcie_data *pdata;
 	struct device *dev = &pdev->dev;
 	struct dw_edma_chip *chip;
 	int err, nr_irqs;
 	int i, mask;
 
+	if (!match)
+		return -ENODEV;
+	pdata = match->data;
+
 	if (!pdata)
 		return -ENODEV;
 
@@ -345,36 +404,13 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
 
 	memcpy(vsec_data, pdata, sizeof(struct dw_edma_pcie_data));
 
-	/*
-	 * Tries to find if exists a PCIe Vendor-Specific Extended Capability
-	 * for the DMA, if one exists, then reconfigures it.
-	 */
-	dw_edma_pcie_get_synopsys_dma_data(pdev, vsec_data);
-
-	if (pdev->vendor == PCI_VENDOR_ID_XILINX) {
-		dw_edma_pcie_get_xilinx_dma_data(pdev, vsec_data);
-
-		/*
-		 * There is no valid address found for the LL memory
-		 * space on the device side. In the absence of LL base
-		 * address use the non-LL mode or simple mode supported by
-		 * the HDMA IP.
-		 */
-		if (vsec_data->devmem_phys_off == DW_PCIE_XILINX_MDB_INVALID_ADDR)
-			vsec_data->cfg_non_ll = true;
-
-		/*
-		 * Configure the channel LL and data blocks if number of
-		 * channels enabled in VSEC capability are more than the
-		 * channels configured in xilinx_mdb_data.
-		 */
-		if (!vsec_data->cfg_non_ll)
-			dw_edma_set_chan_region_offset(vsec_data, BAR_2, 0,
-						       DW_PCIE_XILINX_MDB_LL_OFF_GAP,
-						       DW_PCIE_XILINX_MDB_LL_SIZE,
-						       DW_PCIE_XILINX_MDB_DT_OFF_GAP,
-						       DW_PCIE_XILINX_MDB_DT_SIZE);
-	}
+	/* Let device-specific discovery override the static template data. */
+	if (!match->parse_caps)
+		return -EINVAL;
+
+	err = match->parse_caps(pdev, vsec_data);
+	if (err)
+		return err;
 
 	/* Mapping PCI BAR regions */
 	mask = BIT(vsec_data->rg.bar);
@@ -441,8 +477,8 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
 			return -ENOMEM;
 
 		ll_region->vaddr.io += ll_block->off;
-		ll_region->paddr = dw_edma_get_phys_addr(pdev, vsec_data,
-							 ll_block->bar);
+		ll_region->paddr = dw_edma_get_phys_addr(pdev, match,
+							 vsec_data, ll_block->bar);
 		ll_region->paddr += ll_block->off;
 		ll_region->sz = ll_block->sz;
 
@@ -451,8 +487,8 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
 			return -ENOMEM;
 
 		dt_region->vaddr.io += dt_block->off;
-		dt_region->paddr = dw_edma_get_phys_addr(pdev, vsec_data,
-							 dt_block->bar);
+		dt_region->paddr = dw_edma_get_phys_addr(pdev, match,
+							 vsec_data, dt_block->bar);
 		dt_region->paddr += dt_block->off;
 		dt_region->sz = dt_block->sz;
 	}
@@ -468,8 +504,8 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
 			return -ENOMEM;
 
 		ll_region->vaddr.io += ll_block->off;
-		ll_region->paddr = dw_edma_get_phys_addr(pdev, vsec_data,
-							 ll_block->bar);
+		ll_region->paddr = dw_edma_get_phys_addr(pdev, match,
+							 vsec_data, ll_block->bar);
 		ll_region->paddr += ll_block->off;
 		ll_region->sz = ll_block->sz;
 
@@ -478,8 +514,8 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
 			return -ENOMEM;
 
 		dt_region->vaddr.io += dt_block->off;
-		dt_region->paddr = dw_edma_get_phys_addr(pdev, vsec_data,
-							 dt_block->bar);
+		dt_region->paddr = dw_edma_get_phys_addr(pdev, match,
+							 vsec_data, dt_block->bar);
 		dt_region->paddr += dt_block->off;
 		dt_region->sz = dt_block->sz;
 	}
@@ -557,12 +593,29 @@ static void dw_edma_pcie_remove(struct pci_dev *pdev)
 		pci_warn(pdev, "can't remove device properly: %d\n", err);
 }
 
+static const struct dw_edma_pcie_match_data snps_edda_match_data = {
+	.data = &snps_edda_data,
+	.parse_caps = dw_edma_pcie_parse_synopsys_caps,
+};
+
+static const struct dw_edma_pcie_match_data xilinx_mdb_match_data = {
+	.data = &xilinx_mdb_data,
+	.parse_caps = dw_edma_pcie_parse_xilinx_caps,
+	.flags = DW_EDMA_PCIE_F_DEVMEM_PHYS_OFF,
+};
+
+static const struct dw_edma_pcie_match_data xilinx_cpm6_dma_match_data = {
+	.data = &xilinx_cpm6_dma_data,
+	.parse_caps = dw_edma_pcie_parse_xilinx_caps,
+	.flags = DW_EDMA_PCIE_F_DEVMEM_PHYS_OFF,
+};
+
 static const struct pci_device_id dw_edma_pcie_id_table[] = {
-	{ PCI_DEVICE_DATA(SYNOPSYS, EDDA, &snps_edda_data) },
+	{ PCI_DEVICE_DATA(SYNOPSYS, EDDA, &snps_edda_match_data) },
 	{ PCI_VDEVICE(XILINX, PCI_DEVICE_ID_XILINX_B054),
-	  (kernel_ulong_t)&xilinx_mdb_data },
+	  .driver_data = (kernel_ulong_t)&xilinx_mdb_match_data },
 	{ PCI_VDEVICE(XILINX, PCI_DEVICE_ID_XILINX_B00F),
-	  .driver_data = (kernel_ulong_t)&xilinx_cpm6_dma_data },
+	  .driver_data = (kernel_ulong_t)&xilinx_cpm6_dma_match_data },
 	{ }
 };
 MODULE_DEVICE_TABLE(pci, dw_edma_pcie_id_table);
-- 
2.51.0