[PATCH v5 05/15] dmaengine: dw-edma: Add PCIe VSEC data retrieval support

Gustavo Pimentel
2021-02-11T09:18:51Z

The latest eDMA IP development implements a Vendor-Specific Extended
Capability that contains the eDMA BAR, offset, map format, and the
number of read/write channels available.

Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
---
drivers/dma/dw-edma/dw-edma-core.c | 20 ++++---
drivers/dma/dw-edma/dw-edma-pcie.c | 114 ++++++++++++++++++++++++++++---------
2 files changed, 99 insertions(+), 35 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index b971505..b65c32e1 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -863,15 +863,19 @@ int dw_edma_probe(struct dw_edma_chip *chip)

raw_spin_lock_init(&dw->lock);

- /* Find out how many write channels are supported by hardware */
- dw->wr_ch_cnt = dw_edma_v0_core_ch_count(dw, EDMA_DIR_WRITE);
- if (!dw->wr_ch_cnt)
- return -EINVAL;
+ if (!dw->wr_ch_cnt) {
+ /* Find out how many write channels are supported by hardware */
+ dw->wr_ch_cnt = dw_edma_v0_core_ch_count(dw, EDMA_DIR_WRITE);
+ if (!dw->wr_ch_cnt)
+ return -EINVAL;
+ }

- /* Find out how many read channels are supported by hardware */
- dw->rd_ch_cnt = dw_edma_v0_core_ch_count(dw, EDMA_DIR_READ);
- if (!dw->rd_ch_cnt)
- return -EINVAL;
+ if (!dw->rd_ch_cnt) {
+ /* Find out how many read channels are supported by hardware */
+ dw->rd_ch_cnt = dw_edma_v0_core_ch_count(dw, EDMA_DIR_READ);
+ if (!dw->rd_ch_cnt)
+ return -EINVAL;
+ }

dev_vdbg(dev, "Channels:\twrite=%d, read=%d\n",
dw->wr_ch_cnt, dw->rd_ch_cnt);
diff --git a/drivers/dma/dw-edma/dw-edma-pcie.c b/drivers/dma/dw-edma/dw-edma-pcie.c
index c130549..7077d79 100644
--- a/drivers/dma/dw-edma/dw-edma-pcie.c
+++ b/drivers/dma/dw-edma/dw-edma-pcie.c
@@ -13,9 +13,16 @@
#include <linux/dma/edma.h>
#include <linux/pci-epf.h>
#include <linux/msi.h>
+#include <linux/bitfield.h>

#include "dw-edma-core.h"

+#define DW_PCIE_VSEC_DMA_ID 0x6
+#define DW_PCIE_VSEC_DMA_BAR GENMASK(10, 8)
+#define DW_PCIE_VSEC_DMA_MAP GENMASK(2, 0)
+#define DW_PCIE_VSEC_DMA_RD_CH GENMASK(25, 16)
+#define DW_PCIE_VSEC_DMA_WR_CH GENMASK(9, 0)
+
struct dw_edma_pcie_data {
/* eDMA registers location */
enum pci_barno rg_bar;
@@ -32,6 +39,8 @@ struct dw_edma_pcie_data {
/* Other */
enum dw_edma_map_format mf;
u8 irqs;
+ u16 rd_ch_cnt;
+ u16 wr_ch_cnt;
};

static const struct dw_edma_pcie_data snps_edda_data = {
@@ -50,6 +59,8 @@ static const struct dw_edma_pcie_data snps_edda_data = {
/* Other */
.mf = EDMA_MF_EDMA_UNROLL,
.irqs = 1,
+ .rd_ch_cnt = 0,
+ .wr_ch_cnt = 0,
};

static int dw_edma_pcie_irq_vector(struct device *dev, unsigned int nr)
@@ -61,10 +72,49 @@ static const struct dw_edma_core_ops dw_edma_pcie_core_ops = {
.irq_vector = dw_edma_pcie_irq_vector,
};

+static void dw_edma_pcie_get_vsec_dma_data(struct pci_dev *pdev,
+ struct dw_edma_pcie_data *pdata)
+{
+ u32 val, map;
+ u16 vsec;
+ u64 off;
+
+ vsec = pci_find_vsec_capability(pdev, DW_PCIE_VSEC_DMA_ID);
+ if (!vsec)
+ return;
+
+ pci_read_config_dword(pdev, vsec + PCI_VSEC_HEADER, &val);
+ if (PCI_VSEC_CAP_REV(val) != 0x00 || PCI_VSEC_CAP_LEN(val) != 0x18)
+ return;
+
+ pci_dbg(pdev, "Detected PCIe Vendor-Specific Extended Capability DMA\n");
+ pci_read_config_dword(pdev, vsec + 0x8, &val);
+ map = FIELD_GET(DW_PCIE_VSEC_DMA_MAP, val);
+ if (map != EDMA_MF_EDMA_LEGACY &&
+ map != EDMA_MF_EDMA_UNROLL &&
+ map != EDMA_MF_HDMA_COMPAT)
+ return;
+
+ pdata->mf = map;
+ pdata->rg_bar = FIELD_GET(DW_PCIE_VSEC_DMA_BAR, val);
+
+ pci_read_config_dword(pdev, vsec + 0xc, &val);
+ pdata->rd_ch_cnt = FIELD_GET(DW_PCIE_VSEC_DMA_RD_CH, val);
+ pdata->wr_ch_cnt = FIELD_GET(DW_PCIE_VSEC_DMA_WR_CH, val);
+
+ pci_read_config_dword(pdev, vsec + 0x14, &val);
+ off = val;
+ pci_read_config_dword(pdev, vsec + 0x10, &val);
+ off <<= 32;
+ off |= val;
+ pdata->rg_off = off;
+}
+
static int dw_edma_pcie_probe(struct pci_dev *pdev,
const struct pci_device_id *pid)
{
- const struct dw_edma_pcie_data *pdata = (void *)pid->driver_data;
+ struct dw_edma_pcie_data *pdata = (void *)pid->driver_data;
+ struct dw_edma_pcie_data vsec_data;
struct device *dev = &pdev->dev;
struct dw_edma_chip *chip;
struct dw_edma *dw;
@@ -77,10 +127,18 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
return err;
}

+ 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 exists one, then reconfigures with the new data
+ */
+ dw_edma_pcie_get_vsec_dma_data(pdev, &vsec_data);
+
/* Mapping PCI BAR regions */
- err = pcim_iomap_regions(pdev, BIT(pdata->rg_bar) |
- BIT(pdata->ll_bar) |
- BIT(pdata->dt_bar),
+ err = pcim_iomap_regions(pdev, BIT(vsec_data.rg_bar) |
+ BIT(vsec_data.ll_bar) |
+ BIT(vsec_data.dt_bar),
pci_name(pdev));
if (err) {
pci_err(pdev, "eDMA BAR I/O remapping failed\n");
@@ -123,7 +181,7 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
return -ENOMEM;

/* IRQs allocation */
- nr_irqs = pci_alloc_irq_vectors(pdev, 1, pdata->irqs,
+ nr_irqs = pci_alloc_irq_vectors(pdev, 1, vsec_data.irqs,
PCI_IRQ_MSI | PCI_IRQ_MSIX);
if (nr_irqs < 1) {
pci_err(pdev, "fail to alloc IRQ vector (number of IRQs=%u)\n",
@@ -137,27 +195,29 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
chip->id = pdev->devfn;
chip->irq = pdev->irq;

- dw->rg_region.vaddr = pcim_iomap_table(pdev)[pdata->rg_bar];
- dw->rg_region.vaddr += pdata->rg_off;
- dw->rg_region.paddr = pdev->resource[pdata->rg_bar].start;
- dw->rg_region.paddr += pdata->rg_off;
- dw->rg_region.sz = pdata->rg_sz;
-
- dw->ll_region.vaddr = pcim_iomap_table(pdev)[pdata->ll_bar];
- dw->ll_region.vaddr += pdata->ll_off;
- dw->ll_region.paddr = pdev->resource[pdata->ll_bar].start;
- dw->ll_region.paddr += pdata->ll_off;
- dw->ll_region.sz = pdata->ll_sz;
-
- dw->dt_region.vaddr = pcim_iomap_table(pdev)[pdata->dt_bar];
- dw->dt_region.vaddr += pdata->dt_off;
- dw->dt_region.paddr = pdev->resource[pdata->dt_bar].start;
- dw->dt_region.paddr += pdata->dt_off;
- dw->dt_region.sz = pdata->dt_sz;
-
- dw->mf = pdata->mf;
+ dw->rg_region.vaddr = pcim_iomap_table(pdev)[vsec_data.rg_bar];
+ dw->rg_region.vaddr += vsec_data.rg_off;
+ dw->rg_region.paddr = pdev->resource[vsec_data.rg_bar].start;
+ dw->rg_region.paddr += vsec_data.rg_off;
+ dw->rg_region.sz = vsec_data.rg_sz;
+
+ dw->ll_region.vaddr = pcim_iomap_table(pdev)[vsec_data.ll_bar];
+ dw->ll_region.vaddr += vsec_data.ll_off;
+ dw->ll_region.paddr = pdev->resource[vsec_data.ll_bar].start;
+ dw->ll_region.paddr += vsec_data.ll_off;
+ dw->ll_region.sz = vsec_data.ll_sz;
+
+ dw->dt_region.vaddr = pcim_iomap_table(pdev)[vsec_data.dt_bar];
+ dw->dt_region.vaddr += vsec_data.dt_off;
+ dw->dt_region.paddr = pdev->resource[vsec_data.dt_bar].start;
+ dw->dt_region.paddr += vsec_data.dt_off;
+ dw->dt_region.sz = vsec_data.dt_sz;
+
+ dw->mf = vsec_data.mf;
dw->nr_irqs = nr_irqs;
dw->ops = &dw_edma_pcie_core_ops;
+ dw->rd_ch_cnt = vsec_data.rd_ch_cnt;
+ dw->wr_ch_cnt = vsec_data.wr_ch_cnt;

/* Debug info */
if (dw->mf == EDMA_MF_EDMA_LEGACY)
@@ -170,15 +230,15 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
pci_dbg(pdev, "Version:\tUnknown (0x%x)\n", dw->mf);

pci_dbg(pdev, "Registers:\tBAR=%u, off=0x%.8lx, sz=0x%zx bytes, addr(v=%p, p=%pa)\n",
- pdata->rg_bar, pdata->rg_off, pdata->rg_sz,
+ vsec_data.rg_bar, vsec_data.rg_off, vsec_data.rg_sz,
dw->rg_region.vaddr, &dw->rg_region.paddr);

pci_dbg(pdev, "L. List:\tBAR=%u, off=0x%.8lx, sz=0x%zx bytes, addr(v=%p, p=%pa)\n",
- pdata->ll_bar, pdata->ll_off, pdata->ll_sz,
+ vsec_data.ll_bar, vsec_data.ll_off, vsec_data.ll_sz,
dw->ll_region.vaddr, &dw->ll_region.paddr);

pci_dbg(pdev, "Data:\tBAR=%u, off=0x%.8lx, sz=0x%zx bytes, addr(v=%p, p=%pa)\n",
- pdata->dt_bar, pdata->dt_off, pdata->dt_sz,
+ vsec_data.dt_bar, vsec_data.dt_off, vsec_data.dt_sz,
dw->dt_region.vaddr, &dw->dt_region.paddr);

pci_dbg(pdev, "Nr. IRQs:\t%u\n", dw->nr_irqs);
--
2.7.4