[PATCH v2 10/12] PCI: iproc: Add inbound DMA mapping support

From: Ray Jui
Date: Mon Oct 31 2016 - 20:40:18 EST


This patch adds the support of inbound mapping to the iProc PCIe driver.
The range of the inbound mapping is configured by the optional device
tree property 'dma-ranges'.

While inbound mapping is done automatically in the ASIC on most iProc
based SoCs, newer ASIC (e.g., Stingray) requires inbound mapping to be
configured explicitly in software

Signed-off-by: Oza Oza <oza.oza@xxxxxxxxxxxx>
Signed-off-by: Ray Jui <ray.jui@xxxxxxxxxxxx>
Reviewed-by: Scott Branden <scott.branden@xxxxxxxxxxxx>
---
drivers/pci/host/pcie-iproc.c | 235 ++++++++++++++++++++++++++++++++++++++++++
drivers/pci/host/pcie-iproc.h | 15 +++
2 files changed, 250 insertions(+)

diff --git a/drivers/pci/host/pcie-iproc.c b/drivers/pci/host/pcie-iproc.c
index b466ba6..c4e2211 100644
--- a/drivers/pci/host/pcie-iproc.c
+++ b/drivers/pci/host/pcie-iproc.c
@@ -81,6 +81,15 @@
#define OARR_VALID BIT(OARR_VALID_SHIFT)
#define OARR_SIZE_CFG_SHIFT 1

+/*
+ * Maximum number of inbound mapping region sizes that can be supported by an
+ * IARR
+ */
+#define MAX_NUM_IB_REGION_SIZES 9
+
+#define IMAP_VALID_SHIFT 0
+#define IMAP_VALID BIT(IMAP_VALID_SHIFT)
+
#define PCI_EXP_CAP 0xac

#define IPROC_PCIE_REG_INVALID 0xffff
@@ -109,6 +118,44 @@ static const struct iproc_pcie_ob_map paxb_ob_map[] = {
},
};

+/**
+ * iProc PCIe inbound mapping type
+ */
+enum iproc_pcie_ib_map_type {
+ /* for DDR memory */
+ IPROC_PCIE_IB_MAP_MEM = 0,
+
+ /* for device I/O memory */
+ IPROC_PCIE_IB_MAP_IO,
+
+ /* invalid or unused */
+ IPROC_PCIE_IB_MAP_INVALID
+};
+
+/**
+ * iProc PCIe inbound mapping controller specific parameters
+ *
+ * @type: inbound mapping region type
+ * @size_unit: inbound mapping region size unit, could be SZ_1K, SZ_1M, or
+ * SZ_1G
+ * @region_sizes: list of supported inbound mapping region sizes in KB, MB, or
+ * GB, depedning on the size unit
+ * @nr_sizes: number of supported inbound mapping region sizes
+ * @nr_windows: number of supported inbound mapping windows for the region
+ * @imap_addr_offset: register offset between the upper and lower 32-bit
+ * IMAP address registers
+ * @imap_window_offset: register offset between each IMAP window
+ */
+struct iproc_pcie_ib_map {
+ enum iproc_pcie_ib_map_type type;
+ unsigned int size_unit;
+ resource_size_t region_sizes[MAX_NUM_IB_REGION_SIZES];
+ unsigned int nr_sizes;
+ unsigned int nr_windows;
+ u16 imap_addr_offset;
+ u16 imap_window_offset;
+};
+
/*
* iProc PCIe host registers
*/
@@ -162,6 +209,18 @@ enum iproc_pcie_reg {
IPROC_PCIE_OARR3,
IPROC_PCIE_OMAP3,

+ /* inbound address mapping */
+ IPROC_PCIE_IARR0,
+ IPROC_PCIE_IMAP0,
+ IPROC_PCIE_IARR1,
+ IPROC_PCIE_IMAP1,
+ IPROC_PCIE_IARR2,
+ IPROC_PCIE_IMAP2,
+ IPROC_PCIE_IARR3,
+ IPROC_PCIE_IMAP3,
+ IPROC_PCIE_IARR4,
+ IPROC_PCIE_IMAP4,
+
/* link status */
IPROC_PCIE_LINK_STATUS,

@@ -653,6 +712,178 @@ static int iproc_pcie_map_ranges(struct iproc_pcie *pcie,
return 0;
}

+static inline bool iproc_pcie_ib_is_in_use(struct iproc_pcie *pcie,
+ int region_idx)
+{
+ const struct iproc_pcie_ib_map *ib_map = &pcie->ib_map[region_idx];
+ u32 val;
+
+ val = iproc_pcie_read_reg(pcie, MAP_REG(IPROC_PCIE_IARR0, region_idx));
+
+ return !!(val & (BIT(ib_map->nr_sizes) - 1));
+}
+
+static inline bool iproc_pcie_ib_check_type(const struct iproc_pcie_ib_map *ib_map,
+ enum iproc_pcie_ib_map_type type)
+{
+ return !!(ib_map->type == type);
+}
+
+static int iproc_pcie_ib_write(struct iproc_pcie *pcie, int region_idx,
+ int size_idx, int nr_windows, u64 axi_addr,
+ u64 pci_addr, resource_size_t size)
+{
+ struct device *dev = pcie->dev;
+ const struct iproc_pcie_ib_map *ib_map = &pcie->ib_map[region_idx];
+ u16 iarr_offset, imap_offset;
+ u32 val;
+ int window_idx;
+
+ iarr_offset = iproc_pcie_reg_offset(pcie,
+ MAP_REG(IPROC_PCIE_IARR0, region_idx));
+ imap_offset = iproc_pcie_reg_offset(pcie,
+ MAP_REG(IPROC_PCIE_IMAP0, region_idx));
+ if (iproc_pcie_reg_is_invalid(iarr_offset) ||
+ iproc_pcie_reg_is_invalid(imap_offset))
+ return -EINVAL;
+
+ dev_info(dev, "ib region [%d]: offset 0x%x axi %pap pci %pap\n",
+ region_idx, iarr_offset, &axi_addr, &pci_addr);
+
+ /*
+ * Program the IARR registers. The upper 32-bit IARR register is
+ * always right after the lower 32-bit IARR register
+ */
+ writel(lower_32_bits(pci_addr) | BIT(size_idx),
+ pcie->base + iarr_offset);
+ writel(upper_32_bits(pci_addr), pcie->base + iarr_offset + 4);
+
+ dev_info(dev, "iarr lo 0x%x iarr hi 0x%x\n",
+ readl(pcie->base + iarr_offset),
+ readl(pcie->base + iarr_offset + 4));
+
+ /*
+ * Now program the IMAP registers. Each IARR region may have one or
+ * more IMAP windows
+ */
+ size /= nr_windows;
+ for (window_idx = 0; window_idx < nr_windows; window_idx++) {
+ val = readl(pcie->base + imap_offset);
+ val |= lower_32_bits(axi_addr) | IMAP_VALID;
+ writel(val, pcie->base + imap_offset);
+ writel(upper_32_bits(axi_addr),
+ pcie->base + imap_offset + ib_map->imap_addr_offset);
+
+ dev_info(dev, "imap window [%d] lo 0x%x hi 0x%x\n",
+ window_idx, readl(pcie->base + imap_offset),
+ readl(pcie->base + imap_offset +
+ ib_map->imap_addr_offset));
+
+ imap_offset += ib_map->imap_window_offset;
+ axi_addr += size;
+ }
+
+ return 0;
+}
+
+static int iproc_pcie_setup_ib(struct iproc_pcie *pcie,
+ struct of_pci_range *range,
+ enum iproc_pcie_ib_map_type type)
+{
+ struct device *dev = pcie->dev;
+ struct iproc_pcie_ib *ib = &pcie->ib;
+ int ret;
+ unsigned int region_idx, size_idx;
+ u64 axi_addr = range->cpu_addr, pci_addr = range->pci_addr;
+ resource_size_t size = range->size;
+
+ /* iterate through all IARR mapping regions */
+ for (region_idx = 0; region_idx < ib->nr_regions; region_idx++) {
+ const struct iproc_pcie_ib_map *ib_map =
+ &pcie->ib_map[region_idx];
+
+ /*
+ * If current inbound region is already in use or not a
+ * compatible type, move on to the next
+ */
+ if (iproc_pcie_ib_is_in_use(pcie, region_idx) ||
+ !iproc_pcie_ib_check_type(ib_map, type))
+ continue;
+
+ /* iterate through all supported region sizes to find a match */
+ for (size_idx = 0; size_idx < ib_map->nr_sizes; size_idx++) {
+ resource_size_t region_size =
+ ib_map->region_sizes[size_idx] * ib_map->size_unit;
+
+ if (size != region_size)
+ continue;
+
+ if (!IS_ALIGNED(axi_addr, region_size) ||
+ !IS_ALIGNED(pci_addr, region_size)) {
+ dev_err(dev,
+ "axi %pap or pci %pap not aligned\n",
+ &axi_addr, &pci_addr);
+ return -EINVAL;
+ }
+
+ /* match found! program IARR and all IMAP windows */
+ ret = iproc_pcie_ib_write(pcie, region_idx, size_idx,
+ ib_map->nr_windows, axi_addr,
+ pci_addr, size);
+ if (ret)
+ goto err_ib;
+ else
+ return 0;
+
+ }
+ }
+err_ib:
+ dev_err(dev, "unable to configure inbound mapping\n");
+ dev_err(dev, "axi %pap, pci %pap, res size %pap\n",
+ &axi_addr, &pci_addr, &size);
+
+ return ret;
+}
+
+static int pci_dma_range_parser_init(struct of_pci_range_parser *parser,
+ struct device_node *node)
+{
+ const int na = 3, ns = 2;
+ int rlen;
+
+ parser->node = node;
+ parser->pna = of_n_addr_cells(node);
+ parser->np = parser->pna + na + ns;
+
+ parser->range = of_get_property(node, "dma-ranges", &rlen);
+ if (!parser->range)
+ return -ENOENT;
+
+ parser->end = parser->range + rlen / sizeof(__be32);
+ return 0;
+}
+
+static int iproc_pcie_map_dma_ranges(struct iproc_pcie *pcie)
+{
+ struct of_pci_range range;
+ struct of_pci_range_parser parser;
+ int ret;
+
+ /* get the dma-ranges from DT */
+ ret = pci_dma_range_parser_init(&parser, pcie->dev->of_node);
+ if (ret)
+ return ret;
+
+ for_each_of_pci_range(&parser, &range) {
+ /* each range entry corresponds to an inbound mapping region */
+ ret = iproc_pcie_setup_ib(pcie, &range, IPROC_PCIE_IB_MAP_MEM);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
static int iproce_pcie_get_msi(struct iproc_pcie *pcie,
struct device_node *msi_node,
u64 *msi_addr)
@@ -880,6 +1111,10 @@ int iproc_pcie_setup(struct iproc_pcie *pcie, struct list_head *res)
}
}

+ ret = iproc_pcie_map_dma_ranges(pcie);
+ if (ret && ret != -ENOENT)
+ goto err_power_off_phy;
+
#ifdef CONFIG_ARM
pcie->sysdata.private_data = pcie;
sysdata = &pcie->sysdata;
diff --git a/drivers/pci/host/pcie-iproc.h b/drivers/pci/host/pcie-iproc.h
index 861b526..3f2709a 100644
--- a/drivers/pci/host/pcie-iproc.h
+++ b/drivers/pci/host/pcie-iproc.h
@@ -41,7 +41,16 @@ struct iproc_pcie_ob {
unsigned int nr_windows;
};

+/**
+ * iProc PCIe inbound mapping
+ * @nr_regions: total number of supported inbound mapping regions
+ */
+struct iproc_pcie_ib {
+ unsigned int nr_regions;
+};
+
struct iproc_pcie_ob_map;
+struct iproc_pcie_ib_map;
struct iproc_msi;

/**
@@ -64,6 +73,9 @@ struct iproc_msi;
* @ob: outbound mapping related parameters
* @ob_map: outbound mapping related parameters specific to the controller
*
+ * @ib: inbound mapping related parameters
+ * @ib_map: outbound mapping region related parameters
+ *
* @need_msi_steer: indicates additional configuration of the iProc PCIe
* controller is required to steer MSI writes to external interrupt controller
* @msi: MSI data
@@ -87,6 +99,9 @@ struct iproc_pcie {
struct iproc_pcie_ob ob;
const struct iproc_pcie_ob_map *ob_map;

+ struct iproc_pcie_ib ib;
+ const struct iproc_pcie_ib_map *ib_map;
+
bool need_msi_steer;
struct iproc_msi *msi;
};
--
2.1.4