[PATCH v2 06/12] PCI: iproc: Add PAXC v2 support

From: Ray Jui
Date: Mon Oct 31 2016 - 20:41:31 EST

Add support for the second generation of the iProc PCIe PAXC host
controller to the iProc PCIe host driver

Signed-off-by: Ray Jui <ray.jui@xxxxxxxxxxxx>
Reviewed-by: Anup Patel <anup.patel@xxxxxxxxxxxx>
Reviewed-by: Scott Branden <scott.branden@xxxxxxxxxxxx>
---
drivers/pci/host/pcie-iproc-platform.c | 3 +
drivers/pci/host/pcie-iproc.c | 176 ++++++++++++++++++++++++++++++++-
drivers/pci/host/pcie-iproc.h | 4 +
3 files changed, 180 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/host/pcie-iproc-platform.c b/drivers/pci/host/pcie-iproc-platform.c
index a3de087..f243150 100644
--- a/drivers/pci/host/pcie-iproc-platform.c
+++ b/drivers/pci/host/pcie-iproc-platform.c
@@ -33,6 +33,9 @@ static const struct of_device_id iproc_pcie_of_match_table[] = {
}, {
.compatible = "brcm,iproc-pcie-paxc",
.data = (int *)IPROC_PCIE_PAXC,
+ }, {
+ .compatible = "brcm,iproc-pcie-paxc-v2",
+ .data = (int *)IPROC_PCIE_PAXC_V2,
},
{ /* sentinel */ }
};
diff --git a/drivers/pci/host/pcie-iproc.c b/drivers/pci/host/pcie-iproc.c
index 07ec478..02f3ed3 100644
--- a/drivers/pci/host/pcie-iproc.c
+++ b/drivers/pci/host/pcie-iproc.c
@@ -21,6 +21,7 @@
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
+#include <linux/irqchip/arm-gic-v3.h>
#include <linux/platform_device.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
@@ -38,6 +39,12 @@
#define RC_PCIE_RST_OUTPUT BIT(RC_PCIE_RST_OUTPUT_SHIFT)
#define PAXC_RESET_MASK 0x7f

+#define GIC_V3_CFG_SHIFT 0
+#define GIC_V3_CFG BIT(GIC_V3_CFG_SHIFT)
+
+#define MSI_ENABLE_CFG_SHIFT 0
+#define MSI_ENABLE_CFG BIT(MSI_ENABLE_CFG_SHIFT)
+
#define CFG_IND_ADDR_MASK 0x00001ffc

#define CFG_ADDR_BUS_NUM_SHIFT 20
@@ -79,6 +86,31 @@ enum iproc_pcie_reg {
/* clock/reset signal control */
IPROC_PCIE_CLK_CTRL = 0,

+ /*
+ * To allow MSI to be steered to an external MSI controller (e.g., ARM
+ * GICv3 ITS)
+ */
+ IPROC_PCIE_MSI_GIC_MODE,
+
+ /*
+ * IPROC_PCIE_MSI_BASE_ADDR and IPROC_PCIE_MSI_WINDOW_SIZE define the
+ * window where the MSI posted writes are written, for the writes to be
+ * interpreted as MSI writes
+ */
+ IPROC_PCIE_MSI_BASE_ADDR,
+ IPROC_PCIE_MSI_WINDOW_SIZE,
+
+ /*
+ * To hold the address of the register where the MSI writes are
+ * programed. When ARM GICv3 ITS is used, this should be programmed
+ * with the address of the GITS_TRANSLATER register
+ */
+ IPROC_PCIE_MSI_ADDR_LO,
+ IPROC_PCIE_MSI_ADDR_HI,
+
+ /* enable MSI */
+ IPROC_PCIE_MSI_EN_CFG,
+
/* allow access to root complex configuration space */
IPROC_PCIE_CFG_IND_ADDR,
IPROC_PCIE_CFG_IND_DATA,
@@ -142,6 +174,20 @@ static const u16 iproc_pcie_reg_paxc[] = {
[IPROC_PCIE_CFG_DATA] = 0x1fc,
};

+/* iProc PCIe PAXC v2 registers */
+static const u16 iproc_pcie_reg_paxc_v2[] = {
+ [IPROC_PCIE_MSI_GIC_MODE] = 0x050,
+ [IPROC_PCIE_MSI_BASE_ADDR] = 0x074,
+ [IPROC_PCIE_MSI_WINDOW_SIZE] = 0x078,
+ [IPROC_PCIE_MSI_ADDR_LO] = 0x07c,
+ [IPROC_PCIE_MSI_ADDR_HI] = 0x080,
+ [IPROC_PCIE_MSI_EN_CFG] = 0x09c,
+ [IPROC_PCIE_CFG_IND_ADDR] = 0x1f0,
+ [IPROC_PCIE_CFG_IND_DATA] = 0x1f4,
+ [IPROC_PCIE_CFG_ADDR] = 0x1f8,
+ [IPROC_PCIE_CFG_DATA] = 0x1fc,
+};
+
static inline struct iproc_pcie *iproc_data(struct pci_bus *bus)
{
struct iproc_pcie *pcie;
@@ -506,13 +552,131 @@ static int iproc_pcie_map_ranges(struct iproc_pcie *pcie,
return 0;
}

+static int iproce_pcie_get_msi(struct iproc_pcie *pcie,
+ struct device_node *msi_node,
+ u64 *msi_addr)
+{
+ struct device *dev = pcie->dev;
+ int ret;
+ struct resource res;
+
+ /*
+ * Check if 'msi-map' points to ARM GICv3 ITS, which is the only
+ * supported external MSI controller that requires steering
+ */
+ if (!of_device_is_compatible(msi_node, "arm,gic-v3-its")) {
+ dev_err(dev, "unable to find compatible MSI controller\n");
+ return -ENODEV;
+ }
+
+ /* derive GITS_TRANSLATER address from GICv3 */
+ ret = of_address_to_resource(msi_node, 0, &res);
+ if (ret < 0) {
+ dev_err(dev, "unable to obtain MSI controller resources\n");
+ return ret;
+ }
+
+ *msi_addr = res.start + GITS_TRANSLATER;
+ return 0;
+}
+
+static void iproc_pcie_paxc_v2_msi_steer(struct iproc_pcie *pcie, u64 msi_addr)
+{
+ u32 val;
+
+ /*
+ * Program bits [43:13] of address of GITS_TRANSLATER register into
+ * bits [30:0] of the MSI base address register. In fact, in all iProc
+ * based SoCs, all I/O register bases are well below the 32-bit
+ * boundary, so we can safely assume bits [43:32] are always zeros
+ */
+ iproc_pcie_write_reg(pcie, IPROC_PCIE_MSI_BASE_ADDR,
+ (u32)(msi_addr >> 13));
+
+ /* use a default 8K window size */
+ iproc_pcie_write_reg(pcie, IPROC_PCIE_MSI_WINDOW_SIZE, 0);
+
+ /* steering MSI to GICv3 ITS */
+ val = iproc_pcie_read_reg(pcie, IPROC_PCIE_MSI_GIC_MODE);
+ val |= GIC_V3_CFG;
+ iproc_pcie_write_reg(pcie, IPROC_PCIE_MSI_GIC_MODE, val);
+
+ /*
+ * Program bits [43:2] of address of GITS_TRANSLATER register into the
+ * iProc MSI address registers
+ */
+ msi_addr >>= 2;
+ iproc_pcie_write_reg(pcie, IPROC_PCIE_MSI_ADDR_HI,
+ upper_32_bits(msi_addr));
+ iproc_pcie_write_reg(pcie, IPROC_PCIE_MSI_ADDR_LO,
+ lower_32_bits(msi_addr));
+
+ /* enable MSI */
+ val = iproc_pcie_read_reg(pcie, IPROC_PCIE_MSI_EN_CFG);
+ val |= MSI_ENABLE_CFG;
+ iproc_pcie_write_reg(pcie, IPROC_PCIE_MSI_EN_CFG, val);
+}
+
+static int iproc_pcie_msi_steer(struct iproc_pcie *pcie,
+ struct device_node *msi_node)
+{
+ struct device *dev = pcie->dev;
+ int ret;
+ u64 msi_addr;
+
+ ret = iproce_pcie_get_msi(pcie, msi_node, &msi_addr);
+ if (ret < 0) {
+ dev_err(dev, "msi steering failed\n");
+ return ret;
+ }
+
+ switch (pcie->type) {
+ case IPROC_PCIE_PAXC_V2:
+ iproc_pcie_paxc_v2_msi_steer(pcie, msi_addr);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
static int iproc_pcie_msi_enable(struct iproc_pcie *pcie)
{
struct device_node *msi_node;
+ int ret;
+
+ /*
+ * Either the "msi-parent" or the "msi-map" phandle needs to exist
+ * for us to obtain the MSI node
+ */

msi_node = of_parse_phandle(pcie->dev->of_node, "msi-parent", 0);
- if (!msi_node)
- return -ENODEV;
+ if (!msi_node) {
+ const __be32 *msi_map = NULL;
+ int len;
+ u32 phandle;
+
+ msi_map = of_get_property(pcie->dev->of_node, "msi-map", &len);
+ if (!msi_map)
+ return -ENODEV;
+
+ phandle = be32_to_cpup(msi_map + 1);
+ msi_node = of_find_node_by_phandle(phandle);
+ if (!msi_node)
+ return -ENODEV;
+ }
+
+ /*
+ * Certain revisions of the iProc PCIe controller require additional
+ * configurations to steer the MSI writes towards an external MSI
+ * controller
+ */
+ if (pcie->need_msi_steer) {
+ ret = iproc_pcie_msi_steer(pcie, msi_node);
+ if (ret)
+ return ret;
+ }

/*
* If another MSI controller is being used, the call below should fail
@@ -544,6 +708,11 @@ static int iproc_pcie_rev_init(struct iproc_pcie *pcie)
regs = iproc_pcie_reg_paxc;
pcie->ep_is_internal = true;
break;
+ case IPROC_PCIE_PAXC_V2:
+ regs = iproc_pcie_reg_paxc_v2;
+ pcie->ep_is_internal = true;
+ pcie->need_msi_steer = true;
+ break;
default:
dev_err(dev, "incompatible iProc PCIe interface\n");
return -EINVAL;
@@ -556,7 +725,8 @@ static int iproc_pcie_rev_init(struct iproc_pcie *pcie)
return -ENOMEM;

/* go through the register table and populate all valid registers */
- pcie->reg_offsets[0] = regs[0];
+ pcie->reg_offsets[0] = (pcie->type == IPROC_PCIE_PAXC_V2) ?
+ IPROC_PCIE_REG_INVALID : regs[0];
for (reg_idx = 1; reg_idx < IPROC_PCIE_MAX_NUM_REG; reg_idx++)
pcie->reg_offsets[reg_idx] = regs[reg_idx] ?
regs[reg_idx] : IPROC_PCIE_REG_INVALID;
diff --git a/drivers/pci/host/pcie-iproc.h b/drivers/pci/host/pcie-iproc.h
index 711dd3a..c2da140 100644
--- a/drivers/pci/host/pcie-iproc.h
+++ b/drivers/pci/host/pcie-iproc.h
@@ -27,6 +27,7 @@ enum iproc_pcie_type {
IPROC_PCIE_PAXB_BCMA = 0,
IPROC_PCIE_PAXB,
IPROC_PCIE_PAXC,
+ IPROC_PCIE_PAXC_V2,
};

/**
@@ -61,6 +62,8 @@ struct iproc_msi;
* unsupported request from being forwarded as an APB bus error
* @need_ob_cfg: indicates SW needs to configure the outbound mapping window
* @ob: outbound mapping 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
*/
struct iproc_pcie {
@@ -79,6 +82,7 @@ struct iproc_pcie {
bool has_apb_err_disable;
bool need_ob_cfg;
struct iproc_pcie_ob ob;
+ bool need_msi_steer;
struct iproc_msi *msi;
};

--
2.1.4