[PATCH v6 1/3] PCI: altera: Add Stratix 10 PCIe support

From: Ley Foon Tan
Date: Wed Feb 27 2019 - 21:53:03 EST


Add PCIe Root Port support for Stratix 10 device.

Main differences compare with PCIe Root Port IP on Cyclone V
and Arria 10 devices:

- HIP interface to access Root Port configuration register.
- TLP programming flow:
- One REG0 register
- Don't need to check alignment

Signed-off-by: Ley Foon Tan <ley.foon.tan@xxxxxxxxx>
---
drivers/pci/controller/pcie-altera.c | 264 ++++++++++++++++++++++++---
1 file changed, 240 insertions(+), 24 deletions(-)

diff --git a/drivers/pci/controller/pcie-altera.c b/drivers/pci/controller/pcie-altera.c
index 7d05e51205b3..c57fd7f4e848 100644
--- a/drivers/pci/controller/pcie-altera.c
+++ b/drivers/pci/controller/pcie-altera.c
@@ -11,6 +11,7 @@
#include <linux/irqchip/chained_irq.h>
#include <linux/init.h>
#include <linux/of_address.h>
+#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/of_pci.h>
#include <linux/pci.h>
@@ -37,7 +38,12 @@
#define RP_LTSSM_MASK 0x1f
#define LTSSM_L0 0xf

-#define PCIE_CAP_OFFSET 0x80
+#define S10_RP_TX_CNTRL 0x2004
+#define S10_RP_RXCPL_REG 0x2008
+#define S10_RP_RXCPL_STATUS 0x200C
+#define S10_RP_CFG_ADDR(pcie, reg) \
+ (((pcie)->hip_base) + (reg) + (1 << 20))
+
/* TLP configuration type 0 and 1 */
#define TLP_FMTTYPE_CFGRD0 0x04 /* Configuration Read Type 0 */
#define TLP_FMTTYPE_CFGWR0 0x44 /* Configuration Write Type 0 */
@@ -49,18 +55,19 @@
#define RP_DEVFN 0
#define TLP_REQ_ID(bus, devfn) (((bus) << 8) | (devfn))
#define TLP_CFGRD_DW0(pcie, bus) \
- ((((bus == pcie->root_bus_nr) ? TLP_FMTTYPE_CFGRD0 \
- : TLP_FMTTYPE_CFGRD1) << 24) | \
- TLP_PAYLOAD_SIZE)
+ ((((bus == pcie->root_bus_nr) ? pcie->pcie_data->cfgrd0 \
+ : pcie->pcie_data->cfgrd1) << 24) | \
+ TLP_PAYLOAD_SIZE)
#define TLP_CFGWR_DW0(pcie, bus) \
- ((((bus == pcie->root_bus_nr) ? TLP_FMTTYPE_CFGWR0 \
- : TLP_FMTTYPE_CFGWR1) << 24) | \
- TLP_PAYLOAD_SIZE)
+ ((((bus == pcie->root_bus_nr) ? pcie->pcie_data->cfgwr0 \
+ : pcie->pcie_data->cfgwr1) << 24) | \
+ TLP_PAYLOAD_SIZE)
#define TLP_CFG_DW1(pcie, tag, be) \
- (((TLP_REQ_ID(pcie->root_bus_nr, RP_DEVFN)) << 16) | (tag << 8) | (be))
+ (((TLP_REQ_ID(pcie->root_bus_nr, RP_DEVFN)) << 16) | (tag << 8) | (be))
#define TLP_CFG_DW2(bus, devfn, offset) \
(((bus) << 24) | ((devfn) << 16) | (offset))
#define TLP_COMP_STATUS(s) (((s) >> 13) & 7)
+#define TLP_BYTE_COUNT(s) (((s) >> 0) & 0xfff)
#define TLP_HDR_SIZE 3
#define TLP_LOOP 500

@@ -69,14 +76,47 @@

#define DWORD_MASK 3

+#define S10_TLP_FMTTYPE_CFGRD0 0x05
+#define S10_TLP_FMTTYPE_CFGRD1 0x04
+#define S10_TLP_FMTTYPE_CFGWR0 0x45
+#define S10_TLP_FMTTYPE_CFGWR1 0x44
+
+enum altera_pcie_version {
+ ALTERA_PCIE_V1 = 0,
+ ALTERA_PCIE_V2,
+};
+
struct altera_pcie {
struct platform_device *pdev;
- void __iomem *cra_base; /* DT Cra */
+ void __iomem *cra_base;
+ void __iomem *hip_base;
int irq;
u8 root_bus_nr;
struct irq_domain *irq_domain;
struct resource bus_range;
struct list_head resources;
+ const struct altera_pcie_data *pcie_data;
+};
+
+struct altera_pcie_ops {
+ int (*tlp_read_pkt)(struct altera_pcie *pcie, u32 *value);
+ void (*tlp_write_pkt)(struct altera_pcie *pcie, u32 *headers,
+ u32 data, bool align);
+ bool (*get_link_status)(struct altera_pcie *pcie);
+ int (*rp_read_cfg)(struct altera_pcie *pcie, int where,
+ int size, u32 *value);
+ int (*rp_write_cfg)(struct altera_pcie *pcie, u8 busno,
+ int where, int size, u32 value);
+};
+
+struct altera_pcie_data {
+ const struct altera_pcie_ops *ops;
+ enum altera_pcie_version version;
+ u32 cap_offset; /* PCIe capability structure register offset */
+ u32 cfgrd0;
+ u32 cfgrd1;
+ u32 cfgwr0;
+ u32 cfgwr1;
};

struct tlp_rp_regpair_t {
@@ -101,6 +141,15 @@ static bool altera_pcie_link_up(struct altera_pcie *pcie)
return !!((cra_readl(pcie, RP_LTSSM) & RP_LTSSM_MASK) == LTSSM_L0);
}

+static bool s10_altera_pcie_link_up(struct altera_pcie *pcie)
+{
+ void __iomem *addr = S10_RP_CFG_ADDR(pcie,
+ pcie->pcie_data->cap_offset +
+ PCI_EXP_LNKSTA);
+
+ return !!(readw(addr) & PCI_EXP_LNKSTA_DLLLA);
+}
+
/*
* Altera PCIe port uses BAR0 of RC's configuration space as the translation
* from PCI bus to native BUS. Entire DDR region is mapped into PCIe space
@@ -128,12 +177,18 @@ static void tlp_write_tx(struct altera_pcie *pcie,
cra_writel(pcie, tlp_rp_regdata->ctrl, RP_TX_CNTRL);
}

+static void s10_tlp_write_tx(struct altera_pcie *pcie, u32 reg0, u32 ctrl)
+{
+ cra_writel(pcie, reg0, RP_TX_REG0);
+ cra_writel(pcie, ctrl, S10_RP_TX_CNTRL);
+}
+
static bool altera_pcie_valid_device(struct altera_pcie *pcie,
struct pci_bus *bus, int dev)
{
/* If there is no link, then there is no device */
if (bus->number != pcie->root_bus_nr) {
- if (!altera_pcie_link_up(pcie))
+ if (!pcie->pcie_data->ops->get_link_status(pcie))
return false;
}

@@ -183,6 +238,47 @@ static int tlp_read_packet(struct altera_pcie *pcie, u32 *value)
return PCIBIOS_DEVICE_NOT_FOUND;
}

+static int s10_tlp_read_packet(struct altera_pcie *pcie, u32 *value)
+{
+ int i;
+ u32 ctrl;
+ u32 comp_status;
+ u32 dw[4];
+ u32 count;
+
+ for (i = 0; i < TLP_LOOP; i++) {
+ ctrl = cra_readl(pcie, S10_RP_RXCPL_STATUS);
+ if (!(ctrl & RP_RXCPL_SOP)) {
+ udelay(5);
+ continue;
+ }
+
+ /* Read first DW */
+ dw[0] = cra_readl(pcie, S10_RP_RXCPL_REG);
+ count = 1;
+
+ /* Poll for EOP */
+ for (i = 0; i < TLP_LOOP && count < ARRAY_SIZE(dw); i++) {
+ ctrl = cra_readl(pcie, S10_RP_RXCPL_STATUS);
+ dw[count++] = cra_readl(pcie, S10_RP_RXCPL_REG);
+ if (ctrl & RP_RXCPL_EOP) {
+ comp_status = TLP_COMP_STATUS(dw[1]);
+ if (comp_status)
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ if (value &&
+ TLP_BYTE_COUNT(dw[1]) == sizeof(u32) &&
+ count == 4)
+ *value = dw[3];
+
+ return PCIBIOS_SUCCESSFUL;
+ }
+ }
+ }
+
+ return PCIBIOS_DEVICE_NOT_FOUND;
+}
+
static void tlp_write_packet(struct altera_pcie *pcie, u32 *headers,
u32 data, bool align)
{
@@ -210,6 +306,15 @@ static void tlp_write_packet(struct altera_pcie *pcie, u32 *headers,
tlp_write_tx(pcie, &tlp_rp_regdata);
}

+static void s10_tlp_write_packet(struct altera_pcie *pcie, u32 *headers,
+ u32 data, bool dummy)
+{
+ s10_tlp_write_tx(pcie, headers[0], RP_TX_SOP);
+ s10_tlp_write_tx(pcie, headers[1], 0);
+ s10_tlp_write_tx(pcie, headers[2], 0);
+ s10_tlp_write_tx(pcie, data, RP_TX_EOP);
+}
+
static int tlp_cfg_dword_read(struct altera_pcie *pcie, u8 bus, u32 devfn,
int where, u8 byte_en, u32 *value)
{
@@ -219,9 +324,9 @@ static int tlp_cfg_dword_read(struct altera_pcie *pcie, u8 bus, u32 devfn,
headers[1] = TLP_CFG_DW1(pcie, TLP_READ_TAG, byte_en);
headers[2] = TLP_CFG_DW2(bus, devfn, where);

- tlp_write_packet(pcie, headers, 0, false);
+ pcie->pcie_data->ops->tlp_write_pkt(pcie, headers, 0, false);

- return tlp_read_packet(pcie, value);
+ return pcie->pcie_data->ops->tlp_read_pkt(pcie, value);
}

static int tlp_cfg_dword_write(struct altera_pcie *pcie, u8 bus, u32 devfn,
@@ -236,11 +341,13 @@ static int tlp_cfg_dword_write(struct altera_pcie *pcie, u8 bus, u32 devfn,

/* check alignment to Qword */
if ((where & 0x7) == 0)
- tlp_write_packet(pcie, headers, value, true);
+ pcie->pcie_data->ops->tlp_write_pkt(pcie, headers,
+ value, true);
else
- tlp_write_packet(pcie, headers, value, false);
+ pcie->pcie_data->ops->tlp_write_pkt(pcie, headers,
+ value, false);

- ret = tlp_read_packet(pcie, NULL);
+ ret = pcie->pcie_data->ops->tlp_read_pkt(pcie, NULL);
if (ret != PCIBIOS_SUCCESSFUL)
return ret;

@@ -254,6 +361,53 @@ static int tlp_cfg_dword_write(struct altera_pcie *pcie, u8 bus, u32 devfn,
return PCIBIOS_SUCCESSFUL;
}

+static int s10_rp_read_cfg(struct altera_pcie *pcie, int where,
+ int size, u32 *value)
+{
+ void *addr = S10_RP_CFG_ADDR(pcie, where);
+
+ switch (size) {
+ case 1:
+ *value = readb(addr);
+ break;
+ case 2:
+ *value = readw(addr);
+ break;
+ default:
+ *value = readl(addr);
+ break;
+ }
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
+static int s10_rp_write_cfg(struct altera_pcie *pcie, u8 busno,
+ int where, int size, u32 value)
+{
+ void *addr = S10_RP_CFG_ADDR(pcie, where);
+
+ switch (size) {
+ case 1:
+ writeb(value, addr);
+ break;
+ case 2:
+ writew(value, addr);
+ break;
+ default:
+ writel(value, addr);
+ break;
+ }
+
+ /*
+ * Monitor changes to PCI_PRIMARY_BUS register on root port
+ * and update local copy of root bus number accordingly.
+ */
+ if (busno == pcie->root_bus_nr && where == PCI_PRIMARY_BUS)
+ pcie->root_bus_nr = value & 0xff;
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
static int _altera_pcie_cfg_read(struct altera_pcie *pcie, u8 busno,
unsigned int devfn, int where, int size,
u32 *value)
@@ -262,6 +416,10 @@ static int _altera_pcie_cfg_read(struct altera_pcie *pcie, u8 busno,
u32 data;
u8 byte_en;

+ if (busno == pcie->root_bus_nr && pcie->pcie_data->ops->rp_read_cfg)
+ return pcie->pcie_data->ops->rp_read_cfg(pcie, where,
+ size, value);
+
switch (size) {
case 1:
byte_en = 1 << (where & 3);
@@ -302,6 +460,10 @@ static int _altera_pcie_cfg_write(struct altera_pcie *pcie, u8 busno,
u32 shift = 8 * (where & 3);
u8 byte_en;

+ if (busno == pcie->root_bus_nr && pcie->pcie_data->ops->rp_write_cfg)
+ return pcie->pcie_data->ops->rp_write_cfg(pcie, busno,
+ where, size, value);
+
switch (size) {
case 1:
data32 = (value & 0xff) << shift;
@@ -365,7 +527,8 @@ static int altera_read_cap_word(struct altera_pcie *pcie, u8 busno,
int ret;

ret = _altera_pcie_cfg_read(pcie, busno, devfn,
- PCIE_CAP_OFFSET + offset, sizeof(*value),
+ pcie->pcie_data->cap_offset + offset,
+ sizeof(*value),
&data);
*value = data;
return ret;
@@ -375,7 +538,8 @@ static int altera_write_cap_word(struct altera_pcie *pcie, u8 busno,
unsigned int devfn, int offset, u16 value)
{
return _altera_pcie_cfg_write(pcie, busno, devfn,
- PCIE_CAP_OFFSET + offset, sizeof(value),
+ pcie->pcie_data->cap_offset + offset,
+ sizeof(value),
value);
}

@@ -403,7 +567,7 @@ static void altera_wait_link_retrain(struct altera_pcie *pcie)
/* Wait for link is up */
start_jiffies = jiffies;
for (;;) {
- if (altera_pcie_link_up(pcie))
+ if (pcie->pcie_data->ops->get_link_status(pcie))
break;

if (time_after(jiffies, start_jiffies + LINK_UP_TIMEOUT)) {
@@ -418,7 +582,7 @@ static void altera_pcie_retrain(struct altera_pcie *pcie)
{
u16 linkcap, linkstat, linkctl;

- if (!altera_pcie_link_up(pcie))
+ if (!pcie->pcie_data->ops->get_link_status(pcie))
return;

/*
@@ -540,12 +704,20 @@ static int altera_pcie_parse_dt(struct altera_pcie *pcie)
struct device *dev = &pcie->pdev->dev;
struct platform_device *pdev = pcie->pdev;
struct resource *cra;
+ struct resource *hip;

cra = platform_get_resource_byname(pdev, IORESOURCE_MEM, "Cra");
pcie->cra_base = devm_ioremap_resource(dev, cra);
if (IS_ERR(pcie->cra_base))
return PTR_ERR(pcie->cra_base);

+ if (pcie->pcie_data->version == ALTERA_PCIE_V2) {
+ hip = platform_get_resource_byname(pdev, IORESOURCE_MEM, "Hip");
+ pcie->hip_base = devm_ioremap_resource(&pdev->dev, hip);
+ if (IS_ERR(pcie->hip_base))
+ return PTR_ERR(pcie->hip_base);
+ }
+
/* setup IRQ */
pcie->irq = platform_get_irq(pdev, 0);
if (pcie->irq < 0) {
@@ -562,6 +734,48 @@ static void altera_pcie_host_init(struct altera_pcie *pcie)
altera_pcie_retrain(pcie);
}

+static const struct altera_pcie_ops altera_pcie_ops_1_0 = {
+ .tlp_read_pkt = tlp_read_packet,
+ .tlp_write_pkt = tlp_write_packet,
+ .get_link_status = altera_pcie_link_up,
+};
+
+static const struct altera_pcie_ops altera_pcie_ops_2_0 = {
+ .tlp_read_pkt = s10_tlp_read_packet,
+ .tlp_write_pkt = s10_tlp_write_packet,
+ .get_link_status = s10_altera_pcie_link_up,
+ .rp_read_cfg = s10_rp_read_cfg,
+ .rp_write_cfg = s10_rp_write_cfg,
+};
+
+static const struct altera_pcie_data altera_pcie_1_0_data = {
+ .ops = &altera_pcie_ops_1_0,
+ .cap_offset = 0x80,
+ .version = ALTERA_PCIE_V1,
+ .cfgrd0 = TLP_FMTTYPE_CFGRD0,
+ .cfgrd1 = TLP_FMTTYPE_CFGRD1,
+ .cfgwr0 = TLP_FMTTYPE_CFGWR0,
+ .cfgwr1 = TLP_FMTTYPE_CFGWR1,
+};
+
+static const struct altera_pcie_data altera_pcie_2_0_data = {
+ .ops = &altera_pcie_ops_2_0,
+ .version = ALTERA_PCIE_V2,
+ .cap_offset = 0x70,
+ .cfgrd0 = S10_TLP_FMTTYPE_CFGRD0,
+ .cfgrd1 = S10_TLP_FMTTYPE_CFGRD1,
+ .cfgwr0 = S10_TLP_FMTTYPE_CFGWR0,
+ .cfgwr1 = S10_TLP_FMTTYPE_CFGWR1,
+};
+
+static const struct of_device_id altera_pcie_of_match[] = {
+ {.compatible = "altr,pcie-root-port-1.0",
+ .data = &altera_pcie_1_0_data },
+ {.compatible = "altr,pcie-root-port-2.0",
+ .data = &altera_pcie_2_0_data },
+ {},
+};
+
static int altera_pcie_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -570,6 +784,7 @@ static int altera_pcie_probe(struct platform_device *pdev)
struct pci_bus *child;
struct pci_host_bridge *bridge;
int ret;
+ const struct of_device_id *match;

bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
if (!bridge)
@@ -578,6 +793,12 @@ static int altera_pcie_probe(struct platform_device *pdev)
pcie = pci_host_bridge_priv(bridge);
pcie->pdev = pdev;

+ match = of_match_device(altera_pcie_of_match, &pdev->dev);
+ if (!match)
+ return -ENODEV;
+
+ pcie->pcie_data = match->data;
+
ret = altera_pcie_parse_dt(pcie);
if (ret) {
dev_err(dev, "Parsing DT failed\n");
@@ -628,11 +849,6 @@ static int altera_pcie_probe(struct platform_device *pdev)
return ret;
}

-static const struct of_device_id altera_pcie_of_match[] = {
- { .compatible = "altr,pcie-root-port-1.0", },
- {},
-};
-
static struct platform_driver altera_pcie_driver = {
.probe = altera_pcie_probe,
.driver = {
--
2.19.0