linux/drivers/pci/controller/dwc/pcie-al.c
Jonathan Chocron a8daea9475 PCI: dwc: al: Add Amazon Annapurna Labs PCIe controller driver
This driver is DT based and utilizes the DesignWare APIs.

It allows using a smaller ECAM range for a larger bus range -
usually an entire bus uses 1MB of address space, but the driver
can use it for a larger number of buses. This is achieved by using a HW
mechanism which allows changing the BUS part of the "final" outgoing
config transaction. There are 2 HW regs, one which is basically a
bitmask determining which bits to take from the AXI transaction itself
and another which holds the complementary part programmed by the
driver.

All link initializations are handled by the boot FW.

Signed-off-by: Jonathan Chocron <jonnyc@amazon.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
2019-09-16 14:16:44 +01:00

459 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* PCIe host controller driver for Amazon's Annapurna Labs IP (used in chips
* such as Graviton and Alpine)
*
* Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Author: Jonathan Chocron <jonnyc@amazon.com>
*/
#include <linux/pci.h>
#include <linux/pci-ecam.h>
#include <linux/pci-acpi.h>
#include "../../pci.h"
#if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)
struct al_pcie_acpi {
void __iomem *dbi_base;
};
static void __iomem *al_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
int where)
{
struct pci_config_window *cfg = bus->sysdata;
struct al_pcie_acpi *pcie = cfg->priv;
void __iomem *dbi_base = pcie->dbi_base;
if (bus->number == cfg->busr.start) {
/*
* The DW PCIe core doesn't filter out transactions to other
* devices/functions on the root bus num, so we do this here.
*/
if (PCI_SLOT(devfn) > 0)
return NULL;
else
return dbi_base + where;
}
return pci_ecam_map_bus(bus, devfn, where);
}
static int al_pcie_init(struct pci_config_window *cfg)
{
struct device *dev = cfg->parent;
struct acpi_device *adev = to_acpi_device(dev);
struct acpi_pci_root *root = acpi_driver_data(adev);
struct al_pcie_acpi *al_pcie;
struct resource *res;
int ret;
al_pcie = devm_kzalloc(dev, sizeof(*al_pcie), GFP_KERNEL);
if (!al_pcie)
return -ENOMEM;
res = devm_kzalloc(dev, sizeof(*res), GFP_KERNEL);
if (!res)
return -ENOMEM;
ret = acpi_get_rc_resources(dev, "AMZN0001", root->segment, res);
if (ret) {
dev_err(dev, "can't get rc dbi base address for SEG %d\n",
root->segment);
return ret;
}
dev_dbg(dev, "Root port dbi res: %pR\n", res);
al_pcie->dbi_base = devm_pci_remap_cfg_resource(dev, res);
if (IS_ERR(al_pcie->dbi_base)) {
long err = PTR_ERR(al_pcie->dbi_base);
dev_err(dev, "couldn't remap dbi base %pR (err:%ld)\n",
res, err);
return err;
}
cfg->priv = al_pcie;
return 0;
}
struct pci_ecam_ops al_pcie_ops = {
.bus_shift = 20,
.init = al_pcie_init,
.pci_ops = {
.map_bus = al_pcie_map_bus,
.read = pci_generic_config_read,
.write = pci_generic_config_write,
}
};
#endif /* defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS) */
#ifdef CONFIG_PCIE_AL
#include <linux/of_pci.h>
#include "pcie-designware.h"
#define AL_PCIE_REV_ID_2 2
#define AL_PCIE_REV_ID_3 3
#define AL_PCIE_REV_ID_4 4
#define AXI_BASE_OFFSET 0x0
#define DEVICE_ID_OFFSET 0x16c
#define DEVICE_REV_ID 0x0
#define DEVICE_REV_ID_DEV_ID_MASK GENMASK(31, 16)
#define DEVICE_REV_ID_DEV_ID_X4 0
#define DEVICE_REV_ID_DEV_ID_X8 2
#define DEVICE_REV_ID_DEV_ID_X16 4
#define OB_CTRL_REV1_2_OFFSET 0x0040
#define OB_CTRL_REV3_5_OFFSET 0x0030
#define CFG_TARGET_BUS 0x0
#define CFG_TARGET_BUS_MASK_MASK GENMASK(7, 0)
#define CFG_TARGET_BUS_BUSNUM_MASK GENMASK(15, 8)
#define CFG_CONTROL 0x4
#define CFG_CONTROL_SUBBUS_MASK GENMASK(15, 8)
#define CFG_CONTROL_SEC_BUS_MASK GENMASK(23, 16)
struct al_pcie_reg_offsets {
unsigned int ob_ctrl;
};
struct al_pcie_target_bus_cfg {
u8 reg_val;
u8 reg_mask;
u8 ecam_mask;
};
struct al_pcie {
struct dw_pcie *pci;
void __iomem *controller_base; /* base of PCIe unit (not DW core) */
struct device *dev;
resource_size_t ecam_size;
unsigned int controller_rev_id;
struct al_pcie_reg_offsets reg_offsets;
struct al_pcie_target_bus_cfg target_bus_cfg;
};
#define PCIE_ECAM_DEVFN(x) (((x) & 0xff) << 12)
#define to_al_pcie(x) dev_get_drvdata((x)->dev)
static inline u32 al_pcie_controller_readl(struct al_pcie *pcie, u32 offset)
{
return readl_relaxed(pcie->controller_base + offset);
}
static inline void al_pcie_controller_writel(struct al_pcie *pcie, u32 offset,
u32 val)
{
writel_relaxed(val, pcie->controller_base + offset);
}
static int al_pcie_rev_id_get(struct al_pcie *pcie, unsigned int *rev_id)
{
u32 dev_rev_id_val;
u32 dev_id_val;
dev_rev_id_val = al_pcie_controller_readl(pcie, AXI_BASE_OFFSET +
DEVICE_ID_OFFSET +
DEVICE_REV_ID);
dev_id_val = FIELD_GET(DEVICE_REV_ID_DEV_ID_MASK, dev_rev_id_val);
switch (dev_id_val) {
case DEVICE_REV_ID_DEV_ID_X4:
*rev_id = AL_PCIE_REV_ID_2;
break;
case DEVICE_REV_ID_DEV_ID_X8:
*rev_id = AL_PCIE_REV_ID_3;
break;
case DEVICE_REV_ID_DEV_ID_X16:
*rev_id = AL_PCIE_REV_ID_4;
break;
default:
dev_err(pcie->dev, "Unsupported dev_id_val (0x%x)\n",
dev_id_val);
return -EINVAL;
}
dev_dbg(pcie->dev, "dev_id_val: 0x%x\n", dev_id_val);
return 0;
}
static int al_pcie_reg_offsets_set(struct al_pcie *pcie)
{
switch (pcie->controller_rev_id) {
case AL_PCIE_REV_ID_2:
pcie->reg_offsets.ob_ctrl = OB_CTRL_REV1_2_OFFSET;
break;
case AL_PCIE_REV_ID_3:
case AL_PCIE_REV_ID_4:
pcie->reg_offsets.ob_ctrl = OB_CTRL_REV3_5_OFFSET;
break;
default:
dev_err(pcie->dev, "Unsupported controller rev_id: 0x%x\n",
pcie->controller_rev_id);
return -EINVAL;
}
return 0;
}
static inline void al_pcie_target_bus_set(struct al_pcie *pcie,
u8 target_bus,
u8 mask_target_bus)
{
u32 reg;
reg = FIELD_PREP(CFG_TARGET_BUS_MASK_MASK, mask_target_bus) |
FIELD_PREP(CFG_TARGET_BUS_BUSNUM_MASK, target_bus);
al_pcie_controller_writel(pcie, AXI_BASE_OFFSET +
pcie->reg_offsets.ob_ctrl + CFG_TARGET_BUS,
reg);
}
static void __iomem *al_pcie_conf_addr_map(struct al_pcie *pcie,
unsigned int busnr,
unsigned int devfn)
{
struct al_pcie_target_bus_cfg *target_bus_cfg = &pcie->target_bus_cfg;
unsigned int busnr_ecam = busnr & target_bus_cfg->ecam_mask;
unsigned int busnr_reg = busnr & target_bus_cfg->reg_mask;
struct pcie_port *pp = &pcie->pci->pp;
void __iomem *pci_base_addr;
pci_base_addr = (void __iomem *)((uintptr_t)pp->va_cfg0_base +
(busnr_ecam << 20) +
PCIE_ECAM_DEVFN(devfn));
if (busnr_reg != target_bus_cfg->reg_val) {
dev_dbg(pcie->pci->dev, "Changing target bus busnum val from 0x%x to 0x%x\n",
target_bus_cfg->reg_val, busnr_reg);
target_bus_cfg->reg_val = busnr_reg;
al_pcie_target_bus_set(pcie,
target_bus_cfg->reg_val,
target_bus_cfg->reg_mask);
}
return pci_base_addr;
}
static int al_pcie_rd_other_conf(struct pcie_port *pp, struct pci_bus *bus,
unsigned int devfn, int where, int size,
u32 *val)
{
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
struct al_pcie *pcie = to_al_pcie(pci);
unsigned int busnr = bus->number;
void __iomem *pci_addr;
int rc;
pci_addr = al_pcie_conf_addr_map(pcie, busnr, devfn);
rc = dw_pcie_read(pci_addr + where, size, val);
dev_dbg(pci->dev, "%d-byte config read from %04x:%02x:%02x.%d offset 0x%x (pci_addr: 0x%px) - val:0x%x\n",
size, pci_domain_nr(bus), bus->number,
PCI_SLOT(devfn), PCI_FUNC(devfn), where,
(pci_addr + where), *val);
return rc;
}
static int al_pcie_wr_other_conf(struct pcie_port *pp, struct pci_bus *bus,
unsigned int devfn, int where, int size,
u32 val)
{
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
struct al_pcie *pcie = to_al_pcie(pci);
unsigned int busnr = bus->number;
void __iomem *pci_addr;
int rc;
pci_addr = al_pcie_conf_addr_map(pcie, busnr, devfn);
rc = dw_pcie_write(pci_addr + where, size, val);
dev_dbg(pci->dev, "%d-byte config write to %04x:%02x:%02x.%d offset 0x%x (pci_addr: 0x%px) - val:0x%x\n",
size, pci_domain_nr(bus), bus->number,
PCI_SLOT(devfn), PCI_FUNC(devfn), where,
(pci_addr + where), val);
return rc;
}
static void al_pcie_config_prepare(struct al_pcie *pcie)
{
struct al_pcie_target_bus_cfg *target_bus_cfg;
struct pcie_port *pp = &pcie->pci->pp;
unsigned int ecam_bus_mask;
u32 cfg_control_offset;
u8 subordinate_bus;
u8 secondary_bus;
u32 cfg_control;
u32 reg;
target_bus_cfg = &pcie->target_bus_cfg;
ecam_bus_mask = (pcie->ecam_size >> 20) - 1;
if (ecam_bus_mask > 255) {
dev_warn(pcie->dev, "ECAM window size is larger than 256MB. Cutting off at 256\n");
ecam_bus_mask = 255;
}
/* This portion is taken from the transaction address */
target_bus_cfg->ecam_mask = ecam_bus_mask;
/* This portion is taken from the cfg_target_bus reg */
target_bus_cfg->reg_mask = ~target_bus_cfg->ecam_mask;
target_bus_cfg->reg_val = pp->busn->start & target_bus_cfg->reg_mask;
al_pcie_target_bus_set(pcie, target_bus_cfg->reg_val,
target_bus_cfg->reg_mask);
secondary_bus = pp->busn->start + 1;
subordinate_bus = pp->busn->end;
/* Set the valid values of secondary and subordinate buses */
cfg_control_offset = AXI_BASE_OFFSET + pcie->reg_offsets.ob_ctrl +
CFG_CONTROL;
cfg_control = al_pcie_controller_readl(pcie, cfg_control_offset);
reg = cfg_control &
~(CFG_CONTROL_SEC_BUS_MASK | CFG_CONTROL_SUBBUS_MASK);
reg |= FIELD_PREP(CFG_CONTROL_SUBBUS_MASK, subordinate_bus) |
FIELD_PREP(CFG_CONTROL_SEC_BUS_MASK, secondary_bus);
al_pcie_controller_writel(pcie, cfg_control_offset, reg);
}
static int al_pcie_host_init(struct pcie_port *pp)
{
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
struct al_pcie *pcie = to_al_pcie(pci);
int rc;
rc = al_pcie_rev_id_get(pcie, &pcie->controller_rev_id);
if (rc)
return rc;
rc = al_pcie_reg_offsets_set(pcie);
if (rc)
return rc;
al_pcie_config_prepare(pcie);
return 0;
}
static const struct dw_pcie_host_ops al_pcie_host_ops = {
.rd_other_conf = al_pcie_rd_other_conf,
.wr_other_conf = al_pcie_wr_other_conf,
.host_init = al_pcie_host_init,
};
static int al_add_pcie_port(struct pcie_port *pp,
struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
int ret;
pp->ops = &al_pcie_host_ops;
ret = dw_pcie_host_init(pp);
if (ret) {
dev_err(dev, "failed to initialize host\n");
return ret;
}
return 0;
}
static const struct dw_pcie_ops dw_pcie_ops = {
};
static int al_pcie_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct resource *controller_res;
struct resource *ecam_res;
struct resource *dbi_res;
struct al_pcie *al_pcie;
struct dw_pcie *pci;
al_pcie = devm_kzalloc(dev, sizeof(*al_pcie), GFP_KERNEL);
if (!al_pcie)
return -ENOMEM;
pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
if (!pci)
return -ENOMEM;
pci->dev = dev;
pci->ops = &dw_pcie_ops;
al_pcie->pci = pci;
al_pcie->dev = dev;
dbi_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
pci->dbi_base = devm_pci_remap_cfg_resource(dev, dbi_res);
if (IS_ERR(pci->dbi_base)) {
dev_err(dev, "couldn't remap dbi base %pR\n", dbi_res);
return PTR_ERR(pci->dbi_base);
}
ecam_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config");
if (!ecam_res) {
dev_err(dev, "couldn't find 'config' reg in DT\n");
return -ENOENT;
}
al_pcie->ecam_size = resource_size(ecam_res);
controller_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
"controller");
al_pcie->controller_base = devm_ioremap_resource(dev, controller_res);
if (IS_ERR(al_pcie->controller_base)) {
dev_err(dev, "couldn't remap controller base %pR\n",
controller_res);
return PTR_ERR(al_pcie->controller_base);
}
dev_dbg(dev, "From DT: dbi_base: %pR, controller_base: %pR\n",
dbi_res, controller_res);
platform_set_drvdata(pdev, al_pcie);
return al_add_pcie_port(&pci->pp, pdev);
}
static const struct of_device_id al_pcie_of_match[] = {
{ .compatible = "amazon,al-alpine-v2-pcie",
},
{ .compatible = "amazon,al-alpine-v3-pcie",
},
{},
};
static struct platform_driver al_pcie_driver = {
.driver = {
.name = "al-pcie",
.of_match_table = al_pcie_of_match,
.suppress_bind_attrs = true,
},
.probe = al_pcie_probe,
};
builtin_platform_driver(al_pcie_driver);
#endif /* CONFIG_PCIE_AL*/