linux_dsm_epyc7002/drivers/pci/dwc/pcie-artpec6.c
Guenter Roeck c0464062bf PCI: dwc: Fix crashes seen due to missing assignments
Fix the following crash, seen in dwc/pci-imx6.

  Unable to handle kernel NULL pointer dereference at virtual address 00000070
  pgd = c0004000
  [00000070] *pgd=00000000
  Internal error: Oops: 805 [#1] SMP ARM
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.10.0-09686-g9e31489 #1
  Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
  task: cb850000 task.stack: cb84e000
  PC is at imx6_pcie_probe+0x2f4/0x414
  ...

While at it, fix the same problem in various drivers instead of waiting for
individual crash reports.

The change in the imx6 driver was tested with qemu. The changes in other
drivers are based on code inspection and have been compile tested only.

Fixes: 442ec4c04d ("PCI: dwc: all: Split struct pcie_port into host-only and core structures")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>  # designware-plat
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
2017-02-25 09:06:02 -06:00

296 lines
7.8 KiB
C

/*
* PCIe host controller driver for Axis ARTPEC-6 SoC
*
* Author: Niklas Cassel <niklas.cassel@axis.com>
*
* Based on work done by Phil Edworthy <phil@edworthys.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/resource.h>
#include <linux/signal.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include "pcie-designware.h"
#define to_artpec6_pcie(x) dev_get_drvdata((x)->dev)
struct artpec6_pcie {
struct dw_pcie *pci;
struct regmap *regmap; /* DT axis,syscon-pcie */
void __iomem *phy_base; /* DT phy */
};
/* PCIe Port Logic registers (memory-mapped) */
#define PL_OFFSET 0x700
#define PCIE_PHY_DEBUG_R0 (PL_OFFSET + 0x28)
#define PCIE_PHY_DEBUG_R1 (PL_OFFSET + 0x2c)
#define MISC_CONTROL_1_OFF (PL_OFFSET + 0x1bc)
#define DBI_RO_WR_EN 1
/* ARTPEC-6 specific registers */
#define PCIECFG 0x18
#define PCIECFG_DBG_OEN (1 << 24)
#define PCIECFG_CORE_RESET_REQ (1 << 21)
#define PCIECFG_LTSSM_ENABLE (1 << 20)
#define PCIECFG_CLKREQ_B (1 << 11)
#define PCIECFG_REFCLK_ENABLE (1 << 10)
#define PCIECFG_PLL_ENABLE (1 << 9)
#define PCIECFG_PCLK_ENABLE (1 << 8)
#define PCIECFG_RISRCREN (1 << 4)
#define PCIECFG_MODE_TX_DRV_EN (1 << 3)
#define PCIECFG_CISRREN (1 << 2)
#define PCIECFG_MACRO_ENABLE (1 << 0)
#define NOCCFG 0x40
#define NOCCFG_ENABLE_CLK_PCIE (1 << 4)
#define NOCCFG_POWER_PCIE_IDLEACK (1 << 3)
#define NOCCFG_POWER_PCIE_IDLE (1 << 2)
#define NOCCFG_POWER_PCIE_IDLEREQ (1 << 1)
#define PHY_STATUS 0x118
#define PHY_COSPLLLOCK (1 << 0)
#define ARTPEC6_CPU_TO_BUS_ADDR 0x0fffffff
static u32 artpec6_pcie_readl(struct artpec6_pcie *artpec6_pcie, u32 offset)
{
u32 val;
regmap_read(artpec6_pcie->regmap, offset, &val);
return val;
}
static void artpec6_pcie_writel(struct artpec6_pcie *artpec6_pcie, u32 offset, u32 val)
{
regmap_write(artpec6_pcie->regmap, offset, val);
}
static int artpec6_pcie_establish_link(struct artpec6_pcie *artpec6_pcie)
{
struct dw_pcie *pci = artpec6_pcie->pci;
struct pcie_port *pp = &pci->pp;
u32 val;
unsigned int retries;
/* Hold DW core in reset */
val = artpec6_pcie_readl(artpec6_pcie, PCIECFG);
val |= PCIECFG_CORE_RESET_REQ;
artpec6_pcie_writel(artpec6_pcie, PCIECFG, val);
val = artpec6_pcie_readl(artpec6_pcie, PCIECFG);
val |= PCIECFG_RISRCREN | /* Receiver term. 50 Ohm */
PCIECFG_MODE_TX_DRV_EN |
PCIECFG_CISRREN | /* Reference clock term. 100 Ohm */
PCIECFG_MACRO_ENABLE;
val |= PCIECFG_REFCLK_ENABLE;
val &= ~PCIECFG_DBG_OEN;
val &= ~PCIECFG_CLKREQ_B;
artpec6_pcie_writel(artpec6_pcie, PCIECFG, val);
usleep_range(5000, 6000);
val = artpec6_pcie_readl(artpec6_pcie, NOCCFG);
val |= NOCCFG_ENABLE_CLK_PCIE;
artpec6_pcie_writel(artpec6_pcie, NOCCFG, val);
usleep_range(20, 30);
val = artpec6_pcie_readl(artpec6_pcie, PCIECFG);
val |= PCIECFG_PCLK_ENABLE | PCIECFG_PLL_ENABLE;
artpec6_pcie_writel(artpec6_pcie, PCIECFG, val);
usleep_range(6000, 7000);
val = artpec6_pcie_readl(artpec6_pcie, NOCCFG);
val &= ~NOCCFG_POWER_PCIE_IDLEREQ;
artpec6_pcie_writel(artpec6_pcie, NOCCFG, val);
retries = 50;
do {
usleep_range(1000, 2000);
val = artpec6_pcie_readl(artpec6_pcie, NOCCFG);
retries--;
} while (retries &&
(val & (NOCCFG_POWER_PCIE_IDLEACK | NOCCFG_POWER_PCIE_IDLE)));
retries = 50;
do {
usleep_range(1000, 2000);
val = readl(artpec6_pcie->phy_base + PHY_STATUS);
retries--;
} while (retries && !(val & PHY_COSPLLLOCK));
/* Take DW core out of reset */
val = artpec6_pcie_readl(artpec6_pcie, PCIECFG);
val &= ~PCIECFG_CORE_RESET_REQ;
artpec6_pcie_writel(artpec6_pcie, PCIECFG, val);
usleep_range(100, 200);
/*
* Enable writing to config regs. This is required as the Synopsys
* driver changes the class code. That register needs DBI write enable.
*/
dw_pcie_writel_dbi(pci, MISC_CONTROL_1_OFF, DBI_RO_WR_EN);
pp->io_base &= ARTPEC6_CPU_TO_BUS_ADDR;
pp->mem_base &= ARTPEC6_CPU_TO_BUS_ADDR;
pp->cfg0_base &= ARTPEC6_CPU_TO_BUS_ADDR;
pp->cfg1_base &= ARTPEC6_CPU_TO_BUS_ADDR;
/* setup root complex */
dw_pcie_setup_rc(pp);
/* assert LTSSM enable */
val = artpec6_pcie_readl(artpec6_pcie, PCIECFG);
val |= PCIECFG_LTSSM_ENABLE;
artpec6_pcie_writel(artpec6_pcie, PCIECFG, val);
/* check if the link is up or not */
if (!dw_pcie_wait_for_link(pci))
return 0;
dev_dbg(pci->dev, "DEBUG_R0: 0x%08x, DEBUG_R1: 0x%08x\n",
dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R0),
dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R1));
return -ETIMEDOUT;
}
static void artpec6_pcie_enable_interrupts(struct artpec6_pcie *artpec6_pcie)
{
struct dw_pcie *pci = artpec6_pcie->pci;
struct pcie_port *pp = &pci->pp;
if (IS_ENABLED(CONFIG_PCI_MSI))
dw_pcie_msi_init(pp);
}
static void artpec6_pcie_host_init(struct pcie_port *pp)
{
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
struct artpec6_pcie *artpec6_pcie = to_artpec6_pcie(pci);
artpec6_pcie_establish_link(artpec6_pcie);
artpec6_pcie_enable_interrupts(artpec6_pcie);
}
static struct dw_pcie_host_ops artpec6_pcie_host_ops = {
.host_init = artpec6_pcie_host_init,
};
static irqreturn_t artpec6_pcie_msi_handler(int irq, void *arg)
{
struct artpec6_pcie *artpec6_pcie = arg;
struct dw_pcie *pci = artpec6_pcie->pci;
struct pcie_port *pp = &pci->pp;
return dw_handle_msi_irq(pp);
}
static int artpec6_add_pcie_port(struct artpec6_pcie *artpec6_pcie,
struct platform_device *pdev)
{
struct dw_pcie *pci = artpec6_pcie->pci;
struct pcie_port *pp = &pci->pp;
struct device *dev = pci->dev;
int ret;
if (IS_ENABLED(CONFIG_PCI_MSI)) {
pp->msi_irq = platform_get_irq_byname(pdev, "msi");
if (pp->msi_irq <= 0) {
dev_err(dev, "failed to get MSI irq\n");
return -ENODEV;
}
ret = devm_request_irq(dev, pp->msi_irq,
artpec6_pcie_msi_handler,
IRQF_SHARED | IRQF_NO_THREAD,
"artpec6-pcie-msi", artpec6_pcie);
if (ret) {
dev_err(dev, "failed to request MSI irq\n");
return ret;
}
}
pp->root_bus_nr = -1;
pp->ops = &artpec6_pcie_host_ops;
ret = dw_pcie_host_init(pp);
if (ret) {
dev_err(dev, "failed to initialize host\n");
return ret;
}
return 0;
}
static int artpec6_pcie_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct dw_pcie *pci;
struct artpec6_pcie *artpec6_pcie;
struct resource *dbi_base;
struct resource *phy_base;
int ret;
artpec6_pcie = devm_kzalloc(dev, sizeof(*artpec6_pcie), GFP_KERNEL);
if (!artpec6_pcie)
return -ENOMEM;
pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
if (!pci)
return -ENOMEM;
pci->dev = dev;
artpec6_pcie->pci = pci;
dbi_base = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
pci->dbi_base = devm_ioremap_resource(dev, dbi_base);
if (IS_ERR(pci->dbi_base))
return PTR_ERR(pci->dbi_base);
phy_base = platform_get_resource_byname(pdev, IORESOURCE_MEM, "phy");
artpec6_pcie->phy_base = devm_ioremap_resource(dev, phy_base);
if (IS_ERR(artpec6_pcie->phy_base))
return PTR_ERR(artpec6_pcie->phy_base);
artpec6_pcie->regmap =
syscon_regmap_lookup_by_phandle(dev->of_node,
"axis,syscon-pcie");
if (IS_ERR(artpec6_pcie->regmap))
return PTR_ERR(artpec6_pcie->regmap);
platform_set_drvdata(pdev, artpec6_pcie);
ret = artpec6_add_pcie_port(artpec6_pcie, pdev);
if (ret < 0)
return ret;
return 0;
}
static const struct of_device_id artpec6_pcie_of_match[] = {
{ .compatible = "axis,artpec6-pcie", },
{},
};
static struct platform_driver artpec6_pcie_driver = {
.probe = artpec6_pcie_probe,
.driver = {
.name = "artpec6-pcie",
.of_match_table = artpec6_pcie_of_match,
},
};
builtin_platform_driver(artpec6_pcie_driver);