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Merge branch 'remotes/lorenzo/pci/rcar'

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- Finish transition to L1 state in rcar_pcie_config_access() because R-Car
  can't do it on its own (Marek Vasut)

- Return PCI_ERROR_RESPONSE for reads that trigger PCIe errors (Marek
  Vasut)

* remotes/lorenzo/pci/rcar:
  PCI: rcar: Use PCI_SET_ERROR_RESPONSE after read which triggered an exception
  PCI: rcar: Finish transition to L1 state in rcar_pcie_config_access()
This commit is contained in:
Bjorn Helgaas 2022-03-22 17:16:26 -05:00
commit 4b0f6ecaba
1 changed files with 96 additions and 34 deletions
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130
drivers/pci/controller/pcie-rcar-host.c
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@ -65,6 +65,42 @@ struct rcar_pcie_host {
int (*phy_init_fn)(struct rcar_pcie_host *host);
};
static DEFINE_SPINLOCK(pmsr_lock);
static int rcar_pcie_wakeup(struct device *pcie_dev, void __iomem *pcie_base)
{
unsigned long flags;
u32 pmsr, val;
int ret = 0;
spin_lock_irqsave(&pmsr_lock, flags);
if (!pcie_base || pm_runtime_suspended(pcie_dev)) {
ret = -EINVAL;
goto unlock_exit;
}
pmsr = readl(pcie_base + PMSR);
/*
* Test if the PCIe controller received PM_ENTER_L1 DLLP and
* the PCIe controller is not in L1 link state. If true, apply
* fix, which will put the controller into L1 link state, from
* which it can return to L0s/L0 on its own.
*/
if ((pmsr & PMEL1RX) && ((pmsr & PMSTATE) != PMSTATE_L1)) {
writel(L1IATN, pcie_base + PMCTLR);
ret = readl_poll_timeout_atomic(pcie_base + PMSR, val,
val & L1FAEG, 10, 1000);
WARN(ret, "Timeout waiting for L1 link state, ret=%d\n", ret);
writel(L1FAEG | PMEL1RX, pcie_base + PMSR);
}
unlock_exit:
spin_unlock_irqrestore(&pmsr_lock, flags);
return ret;
}
static struct rcar_pcie_host *msi_to_host(struct rcar_msi *msi)
{
return container_of(msi, struct rcar_pcie_host, msi);
@ -78,6 +114,54 @@ static u32 rcar_read_conf(struct rcar_pcie *pcie, int where)
return val >> shift;
}
#ifdef CONFIG_ARM
#define __rcar_pci_rw_reg_workaround(instr) \
" .arch armv7-a\n" \
"1: " instr " %1, [%2]\n" \
"2: isb\n" \
"3: .pushsection .text.fixup,\"ax\"\n" \
" .align 2\n" \
"4: mov %0, #" __stringify(PCIBIOS_SET_FAILED) "\n" \
" b 3b\n" \
" .popsection\n" \
" .pushsection __ex_table,\"a\"\n" \
" .align 3\n" \
" .long 1b, 4b\n" \
" .long 2b, 4b\n" \
" .popsection\n"
#endif
static int rcar_pci_write_reg_workaround(struct rcar_pcie *pcie, u32 val,
unsigned int reg)
{
int error = PCIBIOS_SUCCESSFUL;
#ifdef CONFIG_ARM
asm volatile(
__rcar_pci_rw_reg_workaround("str")
: "+r"(error):"r"(val), "r"(pcie->base + reg) : "memory");
#else
rcar_pci_write_reg(pcie, val, reg);
#endif
return error;
}
static int rcar_pci_read_reg_workaround(struct rcar_pcie *pcie, u32 *val,
unsigned int reg)
{
int error = PCIBIOS_SUCCESSFUL;
#ifdef CONFIG_ARM
asm volatile(
__rcar_pci_rw_reg_workaround("ldr")
: "+r"(error), "=r"(*val) : "r"(pcie->base + reg) : "memory");
if (error != PCIBIOS_SUCCESSFUL)
PCI_SET_ERROR_RESPONSE(val);
#else
*val = rcar_pci_read_reg(pcie, reg);
#endif
return error;
}
/* Serialization is provided by 'pci_lock' in drivers/pci/access.c */
static int rcar_pcie_config_access(struct rcar_pcie_host *host,
unsigned char access_type, struct pci_bus *bus,
@ -85,6 +169,14 @@ static int rcar_pcie_config_access(struct rcar_pcie_host *host,
{
struct rcar_pcie *pcie = &host->pcie;
unsigned int dev, func, reg, index;
int ret;
/* Wake the bus up in case it is in L1 state. */
ret = rcar_pcie_wakeup(pcie->dev, pcie->base);
if (ret) {
PCI_SET_ERROR_RESPONSE(data);
return PCIBIOS_SET_FAILED;
}
dev = PCI_SLOT(devfn);
func = PCI_FUNC(devfn);
@ -141,14 +233,14 @@ static int rcar_pcie_config_access(struct rcar_pcie_host *host,
return PCIBIOS_DEVICE_NOT_FOUND;
if (access_type == RCAR_PCI_ACCESS_READ)
*data = rcar_pci_read_reg(pcie, PCIECDR);
ret = rcar_pci_read_reg_workaround(pcie, data, PCIECDR);
else
rcar_pci_write_reg(pcie, *data, PCIECDR);
ret = rcar_pci_write_reg_workaround(pcie, *data, PCIECDR);
/* Disable the configuration access */
rcar_pci_write_reg(pcie, 0, PCIECCTLR);
return PCIBIOS_SUCCESSFUL;
return ret;
}
static int rcar_pcie_read_conf(struct pci_bus *bus, unsigned int devfn,
@ -1050,40 +1142,10 @@ static struct platform_driver rcar_pcie_driver = {
};
#ifdef CONFIG_ARM
static DEFINE_SPINLOCK(pmsr_lock);
static int rcar_pcie_aarch32_abort_handler(unsigned long addr,
unsigned int fsr, struct pt_regs *regs)
{
unsigned long flags;
u32 pmsr, val;
int ret = 0;
spin_lock_irqsave(&pmsr_lock, flags);
if (!pcie_base || pm_runtime_suspended(pcie_dev)) {
ret = 1;
goto unlock_exit;
}
pmsr = readl(pcie_base + PMSR);
/*
* Test if the PCIe controller received PM_ENTER_L1 DLLP and
* the PCIe controller is not in L1 link state. If true, apply
* fix, which will put the controller into L1 link state, from
* which it can return to L0s/L0 on its own.
*/
if ((pmsr & PMEL1RX) && ((pmsr & PMSTATE) != PMSTATE_L1)) {
writel(L1IATN, pcie_base + PMCTLR);
ret = readl_poll_timeout_atomic(pcie_base + PMSR, val,
val & L1FAEG, 10, 1000);
WARN(ret, "Timeout waiting for L1 link state, ret=%d\n", ret);
writel(L1FAEG | PMEL1RX, pcie_base + PMSR);
}
unlock_exit:
spin_unlock_irqrestore(&pmsr_lock, flags);
return ret;
return !fixup_exception(regs);
}
static const struct of_device_id rcar_pcie_abort_handler_of_match[] __initconst = {