Commit 4e0e3435 authored by Hongtao Jia's avatar Hongtao Jia Committed by Scott Wood
Browse files

powerpc/85xx: Add machine check handler to fix PCIe erratum on mpc85xx



A PCIe erratum of mpc85xx may causes a core hang when a link of PCIe
goes down. when the link goes down, Non-posted transactions issued
via the ATMU requiring completion result in an instruction stall.
At the same time a machine-check exception is generated to the core
to allow further processing by the handler. We implements the handler
which skips the instruction caused the stall.

This patch depends on patch:
powerpc/85xx: Add platform_device declaration to fsl_pci.h
Signed-off-by: default avatarZhao Chenhui <b35336@freescale.com>
Signed-off-by: default avatarLi Yang <leoli@freescale.com>
Signed-off-by: default avatarLiu Shuo <soniccat.liu@gmail.com>
Signed-off-by: default avatarJia Hongtao <hongtao.jia@freescale.com>
Signed-off-by: default avatarScott Wood <scottwood@freescale.com>
parent 9123c5ed
......@@ -75,7 +75,7 @@ _GLOBAL(__setup_cpu_e500v2)
bl __e500_icache_setup
bl __e500_dcache_setup
bl __setup_e500_ivors
#ifdef CONFIG_FSL_RIO
#if defined(CONFIG_FSL_RIO) || defined(CONFIG_FSL_PCI)
/* Ensure that RFXE is set */
mfspr r3,SPRN_HID1
oris r3,r3,HID1_RFXE@h
......
......@@ -62,6 +62,7 @@
#include <asm/switch_to.h>
#include <asm/tm.h>
#include <asm/debug.h>
#include <sysdev/fsl_pci.h>
#if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
int (*__debugger)(struct pt_regs *regs) __read_mostly;
......@@ -567,6 +568,8 @@ int machine_check_e500(struct pt_regs *regs)
if (reason & MCSR_BUS_RBERR) {
if (fsl_rio_mcheck_exception(regs))
return 1;
if (fsl_pci_mcheck_exception(regs))
return 1;
}
printk("Machine check in kernel mode.\n");
......
......@@ -26,11 +26,15 @@
#include <linux/memblock.h>
#include <linux/log2.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/pci-bridge.h>
#include <asm/ppc-pci.h>
#include <asm/machdep.h>
#include <asm/disassemble.h>
#include <asm/ppc-opcode.h>
#include <sysdev/fsl_soc.h>
#include <sysdev/fsl_pci.h>
......@@ -868,6 +872,160 @@ u64 fsl_pci_immrbar_base(struct pci_controller *hose)
return 0;
}
#ifdef CONFIG_E500
static int mcheck_handle_load(struct pt_regs *regs, u32 inst)
{
unsigned int rd, ra, rb, d;
rd = get_rt(inst);
ra = get_ra(inst);
rb = get_rb(inst);
d = get_d(inst);
switch (get_op(inst)) {
case 31:
switch (get_xop(inst)) {
case OP_31_XOP_LWZX:
case OP_31_XOP_LWBRX:
regs->gpr[rd] = 0xffffffff;
break;
case OP_31_XOP_LWZUX:
regs->gpr[rd] = 0xffffffff;
regs->gpr[ra] += regs->gpr[rb];
break;
case OP_31_XOP_LBZX:
regs->gpr[rd] = 0xff;
break;
case OP_31_XOP_LBZUX:
regs->gpr[rd] = 0xff;
regs->gpr[ra] += regs->gpr[rb];
break;
case OP_31_XOP_LHZX:
case OP_31_XOP_LHBRX:
regs->gpr[rd] = 0xffff;
break;
case OP_31_XOP_LHZUX:
regs->gpr[rd] = 0xffff;
regs->gpr[ra] += regs->gpr[rb];
break;
case OP_31_XOP_LHAX:
regs->gpr[rd] = ~0UL;
break;
case OP_31_XOP_LHAUX:
regs->gpr[rd] = ~0UL;
regs->gpr[ra] += regs->gpr[rb];
break;
default:
return 0;
}
break;
case OP_LWZ:
regs->gpr[rd] = 0xffffffff;
break;
case OP_LWZU:
regs->gpr[rd] = 0xffffffff;
regs->gpr[ra] += (s16)d;
break;
case OP_LBZ:
regs->gpr[rd] = 0xff;
break;
case OP_LBZU:
regs->gpr[rd] = 0xff;
regs->gpr[ra] += (s16)d;
break;
case OP_LHZ:
regs->gpr[rd] = 0xffff;
break;
case OP_LHZU:
regs->gpr[rd] = 0xffff;
regs->gpr[ra] += (s16)d;
break;
case OP_LHA:
regs->gpr[rd] = ~0UL;
break;
case OP_LHAU:
regs->gpr[rd] = ~0UL;
regs->gpr[ra] += (s16)d;
break;
default:
return 0;
}
return 1;
}
static int is_in_pci_mem_space(phys_addr_t addr)
{
struct pci_controller *hose;
struct resource *res;
int i;
list_for_each_entry(hose, &hose_list, list_node) {
if (!(hose->indirect_type & PPC_INDIRECT_TYPE_EXT_REG))
continue;
for (i = 0; i < 3; i++) {
res = &hose->mem_resources[i];
if ((res->flags & IORESOURCE_MEM) &&
addr >= res->start && addr <= res->end)
return 1;
}
}
return 0;
}
int fsl_pci_mcheck_exception(struct pt_regs *regs)
{
u32 inst;
int ret;
phys_addr_t addr = 0;
/* Let KVM/QEMU deal with the exception */
if (regs->msr & MSR_GS)
return 0;
#ifdef CONFIG_PHYS_64BIT
addr = mfspr(SPRN_MCARU);
addr <<= 32;
#endif
addr += mfspr(SPRN_MCAR);
if (is_in_pci_mem_space(addr)) {
if (user_mode(regs)) {
pagefault_disable();
ret = get_user(regs->nip, &inst);
pagefault_enable();
} else {
ret = probe_kernel_address(regs->nip, inst);
}
if (mcheck_handle_load(regs, inst)) {
regs->nip += 4;
return 1;
}
}
return 0;
}
#endif
#if defined(CONFIG_FSL_SOC_BOOKE) || defined(CONFIG_PPC_86xx)
static const struct of_device_id pci_ids[] = {
{ .compatible = "fsl,mpc8540-pci", },
......
......@@ -126,5 +126,11 @@ static inline int mpc85xx_pci_err_probe(struct platform_device *op)
}
#endif
#ifdef CONFIG_FSL_PCI
extern int fsl_pci_mcheck_exception(struct pt_regs *);
#else
static inline int fsl_pci_mcheck_exception(struct pt_regs *regs) {return 0; }
#endif
#endif /* __POWERPC_FSL_PCI_H */
#endif /* __KERNEL__ */
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