From 4e0e3435b50285eafe5898124ce02f7577f6803a Mon Sep 17 00:00:00 2001 From: Hongtao Jia Date: Sun, 28 Apr 2013 13:20:08 +0800 Subject: [PATCH] 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: Zhao Chenhui Signed-off-by: Li Yang Signed-off-by: Liu Shuo Signed-off-by: Jia Hongtao Signed-off-by: Scott Wood --- arch/powerpc/kernel/cpu_setup_fsl_booke.S | 2 +- arch/powerpc/kernel/traps.c | 3 + arch/powerpc/sysdev/fsl_pci.c | 158 ++++++++++++++++++++++ arch/powerpc/sysdev/fsl_pci.h | 6 + 4 files changed, 168 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/cpu_setup_fsl_booke.S b/arch/powerpc/kernel/cpu_setup_fsl_booke.S index 0b9af015bedc..bfb18c7290b7 100644 --- a/arch/powerpc/kernel/cpu_setup_fsl_booke.S +++ b/arch/powerpc/kernel/cpu_setup_fsl_booke.S @@ -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 diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index bf33c22e38a4..f58eaf23e8f1 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -62,6 +62,7 @@ #include #include #include +#include #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"); diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c index 46ac1ddea683..3409758c78b2 100644 --- a/arch/powerpc/sysdev/fsl_pci.c +++ b/arch/powerpc/sysdev/fsl_pci.c @@ -26,11 +26,15 @@ #include #include #include +#include #include #include #include +#include #include +#include +#include #include #include @@ -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", }, diff --git a/arch/powerpc/sysdev/fsl_pci.h b/arch/powerpc/sysdev/fsl_pci.h index 72b5625330e2..defc422a375f 100644 --- a/arch/powerpc/sysdev/fsl_pci.h +++ b/arch/powerpc/sysdev/fsl_pci.h @@ -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__ */ -- 2.20.1