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

[Kumar Gala]

On Feb 10, 2012, at 2:09 AM, <shuo.liu at freesacle.com> <shuo.liu at freesacle.com> wrote:

> From: Liu Shuo <shuo.liu at freescale.com>
> 
> 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.
> 
> Signed-off-by: Zhao Chenhui <b35336 at freescale.com>
> Signed-off-by: Li Yang <leoli at freescale.com>
> Signed-off-by: Liu Shuo <b35362 at freescale.com>
> ---
> arch/powerpc/kernel/cpu_setup_fsl_booke.S |    2 +-
> arch/powerpc/kernel/traps.c               |    3 ++
> arch/powerpc/sysdev/fsl_pci.c             |   36 +++++++++++++++++++++++++++++
> arch/powerpc/sysdev/fsl_pci.h             |    6 +++++
> 4 files changed, 46 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/cpu_setup_fsl_booke.S b/arch/powerpc/kernel/cpu_setup_fsl_booke.S
> index 2c03ac2..beef028 100644
> --- a/arch/powerpc/kernel/cpu_setup_fsl_booke.S
> +++ b/arch/powerpc/kernel/cpu_setup_fsl_booke.S
> @@ -64,7 +64,7 @@ _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 at h
> diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
> index 343c46b..1d6bcc0 100644
> --- a/arch/powerpc/kernel/traps.c
> +++ b/arch/powerpc/kernel/traps.c
> @@ -57,6 +57,7 @@
> #include <asm/kexec.h>
> #include <asm/ppc-opcode.h>
> #include <asm/rio.h>
> +#include <sysdev/fsl_pci.h>
> 
> #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
> int (*__debugger)(struct pt_regs *regs) __read_mostly;
> @@ -525,6 +526,8 @@ 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 6bc3bfd..8ea23f0 100644
> --- a/arch/powerpc/sysdev/fsl_pci.c
> +++ b/arch/powerpc/sysdev/fsl_pci.c
> @@ -30,6 +30,7 @@
> #include <asm/io.h>
> #include <asm/prom.h>
> #include <asm/pci-bridge.h>
> +#include <asm/ppc-pci.h>
> #include <asm/machdep.h>
> #include <sysdev/fsl_soc.h>
> #include <sysdev/fsl_pci.h>
> @@ -727,3 +728,38 @@ u64 fsl_pci_immrbar_base(struct pci_controller *hose)
> 
> 	return 0;
> }
> +
> +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) {
> +		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;

just move this into fsl_pci_mcheck_exception() no need for a separate function.

> +}
> +
> +int fsl_pci_mcheck_exception(struct pt_regs *regs)
> +{
> +	phys_addr_t addr = 0;
> +
> +#ifdef CONFIG_PHYS_64BIT
> +	addr = mfspr(SPRN_MCARU);
> +	addr <<= 32;
> +#endif
> +	addr += mfspr(SPRN_MCAR);
> +
> +	if (is_in_pci_mem_space(addr)) {
> +		regs->nip += 4;
> +		return 1;
> +	}
> +
> +	return 0;
> +}
> diff --git a/arch/powerpc/sysdev/fsl_pci.h b/arch/powerpc/sysdev/fsl_pci.h
> index a39ed5c..96b07ce 100644
> --- a/arch/powerpc/sysdev/fsl_pci.h
> +++ b/arch/powerpc/sysdev/fsl_pci.h
> @@ -93,5 +93,11 @@ extern void fsl_pcibios_fixup_bus(struct pci_bus *bus);
> extern int mpc83xx_add_bridge(struct device_node *dev);
> u64 fsl_pci_immrbar_base(struct pci_controller *hose);
> 
> +#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; }

Add space after {

> +#endif
> +
> #endif /* __POWERPC_FSL_PCI_H */
> #endif /* __KERNEL__ */
> -- 
> 1.7.1
> 
> 
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev at lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev