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 <b35...@freescale.com>
Signed-off-by: Li Yang <le...@freescale.com>
Signed-off-by: Liu Shuo <soniccat....@gmail.com>
Signed-off-by: Jia Hongtao <hongtao....@freescale.com>
---
V5:
* Move OP and XOP defines to a new header file: asm/ppc-disassemble.h
* Add X UX BRX variant of load instruction emulation
* Remove A variant of load instruction emulation
V4:
* Fill rd with all-Fs if the skipped instruction is load and emulate the
instruction.
* Let KVM/QEMU deal with the exception if the machine check comes from KVM.
arch/powerpc/include/asm/ppc-disassemble.h | 31 +++++++
arch/powerpc/kernel/cpu_setup_fsl_booke.S | 2 +-
arch/powerpc/kernel/traps.c | 3 +
arch/powerpc/sysdev/fsl_pci.c | 140 +++++++++++++++++++++++++++++
arch/powerpc/sysdev/fsl_pci.h | 6 ++
5 files changed, 181 insertions(+), 1 deletion(-)
create mode 100644 arch/powerpc/include/asm/ppc-disassemble.h
diff --git a/arch/powerpc/include/asm/ppc-disassemble.h
b/arch/powerpc/include/asm/ppc-disassemble.h
new file mode 100644
index 0000000..f9782b8
--- /dev/null
+++ b/arch/powerpc/include/asm/ppc-disassemble.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright 2012-2013 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * provides opcode and xopcode images for use by emulating
+ * instructions
+ */
+#ifndef _ASM_POWERPC_PPC_DISASSEMBLE_H
+#define _ASM_POWERPC_PPC_DISASSEMBLE_H
+
+#define OP_LWZ 32
+#define OP_LWZU 33
+#define OP_LBZ 34
+#define OP_LBZU 35
+#define OP_LHZ 40
+#define OP_LHZU 41
+
+#define OP_31_XOP_LWZX 23
+#define OP_31_XOP_LWZUX 55
+#define OP_31_XOP_LBZX 87
+#define OP_31_XOP_LBZUX 119
+#define OP_31_XOP_LHZX 279
+#define OP_31_XOP_LHZUX 311
+#define OP_31_XOP_LWBRX 534
+#define OP_31_XOP_LHBRX 790
+
+#endif
diff --git a/arch/powerpc/kernel/cpu_setup_fsl_booke.S
b/arch/powerpc/kernel/cpu_setup_fsl_booke.S
index dcd8819..f1bde90 100644
--- a/arch/powerpc/kernel/cpu_setup_fsl_booke.S
+++ b/arch/powerpc/kernel/cpu_setup_fsl_booke.S
@@ -66,7 +66,7 @@ _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 a008cf5..dd275a4 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -59,6 +59,7 @@
#include <asm/fadump.h>
#include <asm/switch_to.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;
@@ -556,6 +557,8 @@ 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 682084d..aaa54c5 100644
--- a/arch/powerpc/sysdev/fsl_pci.c
+++ b/arch/powerpc/sysdev/fsl_pci.c
@@ -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-disassemble.h>
#include <sysdev/fsl_soc.h>
#include <sysdev/fsl_pci.h>
@@ -826,6 +830,142 @@ 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;
+
+ 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;
+
+ 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 (!early_find_capability(hose, 0, 0, PCI_CAP_ID_EXP))
+ 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 851dd56..b0d01ea 100644
--- a/arch/powerpc/sysdev/fsl_pci.h
+++ b/arch/powerpc/sysdev/fsl_pci.h
@@ -115,5 +115,11 @@ 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__ */
--
1.8.0
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