diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/Kconfig | 11 | ||||
| -rw-r--r-- | arch/arm/kernel/hw_breakpoint.c | 26 |
2 files changed, 37 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 2e8091e2d8a8..0dcf88e7f9cf 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -972,6 +972,17 @@ config ARM_ERRATA_764369 relevant cache maintenance functions and sets a specific bit in the diagnostic control register of the SCU. +config ARM_ERRATA_764319 + bool "ARM errata: Read to DBGPRSR and DBGOSLSR may generate Undefined instruction" + depends on CPU_V7 + help + This option enables the workaround for the 764319 Cortex A-9 erratum. + CP14 read accesses to the DBGPRSR and DBGOSLSR registers generate an + unexpected Undefined Instruction exception when the DBGSWENABLE + external pin is set to 0, even when the CP14 accesses are performed + from a privileged mode. This work around catches the exception in a + way the kernel does not stop execution. + config ARM_ERRATA_775420 bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock" depends on CPU_V7 diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c index b1423fb130ea..054e9199f30d 100644 --- a/arch/arm/kernel/hw_breakpoint.c +++ b/arch/arm/kernel/hw_breakpoint.c @@ -941,6 +941,23 @@ static int hw_breakpoint_pending(unsigned long addr, unsigned int fsr, return ret; } +#ifdef CONFIG_ARM_ERRATA_764319 +static int oslsr_fault; + +static int debug_oslsr_trap(struct pt_regs *regs, unsigned int instr) +{ + oslsr_fault = 1; + instruction_pointer(regs) += 4; + return 0; +} + +static struct undef_hook debug_oslsr_hook = { + .instr_mask = 0xffffffff, + .instr_val = 0xee115e91, + .fn = debug_oslsr_trap, +}; +#endif + /* * One-time initialisation. */ @@ -974,7 +991,16 @@ static bool core_has_os_save_restore(void) case ARM_DEBUG_ARCH_V7_1: return true; case ARM_DEBUG_ARCH_V7_ECP14: +#ifdef CONFIG_ARM_ERRATA_764319 + oslsr_fault = 0; + register_undef_hook(&debug_oslsr_hook); ARM_DBG_READ(c1, c1, 4, oslsr); + unregister_undef_hook(&debug_oslsr_hook); + if (oslsr_fault) + return false; +#else + ARM_DBG_READ(c1, c1, 4, oslsr); +#endif if (oslsr & ARM_OSLSR_OSLM0) return true; fallthrough; |