diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2022-09-26 15:56:17 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-09-28 19:22:13 +1000 |
| commit | 2f5182cffa43f31c241131a2c10a4ecd8e90fb3e (patch) | |
| tree | a7393ae14c674e9b50b754a75c500070ccb15fe2 /arch/powerpc/kernel/setup_64.c | |
| parent | bf75a3258a40327b73c5b4458ae8102cfa921b40 (diff) | |
| download | linux-2f5182cffa43f31c241131a2c10a4ecd8e90fb3e.tar.gz | |
powerpc/64s: early boot machine check handler
Use the early boot interrupt fixup in the machine check handler to allow
the machine check handler to run before interrupt endian is set up.
Branch to an early boot handler that just does a basic crash, which
allows it to run before ppc_md is set up. MSR[ME] is enabled on the boot
CPU earlier, and the machine check stack is temporarily set to the
middle of the init task stack.
This allows machine checks (e.g., due to invalid data access in real
mode) to print something useful earlier in boot (as soon as udbg is set
up, if CONFIG_PPC_EARLY_DEBUG=y).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220926055620.2676869-3-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/kernel/setup_64.c')
| -rw-r--r-- | arch/powerpc/kernel/setup_64.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index e1ac803c9046d..f50476da2f2cc 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -34,6 +34,7 @@ #include <linux/of.h> #include <linux/of_fdt.h> +#include <asm/asm-prototypes.h> #include <asm/kvm_guest.h> #include <asm/io.h> #include <asm/kdump.h> @@ -180,6 +181,16 @@ static void __init fixup_boot_paca(void) { /* The boot cpu is started */ get_paca()->cpu_start = 1; +#ifdef CONFIG_PPC_BOOK3S_64 + /* + * Give the early boot machine check stack somewhere to use, use + * half of the init stack. This is a bit hacky but there should not be + * deep stack usage in early init so shouldn't overflow it or overwrite + * things. + */ + get_paca()->mc_emergency_sp = (void *)&init_thread_union + + (THREAD_SIZE/2); +#endif /* Allow percpu accesses to work until we setup percpu data */ get_paca()->data_offset = 0; /* Mark interrupts soft and hard disabled in PACA */ @@ -357,6 +368,9 @@ void __init early_setup(unsigned long dt_ptr) /* -------- printk is now safe to use ------- */ + if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && (mfmsr() & MSR_HV)) + enable_machine_check(); + /* Try new device tree based feature discovery ... */ if (!dt_cpu_ftrs_init(__va(dt_ptr))) /* Otherwise use the old style CPU table */ |