On Tue, Mar 07, 2017 at 05:46:41PM -0800, Florian Fainelli wrote:
> On SMP r4k cache style systems, we cannot issue a
> smp_function_call_many() like what __flush_cache_all() does *after* we
> have disabled interrupts for the calling CPU. Add a special check, and
> do a local cache operation instead.
>
> Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
> ---
> arch/mips/mm/c-r4k.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
> index e7f798d55fbc..ea2998f1f5c5 100644
> --- a/arch/mips/mm/c-r4k.c
> +++ b/arch/mips/mm/c-r4k.c
> @@ -19,6 +19,7 @@
> #include <linux/mm.h>
> #include <linux/export.h>
> #include <linux/bitops.h>
> +#include <linux/kexec.h>
>
> #include <asm/bcache.h>
> #include <asm/bootinfo.h>
> @@ -494,7 +495,10 @@ static inline void local_r4k___flush_cache_all(void * args)
>
> static void r4k___flush_cache_all(void)
> {
> - r4k_on_each_cpu(R4K_INDEX, local_r4k___flush_cache_all, NULL);
> + if (!kexec_in_progress)
> + r4k_on_each_cpu(R4K_INDEX, local_r4k___flush_cache_all, NULL);
> + else
> + local_r4k___flush_cache_all(NULL);
> }
The cache management code shouldn't know about kexec. And if the problem
is calling __flush_cache_all with interrupts disabled, then why not
calling it with interrupts enabled which can be trivially done by moving
the call by a few lines?
Suggested by untested patch below, so testing would be appreciated.
Ralf
Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
arch/mips/kernel/machine_kexec.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/mips/kernel/machine_kexec.c b/arch/mips/kernel/machine_kexec.c
index 8b574bc..d6a6abe 100644
--- a/arch/mips/kernel/machine_kexec.c
+++ b/arch/mips/kernel/machine_kexec.c
@@ -117,6 +117,7 @@ machine_kexec(struct kimage *image)
*ptr & IND_DESTINATION)
*ptr = (unsigned long) phys_to_virt(*ptr);
}
+ __flush_cache_all();
/*
* we do not want to be bothered.
@@ -125,7 +126,6 @@ machine_kexec(struct kimage *image)
printk("Will call new kernel at %08lx\n", image->start);
printk("Bye ...\n");
- __flush_cache_all();
#ifdef CONFIG_SMP
/* All secondary cpus now may jump to kexec_wait cycle */
relocated_kexec_smp_wait = reboot_code_buffer +
