Message ID | 1373357007-30785-6-git-send-email-tiejun.chen@windriver.com (mailing list archive) |
---|---|
State | Changes Requested |
Delegated to: | Scott Wood |
Headers | show |
On Tue, 2013-07-09 at 16:03 +0800, Tiejun Chen wrote: > We need to introduce a flag to indicate we're already running > a kexec kernel then we can go proper path. For example, We > shouldn't access spin_table from the bootloader to up any secondary > cpu for kexec kernel, and kexec kernel already know how to jump to > generic_secondary_smp_init. > > Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com> > --- > arch/powerpc/include/asm/smp.h | 1 + > arch/powerpc/kernel/head_64.S | 10 ++++++++++ > arch/powerpc/kernel/misc_64.S | 6 ++++++ > arch/powerpc/platforms/85xx/smp.c | 20 +++++++++++++++----- > 4 files changed, 32 insertions(+), 5 deletions(-) > > diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h > index ffbaabe..59165a3 100644 > --- a/arch/powerpc/include/asm/smp.h > +++ b/arch/powerpc/include/asm/smp.h > @@ -200,6 +200,7 @@ extern void generic_secondary_thread_init(void); > extern unsigned long __secondary_hold_spinloop; > extern unsigned long __secondary_hold_acknowledge; > extern char __secondary_hold; > +extern unsigned long __run_at_kexec; > > extern void __early_start(void); > #endif /* __ASSEMBLY__ */ > diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S > index 7dc56be..0b46c9d 100644 > --- a/arch/powerpc/kernel/head_64.S > +++ b/arch/powerpc/kernel/head_64.S > @@ -89,6 +89,10 @@ __secondary_hold_spinloop: > __secondary_hold_acknowledge: > .llong 0x0 > > + .globl __run_at_kexec > +__run_at_kexec: > + .llong 0x0 /* Flag for the secondary kernel from kexec. */ > + No leading underscores please -- and why does this need to be 64-bit? > #ifdef CONFIG_RELOCATABLE > /* This flag is set to 1 by a loader if the kernel should run > * at the loaded address instead of the linked address. This > @@ -417,6 +421,12 @@ _STATIC(__after_prom_start) > #if defined(CONFIG_PPC_BOOK3E) > tovirt(r26,r26) /* on booke, we already run at PAGE_OFFSET */ > #endif > +#if defined(CONFIG_KEXEC) || defined(CONFIG_CRASH_DUMP) > + /* If relocated we need to restore this flag on that relocated address. */ > + ld r7,__run_at_kexec-_stext(r26) > + std r7,__run_at_kexec-_stext(r26) > +#endif > + > lwz r7,__run_at_load-_stext(r26) > #if defined(CONFIG_PPC_BOOK3E) > tophys(r26,r26) /* Restore for the remains. */ > diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S > index 20cbb98..c89aead 100644 > --- a/arch/powerpc/kernel/misc_64.S > +++ b/arch/powerpc/kernel/misc_64.S > @@ -619,6 +619,12 @@ _GLOBAL(kexec_sequence) > bl .copy_and_flush /* (dest, src, copy limit, start offset) */ > 1: /* assume normal blr return */ > > + /* notify we're going into kexec kernel for SMP. */ > + LOAD_REG_ADDR(r3,__run_at_kexec) > + li r4,1 > + std r4,0(r3) > + sync > + > /* release other cpus to the new kernel secondary start at 0x60 */ > mflr r5 > li r6,1 > diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c > index 5ced4f5..14d461b 100644 > --- a/arch/powerpc/platforms/85xx/smp.c > +++ b/arch/powerpc/platforms/85xx/smp.c > @@ -150,6 +150,9 @@ static int smp_85xx_kick_cpu(int nr) > int hw_cpu = get_hard_smp_processor_id(nr); > int ioremappable; > int ret = 0; > +#ifdef CONFIG_PPC64 > + unsigned long *ptr = NULL; > +#endif Looks like an unnecessary initialization. > > WARN_ON(nr < 0 || nr >= NR_CPUS); > WARN_ON(hw_cpu < 0 || hw_cpu >= NR_CPUS); > @@ -238,11 +241,18 @@ out: > #else > smp_generic_kick_cpu(nr); > > - flush_spin_table(spin_table); > - out_be32(&spin_table->pir, hw_cpu); > - out_be64((u64 *)(&spin_table->addr_h), > - __pa((u64)*((unsigned long long *)generic_secondary_smp_init))); > - flush_spin_table(spin_table); > + ptr = (unsigned long *)((unsigned long)&__run_at_kexec); > + /* We shouldn't access spin_table from the bootloader to up any > + * secondary cpu for kexec kernel, and kexec kernel already > + * know how to jump to generic_secondary_smp_init. > + */ > + if (!*ptr) { > + flush_spin_table(spin_table); > + out_be32(&spin_table->pir, hw_cpu); > + out_be64((u64 *)(&spin_table->addr_h), > + __pa((u64)*((unsigned long long *)generic_secondary_smp_init))); > + flush_spin_table(spin_table); > + } > #endif Please use a more descriptive name than "ptr". How is all that different than just: if (!__run_at_kexec) { ... } -Scott
diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h index ffbaabe..59165a3 100644 --- a/arch/powerpc/include/asm/smp.h +++ b/arch/powerpc/include/asm/smp.h @@ -200,6 +200,7 @@ extern void generic_secondary_thread_init(void); extern unsigned long __secondary_hold_spinloop; extern unsigned long __secondary_hold_acknowledge; extern char __secondary_hold; +extern unsigned long __run_at_kexec; extern void __early_start(void); #endif /* __ASSEMBLY__ */ diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S index 7dc56be..0b46c9d 100644 --- a/arch/powerpc/kernel/head_64.S +++ b/arch/powerpc/kernel/head_64.S @@ -89,6 +89,10 @@ __secondary_hold_spinloop: __secondary_hold_acknowledge: .llong 0x0 + .globl __run_at_kexec +__run_at_kexec: + .llong 0x0 /* Flag for the secondary kernel from kexec. */ + #ifdef CONFIG_RELOCATABLE /* This flag is set to 1 by a loader if the kernel should run * at the loaded address instead of the linked address. This @@ -417,6 +421,12 @@ _STATIC(__after_prom_start) #if defined(CONFIG_PPC_BOOK3E) tovirt(r26,r26) /* on booke, we already run at PAGE_OFFSET */ #endif +#if defined(CONFIG_KEXEC) || defined(CONFIG_CRASH_DUMP) + /* If relocated we need to restore this flag on that relocated address. */ + ld r7,__run_at_kexec-_stext(r26) + std r7,__run_at_kexec-_stext(r26) +#endif + lwz r7,__run_at_load-_stext(r26) #if defined(CONFIG_PPC_BOOK3E) tophys(r26,r26) /* Restore for the remains. */ diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S index 20cbb98..c89aead 100644 --- a/arch/powerpc/kernel/misc_64.S +++ b/arch/powerpc/kernel/misc_64.S @@ -619,6 +619,12 @@ _GLOBAL(kexec_sequence) bl .copy_and_flush /* (dest, src, copy limit, start offset) */ 1: /* assume normal blr return */ + /* notify we're going into kexec kernel for SMP. */ + LOAD_REG_ADDR(r3,__run_at_kexec) + li r4,1 + std r4,0(r3) + sync + /* release other cpus to the new kernel secondary start at 0x60 */ mflr r5 li r6,1 diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c index 5ced4f5..14d461b 100644 --- a/arch/powerpc/platforms/85xx/smp.c +++ b/arch/powerpc/platforms/85xx/smp.c @@ -150,6 +150,9 @@ static int smp_85xx_kick_cpu(int nr) int hw_cpu = get_hard_smp_processor_id(nr); int ioremappable; int ret = 0; +#ifdef CONFIG_PPC64 + unsigned long *ptr = NULL; +#endif WARN_ON(nr < 0 || nr >= NR_CPUS); WARN_ON(hw_cpu < 0 || hw_cpu >= NR_CPUS); @@ -238,11 +241,18 @@ out: #else smp_generic_kick_cpu(nr); - flush_spin_table(spin_table); - out_be32(&spin_table->pir, hw_cpu); - out_be64((u64 *)(&spin_table->addr_h), - __pa((u64)*((unsigned long long *)generic_secondary_smp_init))); - flush_spin_table(spin_table); + ptr = (unsigned long *)((unsigned long)&__run_at_kexec); + /* We shouldn't access spin_table from the bootloader to up any + * secondary cpu for kexec kernel, and kexec kernel already + * know how to jump to generic_secondary_smp_init. + */ + if (!*ptr) { + flush_spin_table(spin_table); + out_be32(&spin_table->pir, hw_cpu); + out_be64((u64 *)(&spin_table->addr_h), + __pa((u64)*((unsigned long long *)generic_secondary_smp_init))); + flush_spin_table(spin_table); + } #endif local_irq_restore(flags);
We need to introduce a flag to indicate we're already running a kexec kernel then we can go proper path. For example, We shouldn't access spin_table from the bootloader to up any secondary cpu for kexec kernel, and kexec kernel already know how to jump to generic_secondary_smp_init. Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com> --- arch/powerpc/include/asm/smp.h | 1 + arch/powerpc/kernel/head_64.S | 10 ++++++++++ arch/powerpc/kernel/misc_64.S | 6 ++++++ arch/powerpc/platforms/85xx/smp.c | 20 +++++++++++++++----- 4 files changed, 32 insertions(+), 5 deletions(-)