| Message ID | d878ad0595c9372fcbbf5e299b3949f2b59d8968.1414099246.git.geoff@infradead.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Oct 24, 2014 at 12:10:58AM +0100, Geoff Levand wrote: > When a CPU is reset it needs to be put into the exception level it had when it > entered the kernel. Update cpu_reset() to accept an argument el2_switch which > signals cpu_reset() to enter the soft reset address at EL2. If el2_switch is > not set the soft reset address will be entered at EL1. > > Update cpu_soft_restart() and soft_restart() to pass the return of > is_hyp_mode_available() as the el2_switch value to cpu_reset(). Also update the > comments of cpu_reset(), cpu_soft_restart() and soft_restart() to reflect this > change. This will blow up without warning with KVM, and I think we need to address that first. Mark. > Signed-off-by: Geoff Levand <geoff@infradead.org> > --- > arch/arm64/include/asm/proc-fns.h | 4 ++-- > arch/arm64/kernel/process.c | 6 ++++- > arch/arm64/mm/proc.S | 47 +++++++++++++++++++++++++++++---------- > 3 files changed, 42 insertions(+), 15 deletions(-) > > diff --git a/arch/arm64/include/asm/proc-fns.h b/arch/arm64/include/asm/proc-fns.h > index 9a8fd84..339394d 100644 > --- a/arch/arm64/include/asm/proc-fns.h > +++ b/arch/arm64/include/asm/proc-fns.h > @@ -32,8 +32,8 @@ extern void cpu_cache_off(void); > extern void cpu_do_idle(void); > extern void cpu_do_switch_mm(unsigned long pgd_phys, struct mm_struct *mm); > extern void cpu_reset(unsigned long addr) __attribute__((noreturn)); > -void cpu_soft_restart(phys_addr_t cpu_reset, > - unsigned long addr) __attribute__((noreturn)); > +void cpu_soft_restart(phys_addr_t cpu_reset, unsigned long el2_switch, > + unsigned long addr) __attribute__((noreturn)); > extern void cpu_do_suspend(struct cpu_suspend_ctx *ptr); > extern u64 cpu_do_resume(phys_addr_t ptr, u64 idmap_ttbr); > > diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c > index bf66922..0a3414b 100644 > --- a/arch/arm64/kernel/process.c > +++ b/arch/arm64/kernel/process.c > @@ -50,6 +50,7 @@ > #include <asm/mmu_context.h> > #include <asm/processor.h> > #include <asm/stacktrace.h> > +#include <asm/virt.h> > > #ifdef CONFIG_CC_STACKPROTECTOR > #include <linux/stackprotector.h> > @@ -60,7 +61,10 @@ EXPORT_SYMBOL(__stack_chk_guard); > void soft_restart(unsigned long addr) > { > setup_mm_for_reboot(); > - cpu_soft_restart(virt_to_phys(cpu_reset), addr); > + > + cpu_soft_restart(virt_to_phys(cpu_reset), is_hyp_mode_available(), > + addr); > + > /* Should never get here */ > BUG(); > } > diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S > index 4e778b1..7467199 100644 > --- a/arch/arm64/mm/proc.S > +++ b/arch/arm64/mm/proc.S > @@ -25,6 +25,7 @@ > #include <asm/hwcap.h> > #include <asm/pgtable-hwdef.h> > #include <asm/pgtable.h> > +#include <asm/virt.h> > > #include "proc-macros.S" > > @@ -59,27 +60,48 @@ ENTRY(cpu_cache_off) > ENDPROC(cpu_cache_off) > > /* > - * cpu_reset(loc) > + * cpu_reset(el2_switch, loc) - Helper for cpu_soft_restart. > * > - * Perform a soft reset of the system. Put the CPU into the same state > - * as it would be if it had been reset, and branch to what would be the > - * reset vector. It must be executed with the flat identity mapping. > + * @cpu_reset: Physical address of the cpu_reset routine. > + * @el2_switch: Flag to indicate a swich to EL2 is needed. > + * @addr: Location to jump to for soft reset. > * > - * - loc - location to jump to for soft reset > + * Put the CPU into the same state as it would be if it had been reset, and > + * branch to what would be the reset vector. It must be executed with the > + * flat identity mapping. > */ > + > .align 5 > + > ENTRY(cpu_reset) > - mrs x1, sctlr_el1 > - bic x1, x1, #1 > - msr sctlr_el1, x1 // disable the MMU > + mrs x2, sctlr_el1 > + bic x2, x2, #1 > + msr sctlr_el1, x2 // disable the MMU > isb > - ret x0 > + > + cbz x0, 1f // el2_switch? > + mov x0, x1 > + mov x1, xzr > + mov x2, xzr > + mov x3, xzr > + hvc #HVC_CALL_FUNC // no return > + > +1: ret x1 > ENDPROC(cpu_reset) > > +/* > + * cpu_soft_restart(cpu_reset, el2_switch, addr) - Perform a cpu soft reset. > + * > + * @cpu_reset: Physical address of the cpu_reset routine. > + * @el2_switch: Flag to indicate a swich to EL2 is needed, passed to cpu_reset. > + * @addr: Location to jump to for soft reset, passed to cpu_reset. > + * > + */ > + > ENTRY(cpu_soft_restart) > - /* Save address of cpu_reset() and reset address */ > - mov x19, x0 > - mov x20, x1 > + mov x19, x0 // cpu_reset > + mov x20, x1 // el2_switch > + mov x21, x2 // addr > > /* Turn D-cache off */ > bl cpu_cache_off > @@ -88,6 +110,7 @@ ENTRY(cpu_soft_restart) > bl flush_cache_all > > mov x0, x20 > + mov x1, x21 > ret x19 > ENDPROC(cpu_soft_restart) > > -- > 1.9.1 > > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >
On Fri, 2014-10-24 at 11:57 +0100, Mark Rutland wrote: > On Fri, Oct 24, 2014 at 12:10:58AM +0100, Geoff Levand wrote: > > When a CPU is reset it needs to be put into the exception level it had when it > > entered the kernel. Update cpu_reset() to accept an argument el2_switch which > > signals cpu_reset() to enter the soft reset address at EL2. If el2_switch is > > not set the soft reset address will be entered at EL1. > > > > Update cpu_soft_restart() and soft_restart() to pass the return of > > is_hyp_mode_available() as the el2_switch value to cpu_reset(). Also update the > > comments of cpu_reset(), cpu_soft_restart() and soft_restart() to reflect this > > change. > > This will blow up without warning with KVM, and I think we need to > address that first. Yes. I think we can just put in a conditional on KVM as a workaround until KVM will work with this. -Geoff
diff --git a/arch/arm64/include/asm/proc-fns.h b/arch/arm64/include/asm/proc-fns.h index 9a8fd84..339394d 100644 --- a/arch/arm64/include/asm/proc-fns.h +++ b/arch/arm64/include/asm/proc-fns.h @@ -32,8 +32,8 @@ extern void cpu_cache_off(void); extern void cpu_do_idle(void); extern void cpu_do_switch_mm(unsigned long pgd_phys, struct mm_struct *mm); extern void cpu_reset(unsigned long addr) __attribute__((noreturn)); -void cpu_soft_restart(phys_addr_t cpu_reset, - unsigned long addr) __attribute__((noreturn)); +void cpu_soft_restart(phys_addr_t cpu_reset, unsigned long el2_switch, + unsigned long addr) __attribute__((noreturn)); extern void cpu_do_suspend(struct cpu_suspend_ctx *ptr); extern u64 cpu_do_resume(phys_addr_t ptr, u64 idmap_ttbr); diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index bf66922..0a3414b 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -50,6 +50,7 @@ #include <asm/mmu_context.h> #include <asm/processor.h> #include <asm/stacktrace.h> +#include <asm/virt.h> #ifdef CONFIG_CC_STACKPROTECTOR #include <linux/stackprotector.h> @@ -60,7 +61,10 @@ EXPORT_SYMBOL(__stack_chk_guard); void soft_restart(unsigned long addr) { setup_mm_for_reboot(); - cpu_soft_restart(virt_to_phys(cpu_reset), addr); + + cpu_soft_restart(virt_to_phys(cpu_reset), is_hyp_mode_available(), + addr); + /* Should never get here */ BUG(); } diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 4e778b1..7467199 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -25,6 +25,7 @@ #include <asm/hwcap.h> #include <asm/pgtable-hwdef.h> #include <asm/pgtable.h> +#include <asm/virt.h> #include "proc-macros.S" @@ -59,27 +60,48 @@ ENTRY(cpu_cache_off) ENDPROC(cpu_cache_off) /* - * cpu_reset(loc) + * cpu_reset(el2_switch, loc) - Helper for cpu_soft_restart. * - * Perform a soft reset of the system. Put the CPU into the same state - * as it would be if it had been reset, and branch to what would be the - * reset vector. It must be executed with the flat identity mapping. + * @cpu_reset: Physical address of the cpu_reset routine. + * @el2_switch: Flag to indicate a swich to EL2 is needed. + * @addr: Location to jump to for soft reset. * - * - loc - location to jump to for soft reset + * Put the CPU into the same state as it would be if it had been reset, and + * branch to what would be the reset vector. It must be executed with the + * flat identity mapping. */ + .align 5 + ENTRY(cpu_reset) - mrs x1, sctlr_el1 - bic x1, x1, #1 - msr sctlr_el1, x1 // disable the MMU + mrs x2, sctlr_el1 + bic x2, x2, #1 + msr sctlr_el1, x2 // disable the MMU isb - ret x0 + + cbz x0, 1f // el2_switch? + mov x0, x1 + mov x1, xzr + mov x2, xzr + mov x3, xzr + hvc #HVC_CALL_FUNC // no return + +1: ret x1 ENDPROC(cpu_reset) +/* + * cpu_soft_restart(cpu_reset, el2_switch, addr) - Perform a cpu soft reset. + * + * @cpu_reset: Physical address of the cpu_reset routine. + * @el2_switch: Flag to indicate a swich to EL2 is needed, passed to cpu_reset. + * @addr: Location to jump to for soft reset, passed to cpu_reset. + * + */ + ENTRY(cpu_soft_restart) - /* Save address of cpu_reset() and reset address */ - mov x19, x0 - mov x20, x1 + mov x19, x0 // cpu_reset + mov x20, x1 // el2_switch + mov x21, x2 // addr /* Turn D-cache off */ bl cpu_cache_off @@ -88,6 +110,7 @@ ENTRY(cpu_soft_restart) bl flush_cache_all mov x0, x20 + mov x1, x21 ret x19 ENDPROC(cpu_soft_restart)
When a CPU is reset it needs to be put into the exception level it had when it entered the kernel. Update cpu_reset() to accept an argument el2_switch which signals cpu_reset() to enter the soft reset address at EL2. If el2_switch is not set the soft reset address will be entered at EL1. Update cpu_soft_restart() and soft_restart() to pass the return of is_hyp_mode_available() as the el2_switch value to cpu_reset(). Also update the comments of cpu_reset(), cpu_soft_restart() and soft_restart() to reflect this change. Signed-off-by: Geoff Levand <geoff@infradead.org> --- arch/arm64/include/asm/proc-fns.h | 4 ++-- arch/arm64/kernel/process.c | 6 ++++- arch/arm64/mm/proc.S | 47 +++++++++++++++++++++++++++++---------- 3 files changed, 42 insertions(+), 15 deletions(-)