linux/arch/arm/include/asm/proc-fns.h
Russell King 9da5ac236d ARM: soft-reboot into same mode that we entered the kernel
When we soft-reboot (eg, kexec) from one kernel into the next, we need
to ensure that we enter the new kernel in the same processor mode as
when we were entered, so that (eg) the new kernel can install its own
hypervisor - the old kernel's hypervisor will have been overwritten.

In order to do this, we need to pass a flag to cpu_reset() so it knows
what to do, and we need to modify the kernel's own hypervisor stub to
allow it to handle a soft-reboot.

As we are always guaranteed to install our own hypervisor if we're
entered in HYP32 mode, and KVM will have moved itself out of the way
on kexec/normal reboot, we can assume that our hypervisor is in place
when we want to kexec, so changing our hypervisor API should not be a
problem.

Tested-by: Keerthy <j-keerthy@ti.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09 07:49:24 -07:00

154 lines
3.5 KiB
C

/*
* arch/arm/include/asm/proc-fns.h
*
* Copyright (C) 1997-1999 Russell King
* Copyright (C) 2000 Deep Blue Solutions Ltd
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_PROCFNS_H
#define __ASM_PROCFNS_H
#ifdef __KERNEL__
#include <asm/glue-proc.h>
#include <asm/page.h>
#ifndef __ASSEMBLY__
struct mm_struct;
/*
* Don't change this structure - ASM code relies on it.
*/
extern struct processor {
/* MISC
* get data abort address/flags
*/
void (*_data_abort)(unsigned long pc);
/*
* Retrieve prefetch fault address
*/
unsigned long (*_prefetch_abort)(unsigned long lr);
/*
* Set up any processor specifics
*/
void (*_proc_init)(void);
/*
* Disable any processor specifics
*/
void (*_proc_fin)(void);
/*
* Special stuff for a reset
*/
void (*reset)(unsigned long addr, bool hvc) __attribute__((noreturn));
/*
* Idle the processor
*/
int (*_do_idle)(void);
/*
* Processor architecture specific
*/
/*
* clean a virtual address range from the
* D-cache without flushing the cache.
*/
void (*dcache_clean_area)(void *addr, int size);
/*
* Set the page table
*/
void (*switch_mm)(phys_addr_t pgd_phys, struct mm_struct *mm);
/*
* Set a possibly extended PTE. Non-extended PTEs should
* ignore 'ext'.
*/
#ifdef CONFIG_ARM_LPAE
void (*set_pte_ext)(pte_t *ptep, pte_t pte);
#else
void (*set_pte_ext)(pte_t *ptep, pte_t pte, unsigned int ext);
#endif
/* Suspend/resume */
unsigned int suspend_size;
void (*do_suspend)(void *);
void (*do_resume)(void *);
} processor;
#ifndef MULTI_CPU
extern void cpu_proc_init(void);
extern void cpu_proc_fin(void);
extern int cpu_do_idle(void);
extern void cpu_dcache_clean_area(void *, int);
extern void cpu_do_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
#ifdef CONFIG_ARM_LPAE
extern void cpu_set_pte_ext(pte_t *ptep, pte_t pte);
#else
extern void cpu_set_pte_ext(pte_t *ptep, pte_t pte, unsigned int ext);
#endif
extern void cpu_reset(unsigned long addr, bool hvc) __attribute__((noreturn));
/* These three are private to arch/arm/kernel/suspend.c */
extern void cpu_do_suspend(void *);
extern void cpu_do_resume(void *);
#else
#define cpu_proc_init processor._proc_init
#define cpu_proc_fin processor._proc_fin
#define cpu_reset processor.reset
#define cpu_do_idle processor._do_idle
#define cpu_dcache_clean_area processor.dcache_clean_area
#define cpu_set_pte_ext processor.set_pte_ext
#define cpu_do_switch_mm processor.switch_mm
/* These three are private to arch/arm/kernel/suspend.c */
#define cpu_do_suspend processor.do_suspend
#define cpu_do_resume processor.do_resume
#endif
extern void cpu_resume(void);
#include <asm/memory.h>
#ifdef CONFIG_MMU
#define cpu_switch_mm(pgd,mm) cpu_do_switch_mm(virt_to_phys(pgd),mm)
#ifdef CONFIG_ARM_LPAE
#define cpu_get_ttbr(nr) \
({ \
u64 ttbr; \
__asm__("mrrc p15, " #nr ", %Q0, %R0, c2" \
: "=r" (ttbr)); \
ttbr; \
})
#define cpu_get_pgd() \
({ \
u64 pg = cpu_get_ttbr(0); \
pg &= ~(PTRS_PER_PGD*sizeof(pgd_t)-1); \
(pgd_t *)phys_to_virt(pg); \
})
#else
#define cpu_get_pgd() \
({ \
unsigned long pg; \
__asm__("mrc p15, 0, %0, c2, c0, 0" \
: "=r" (pg) : : "cc"); \
pg &= ~0x3fff; \
(pgd_t *)phys_to_virt(pg); \
})
#endif
#else /*!CONFIG_MMU */
#define cpu_switch_mm(pgd,mm) { }
#endif
#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
#endif /* __ASM_PROCFNS_H */