linux/arch/arm/include/asm/smp_plat.h
Stephen Warren 2103f6cba6 ARM: 7807/1: kexec: validate CPU hotplug support
Architectures should fully validate whether kexec is possible as part of
machine_kexec_prepare(), so that user-space's kexec_load() operation can
report any problems. Performing validation in machine_kexec() itself is
too late, since it is not allowed to return.

Prior to this patch, ARM's machine_kexec() was testing after-the-fact
whether machine_kexec_prepare() was able to disable all but one CPU.
Instead, modify machine_kexec_prepare() to validate all conditions
necessary for machine_kexec_prepare()'s to succeed. BUG if the validation
succeeded, yet disabling the CPUs didn't actually work.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-08-13 20:23:18 +01:00

95 lines
1.9 KiB
C

/*
* ARM specific SMP header, this contains our implementation
* details.
*/
#ifndef __ASMARM_SMP_PLAT_H
#define __ASMARM_SMP_PLAT_H
#include <linux/cpumask.h>
#include <linux/err.h>
#include <asm/cputype.h>
/*
* Return true if we are running on a SMP platform
*/
static inline bool is_smp(void)
{
#ifndef CONFIG_SMP
return false;
#elif defined(CONFIG_SMP_ON_UP)
extern unsigned int smp_on_up;
return !!smp_on_up;
#else
return true;
#endif
}
/* all SMP configurations have the extended CPUID registers */
#ifndef CONFIG_MMU
#define tlb_ops_need_broadcast() 0
#else
static inline int tlb_ops_need_broadcast(void)
{
if (!is_smp())
return 0;
return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 2;
}
#endif
#if !defined(CONFIG_SMP) || __LINUX_ARM_ARCH__ >= 7
#define cache_ops_need_broadcast() 0
#else
static inline int cache_ops_need_broadcast(void)
{
if (!is_smp())
return 0;
return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 1;
}
#endif
/*
* Logical CPU mapping.
*/
extern u32 __cpu_logical_map[];
#define cpu_logical_map(cpu) __cpu_logical_map[cpu]
/*
* Retrieve logical cpu index corresponding to a given MPIDR[23:0]
* - mpidr: MPIDR[23:0] to be used for the look-up
*
* Returns the cpu logical index or -EINVAL on look-up error
*/
static inline int get_logical_index(u32 mpidr)
{
int cpu;
for (cpu = 0; cpu < nr_cpu_ids; cpu++)
if (cpu_logical_map(cpu) == mpidr)
return cpu;
return -EINVAL;
}
/*
* NOTE ! Assembly code relies on the following
* structure memory layout in order to carry out load
* multiple from its base address. For more
* information check arch/arm/kernel/sleep.S
*/
struct mpidr_hash {
u32 mask; /* used by sleep.S */
u32 shift_aff[3]; /* used by sleep.S */
u32 bits;
};
extern struct mpidr_hash mpidr_hash;
static inline u32 mpidr_hash_size(void)
{
return 1 << mpidr_hash.bits;
}
extern int platform_can_cpu_hotplug(void);
#endif