mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-28 15:13:55 +08:00
5b09b2876e
As a stopgap until Mike Travis's x86-64 gs-based percpu patches are ready, provide workaround functions for x86_read/write_percpu for Xen's use. Specifically, this means that we can't really make use of vcpu placement, because we can't use a single gs-based memory access to get to vcpu fields. So disable all that for now. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
219 lines
5.7 KiB
C
219 lines
5.7 KiB
C
#ifndef _ASM_X86_PERCPU_H_
|
|
#define _ASM_X86_PERCPU_H_
|
|
|
|
#ifdef CONFIG_X86_64
|
|
#include <linux/compiler.h>
|
|
|
|
/* Same as asm-generic/percpu.h, except that we store the per cpu offset
|
|
in the PDA. Longer term the PDA and every per cpu variable
|
|
should be just put into a single section and referenced directly
|
|
from %gs */
|
|
|
|
#ifdef CONFIG_SMP
|
|
#include <asm/pda.h>
|
|
|
|
#define __per_cpu_offset(cpu) (cpu_pda(cpu)->data_offset)
|
|
#define __my_cpu_offset read_pda(data_offset)
|
|
|
|
#define per_cpu_offset(x) (__per_cpu_offset(x))
|
|
|
|
#endif
|
|
#include <asm-generic/percpu.h>
|
|
|
|
DECLARE_PER_CPU(struct x8664_pda, pda);
|
|
|
|
/*
|
|
* These are supposed to be implemented as a single instruction which
|
|
* operates on the per-cpu data base segment. x86-64 doesn't have
|
|
* that yet, so this is a fairly inefficient workaround for the
|
|
* meantime. The single instruction is atomic with respect to
|
|
* preemption and interrupts, so we need to explicitly disable
|
|
* interrupts here to achieve the same effect. However, because it
|
|
* can be used from within interrupt-disable/enable, we can't actually
|
|
* disable interrupts; disabling preemption is enough.
|
|
*/
|
|
#define x86_read_percpu(var) \
|
|
({ \
|
|
typeof(per_cpu_var(var)) __tmp; \
|
|
preempt_disable(); \
|
|
__tmp = __get_cpu_var(var); \
|
|
preempt_enable(); \
|
|
__tmp; \
|
|
})
|
|
|
|
#define x86_write_percpu(var, val) \
|
|
do { \
|
|
preempt_disable(); \
|
|
__get_cpu_var(var) = (val); \
|
|
preempt_enable(); \
|
|
} while(0)
|
|
|
|
#else /* CONFIG_X86_64 */
|
|
|
|
#ifdef __ASSEMBLY__
|
|
|
|
/*
|
|
* PER_CPU finds an address of a per-cpu variable.
|
|
*
|
|
* Args:
|
|
* var - variable name
|
|
* reg - 32bit register
|
|
*
|
|
* The resulting address is stored in the "reg" argument.
|
|
*
|
|
* Example:
|
|
* PER_CPU(cpu_gdt_descr, %ebx)
|
|
*/
|
|
#ifdef CONFIG_SMP
|
|
#define PER_CPU(var, reg) \
|
|
movl %fs:per_cpu__##this_cpu_off, reg; \
|
|
lea per_cpu__##var(reg), reg
|
|
#define PER_CPU_VAR(var) %fs:per_cpu__##var
|
|
#else /* ! SMP */
|
|
#define PER_CPU(var, reg) \
|
|
movl $per_cpu__##var, reg
|
|
#define PER_CPU_VAR(var) per_cpu__##var
|
|
#endif /* SMP */
|
|
|
|
#else /* ...!ASSEMBLY */
|
|
|
|
/*
|
|
* PER_CPU finds an address of a per-cpu variable.
|
|
*
|
|
* Args:
|
|
* var - variable name
|
|
* cpu - 32bit register containing the current CPU number
|
|
*
|
|
* The resulting address is stored in the "cpu" argument.
|
|
*
|
|
* Example:
|
|
* PER_CPU(cpu_gdt_descr, %ebx)
|
|
*/
|
|
#ifdef CONFIG_SMP
|
|
|
|
#define __my_cpu_offset x86_read_percpu(this_cpu_off)
|
|
|
|
/* fs segment starts at (positive) offset == __per_cpu_offset[cpu] */
|
|
#define __percpu_seg "%%fs:"
|
|
|
|
#else /* !SMP */
|
|
|
|
#define __percpu_seg ""
|
|
|
|
#endif /* SMP */
|
|
|
|
#include <asm-generic/percpu.h>
|
|
|
|
/* We can use this directly for local CPU (faster). */
|
|
DECLARE_PER_CPU(unsigned long, this_cpu_off);
|
|
|
|
/* For arch-specific code, we can use direct single-insn ops (they
|
|
* don't give an lvalue though). */
|
|
extern void __bad_percpu_size(void);
|
|
|
|
#define percpu_to_op(op, var, val) \
|
|
do { \
|
|
typedef typeof(var) T__; \
|
|
if (0) { \
|
|
T__ tmp__; \
|
|
tmp__ = (val); \
|
|
} \
|
|
switch (sizeof(var)) { \
|
|
case 1: \
|
|
asm(op "b %1,"__percpu_seg"%0" \
|
|
: "+m" (var) \
|
|
: "ri" ((T__)val)); \
|
|
break; \
|
|
case 2: \
|
|
asm(op "w %1,"__percpu_seg"%0" \
|
|
: "+m" (var) \
|
|
: "ri" ((T__)val)); \
|
|
break; \
|
|
case 4: \
|
|
asm(op "l %1,"__percpu_seg"%0" \
|
|
: "+m" (var) \
|
|
: "ri" ((T__)val)); \
|
|
break; \
|
|
default: __bad_percpu_size(); \
|
|
} \
|
|
} while (0)
|
|
|
|
#define percpu_from_op(op, var) \
|
|
({ \
|
|
typeof(var) ret__; \
|
|
switch (sizeof(var)) { \
|
|
case 1: \
|
|
asm(op "b "__percpu_seg"%1,%0" \
|
|
: "=r" (ret__) \
|
|
: "m" (var)); \
|
|
break; \
|
|
case 2: \
|
|
asm(op "w "__percpu_seg"%1,%0" \
|
|
: "=r" (ret__) \
|
|
: "m" (var)); \
|
|
break; \
|
|
case 4: \
|
|
asm(op "l "__percpu_seg"%1,%0" \
|
|
: "=r" (ret__) \
|
|
: "m" (var)); \
|
|
break; \
|
|
default: __bad_percpu_size(); \
|
|
} \
|
|
ret__; \
|
|
})
|
|
|
|
#define x86_read_percpu(var) percpu_from_op("mov", per_cpu__##var)
|
|
#define x86_write_percpu(var, val) percpu_to_op("mov", per_cpu__##var, val)
|
|
#define x86_add_percpu(var, val) percpu_to_op("add", per_cpu__##var, val)
|
|
#define x86_sub_percpu(var, val) percpu_to_op("sub", per_cpu__##var, val)
|
|
#define x86_or_percpu(var, val) percpu_to_op("or", per_cpu__##var, val)
|
|
#endif /* !__ASSEMBLY__ */
|
|
#endif /* !CONFIG_X86_64 */
|
|
|
|
#ifdef CONFIG_SMP
|
|
|
|
/*
|
|
* Define the "EARLY_PER_CPU" macros. These are used for some per_cpu
|
|
* variables that are initialized and accessed before there are per_cpu
|
|
* areas allocated.
|
|
*/
|
|
|
|
#define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \
|
|
DEFINE_PER_CPU(_type, _name) = _initvalue; \
|
|
__typeof__(_type) _name##_early_map[NR_CPUS] __initdata = \
|
|
{ [0 ... NR_CPUS-1] = _initvalue }; \
|
|
__typeof__(_type) *_name##_early_ptr = _name##_early_map
|
|
|
|
#define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \
|
|
EXPORT_PER_CPU_SYMBOL(_name)
|
|
|
|
#define DECLARE_EARLY_PER_CPU(_type, _name) \
|
|
DECLARE_PER_CPU(_type, _name); \
|
|
extern __typeof__(_type) *_name##_early_ptr; \
|
|
extern __typeof__(_type) _name##_early_map[]
|
|
|
|
#define early_per_cpu_ptr(_name) (_name##_early_ptr)
|
|
#define early_per_cpu_map(_name, _idx) (_name##_early_map[_idx])
|
|
#define early_per_cpu(_name, _cpu) \
|
|
(early_per_cpu_ptr(_name) ? \
|
|
early_per_cpu_ptr(_name)[_cpu] : \
|
|
per_cpu(_name, _cpu))
|
|
|
|
#else /* !CONFIG_SMP */
|
|
#define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \
|
|
DEFINE_PER_CPU(_type, _name) = _initvalue
|
|
|
|
#define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \
|
|
EXPORT_PER_CPU_SYMBOL(_name)
|
|
|
|
#define DECLARE_EARLY_PER_CPU(_type, _name) \
|
|
DECLARE_PER_CPU(_type, _name)
|
|
|
|
#define early_per_cpu(_name, _cpu) per_cpu(_name, _cpu)
|
|
#define early_per_cpu_ptr(_name) NULL
|
|
/* no early_per_cpu_map() */
|
|
|
|
#endif /* !CONFIG_SMP */
|
|
|
|
#endif /* _ASM_X86_PERCPU_H_ */
|