Commit 9998a983 authored by Ricardo Neri's avatar Ricardo Neri Committed by Ingo Molnar
Browse files

x86/cpu: Relocate sync_core() to sync_core.h



Having sync_core() in processor.h is problematic since it is not possible
to check for hardware capabilities via the *cpu_has() family of macros.
The latter needs the definitions in processor.h.

It also looks more intuitive to relocate the function to sync_core.h.

This changeset does not make changes in functionality.

Signed-off-by: default avatarRicardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Reviewed-by: default avatarTony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20200727043132.15082-3-ricardo.neri-calderon@linux.intel.com
parent 85b23fbc
......@@ -678,70 +678,6 @@ static inline unsigned int cpuid_edx(unsigned int op)
return edx;
}
/*
* This function forces the icache and prefetched instruction stream to
* catch up with reality in two very specific cases:
*
* a) Text was modified using one virtual address and is about to be executed
* from the same physical page at a different virtual address.
*
* b) Text was modified on a different CPU, may subsequently be
* executed on this CPU, and you want to make sure the new version
* gets executed. This generally means you're calling this in a IPI.
*
* If you're calling this for a different reason, you're probably doing
* it wrong.
*/
static inline void sync_core(void)
{
/*
* There are quite a few ways to do this. IRET-to-self is nice
* because it works on every CPU, at any CPL (so it's compatible
* with paravirtualization), and it never exits to a hypervisor.
* The only down sides are that it's a bit slow (it seems to be
* a bit more than 2x slower than the fastest options) and that
* it unmasks NMIs. The "push %cs" is needed because, in
* paravirtual environments, __KERNEL_CS may not be a valid CS
* value when we do IRET directly.
*
* In case NMI unmasking or performance ever becomes a problem,
* the next best option appears to be MOV-to-CR2 and an
* unconditional jump. That sequence also works on all CPUs,
* but it will fault at CPL3 (i.e. Xen PV).
*
* CPUID is the conventional way, but it's nasty: it doesn't
* exist on some 486-like CPUs, and it usually exits to a
* hypervisor.
*
* Like all of Linux's memory ordering operations, this is a
* compiler barrier as well.
*/
#ifdef CONFIG_X86_32
asm volatile (
"pushfl\n\t"
"pushl %%cs\n\t"
"pushl $1f\n\t"
"iret\n\t"
"1:"
: ASM_CALL_CONSTRAINT : : "memory");
#else
unsigned int tmp;
asm volatile (
"mov %%ss, %0\n\t"
"pushq %q0\n\t"
"pushq %%rsp\n\t"
"addq $8, (%%rsp)\n\t"
"pushfq\n\t"
"mov %%cs, %0\n\t"
"pushq %q0\n\t"
"pushq $1f\n\t"
"iretq\n\t"
"1:"
: "=&r" (tmp), ASM_CALL_CONSTRAINT : : "cc", "memory");
#endif
}
extern void select_idle_routine(const struct cpuinfo_x86 *c);
extern void amd_e400_c1e_apic_setup(void);
......
......@@ -6,6 +6,70 @@
#include <asm/processor.h>
#include <asm/cpufeature.h>
/*
* This function forces the icache and prefetched instruction stream to
* catch up with reality in two very specific cases:
*
* a) Text was modified using one virtual address and is about to be executed
* from the same physical page at a different virtual address.
*
* b) Text was modified on a different CPU, may subsequently be
* executed on this CPU, and you want to make sure the new version
* gets executed. This generally means you're calling this in a IPI.
*
* If you're calling this for a different reason, you're probably doing
* it wrong.
*/
static inline void sync_core(void)
{
/*
* There are quite a few ways to do this. IRET-to-self is nice
* because it works on every CPU, at any CPL (so it's compatible
* with paravirtualization), and it never exits to a hypervisor.
* The only down sides are that it's a bit slow (it seems to be
* a bit more than 2x slower than the fastest options) and that
* it unmasks NMIs. The "push %cs" is needed because, in
* paravirtual environments, __KERNEL_CS may not be a valid CS
* value when we do IRET directly.
*
* In case NMI unmasking or performance ever becomes a problem,
* the next best option appears to be MOV-to-CR2 and an
* unconditional jump. That sequence also works on all CPUs,
* but it will fault at CPL3 (i.e. Xen PV).
*
* CPUID is the conventional way, but it's nasty: it doesn't
* exist on some 486-like CPUs, and it usually exits to a
* hypervisor.
*
* Like all of Linux's memory ordering operations, this is a
* compiler barrier as well.
*/
#ifdef CONFIG_X86_32
asm volatile (
"pushfl\n\t"
"pushl %%cs\n\t"
"pushl $1f\n\t"
"iret\n\t"
"1:"
: ASM_CALL_CONSTRAINT : : "memory");
#else
unsigned int tmp;
asm volatile (
"mov %%ss, %0\n\t"
"pushq %q0\n\t"
"pushq %%rsp\n\t"
"addq $8, (%%rsp)\n\t"
"pushfq\n\t"
"mov %%cs, %0\n\t"
"pushq %q0\n\t"
"pushq $1f\n\t"
"iretq\n\t"
"1:"
: "=&r" (tmp), ASM_CALL_CONSTRAINT : : "cc", "memory");
#endif
}
/*
* Ensure that a core serializing instruction is issued before returning
* to user-mode. x86 implements return to user-space through sysexit,
......
......@@ -15,6 +15,7 @@
#include <linux/kprobes.h>
#include <linux/mmu_context.h>
#include <linux/bsearch.h>
#include <linux/sync_core.h>
#include <asm/text-patching.h>
#include <asm/alternative.h>
#include <asm/sections.h>
......
......@@ -42,6 +42,7 @@
#include <linux/export.h>
#include <linux/jump_label.h>
#include <linux/set_memory.h>
#include <linux/sync_core.h>
#include <linux/task_work.h>
#include <linux/hardirq.h>
......
......@@ -20,6 +20,7 @@
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/security.h>
#include <linux/sync_core.h>
#include <linux/prefetch.h>
#include "gru.h"
#include "grutables.h"
......
......@@ -16,6 +16,7 @@
#define GRU_OPERATION_TIMEOUT (((cycles_t) local_cpu_data->itc_freq)*10)
#define CLKS2NSEC(c) ((c) *1000000000 / local_cpu_data->itc_freq)
#else
#include <linux/sync_core.h>
#include <asm/tsc.h>
#define GRU_OPERATION_TIMEOUT ((cycles_t) tsc_khz*10*1000)
#define CLKS2NSEC(c) ((c) * 1000000 / tsc_khz)
......
......@@ -16,6 +16,7 @@
#include <linux/miscdevice.h>
#include <linux/proc_fs.h>
#include <linux/interrupt.h>
#include <linux/sync_core.h>
#include <linux/uaccess.h>
#include <linux/delay.h>
#include <linux/export.h>
......
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