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: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20200727043132.15082-3-ricardo.neri-calderon@linux.intel.com

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 03b7c4c..68ba42f 100644 (file)
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -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);
 

diff --git a/arch/x86/include/asm/sync_core.h b/arch/x86/include/asm/sync_core.h
index c67caaf..9c5573f 100644 (file)
--- a/arch/x86/include/asm/sync_core.h
+++ b/arch/x86/include/asm/sync_core.h
@@ -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,

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 8fd39ff..6e63231 100644 (file)
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -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>

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 14e4b4d..9246595 100644 (file)
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -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>
 

diff --git a/drivers/misc/sgi-gru/grufault.c b/drivers/misc/sgi-gru/grufault.c
index b152111..7238255 100644 (file)
--- a/drivers/misc/sgi-gru/grufault.c
+++ b/drivers/misc/sgi-gru/grufault.c
@@ -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"

diff --git a/drivers/misc/sgi-gru/gruhandles.c b/drivers/misc/sgi-gru/gruhandles.c
index f7224f9..1d75d5e 100644 (file)
--- a/drivers/misc/sgi-gru/gruhandles.c
+++ b/drivers/misc/sgi-gru/gruhandles.c
@@ -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)

diff --git a/drivers/misc/sgi-gru/grukservices.c b/drivers/misc/sgi-gru/grukservices.c
index 0197441..f6e600b 100644 (file)
--- a/drivers/misc/sgi-gru/grukservices.c
+++ b/drivers/misc/sgi-gru/grukservices.c
@@ -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>