[PATCH 6/7] paravirtualization: Add APIC accessors to paravirt-ops.

Rusty Russell
2006-11-01T10:32:37Z

Add APIC accessors to paravirt-ops. Unfortunately, we need two write
functions, as some older broken hardware requires workarounds for
Pentium APIC errata - this is the purpose of apic_write_atomic.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -29,6 +29,8 @@
#include <asm/time.h>
#include <asm/irq.h>
#include <asm/delay.h>
+#include <asm/fixmap.h>
+#include <asm/apic.h>

/* nop stub */
static void native_nop(void)
@@ -441,6 +443,12 @@ struct paravirt_ops paravirt_ops = {
.io_delay = native_io_delay,
.const_udelay = __const_udelay,

+#ifdef CONFIG_X86_LOCAL_APIC
+ .apic_write = native_apic_write,
+ .apic_write_atomic = native_apic_write_atomic,
+ .apic_read = native_apic_read,
+#endif
+
.irq_enable_sysexit = native_irq_enable_sysexit,
.iret = native_iret,
};
===================================================================
--- a/include/asm-i386/apic.h
+++ b/include/asm-i386/apic.h
@@ -37,18 +37,27 @@ extern void generic_apic_probe(void);
/*
* Basic functions accessing APICs.
*/
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#else
+#define apic_write native_apic_write
+#define apic_write_atomic native_apic_write_atomic
+#define apic_read native_apic_read
+#endif

-static __inline void apic_write(unsigned long reg, unsigned long v)
+static __inline fastcall void native_apic_write(unsigned long reg,
+ unsigned long v)
{
*((volatile unsigned long *)(APIC_BASE+reg)) = v;
}

-static __inline void apic_write_atomic(unsigned long reg, unsigned long v)
+static __inline fastcall void native_apic_write_atomic(unsigned long reg,
+ unsigned long v)
{
xchg((volatile unsigned long *)(APIC_BASE+reg), v);
}

-static __inline unsigned long apic_read(unsigned long reg)
+static __inline fastcall unsigned long native_apic_read(unsigned long reg)
{
return *((volatile unsigned long *)(APIC_BASE+reg));
}
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -114,6 +114,12 @@ struct paravirt_ops

void (fastcall *io_delay)(void);
void (*const_udelay)(unsigned long loops);
+
+#ifdef CONFIG_X86_LOCAL_APIC
+ void (fastcall *apic_write)(unsigned long reg, unsigned long v);
+ void (fastcall *apic_write_atomic)(unsigned long reg, unsigned long v);
+ unsigned long (fastcall *apic_read)(unsigned long reg);
+#endif

/* These two are jmp to, not actually called. */
void (fastcall *irq_enable_sysexit)(void);
@@ -275,6 +281,27 @@ static inline void slow_down_io(void) {
#endif
}

+#ifdef CONFIG_X86_LOCAL_APIC
+/*
+ * Basic functions accessing APICs.
+ */
+static __inline void apic_write(unsigned long reg, unsigned long v)
+{
+ paravirt_ops.apic_write(reg,v);
+}
+
+static __inline void apic_write_atomic(unsigned long reg, unsigned long v)
+{
+ paravirt_ops.apic_write_atomic(reg,v);
+}
+
+static __inline unsigned long apic_read(unsigned long reg)
+{
+ return paravirt_ops.apic_read(reg);
+}
+#endif
+
+
/* These all sit in the .parainstructions section to tell us what to patch. */
struct paravirt_patch {
u8 *instr; /* original instructions */