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

Chris Wright
2006-10-29T02:45:43Z

[-- Attachment #1: 01A-apicops.patch --]
[-- Type: text/plain, Size: 3811 bytes --]

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>

---
arch/i386/kernel/paravirt.c | 28 ++++++++++++++++++++++++++++
include/asm-i386/apic.h | 5 ++++-
include/asm-i386/paravirt.h | 27 +++++++++++++++++++++++++++
3 files changed, 59 insertions(+), 1 deletion(-)

--- linux-2.6-pv.orig/arch/i386/kernel/paravirt.c
+++ linux-2.6-pv/arch/i386/kernel/paravirt.c
@@ -28,6 +28,8 @@
#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)
@@ -382,6 +384,26 @@ static fastcall void native_io_delay(voi
asm volatile("outb %al,$0x80");
}

+#ifdef CONFIG_X86_LOCAL_APIC
+/*
+ * Basic functions for reading and writing APIC registers
+ */
+static fastcall void native_apic_write(unsigned long reg, unsigned long v)
+{
+ *((volatile unsigned long *)(APIC_BASE+reg)) = v;
+}
+
+static fastcall void native_apic_write_atomic(unsigned long reg, unsigned long v)
+{
+ xchg((volatile unsigned long *)(APIC_BASE+reg), v);
+}
+
+static fastcall unsigned long native_apic_read(unsigned long reg)
+{
+ return *((volatile unsigned long *)(APIC_BASE+reg));
+}
+#endif /* CONFIG_X86_LOCAL_APIC */
+
/* These are in entry.S */
extern fastcall void native_iret(void);
extern fastcall void native_irq_enable_sysexit(void);
@@ -452,6 +474,12 @@ 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,
};
--- linux-2.6-pv.orig/include/asm-i386/apic.h
+++ linux-2.6-pv/include/asm-i386/apic.h
@@ -37,7 +37,9 @@ extern void generic_apic_probe(void);
/*
* Basic functions accessing APICs.
*/
-
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#else
static __inline void apic_write(unsigned long reg, unsigned long v)
{
*((volatile unsigned long *)(APIC_BASE+reg)) = v;
@@ -52,6 +54,7 @@ static __inline unsigned long apic_read(
{
return *((volatile unsigned long *)(APIC_BASE+reg));
}
+#endif

static __inline__ void apic_wait_icr_idle(void)
{
--- linux-2.6-pv.orig/include/asm-i386/paravirt.h
+++ linux-2.6-pv/include/asm-i386/paravirt.h
@@ -115,6 +115,12 @@ 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);
void (fastcall *iret)(void);
@@ -280,6 +286,27 @@ 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 */

--