[RFC, PATCH 13/24] i386 Vmi system header
From: Zachary Amsden
Date: Mon Mar 13 2006 - 13:06:55 EST
Fairly straightforward code motion in system.h into the sub-arch
layer. Affected functionality include control register accessors,
which are virtualizable but with great overhead due to the #GP
cost; wbinvd, and most importantly, halt and interrupt control,
which is non-virtualizable.
Since read_cr4_safe can never fault on a VMI kernel (P5+ processor
is required for VMI), we can omit the fault fixup, which does not
play well with the VMI inline assembler, and just call read_cr4()
directly.
Note that shutdown_halt is unused, but provided in case there is
really a use for it. See arch/i386/kernel/smp.c for a potential
call site during AP shutdown.
Signed-off-by: Zachary Amsden <zach@xxxxxxxxxx>
Index: linux-2.6.16-rc5/include/asm-i386/system.h
===================================================================
--- linux-2.6.16-rc5.orig/include/asm-i386/system.h 2006-03-10 12:55:08.000000000 -0800
+++ linux-2.6.16-rc5/include/asm-i386/system.h 2006-03-10 13:03:36.000000000 -0800
@@ -9,6 +9,8 @@
#ifdef __KERNEL__
+#include <mach_system.h>
+
struct task_struct; /* one of the stranger aspects of C forward declarations.. */
extern struct task_struct * FASTCALL(__switch_to(struct task_struct *prev, struct task_struct *next));
@@ -83,69 +85,8 @@ __asm__ __volatile__ ("movw %%dx,%1\n\t"
#define savesegment(seg, value) \
asm volatile("mov %%" #seg ",%0":"=rm" (value))
-/*
- * Clear and set 'TS' bit respectively
- */
-#define clts() __asm__ __volatile__ ("clts")
-#define read_cr0() ({ \
- unsigned int __dummy; \
- __asm__ __volatile__( \
- "movl %%cr0,%0\n\t" \
- :"=r" (__dummy)); \
- __dummy; \
-})
-#define write_cr0(x) \
- __asm__ __volatile__("movl %0,%%cr0": :"r" (x));
-
-#define read_cr2() ({ \
- unsigned int __dummy; \
- __asm__ __volatile__( \
- "movl %%cr2,%0\n\t" \
- :"=r" (__dummy)); \
- __dummy; \
-})
-#define write_cr2(x) \
- __asm__ __volatile__("movl %0,%%cr2": :"r" (x));
-
-#define read_cr3() ({ \
- unsigned int __dummy; \
- __asm__ ( \
- "movl %%cr3,%0\n\t" \
- :"=r" (__dummy)); \
- __dummy; \
-})
-#define write_cr3(x) \
- __asm__ __volatile__("movl %0,%%cr3": :"r" (x));
-
-#define read_cr4() ({ \
- unsigned int __dummy; \
- __asm__( \
- "movl %%cr4,%0\n\t" \
- :"=r" (__dummy)); \
- __dummy; \
-})
-
-#define read_cr4_safe() ({ \
- unsigned int __dummy; \
- /* This could fault if %cr4 does not exist */ \
- __asm__("1: movl %%cr4, %0 \n" \
- "2: \n" \
- ".section __ex_table,\"a\" \n" \
- ".long 1b,2b \n" \
- ".previous \n" \
- : "=r" (__dummy): "0" (0)); \
- __dummy; \
-})
-
-#define write_cr4(x) \
- __asm__ __volatile__("movl %0,%%cr4": :"r" (x));
-#define stts() write_cr0(8 | read_cr0())
-
#endif /* __KERNEL__ */
-#define wbinvd() \
- __asm__ __volatile__ ("wbinvd": : :"memory");
-
static inline unsigned long get_limit(unsigned long segment)
{
unsigned long __limit;
@@ -518,16 +459,7 @@ struct alt_instr {
#define set_wmb(var, value) do { var = value; wmb(); } while (0)
-/* interrupt control.. */
-#define local_save_flags(x) do { typecheck(unsigned long,x); __asm__ __volatile__("pushfl ; popl %0":"=g" (x): /* no input */); } while (0)
-#define local_irq_restore(x) do { typecheck(unsigned long,x); __asm__ __volatile__("pushl %0 ; popfl": /* no output */ :"g" (x):"memory", "cc"); } while (0)
-#define local_irq_disable() __asm__ __volatile__("cli": : :"memory")
-#define local_irq_enable() __asm__ __volatile__("sti": : :"memory")
-/* used in the idle loop; sti takes one instruction cycle to complete */
-#define safe_halt() __asm__ __volatile__("sti; hlt": : :"memory")
-/* used when interrupts are already enabled or to shutdown the processor */
-#define halt() __asm__ __volatile__("hlt": : :"memory")
-
+#define local_irq_save(x) do { typecheck(unsigned long,x); local_save_flags(x); local_irq_disable(); } while (0)
#define irqs_disabled() \
({ \
unsigned long flags; \
@@ -535,9 +467,6 @@ struct alt_instr {
!(flags & (1<<9)); \
})
-/* For spinlocks etc */
-#define local_irq_save(x) __asm__ __volatile__("pushfl ; popl %0 ; cli":"=g" (x): /* no input */ :"memory")
-
/*
* disable hlt during certain critical i/o operations
*/
Index: linux-2.6.16-rc5/include/asm-i386/mach-vmi/mach_system.h
===================================================================
--- linux-2.6.16-rc5.orig/include/asm-i386/mach-vmi/mach_system.h 2006-03-10 13:03:36.000000000 -0800
+++ linux-2.6.16-rc5/include/asm-i386/mach-vmi/mach_system.h 2006-03-10 13:03:36.000000000 -0800
@@ -0,0 +1,216 @@
+/*
+ * Copyright (C) 2005, VMware, Inc.
+ *
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Send feedback to zach@xxxxxxxxxx
+ *
+ */
+
+
+#ifndef _MACH_SYSTEM_H
+#define _MACH_SYSTEM_H
+
+#include <vmi.h>
+
+static inline void write_cr0(const u32 val)
+{
+ vmi_wrap_call(
+ SetCR0, "mov %0, %%cr0",
+ VMI_NO_OUTPUT,
+ 1, VMI_IREG1(val),
+ VMI_CLOBBER_EXTENDED(ZERO_RETURNS, "memory"));
+}
+
+static inline void write_cr2(const u32 val)
+{
+ vmi_wrap_call(
+ SetCR2, "mov %0, %%cr2",
+ VMI_NO_OUTPUT,
+ 1, VMI_IREG1(val),
+ VMI_CLOBBER_EXTENDED(ZERO_RETURNS, "memory"));
+}
+
+static inline void write_cr3(const u32 val)
+{
+ vmi_wrap_call(
+ SetCR3, "mov %0, %%cr3",
+ VMI_NO_OUTPUT,
+ 1, VMI_IREG1(val),
+ VMI_CLOBBER_EXTENDED(ZERO_RETURNS, "memory"));
+}
+
+static inline void write_cr4(const u32 val)
+{
+ vmi_wrap_call(
+ SetCR4, "mov %0, %%cr4",
+ VMI_NO_OUTPUT,
+ 1, VMI_IREG1(val),
+ VMI_CLOBBER_EXTENDED(ZERO_RETURNS, "memory"));
+}
+
+static inline u32 read_cr0(void)
+{
+ u32 ret;
+ vmi_wrap_call(
+ GetCR0, "mov %%cr0, %%eax",
+ VMI_OREG1(ret),
+ 0, VMI_NO_INPUT,
+ VMI_CLOBBER(ONE_RETURN));
+ return ret;
+}
+
+static inline u32 read_cr2(void)
+{
+ u32 ret;
+ vmi_wrap_call(
+ GetCR2, "mov %%cr2, %%eax",
+ VMI_OREG1(ret),
+ 0, VMI_NO_INPUT,
+ VMI_CLOBBER(ONE_RETURN));
+ return ret;
+}
+
+static inline u32 read_cr3(void)
+{
+ u32 ret;
+ vmi_wrap_call(
+ GetCR3, "mov %%cr3, %%eax",
+ VMI_OREG1(ret),
+ 0, VMI_NO_INPUT,
+ VMI_CLOBBER(ONE_RETURN));
+ return ret;
+}
+
+static inline u32 read_cr4(void)
+{
+ u32 ret;
+ vmi_wrap_call(
+ GetCR4, "mov %%cr4, %%eax",
+ VMI_OREG1(ret),
+ 0, VMI_NO_INPUT,
+ VMI_CLOBBER(ONE_RETURN));
+ return ret;
+}
+
+#define read_cr4_safe() read_cr4()
+#define load_cr3(pgdir) write_cr3(__pa(pgdir))
+
+static inline void clts(void)
+{
+ vmi_wrap_call(
+ CLTS, "clts",
+ VMI_NO_OUTPUT,
+ 0, VMI_NO_INPUT,
+ VMI_CLOBBER(ZERO_RETURNS));
+}
+
+static inline void wbinvd(void)
+{
+ vmi_wrap_call(
+ WBINVD, "wbinvd",
+ VMI_NO_OUTPUT,
+ 0, VMI_NO_INPUT,
+ VMI_CLOBBER_EXTENDED(ZERO_RETURNS, "memory"));
+}
+
+/*
+ * For EnableInterrupts, DisableInterrupts, GetInterruptMask, SetInterruptMask,
+ * only flags are clobbered by these calls, since they have assembler call
+ * convention. We can get better C code by indicating only "cc" clobber.
+ * Both setting and disabling interrupts must use memory clobber as well, to
+ * prevent GCC from reordering memory access around them.
+ */
+static inline void local_irq_disable(void)
+{
+ vmi_wrap_call(
+ DisableInterrupts, "cli",
+ VMI_NO_OUTPUT,
+ 0, VMI_NO_INPUT,
+ XCONC("cc", "memory"));
+}
+
+static inline void local_irq_enable(void)
+{
+ vmi_wrap_call(
+ EnableInterrupts, "sti",
+ VMI_NO_OUTPUT,
+ 0, VMI_NO_INPUT,
+ XCONC("cc", "memory"));
+}
+
+static inline void local_irq_restore(const unsigned long flags)
+{
+ vmi_wrap_call(
+ SetInterruptMask, "pushl %0; popfl",
+ VMI_NO_OUTPUT,
+ 1, VMI_IREG1 (flags),
+ XCONC("cc", "memory"));
+}
+
+static inline unsigned long vmi_get_flags(void)
+{
+ unsigned long ret;
+ vmi_wrap_call(
+ GetInterruptMask, "pushfl; popl %%eax",
+ VMI_OREG1 (ret),
+ 0, VMI_NO_INPUT,
+ "cc");
+ return ret;
+}
+
+#define local_save_flags(x) do { typecheck(unsigned long,x); (x) = vmi_get_flags(); } while (0)
+
+static inline void vmi_reboot(int how)
+{
+ vmi_wrap_call(
+ Reboot, "",
+ VMI_NO_OUTPUT,
+ 1, VMI_IREG1(how),
+ "memory"); /* only memory clobber for better code */
+}
+
+static inline void safe_halt(void)
+{
+ vmi_wrap_call(
+ Halt, "sti; hlt",
+ VMI_NO_OUTPUT,
+ 0, VMI_NO_INPUT,
+ VMI_CLOBBER(ZERO_RETURNS));
+}
+
+/* By default, halt is assumed safe, but we can drop the sti */
+static inline void halt(void)
+{
+ vmi_wrap_call(
+ Halt, "hlt",
+ VMI_NO_OUTPUT,
+ 0, VMI_NO_INPUT,
+ VMI_CLOBBER(ZERO_RETURNS));
+}
+
+static inline void shutdown_halt(void)
+{
+ vmi_wrap_call(
+ Shutdown, "cli; hlt",
+ VMI_NO_OUTPUT,
+ 0, VMI_NO_INPUT,
+ "memory"); /* only memory clobber for better code */
+}
+
+#endif
Index: linux-2.6.16-rc5/include/asm-i386/mach-default/mach_system.h
===================================================================
--- linux-2.6.16-rc5.orig/include/asm-i386/mach-default/mach_system.h 2006-03-10 13:03:36.000000000 -0800
+++ linux-2.6.16-rc5/include/asm-i386/mach-default/mach_system.h 2006-03-10 16:00:38.000000000 -0800
@@ -0,0 +1,80 @@
+#ifndef _MACH_SYSTEM_H
+#define _MACH_SYSTEM_H
+
+#define clts() __asm__ __volatile__ ("clts")
+#define read_cr0() ({ \
+ unsigned int __dummy; \
+ __asm__ __volatile__( \
+ "movl %%cr0,%0\n\t" \
+ :"=r" (__dummy)); \
+ __dummy; \
+})
+
+#define write_cr0(x) \
+ __asm__ __volatile__("movl %0,%%cr0": :"r" (x));
+
+#define read_cr2() ({ \
+ unsigned int __dummy; \
+ __asm__ __volatile__( \
+ "movl %%cr2,%0\n\t" \
+ :"=r" (__dummy)); \
+ __dummy; \
+})
+#define write_cr2(x) \
+ __asm__ __volatile__("movl %0,%%cr2": :"r" (x));
+
+#define read_cr3() ({ \
+ unsigned int __dummy; \
+ __asm__( \
+ "movl %%cr3,%0\n\t" \
+ :"=r" (__dummy)); \
+ __dummy; \
+})
+#define write_cr3(x) \
+ __asm__ __volatile__("movl %0,%%cr3": :"r" (x));
+
+#define read_cr4() ({ \
+ unsigned int __dummy; \
+ __asm__( \
+ "movl %%cr4,%0\n\t" \
+ :"=r" (__dummy)); \
+ __dummy; \
+})
+
+#define read_cr4_safe() ({ \
+ unsigned int __dummy; \
+ /* This could fault if %cr4 does not exist */ \
+ __asm__("1: movl %%cr4, %0 \n" \
+ "2: \n" \
+ ".section __ex_table,\"a\" \n" \
+ ".long 1b,2b \n" \
+ ".previous \n" \
+ : "=r" (__dummy): "0" (0)); \
+ __dummy; \
+})
+
+#define write_cr4(x) \
+ __asm__ __volatile__("movl %0,%%cr4": :"r" (x));
+
+#define wbinvd() \
+ __asm__ __volatile__ ("wbinvd": : :"memory");
+
+/* interrupt control.. */
+#define local_save_flags(x) do { typecheck(unsigned long,x); __asm__ __volatile__("pushfl ; popl %0":"=g" (x): /* no input */); } while (0)
+
+/* For spinlocks etc */
+#define local_irq_restore(x) do { typecheck(unsigned long,x); __asm__ __volatile__("pushl %0 ; popfl": /* no output */ :"g" (x):"memory", "cc"); } while (0)
+
+#define local_irq_disable() __asm__ __volatile__("cli": : :"memory")
+#define local_irq_enable() __asm__ __volatile__("sti": : :"memory")
+
+/* used in the idle loop; sti holds off interrupts for 1 instruction */
+#define safe_halt() __asm__ __volatile__("sti; hlt": : :"memory")
+
+/* force shutdown of the processor; used when IRQs are disabled */
+#define shutdown_halt() __asm__ __volatile__("hlt": : :"memory")
+
+/* halt until interrupted */
+#define halt() __asm__ __volatile__("hlt")
+
+#endif
-
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