lkml.org 
[lkml]   [2007]   [Aug]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 12/25][V3] turn msr.h functions into native versions
Date
This patch turns makes the basic operations in msr.h out of native
ones. Those operations are: rdmsr, wrmsr, rdtsc, rdtscp, rdpmc, and
cpuid. After they are turned into functions, some call sites need
casts, and so we provide them.

There is also a fixup needed in the functions located in the vsyscall
area, as they cannot call any of them anymore (otherwise, the call
would go through a kernel address, invalid in userspace mapping).

The solution is to call the now-provided native_ versions instead.

[ updates from v1
* Call read_tscp rdtscp, to match instruction name
* Avoid duplication of code in get_cycles_sync
* Get rid of rdtsc(), since it is used nowhere else
All three suggested by Andi Kleen
]

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
arch/x86_64/ia32/syscall32.c | 2 +-
arch/x86_64/kernel/setup64.c | 6 +-
arch/x86_64/kernel/tsc.c | 24 ++++-
arch/x86_64/kernel/vsyscall.c | 4 +-
arch/x86_64/vdso/vgetcpu.c | 4 +-
include/asm-i386/tsc.h | 12 ++-
include/asm-x86_64/msr.h | 277 +++++++++++++++++++++++++----------------
7 files changed, 211 insertions(+), 118 deletions(-)
diff --git a/arch/x86_64/ia32/syscall32.c b/arch/x86_64/ia32/syscall32.c
index 15013ba..dd1b4a3 100644
--- a/arch/x86_64/ia32/syscall32.c
+++ b/arch/x86_64/ia32/syscall32.c
@@ -79,5 +79,5 @@ void syscall32_cpu_init(void)
checking_wrmsrl(MSR_IA32_SYSENTER_ESP, 0ULL);
checking_wrmsrl(MSR_IA32_SYSENTER_EIP, (u64)ia32_sysenter_target);

- wrmsrl(MSR_CSTAR, ia32_cstar_target);
+ wrmsrl(MSR_CSTAR, (u64)ia32_cstar_target);
}
diff --git a/arch/x86_64/kernel/setup64.c b/arch/x86_64/kernel/setup64.c
index 1200aaa..395cf02 100644
--- a/arch/x86_64/kernel/setup64.c
+++ b/arch/x86_64/kernel/setup64.c
@@ -122,7 +122,7 @@ void pda_init(int cpu)
asm volatile("movl %0,%%fs ; movl %0,%%gs" :: "r" (0));
/* Memory clobbers used to order PDA accessed */
mb();
- wrmsrl(MSR_GS_BASE, pda);
+ wrmsrl(MSR_GS_BASE, (u64)pda);
mb();

pda->cpunumber = cpu;
@@ -161,8 +161,8 @@ void syscall_init(void)
* but only a 32bit target. LSTAR sets the 64bit rip.
*/
wrmsrl(MSR_STAR, ((u64)__USER32_CS)<<48 | ((u64)__KERNEL_CS)<<32);
- wrmsrl(MSR_LSTAR, system_call);
- wrmsrl(MSR_CSTAR, ignore_sysret);
+ wrmsrl(MSR_LSTAR, (u64)system_call);
+ wrmsrl(MSR_CSTAR, (u64)ignore_sysret);

#ifdef CONFIG_IA32_EMULATION
syscall32_cpu_init ();
diff --git a/arch/x86_64/kernel/tsc.c b/arch/x86_64/kernel/tsc.c
index 2a59bde..2a5fbc9 100644
--- a/arch/x86_64/kernel/tsc.c
+++ b/arch/x86_64/kernel/tsc.c
@@ -9,6 +9,28 @@

#include <asm/timex.h>

+#ifdef CONFIG_PARAVIRT
+/*
+ * When paravirt is on, some functionalities are executed through function
+ * pointers in the paravirt_ops structure, for both the host and guest.
+ * These function pointers exist inside the kernel and can not
+ * be accessed by user space. To avoid this, we make a copy of the
+ * get_cycles_sync (called in kernel) but force the use of native_read_tsc.
+ * For the host, it will simply do the native rdtsc. The guest
+ * should set up it's own clock and vread
+ */
+static __always_inline long long vget_cycles_sync(void)
+{
+ unsigned long long ret;
+ ret =__get_cycles_sync();
+ if (!ret)
+ ret = native_read_tsc();
+ return ret;
+}
+#else
+# define vget_cycles_sync() get_cycles_sync()
+#endif
+
static int notsc __initdata = 0;

unsigned int cpu_khz; /* TSC clocks / usec, not used here */
@@ -165,7 +187,7 @@ static cycle_t read_tsc(void)

static cycle_t __vsyscall_fn vread_tsc(void)
{
- cycle_t ret = (cycle_t)get_cycles_sync();
+ cycle_t ret = (cycle_t)vget_cycles_sync();
return ret;
}

diff --git a/arch/x86_64/kernel/vsyscall.c b/arch/x86_64/kernel/vsyscall.c
index 06c3494..757874e 100644
--- a/arch/x86_64/kernel/vsyscall.c
+++ b/arch/x86_64/kernel/vsyscall.c
@@ -184,7 +184,7 @@ time_t __vsyscall(1) vtime(time_t *t)
long __vsyscall(2)
vgetcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache)
{
- unsigned int dummy, p;
+ unsigned int p;
unsigned long j = 0;

/* Fast cache - only recompute value once per jiffies and avoid
@@ -199,7 +199,7 @@ vgetcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache)
p = tcache->blob[1];
} else if (__vgetcpu_mode == VGETCPU_RDTSCP) {
/* Load per CPU data from RDTSCP */
- rdtscp(dummy, dummy, p);
+ native_rdtscp(&p);
} else {
/* Load per CPU data from GDT */
asm("lsl %1,%0" : "=r" (p) : "r" (__PER_CPU_SEG));
diff --git a/arch/x86_64/vdso/vgetcpu.c b/arch/x86_64/vdso/vgetcpu.c
index 91f6e85..1f38f61 100644
--- a/arch/x86_64/vdso/vgetcpu.c
+++ b/arch/x86_64/vdso/vgetcpu.c
@@ -15,7 +15,7 @@

long __vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache)
{
- unsigned int dummy, p;
+ unsigned int p;
unsigned long j = 0;

/* Fast cache - only recompute value once per jiffies and avoid
@@ -30,7 +30,7 @@ long __vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache)
p = tcache->blob[1];
} else if (*vdso_vgetcpu_mode == VGETCPU_RDTSCP) {
/* Load per CPU data from RDTSCP */
- rdtscp(dummy, dummy, p);
+ native_rdtscp(&p);
} else {
/* Load per CPU data from GDT */
asm("lsl %1,%0" : "=r" (p) : "r" (__PER_CPU_SEG));
diff --git a/include/asm-i386/tsc.h b/include/asm-i386/tsc.h
index a4d8066..a1f213e 100644
--- a/include/asm-i386/tsc.h
+++ b/include/asm-i386/tsc.h
@@ -32,7 +32,7 @@ static inline cycles_t get_cycles(void)
}

/* Like get_cycles, but make sure the CPU is synchronized. */
-static __always_inline cycles_t get_cycles_sync(void)
+static __always_inline cycles_t __get_cycles_sync(void)
{
unsigned long long ret;
unsigned eax, edx;
@@ -54,8 +54,16 @@ static __always_inline cycles_t get_cycles_sync(void)
*/
alternative_io("cpuid", ASM_NOP2, X86_FEATURE_SYNC_RDTSC,
"=a" (eax), "0" (1) : "ebx","ecx","edx","memory");
- rdtscll(ret);

+ return 0;
+}
+
+static __always_inline cycles_t get_cycles_sync(void)
+{
+ unsigned long long ret;
+ ret = __get_cycles_sync();
+ if (!ret)
+ rdtscll(ret);
return ret;
}

diff --git a/include/asm-x86_64/msr.h b/include/asm-x86_64/msr.h
index d5c55b8..3176d30 100644
--- a/include/asm-x86_64/msr.h
+++ b/include/asm-x86_64/msr.h
@@ -10,110 +10,186 @@
* Note: the rd* operations modify the parameters directly (without using
* pointer indirection), this allows gcc to optimize better
*/
+static inline unsigned long native_read_msr(unsigned int msr)
+{
+ unsigned long a, d;
+ asm volatile("rdmsr" : "=a" (a), "=d" (d) : "c" (msr));
+ return a | (d << 32);
+}
+
+static inline unsigned long native_read_msr_safe(unsigned int msr, int *err)
+{
+ unsigned long a, d;
+ asm volatile ( "1: rdmsr; xorl %0, %0\n"
+ "2:\n"
+ ".section .fixup,\"ax\"\n"
+ "3: movl %4,%0\n"
+ " jmp 2b\n"
+ ".previous\n"
+ ".section __ex_table,\"a\"\n"
+ " .align 8\n"
+ " .quad 1b,3b\n"
+ ".previous":"=&bDS" (*err), "=a"((a)), "=d"((d))
+ :"c"(msr), "i"(-EIO), "0"(0));
+ return a | (d << 32);
+}

-#define rdmsr(msr,val1,val2) \
- __asm__ __volatile__("rdmsr" \
- : "=a" (val1), "=d" (val2) \
- : "c" (msr))
+static inline unsigned long native_write_msr(unsigned int msr,
+ unsigned long val)
+{
+ asm volatile( "wrmsr"
+ : /* no outputs */
+ : "c" (msr), "a" ((u32)val), "d" ((u32)(val>>32)));
+ return 0;
+}
+
+/* wrmsr with exception handling */
+static inline long native_write_msr_safe(unsigned int msr, unsigned long val)
+{
+ unsigned long ret;
+ asm volatile("2: wrmsr ; xorq %0,%0\n"
+ "1:\n\t"
+ ".section .fixup,\"ax\"\n\t"
+ "3: movq %4,%0 ; jmp 1b\n\t"
+ ".previous\n\t"
+ ".section __ex_table,\"a\"\n"
+ " .align 8\n\t"
+ " .quad 2b,3b\n\t"
+ ".previous"
+ : "=r" (ret)
+ : "c" (msr), "a" ((u32)val), "d" ((u32)(val>>32)),
+ "i" (-EFAULT));
+ return ret;
+}

+static inline unsigned long native_read_tsc(void)
+{
+ unsigned long low, high;
+ asm volatile("rdtsc" : "=a" (low), "=d" (high));
+ return low | (high << 32);
+}

-#define rdmsrl(msr,val) do { unsigned long a__,b__; \
- __asm__ __volatile__("rdmsr" \
- : "=a" (a__), "=d" (b__) \
- : "c" (msr)); \
- val = a__ | (b__<<32); \
-} while(0)
+static inline unsigned long native_read_pmc(int counter)
+{
+ unsigned long low, high;
+ asm volatile ("rdpmc"
+ : "=a" (low), "=d" (high)
+ : "c" (counter));

-#define wrmsr(msr,val1,val2) \
- __asm__ __volatile__("wrmsr" \
- : /* no outputs */ \
- : "c" (msr), "a" (val1), "d" (val2))
+ return low | (high << 32);
+}

-#define wrmsrl(msr,val) wrmsr(msr,(__u32)((__u64)(val)),((__u64)(val))>>32)
+static inline void native_cpuid(unsigned int *eax, unsigned int *ebx,
+ unsigned int *ecx, unsigned int *edx)
+{
+ asm volatile ("cpuid"
+ : "=a" (*eax),
+ "=b" (*ebx),
+ "=c" (*ecx),
+ "=d" (*edx)
+ : "0" (*eax), "2" (*ecx));
+}

-/* wrmsr with exception handling */
-#define wrmsr_safe(msr,a,b) ({ int ret__; \
- asm volatile("2: wrmsr ; xorl %0,%0\n" \
- "1:\n\t" \
- ".section .fixup,\"ax\"\n\t" \
- "3: movl %4,%0 ; jmp 1b\n\t" \
- ".previous\n\t" \
- ".section __ex_table,\"a\"\n" \
- " .align 8\n\t" \
- " .quad 2b,3b\n\t" \
- ".previous" \
- : "=a" (ret__) \
- : "c" (msr), "0" (a), "d" (b), "i" (-EFAULT)); \
- ret__; })
-
-#define checking_wrmsrl(msr,val) wrmsr_safe(msr,(u32)(val),(u32)((val)>>32))
-
-#define rdmsr_safe(msr,a,b) \
- ({ int ret__; \
- asm volatile ("1: rdmsr\n" \
- "2:\n" \
- ".section .fixup,\"ax\"\n" \
- "3: movl %4,%0\n" \
- " jmp 2b\n" \
- ".previous\n" \
- ".section __ex_table,\"a\"\n" \
- " .align 8\n" \
- " .quad 1b,3b\n" \
- ".previous":"=&bDS" (ret__), "=a"(*(a)), "=d"(*(b))\
- :"c"(msr), "i"(-EIO), "0"(0)); \
- ret__; })
-
-#define rdtsc(low,high) \
- __asm__ __volatile__("rdtsc" : "=a" (low), "=d" (high))
-
-#define rdtscl(low) \
- __asm__ __volatile__ ("rdtsc" : "=a" (low) : : "edx")
-
-#define rdtscp(low,high,aux) \
- asm volatile (".byte 0x0f,0x01,0xf9" : "=a" (low), "=d" (high), "=c" (aux))
-
-#define rdtscll(val) do { \
- unsigned int __a,__d; \
- asm volatile("rdtsc" : "=a" (__a), "=d" (__d)); \
- (val) = ((unsigned long)__a) | (((unsigned long)__d)<<32); \
-} while(0)
-
-#define rdtscpll(val, aux) do { \
- unsigned long __a, __d; \
- asm volatile (".byte 0x0f,0x01,0xf9" : "=a" (__a), "=d" (__d), "=c" (aux)); \
- (val) = (__d << 32) | __a; \
+static inline unsigned long native_rdtscp(int *aux)
+{
+ unsigned long low, high;
+ asm volatile (".byte 0x0f,0x01,0xf9"
+ : "=a" (low), "=d" (high), "=c" (*aux));
+ return low | (high >> 32);
+}
+
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#else
+#define read_msr(msr) native_read_msr(msr)
+#define read_msr_safe(msr, err) native_read_msr_safe(msr, err)
+#define write_msr(msr, val) native_write_msr(msr, val)
+#define write_msr_safe(msr, val) native_write_msr_safe(msr, val)
+#define read_tsc_reg() native_read_tsc()
+#define __rdtscp(aux) native_rdtscp(aux)
+#define read_pmc(counter) native_read_pmc(counter)
+#define __cpuid native_cpuid
+#endif
+
+#define rdmsr(msr, low, high) \
+do { \
+ unsigned long __val = read_msr(msr); \
+ low = (u32)__val; \
+ high = (u32)(__val >> 32); \
+} while (0)
+
+#define rdmsrl(msr, val) (val) = read_msr(msr)
+
+#define rdmsr_safe(msr, a, d) \
+({ \
+ int __ret; \
+ unsigned long __val = read_msr_safe(msr, &__ret); \
+ (*a) = (u32)(__val); \
+ (*d) = (u32)(__val >> 32); \
+ __ret; \
+})
+
+#define wrmsr(msr, val1, val2) \
+do { \
+ unsigned long __val; \
+ __val = (unsigned long)val2 << 32; \
+ __val |= val1; \
+ write_msr(msr, __val); \
} while (0)

-#define write_tsc(val1,val2) wrmsr(0x10, val1, val2)
+#define wrmsrl(msr, val) write_msr(msr, val)
+
+#define wrmsr_safe(msr, a, d) \
+ write_msr_safe(msr, a | ( ((u64)d) << 32))
+
+#define checking_wrmsrl(msr, val) wrmsr_safe(msr, (u32)(val),(u32)((val)>>32))
+
+#define write_tsc(val1, val2) wrmsr(0x10, val1, val2)

#define write_rdtscp_aux(val) wrmsr(0xc0000103, val, 0)

-#define rdpmc(counter,low,high) \
- __asm__ __volatile__("rdpmc" \
- : "=a" (low), "=d" (high) \
- : "c" (counter))
+#define rdtscl(low) (low) = (u32)read_tsc_reg()
+
+#define rdtscll(val) (val) = read_tsc_reg()
+
+#define rdtscp(low, high, aux) \
+do { \
+ int __aux; \
+ unsigned long __val = __rdtscp(&__aux); \
+ (low) = (u32)__val; \
+ (high) = (u32)(__val >> 32); \
+ (aux) = __aux; \
+} while (0)
+
+#define rdtscpll(val, aux) \
+do { \
+ unsigned long __aux; \
+ val = __rdtscp(&__aux); \
+ (aux) = __aux; \
+} while (0)
+
+#define rdpmc(counter, low, high) \
+do { \
+ unsigned long __val = read_pmc(counter); \
+ (low) = (u32)(__val); \
+ (high) = (u32)(__val >> 32); \
+} while (0)

static inline void cpuid(int op, unsigned int *eax, unsigned int *ebx,
unsigned int *ecx, unsigned int *edx)
{
- __asm__("cpuid"
- : "=a" (*eax),
- "=b" (*ebx),
- "=c" (*ecx),
- "=d" (*edx)
- : "0" (op));
+ *eax = op;
+ *ecx = 0;
+ __cpuid(eax, ebx, ecx, edx);
}

/* Some CPUID calls want 'count' to be placed in ecx */
static inline void cpuid_count(int op, int count, int *eax, int *ebx, int *ecx,
int *edx)
{
- __asm__("cpuid"
- : "=a" (*eax),
- "=b" (*ebx),
- "=c" (*ecx),
- "=d" (*edx)
- : "0" (op), "c" (count));
+ *eax = op;
+ *ecx = count;
+ __cpuid(eax, ebx, ecx, edx);
}

/*
@@ -121,42 +197,29 @@ static inline void cpuid_count(int op, int count, int *eax, int *ebx, int *ecx,
*/
static inline unsigned int cpuid_eax(unsigned int op)
{
- unsigned int eax;
-
- __asm__("cpuid"
- : "=a" (eax)
- : "0" (op)
- : "bx", "cx", "dx");
+ unsigned int eax, ebx, ecx, edx;
+ cpuid(op, &eax, &ebx, &ecx, &edx);
return eax;
}
+
static inline unsigned int cpuid_ebx(unsigned int op)
{
- unsigned int eax, ebx;
-
- __asm__("cpuid"
- : "=a" (eax), "=b" (ebx)
- : "0" (op)
- : "cx", "dx" );
+ unsigned int eax, ebx, ecx, edx;
+ cpuid(op, &eax, &ebx, &ecx, &edx);
return ebx;
}
+
static inline unsigned int cpuid_ecx(unsigned int op)
{
- unsigned int eax, ecx;
-
- __asm__("cpuid"
- : "=a" (eax), "=c" (ecx)
- : "0" (op)
- : "bx", "dx" );
+ unsigned int eax, ebx, ecx, edx;
+ cpuid(op, &eax, &ebx, &ecx, &edx);
return ecx;
}
+
static inline unsigned int cpuid_edx(unsigned int op)
{
- unsigned int eax, edx;
-
- __asm__("cpuid"
- : "=a" (eax), "=d" (edx)
- : "0" (op)
- : "bx", "cx");
+ unsigned int eax, ebx, ecx, edx;
+ cpuid(op, &eax, &ebx, &ecx, &edx);
return edx;
}

--
1.4.4.2
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-08-15 14:57    [from the cache]
©2003-2011 Jasper Spaans