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-rw-r--r--include/asm-i386/alternative.h129
-rw-r--r--include/asm-i386/atomic.h28
-rw-r--r--include/asm-i386/bitops.h7
-rw-r--r--include/asm-i386/cpufeature.h1
-rw-r--r--include/asm-i386/mutex.h6
-rw-r--r--include/asm-i386/rwlock.h56
-rw-r--r--include/asm-i386/semaphore.h8
-rw-r--r--include/asm-i386/spinlock.h21
-rw-r--r--include/asm-i386/system.h62
-rw-r--r--include/asm-um/alternative.h6
10 files changed, 200 insertions, 124 deletions
diff --git a/include/asm-i386/alternative.h b/include/asm-i386/alternative.h
new file mode 100644
index 000000000000..e201decea0c9
--- /dev/null
+++ b/include/asm-i386/alternative.h
@@ -0,0 +1,129 @@
+#ifndef _I386_ALTERNATIVE_H
+#define _I386_ALTERNATIVE_H
+
+#ifdef __KERNEL__
+
+struct alt_instr {
+ u8 *instr; /* original instruction */
+ u8 *replacement;
+ u8 cpuid; /* cpuid bit set for replacement */
+ u8 instrlen; /* length of original instruction */
+ u8 replacementlen; /* length of new instruction, <= instrlen */
+ u8 pad;
+};
+
+extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end);
+
+struct module;
+extern void alternatives_smp_module_add(struct module *mod, char *name,
+ void *locks, void *locks_end,
+ void *text, void *text_end);
+extern void alternatives_smp_module_del(struct module *mod);
+extern void alternatives_smp_switch(int smp);
+
+#endif
+
+/*
+ * Alternative instructions for different CPU types or capabilities.
+ *
+ * This allows to use optimized instructions even on generic binary
+ * kernels.
+ *
+ * length of oldinstr must be longer or equal the length of newinstr
+ * It can be padded with nops as needed.
+ *
+ * For non barrier like inlines please define new variants
+ * without volatile and memory clobber.
+ */
+#define alternative(oldinstr, newinstr, feature) \
+ asm volatile ("661:\n\t" oldinstr "\n662:\n" \
+ ".section .altinstructions,\"a\"\n" \
+ " .align 4\n" \
+ " .long 661b\n" /* label */ \
+ " .long 663f\n" /* new instruction */ \
+ " .byte %c0\n" /* feature bit */ \
+ " .byte 662b-661b\n" /* sourcelen */ \
+ " .byte 664f-663f\n" /* replacementlen */ \
+ ".previous\n" \
+ ".section .altinstr_replacement,\"ax\"\n" \
+ "663:\n\t" newinstr "\n664:\n" /* replacement */\
+ ".previous" :: "i" (feature) : "memory")
+
+/*
+ * Alternative inline assembly with input.
+ *
+ * Pecularities:
+ * No memory clobber here.
+ * Argument numbers start with 1.
+ * Best is to use constraints that are fixed size (like (%1) ... "r")
+ * If you use variable sized constraints like "m" or "g" in the
+ * replacement maake sure to pad to the worst case length.
+ */
+#define alternative_input(oldinstr, newinstr, feature, input...) \
+ asm volatile ("661:\n\t" oldinstr "\n662:\n" \
+ ".section .altinstructions,\"a\"\n" \
+ " .align 4\n" \
+ " .long 661b\n" /* label */ \
+ " .long 663f\n" /* new instruction */ \
+ " .byte %c0\n" /* feature bit */ \
+ " .byte 662b-661b\n" /* sourcelen */ \
+ " .byte 664f-663f\n" /* replacementlen */ \
+ ".previous\n" \
+ ".section .altinstr_replacement,\"ax\"\n" \
+ "663:\n\t" newinstr "\n664:\n" /* replacement */\
+ ".previous" :: "i" (feature), ##input)
+
+/*
+ * Alternative inline assembly for SMP.
+ *
+ * alternative_smp() takes two versions (SMP first, UP second) and is
+ * for more complex stuff such as spinlocks.
+ *
+ * The LOCK_PREFIX macro defined here replaces the LOCK and
+ * LOCK_PREFIX macros used everywhere in the source tree.
+ *
+ * SMP alternatives use the same data structures as the other
+ * alternatives and the X86_FEATURE_UP flag to indicate the case of a
+ * UP system running a SMP kernel. The existing apply_alternatives()
+ * works fine for patching a SMP kernel for UP.
+ *
+ * The SMP alternative tables can be kept after boot and contain both
+ * UP and SMP versions of the instructions to allow switching back to
+ * SMP at runtime, when hotplugging in a new CPU, which is especially
+ * useful in virtualized environments.
+ *
+ * The very common lock prefix is handled as special case in a
+ * separate table which is a pure address list without replacement ptr
+ * and size information. That keeps the table sizes small.
+ */
+
+#ifdef CONFIG_SMP
+#define alternative_smp(smpinstr, upinstr, args...) \
+ asm volatile ("661:\n\t" smpinstr "\n662:\n" \
+ ".section .smp_altinstructions,\"a\"\n" \
+ " .align 4\n" \
+ " .long 661b\n" /* label */ \
+ " .long 663f\n" /* new instruction */ \
+ " .byte 0x68\n" /* X86_FEATURE_UP */ \
+ " .byte 662b-661b\n" /* sourcelen */ \
+ " .byte 664f-663f\n" /* replacementlen */ \
+ ".previous\n" \
+ ".section .smp_altinstr_replacement,\"awx\"\n" \
+ "663:\n\t" upinstr "\n" /* replacement */ \
+ "664:\n\t.fill 662b-661b,1,0x42\n" /* space for original */ \
+ ".previous" : args)
+
+#define LOCK_PREFIX \
+ ".section .smp_locks,\"a\"\n" \
+ " .align 4\n" \
+ " .long 661f\n" /* address */ \
+ ".previous\n" \
+ "661:\n\tlock; "
+
+#else /* ! CONFIG_SMP */
+#define alternative_smp(smpinstr, upinstr, args...) \
+ asm volatile (upinstr : args)
+#define LOCK_PREFIX ""
+#endif
+
+#endif /* _I386_ALTERNATIVE_H */
diff --git a/include/asm-i386/atomic.h b/include/asm-i386/atomic.h
index de649d3aa2d4..78b0032d1f29 100644
--- a/include/asm-i386/atomic.h
+++ b/include/asm-i386/atomic.h
@@ -10,12 +10,6 @@
* resource counting etc..
*/
-#ifdef CONFIG_SMP
-#define LOCK "lock ; "
-#else
-#define LOCK ""
-#endif
-
/*
* Make sure gcc doesn't try to be clever and move things around
* on us. We need to use _exactly_ the address the user gave us,
@@ -52,7 +46,7 @@ typedef struct { volatile int counter; } atomic_t;
static __inline__ void atomic_add(int i, atomic_t *v)
{
__asm__ __volatile__(
- LOCK "addl %1,%0"
+ LOCK_PREFIX "addl %1,%0"
:"=m" (v->counter)
:"ir" (i), "m" (v->counter));
}
@@ -67,7 +61,7 @@ static __inline__ void atomic_add(int i, atomic_t *v)
static __inline__ void atomic_sub(int i, atomic_t *v)
{
__asm__ __volatile__(
- LOCK "subl %1,%0"
+ LOCK_PREFIX "subl %1,%0"
:"=m" (v->counter)
:"ir" (i), "m" (v->counter));
}
@@ -86,7 +80,7 @@ static __inline__ int atomic_sub_and_test(int i, atomic_t *v)
unsigned char c;
__asm__ __volatile__(
- LOCK "subl %2,%0; sete %1"
+ LOCK_PREFIX "subl %2,%0; sete %1"
:"=m" (v->counter), "=qm" (c)
:"ir" (i), "m" (v->counter) : "memory");
return c;
@@ -101,7 +95,7 @@ static __inline__ int atomic_sub_and_test(int i, atomic_t *v)
static __inline__ void atomic_inc(atomic_t *v)
{
__asm__ __volatile__(
- LOCK "incl %0"
+ LOCK_PREFIX "incl %0"
:"=m" (v->counter)
:"m" (v->counter));
}
@@ -115,7 +109,7 @@ static __inline__ void atomic_inc(atomic_t *v)
static __inline__ void atomic_dec(atomic_t *v)
{
__asm__ __volatile__(
- LOCK "decl %0"
+ LOCK_PREFIX "decl %0"
:"=m" (v->counter)
:"m" (v->counter));
}
@@ -133,7 +127,7 @@ static __inline__ int atomic_dec_and_test(atomic_t *v)
unsigned char c;
__asm__ __volatile__(
- LOCK "decl %0; sete %1"
+ LOCK_PREFIX "decl %0; sete %1"
:"=m" (v->counter), "=qm" (c)
:"m" (v->counter) : "memory");
return c != 0;
@@ -152,7 +146,7 @@ static __inline__ int atomic_inc_and_test(atomic_t *v)
unsigned char c;
__asm__ __volatile__(
- LOCK "incl %0; sete %1"
+ LOCK_PREFIX "incl %0; sete %1"
:"=m" (v->counter), "=qm" (c)
:"m" (v->counter) : "memory");
return c != 0;
@@ -172,7 +166,7 @@ static __inline__ int atomic_add_negative(int i, atomic_t *v)
unsigned char c;
__asm__ __volatile__(
- LOCK "addl %2,%0; sets %1"
+ LOCK_PREFIX "addl %2,%0; sets %1"
:"=m" (v->counter), "=qm" (c)
:"ir" (i), "m" (v->counter) : "memory");
return c;
@@ -195,7 +189,7 @@ static __inline__ int atomic_add_return(int i, atomic_t *v)
/* Modern 486+ processor */
__i = i;
__asm__ __volatile__(
- LOCK "xaddl %0, %1;"
+ LOCK_PREFIX "xaddl %0, %1;"
:"=r"(i)
:"m"(v->counter), "0"(i));
return i + __i;
@@ -242,11 +236,11 @@ static __inline__ int atomic_sub_return(int i, atomic_t *v)
/* These are x86-specific, used by some header files */
#define atomic_clear_mask(mask, addr) \
-__asm__ __volatile__(LOCK "andl %0,%1" \
+__asm__ __volatile__(LOCK_PREFIX "andl %0,%1" \
: : "r" (~(mask)),"m" (*addr) : "memory")
#define atomic_set_mask(mask, addr) \
-__asm__ __volatile__(LOCK "orl %0,%1" \
+__asm__ __volatile__(LOCK_PREFIX "orl %0,%1" \
: : "r" (mask),"m" (*(addr)) : "memory")
/* Atomic operations are already serializing on x86 */
diff --git a/include/asm-i386/bitops.h b/include/asm-i386/bitops.h
index 88e6ca248cd7..7d20b95edb3b 100644
--- a/include/asm-i386/bitops.h
+++ b/include/asm-i386/bitops.h
@@ -7,6 +7,7 @@
#include <linux/config.h>
#include <linux/compiler.h>
+#include <asm/alternative.h>
/*
* These have to be done with inline assembly: that way the bit-setting
@@ -16,12 +17,6 @@
* bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
*/
-#ifdef CONFIG_SMP
-#define LOCK_PREFIX "lock ; "
-#else
-#define LOCK_PREFIX ""
-#endif
-
#define ADDR (*(volatile long *) addr)
/**
diff --git a/include/asm-i386/cpufeature.h b/include/asm-i386/cpufeature.h
index c4ec2a4d8fdf..5c0b5876b931 100644
--- a/include/asm-i386/cpufeature.h
+++ b/include/asm-i386/cpufeature.h
@@ -70,6 +70,7 @@
#define X86_FEATURE_P3 (3*32+ 6) /* P3 */
#define X86_FEATURE_P4 (3*32+ 7) /* P4 */
#define X86_FEATURE_CONSTANT_TSC (3*32+ 8) /* TSC ticks at a constant rate */
+#define X86_FEATURE_UP (3*32+ 9) /* smp kernel running on up */
/* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
#define X86_FEATURE_XMM3 (4*32+ 0) /* Streaming SIMD Extensions-3 */
diff --git a/include/asm-i386/mutex.h b/include/asm-i386/mutex.h
index 9b2199e829f3..05a538531229 100644
--- a/include/asm-i386/mutex.h
+++ b/include/asm-i386/mutex.h
@@ -9,6 +9,8 @@
#ifndef _ASM_MUTEX_H
#define _ASM_MUTEX_H
+#include "asm/alternative.h"
+
/**
* __mutex_fastpath_lock - try to take the lock by moving the count
* from 1 to a 0 value
@@ -27,7 +29,7 @@ do { \
typecheck_fn(fastcall void (*)(atomic_t *), fail_fn); \
\
__asm__ __volatile__( \
- LOCK " decl (%%eax) \n" \
+ LOCK_PREFIX " decl (%%eax) \n" \
" js 2f \n" \
"1: \n" \
\
@@ -83,7 +85,7 @@ do { \
typecheck_fn(fastcall void (*)(atomic_t *), fail_fn); \
\
__asm__ __volatile__( \
- LOCK " incl (%%eax) \n" \
+ LOCK_PREFIX " incl (%%eax) \n" \
" jle 2f \n" \
"1: \n" \
\
diff --git a/include/asm-i386/rwlock.h b/include/asm-i386/rwlock.h
index b57cc7afdf7e..94f00195d543 100644
--- a/include/asm-i386/rwlock.h
+++ b/include/asm-i386/rwlock.h
@@ -21,21 +21,23 @@
#define RW_LOCK_BIAS_STR "0x01000000"
#define __build_read_lock_ptr(rw, helper) \
- asm volatile(LOCK "subl $1,(%0)\n\t" \
- "jns 1f\n" \
- "call " helper "\n\t" \
- "1:\n" \
- ::"a" (rw) : "memory")
+ alternative_smp("lock; subl $1,(%0)\n\t" \
+ "jns 1f\n" \
+ "call " helper "\n\t" \
+ "1:\n", \
+ "subl $1,(%0)\n\t", \
+ :"a" (rw) : "memory")
#define __build_read_lock_const(rw, helper) \
- asm volatile(LOCK "subl $1,%0\n\t" \
- "jns 1f\n" \
- "pushl %%eax\n\t" \
- "leal %0,%%eax\n\t" \
- "call " helper "\n\t" \
- "popl %%eax\n\t" \
- "1:\n" \
- :"=m" (*(volatile int *)rw) : : "memory")
+ alternative_smp("lock; subl $1,%0\n\t" \
+ "jns 1f\n" \
+ "pushl %%eax\n\t" \
+ "leal %0,%%eax\n\t" \
+ "call " helper "\n\t" \
+ "popl %%eax\n\t" \
+ "1:\n", \
+ "subl $1,%0\n\t", \
+ "=m" (*(volatile int *)rw) : : "memory")
#define __build_read_lock(rw, helper) do { \
if (__builtin_constant_p(rw)) \
@@ -45,21 +47,23 @@
} while (0)
#define __build_write_lock_ptr(rw, helper) \
- asm volatile(LOCK "subl $" RW_LOCK_BIAS_STR ",(%0)\n\t" \
- "jz 1f\n" \
- "call " helper "\n\t" \
- "1:\n" \
- ::"a" (rw) : "memory")
+ alternative_smp("lock; subl $" RW_LOCK_BIAS_STR ",(%0)\n\t" \
+ "jz 1f\n" \
+ "call " helper "\n\t" \
+ "1:\n", \
+ "subl $" RW_LOCK_BIAS_STR ",(%0)\n\t", \
+ :"a" (rw) : "memory")
#define __build_write_lock_const(rw, helper) \
- asm volatile(LOCK "subl $" RW_LOCK_BIAS_STR ",%0\n\t" \
- "jz 1f\n" \
- "pushl %%eax\n\t" \
- "leal %0,%%eax\n\t" \
- "call " helper "\n\t" \
- "popl %%eax\n\t" \
- "1:\n" \
- :"=m" (*(volatile int *)rw) : : "memory")
+ alternative_smp("lock; subl $" RW_LOCK_BIAS_STR ",%0\n\t" \
+ "jz 1f\n" \
+ "pushl %%eax\n\t" \
+ "leal %0,%%eax\n\t" \
+ "call " helper "\n\t" \
+ "popl %%eax\n\t" \
+ "1:\n", \
+ "subl $" RW_LOCK_BIAS_STR ",%0\n\t", \
+ "=m" (*(volatile int *)rw) : : "memory")
#define __build_write_lock(rw, helper) do { \
if (__builtin_constant_p(rw)) \
diff --git a/include/asm-i386/semaphore.h b/include/asm-i386/semaphore.h
index 6a42b2142fd6..f7a0f310c524 100644
--- a/include/asm-i386/semaphore.h
+++ b/include/asm-i386/semaphore.h
@@ -99,7 +99,7 @@ static inline void down(struct semaphore * sem)
might_sleep();
__asm__ __volatile__(
"# atomic down operation\n\t"
- LOCK "decl %0\n\t" /* --sem->count */
+ LOCK_PREFIX "decl %0\n\t" /* --sem->count */
"js 2f\n"
"1:\n"
LOCK_SECTION_START("")
@@ -123,7 +123,7 @@ static inline int down_interruptible(struct semaphore * sem)
might_sleep();
__asm__ __volatile__(
"# atomic interruptible down operation\n\t"
- LOCK "decl %1\n\t" /* --sem->count */
+ LOCK_PREFIX "decl %1\n\t" /* --sem->count */
"js 2f\n\t"
"xorl %0,%0\n"
"1:\n"
@@ -148,7 +148,7 @@ static inline int down_trylock(struct semaphore * sem)
__asm__ __volatile__(
"# atomic interruptible down operation\n\t"
- LOCK "decl %1\n\t" /* --sem->count */
+ LOCK_PREFIX "decl %1\n\t" /* --sem->count */
"js 2f\n\t"
"xorl %0,%0\n"
"1:\n"
@@ -173,7 +173,7 @@ static inline void up(struct semaphore * sem)
{
__asm__ __volatile__(
"# atomic up operation\n\t"
- LOCK "incl %0\n\t" /* ++sem->count */
+ LOCK_PREFIX "incl %0\n\t" /* ++sem->count */
"jle 2f\n"
"1:\n"
LOCK_SECTION_START("")
diff --git a/include/asm-i386/spinlock.h b/include/asm-i386/spinlock.h
index 23604350cdf4..a1b8a8a30e21 100644
--- a/include/asm-i386/spinlock.h
+++ b/include/asm-i386/spinlock.h
@@ -48,18 +48,23 @@
"jmp 1b\n" \
"4:\n\t"
+#define __raw_spin_lock_string_up \
+ "\n\tdecb %0"
+
static inline void __raw_spin_lock(raw_spinlock_t *lock)
{
- __asm__ __volatile__(
- __raw_spin_lock_string
- :"=m" (lock->slock) : : "memory");
+ alternative_smp(
+ __raw_spin_lock_string,
+ __raw_spin_lock_string_up,
+ "=m" (lock->slock) : : "memory");
}
static inline void __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags)
{
- __asm__ __volatile__(
- __raw_spin_lock_string_flags
- :"=m" (lock->slock) : "r" (flags) : "memory");
+ alternative_smp(
+ __raw_spin_lock_string_flags,
+ __raw_spin_lock_string_up,
+ "=m" (lock->slock) : "r" (flags) : "memory");
}
static inline int __raw_spin_trylock(raw_spinlock_t *lock)
@@ -178,12 +183,12 @@ static inline int __raw_write_trylock(raw_rwlock_t *lock)
static inline void __raw_read_unlock(raw_rwlock_t *rw)
{
- asm volatile("lock ; incl %0" :"=m" (rw->lock) : : "memory");
+ asm volatile(LOCK_PREFIX "incl %0" :"=m" (rw->lock) : : "memory");
}
static inline void __raw_write_unlock(raw_rwlock_t *rw)
{
- asm volatile("lock ; addl $" RW_LOCK_BIAS_STR ", %0"
+ asm volatile(LOCK_PREFIX "addl $" RW_LOCK_BIAS_STR ", %0"
: "=m" (rw->lock) : : "memory");
}
diff --git a/include/asm-i386/system.h b/include/asm-i386/system.h
index 399145a247f2..d0d8d7448d88 100644
--- a/include/asm-i386/system.h
+++ b/include/asm-i386/system.h
@@ -352,67 +352,6 @@ static inline unsigned long long __cmpxchg64(volatile void *ptr, unsigned long l
#endif
-#ifdef __KERNEL__
-struct alt_instr {
- __u8 *instr; /* original instruction */
- __u8 *replacement;
- __u8 cpuid; /* cpuid bit set for replacement */
- __u8 instrlen; /* length of original instruction */
- __u8 replacementlen; /* length of new instruction, <= instrlen */
- __u8 pad;
-};
-#endif
-
-/*
- * Alternative instructions for different CPU types or capabilities.
- *
- * This allows to use optimized instructions even on generic binary
- * kernels.
- *
- * length of oldinstr must be longer or equal the length of newinstr
- * It can be padded with nops as needed.
- *
- * For non barrier like inlines please define new variants
- * without volatile and memory clobber.
- */
-#define alternative(oldinstr, newinstr, feature) \
- asm volatile ("661:\n\t" oldinstr "\n662:\n" \
- ".section .altinstructions,\"a\"\n" \
- " .align 4\n" \
- " .long 661b\n" /* label */ \
- " .long 663f\n" /* new instruction */ \
- " .byte %c0\n" /* feature bit */ \
- " .byte 662b-661b\n" /* sourcelen */ \
- " .byte 664f-663f\n" /* replacementlen */ \
- ".previous\n" \
- ".section .altinstr_replacement,\"ax\"\n" \
- "663:\n\t" newinstr "\n664:\n" /* replacement */ \
- ".previous" :: "i" (feature) : "memory")
-
-/*
- * Alternative inline assembly with input.
- *
- * Pecularities:
- * No memory clobber here.
- * Argument numbers start with 1.
- * Best is to use constraints that are fixed size (like (%1) ... "r")
- * If you use variable sized constraints like "m" or "g" in the
- * replacement maake sure to pad to the worst case length.
- */
-#define alternative_input(oldinstr, newinstr, feature, input...) \
- asm volatile ("661:\n\t" oldinstr "\n662:\n" \
- ".section .altinstructions,\"a\"\n" \
- " .align 4\n" \
- " .long 661b\n" /* label */ \
- " .long 663f\n" /* new instruction */ \
- " .byte %c0\n" /* feature bit */ \
- " .byte 662b-661b\n" /* sourcelen */ \
- " .byte 664f-663f\n" /* replacementlen */ \
- ".previous\n" \
- ".section .altinstr_replacement,\"ax\"\n" \
- "663:\n\t" newinstr "\n664:\n" /* replacement */ \
- ".previous" :: "i" (feature), ##input)
-
/*
* Force strict CPU ordering.
* And yes, this is required on UP too when we're talking
@@ -558,5 +497,6 @@ static inline void sched_cacheflush(void)
}
extern unsigned long arch_align_stack(unsigned long sp);
+extern void free_init_pages(char *what, unsigned long begin, unsigned long end);
#endif
diff --git a/include/asm-um/alternative.h b/include/asm-um/alternative.h
new file mode 100644
index 000000000000..b6434396bd42
--- /dev/null
+++ b/include/asm-um/alternative.h
@@ -0,0 +1,6 @@
+#ifndef __UM_ALTERNATIVE_H
+#define __UM_ALTERNATIVE_H
+
+#include "asm/arch/alternative.h"
+
+#endif
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.