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linux/arch/x86/include/asm/percpu.h
Christoph Lameter b3ca1c10d7 percpu: add raw_cpu_ops 
The kernel has never been audited to ensure that this_cpu operations are
consistently used throughout the kernel.  The code generated in many
places can be improved through the use of this_cpu operations (which
uses a segment register for relocation of per cpu offsets instead of
performing address calculations).

The patch set also addresses various consistency issues in general with
the per cpu macros.

A. The semantics of __this_cpu_ptr() differs from this_cpu_ptr only
   because checks are skipped. This is typically shown through a raw_
   prefix. So this patch set changes the places where __this_cpu_ptr()
   is used to raw_cpu_ptr().

B. There has been the long term wish by some that __this_cpu operations
   would check for preemption. However, there are cases where preemption
   checks need to be skipped. This patch set adds raw_cpu operations that
   do not check for preemption and then adds preemption checks to the
   __this_cpu operations.

C. The use of __get_cpu_var is always a reference to a percpu variable
   that can also be handled via a this_cpu operation. This patch set
   replaces all uses of __get_cpu_var with this_cpu operations.

D. We can then use this_cpu RMW operations in various places replacing
   sequences of instructions by a single one.

E. The use of this_cpu operations throughout will allow other arches than
   x86 to implement optimized references and RMV operations to work with
   per cpu local data.

F. The use of this_cpu operations opens up the possibility to
   further optimize code that relies on synchronization through
   per cpu data.

The patch set works in a couple of stages:

I. Patch 1 adds the additional raw_cpu operations and raw_cpu_ptr().
    Also converts the existing __this_cpu_xx_# primitive in the x86
    code to raw_cpu_xx_#.

II. Patch 2-4 use the raw_cpu operations in places that would give
     us false positives once they are enabled.

III. Patch 5 adds preemption checks to __this_cpu operations to allow
    checking if preemption is properly disabled when these functions
    are used.

IV. Patches 6-20 are patches that simply replace uses of __get_cpu_var
   with this_cpu_ptr. They do not depend on any changes to the percpu
   code. No preemption tests are skipped if they are applied.

V. Patches 21-46 are conversion patches that use this_cpu operations
   in various kernel subsystems/drivers or arch code.

VI.  Patches 47/48 (not included in this series) remove no longer used
    functions (__this_cpu_ptr and __get_cpu_var).  These should only be
    applied after all the conversion patches have made it and after we
    have done additional passes through the kernel to ensure that none of
    the uses of these functions remain.

This patch (of 46):

The patches following this one will add preemption checks to __this_cpu
ops so we need to have an alternative way to use this_cpu operations
without preemption checks.

raw_cpu_ops will be the basis for all other ops since these will be the
operations that do not implement any checks.

Primitive operations are renamed by this patch from __this_cpu_xxx to
raw_cpu_xxxx.

Also change the uses of the x86 percpu primitives in preempt.h.
These depend directly on asm/percpu.h (header #include nesting issue).

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Christoph Lameter <cl@linux.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Alex Shi <alex.shi@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Bryan Wu <cooloney@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: David Daney <david.daney@cavium.com>
Cc: David Miller <davem@davemloft.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Hedi Berriche <hedi@sgi.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Mike Travis <travis@sgi.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Robert Richter <rric@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:13 -07:00

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#ifndef _ASM_X86_PERCPU_H
#define _ASM_X86_PERCPU_H
#ifdef CONFIG_X86_64
#define __percpu_seg gs
#define __percpu_mov_op movq
#else
#define __percpu_seg fs
#define __percpu_mov_op movl
#endif
#ifdef __ASSEMBLY__
/*
* PER_CPU finds an address of a per-cpu variable.
*
* Args:
* var - variable name
* reg - 32bit register
*
* The resulting address is stored in the "reg" argument.
*
* Example:
* PER_CPU(cpu_gdt_descr, %ebx)
*/
#ifdef CONFIG_SMP
#define PER_CPU(var, reg) \
__percpu_mov_op %__percpu_seg:this_cpu_off, reg; \
lea var(reg), reg
#define PER_CPU_VAR(var) %__percpu_seg:var
#else /* ! SMP */
#define PER_CPU(var, reg) __percpu_mov_op $var, reg
#define PER_CPU_VAR(var) var
#endif /* SMP */
#ifdef CONFIG_X86_64_SMP
#define INIT_PER_CPU_VAR(var) init_per_cpu__##var
#else
#define INIT_PER_CPU_VAR(var) var
#endif
#else /* ...!ASSEMBLY */
#include <linux/kernel.h>
#include <linux/stringify.h>
#ifdef CONFIG_SMP
#define __percpu_prefix "%%"__stringify(__percpu_seg)":"
#define __my_cpu_offset this_cpu_read(this_cpu_off)
/*
* Compared to the generic __my_cpu_offset version, the following
* saves one instruction and avoids clobbering a temp register.
*/
#define raw_cpu_ptr(ptr) \
({ \
unsigned long tcp_ptr__; \
__verify_pcpu_ptr(ptr); \
asm volatile("add " __percpu_arg(1) ", %0" \
: "=r" (tcp_ptr__) \
: "m" (this_cpu_off), "0" (ptr)); \
(typeof(*(ptr)) __kernel __force *)tcp_ptr__; \
})
#else
#define __percpu_prefix ""
#endif
#define __percpu_arg(x) __percpu_prefix "%P" #x
/*
* Initialized pointers to per-cpu variables needed for the boot
* processor need to use these macros to get the proper address
* offset from __per_cpu_load on SMP.
*
* There also must be an entry in vmlinux_64.lds.S
*/
#define DECLARE_INIT_PER_CPU(var) \
extern typeof(var) init_per_cpu_var(var)
#ifdef CONFIG_X86_64_SMP
#define init_per_cpu_var(var) init_per_cpu__##var
#else
#define init_per_cpu_var(var) var
#endif
/* For arch-specific code, we can use direct single-insn ops (they
* don't give an lvalue though). */
extern void __bad_percpu_size(void);
#define percpu_to_op(op, var, val) \
do { \
typedef typeof(var) pto_T__; \
if (0) { \
pto_T__ pto_tmp__; \
pto_tmp__ = (val); \
(void)pto_tmp__; \
} \
switch (sizeof(var)) { \
case 1: \
asm(op "b %1,"__percpu_arg(0) \
: "+m" (var) \
: "qi" ((pto_T__)(val))); \
break; \
case 2: \
asm(op "w %1,"__percpu_arg(0) \
: "+m" (var) \
: "ri" ((pto_T__)(val))); \
break; \
case 4: \
asm(op "l %1,"__percpu_arg(0) \
: "+m" (var) \
: "ri" ((pto_T__)(val))); \
break; \
case 8: \
asm(op "q %1,"__percpu_arg(0) \
: "+m" (var) \
: "re" ((pto_T__)(val))); \
break; \
default: __bad_percpu_size(); \
} \
} while (0)
/*
* Generate a percpu add to memory instruction and optimize code
* if one is added or subtracted.
*/
#define percpu_add_op(var, val) \
do { \
typedef typeof(var) pao_T__; \
const int pao_ID__ = (__builtin_constant_p(val) && \
((val) == 1 || (val) == -1)) ? \
(int)(val) : 0; \
if (0) { \
pao_T__ pao_tmp__; \
pao_tmp__ = (val); \
(void)pao_tmp__; \
} \
switch (sizeof(var)) { \
case 1: \
if (pao_ID__ == 1) \
asm("incb "__percpu_arg(0) : "+m" (var)); \
else if (pao_ID__ == -1) \
asm("decb "__percpu_arg(0) : "+m" (var)); \
else \
asm("addb %1, "__percpu_arg(0) \
: "+m" (var) \
: "qi" ((pao_T__)(val))); \
break; \
case 2: \
if (pao_ID__ == 1) \
asm("incw "__percpu_arg(0) : "+m" (var)); \
else if (pao_ID__ == -1) \
asm("decw "__percpu_arg(0) : "+m" (var)); \
else \
asm("addw %1, "__percpu_arg(0) \
: "+m" (var) \
: "ri" ((pao_T__)(val))); \
break; \
case 4: \
if (pao_ID__ == 1) \
asm("incl "__percpu_arg(0) : "+m" (var)); \
else if (pao_ID__ == -1) \
asm("decl "__percpu_arg(0) : "+m" (var)); \
else \
asm("addl %1, "__percpu_arg(0) \
: "+m" (var) \
: "ri" ((pao_T__)(val))); \
break; \
case 8: \
if (pao_ID__ == 1) \
asm("incq "__percpu_arg(0) : "+m" (var)); \
else if (pao_ID__ == -1) \
asm("decq "__percpu_arg(0) : "+m" (var)); \
else \
asm("addq %1, "__percpu_arg(0) \
: "+m" (var) \
: "re" ((pao_T__)(val))); \
break; \
default: __bad_percpu_size(); \
} \
} while (0)
#define percpu_from_op(op, var, constraint) \
({ \
typeof(var) pfo_ret__; \
switch (sizeof(var)) { \
case 1: \
asm(op "b "__percpu_arg(1)",%0" \
: "=q" (pfo_ret__) \
: constraint); \
break; \
case 2: \
asm(op "w "__percpu_arg(1)",%0" \
: "=r" (pfo_ret__) \
: constraint); \
break; \
case 4: \
asm(op "l "__percpu_arg(1)",%0" \
: "=r" (pfo_ret__) \
: constraint); \
break; \
case 8: \
asm(op "q "__percpu_arg(1)",%0" \
: "=r" (pfo_ret__) \
: constraint); \
break; \
default: __bad_percpu_size(); \
} \
pfo_ret__; \
})
#define percpu_unary_op(op, var) \
({ \
switch (sizeof(var)) { \
case 1: \
asm(op "b "__percpu_arg(0) \
: "+m" (var)); \
break; \
case 2: \
asm(op "w "__percpu_arg(0) \
: "+m" (var)); \
break; \
case 4: \
asm(op "l "__percpu_arg(0) \
: "+m" (var)); \
break; \
case 8: \
asm(op "q "__percpu_arg(0) \
: "+m" (var)); \
break; \
default: __bad_percpu_size(); \
} \
})
/*
* Add return operation
*/
#define percpu_add_return_op(var, val) \
({ \
typeof(var) paro_ret__ = val; \
switch (sizeof(var)) { \
case 1: \
asm("xaddb %0, "__percpu_arg(1) \
: "+q" (paro_ret__), "+m" (var) \
: : "memory"); \
break; \
case 2: \
asm("xaddw %0, "__percpu_arg(1) \
: "+r" (paro_ret__), "+m" (var) \
: : "memory"); \
break; \
case 4: \
asm("xaddl %0, "__percpu_arg(1) \
: "+r" (paro_ret__), "+m" (var) \
: : "memory"); \
break; \
case 8: \
asm("xaddq %0, "__percpu_arg(1) \
: "+re" (paro_ret__), "+m" (var) \
: : "memory"); \
break; \
default: __bad_percpu_size(); \
} \
paro_ret__ += val; \
paro_ret__; \
})
/*
* xchg is implemented using cmpxchg without a lock prefix. xchg is
* expensive due to the implied lock prefix. The processor cannot prefetch
* cachelines if xchg is used.
*/
#define percpu_xchg_op(var, nval) \
({ \
typeof(var) pxo_ret__; \
typeof(var) pxo_new__ = (nval); \
switch (sizeof(var)) { \
case 1: \
asm("\n\tmov "__percpu_arg(1)",%%al" \
"\n1:\tcmpxchgb %2, "__percpu_arg(1) \
"\n\tjnz 1b" \
: "=&a" (pxo_ret__), "+m" (var) \
: "q" (pxo_new__) \
: "memory"); \
break; \
case 2: \
asm("\n\tmov "__percpu_arg(1)",%%ax" \
"\n1:\tcmpxchgw %2, "__percpu_arg(1) \
"\n\tjnz 1b" \
: "=&a" (pxo_ret__), "+m" (var) \
: "r" (pxo_new__) \
: "memory"); \
break; \
case 4: \
asm("\n\tmov "__percpu_arg(1)",%%eax" \
"\n1:\tcmpxchgl %2, "__percpu_arg(1) \
"\n\tjnz 1b" \
: "=&a" (pxo_ret__), "+m" (var) \
: "r" (pxo_new__) \
: "memory"); \
break; \
case 8: \
asm("\n\tmov "__percpu_arg(1)",%%rax" \
"\n1:\tcmpxchgq %2, "__percpu_arg(1) \
"\n\tjnz 1b" \
: "=&a" (pxo_ret__), "+m" (var) \
: "r" (pxo_new__) \
: "memory"); \
break; \
default: __bad_percpu_size(); \
} \
pxo_ret__; \
})
/*
* cmpxchg has no such implied lock semantics as a result it is much
* more efficient for cpu local operations.
*/
#define percpu_cmpxchg_op(var, oval, nval) \
({ \
typeof(var) pco_ret__; \
typeof(var) pco_old__ = (oval); \
typeof(var) pco_new__ = (nval); \
switch (sizeof(var)) { \
case 1: \
asm("cmpxchgb %2, "__percpu_arg(1) \
: "=a" (pco_ret__), "+m" (var) \
: "q" (pco_new__), "0" (pco_old__) \
: "memory"); \
break; \
case 2: \
asm("cmpxchgw %2, "__percpu_arg(1) \
: "=a" (pco_ret__), "+m" (var) \
: "r" (pco_new__), "0" (pco_old__) \
: "memory"); \
break; \
case 4: \
asm("cmpxchgl %2, "__percpu_arg(1) \
: "=a" (pco_ret__), "+m" (var) \
: "r" (pco_new__), "0" (pco_old__) \
: "memory"); \
break; \
case 8: \
asm("cmpxchgq %2, "__percpu_arg(1) \
: "=a" (pco_ret__), "+m" (var) \
: "r" (pco_new__), "0" (pco_old__) \
: "memory"); \
break; \
default: __bad_percpu_size(); \
} \
pco_ret__; \
})
/*
* this_cpu_read() makes gcc load the percpu variable every time it is
* accessed while this_cpu_read_stable() allows the value to be cached.
* this_cpu_read_stable() is more efficient and can be used if its value
* is guaranteed to be valid across cpus. The current users include
* get_current() and get_thread_info() both of which are actually
* per-thread variables implemented as per-cpu variables and thus
* stable for the duration of the respective task.
*/
#define this_cpu_read_stable(var) percpu_from_op("mov", var, "p" (&(var)))
#define raw_cpu_read_1(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
#define raw_cpu_read_2(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
#define raw_cpu_read_4(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
#define raw_cpu_write_1(pcp, val) percpu_to_op("mov", (pcp), val)
#define raw_cpu_write_2(pcp, val) percpu_to_op("mov", (pcp), val)
#define raw_cpu_write_4(pcp, val) percpu_to_op("mov", (pcp), val)
#define raw_cpu_add_1(pcp, val) percpu_add_op((pcp), val)
#define raw_cpu_add_2(pcp, val) percpu_add_op((pcp), val)
#define raw_cpu_add_4(pcp, val) percpu_add_op((pcp), val)
#define raw_cpu_and_1(pcp, val) percpu_to_op("and", (pcp), val)
#define raw_cpu_and_2(pcp, val) percpu_to_op("and", (pcp), val)
#define raw_cpu_and_4(pcp, val) percpu_to_op("and", (pcp), val)
#define raw_cpu_or_1(pcp, val) percpu_to_op("or", (pcp), val)
#define raw_cpu_or_2(pcp, val) percpu_to_op("or", (pcp), val)
#define raw_cpu_or_4(pcp, val) percpu_to_op("or", (pcp), val)
#define raw_cpu_xchg_1(pcp, val) percpu_xchg_op(pcp, val)
#define raw_cpu_xchg_2(pcp, val) percpu_xchg_op(pcp, val)
#define raw_cpu_xchg_4(pcp, val) percpu_xchg_op(pcp, val)
#define this_cpu_read_1(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
#define this_cpu_read_2(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
#define this_cpu_read_4(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
#define this_cpu_write_1(pcp, val) percpu_to_op("mov", (pcp), val)
#define this_cpu_write_2(pcp, val) percpu_to_op("mov", (pcp), val)
#define this_cpu_write_4(pcp, val) percpu_to_op("mov", (pcp), val)
#define this_cpu_add_1(pcp, val) percpu_add_op((pcp), val)
#define this_cpu_add_2(pcp, val) percpu_add_op((pcp), val)
#define this_cpu_add_4(pcp, val) percpu_add_op((pcp), val)
#define this_cpu_and_1(pcp, val) percpu_to_op("and", (pcp), val)
#define this_cpu_and_2(pcp, val) percpu_to_op("and", (pcp), val)
#define this_cpu_and_4(pcp, val) percpu_to_op("and", (pcp), val)
#define this_cpu_or_1(pcp, val) percpu_to_op("or", (pcp), val)
#define this_cpu_or_2(pcp, val) percpu_to_op("or", (pcp), val)
#define this_cpu_or_4(pcp, val) percpu_to_op("or", (pcp), val)
#define this_cpu_xchg_1(pcp, nval) percpu_xchg_op(pcp, nval)
#define this_cpu_xchg_2(pcp, nval) percpu_xchg_op(pcp, nval)
#define this_cpu_xchg_4(pcp, nval) percpu_xchg_op(pcp, nval)
#define raw_cpu_add_return_1(pcp, val) percpu_add_return_op(pcp, val)
#define raw_cpu_add_return_2(pcp, val) percpu_add_return_op(pcp, val)
#define raw_cpu_add_return_4(pcp, val) percpu_add_return_op(pcp, val)
#define raw_cpu_cmpxchg_1(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
#define raw_cpu_cmpxchg_2(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
#define raw_cpu_cmpxchg_4(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
#define this_cpu_add_return_1(pcp, val) percpu_add_return_op(pcp, val)
#define this_cpu_add_return_2(pcp, val) percpu_add_return_op(pcp, val)
#define this_cpu_add_return_4(pcp, val) percpu_add_return_op(pcp, val)
#define this_cpu_cmpxchg_1(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
#define this_cpu_cmpxchg_2(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
#define this_cpu_cmpxchg_4(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
#ifdef CONFIG_X86_CMPXCHG64
#define percpu_cmpxchg8b_double(pcp1, pcp2, o1, o2, n1, n2) \
({ \
bool __ret; \
typeof(pcp1) __o1 = (o1), __n1 = (n1); \
typeof(pcp2) __o2 = (o2), __n2 = (n2); \
asm volatile("cmpxchg8b "__percpu_arg(1)"\n\tsetz %0\n\t" \
: "=a" (__ret), "+m" (pcp1), "+m" (pcp2), "+d" (__o2) \
: "b" (__n1), "c" (__n2), "a" (__o1)); \
__ret; \
})
#define raw_cpu_cmpxchg_double_4 percpu_cmpxchg8b_double
#define this_cpu_cmpxchg_double_4 percpu_cmpxchg8b_double
#endif /* CONFIG_X86_CMPXCHG64 */
/*
* Per cpu atomic 64 bit operations are only available under 64 bit.
* 32 bit must fall back to generic operations.
*/
#ifdef CONFIG_X86_64
#define raw_cpu_read_8(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
#define raw_cpu_write_8(pcp, val) percpu_to_op("mov", (pcp), val)
#define raw_cpu_add_8(pcp, val) percpu_add_op((pcp), val)
#define raw_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val)
#define raw_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val)
#define raw_cpu_add_return_8(pcp, val) percpu_add_return_op(pcp, val)
#define raw_cpu_xchg_8(pcp, nval) percpu_xchg_op(pcp, nval)
#define raw_cpu_cmpxchg_8(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
#define this_cpu_read_8(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
#define this_cpu_write_8(pcp, val) percpu_to_op("mov", (pcp), val)
#define this_cpu_add_8(pcp, val) percpu_add_op((pcp), val)
#define this_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val)
#define this_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val)
#define this_cpu_add_return_8(pcp, val) percpu_add_return_op(pcp, val)
#define this_cpu_xchg_8(pcp, nval) percpu_xchg_op(pcp, nval)
#define this_cpu_cmpxchg_8(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
/*
* Pretty complex macro to generate cmpxchg16 instruction. The instruction
* is not supported on early AMD64 processors so we must be able to emulate
* it in software. The address used in the cmpxchg16 instruction must be
* aligned to a 16 byte boundary.
*/
#define percpu_cmpxchg16b_double(pcp1, pcp2, o1, o2, n1, n2) \
({ \
bool __ret; \
typeof(pcp1) __o1 = (o1), __n1 = (n1); \
typeof(pcp2) __o2 = (o2), __n2 = (n2); \
alternative_io("leaq %P1,%%rsi\n\tcall this_cpu_cmpxchg16b_emu\n\t", \
"cmpxchg16b " __percpu_arg(1) "\n\tsetz %0\n\t", \
X86_FEATURE_CX16, \
ASM_OUTPUT2("=a" (__ret), "+m" (pcp1), \
"+m" (pcp2), "+d" (__o2)), \
"b" (__n1), "c" (__n2), "a" (__o1) : "rsi"); \
__ret; \
})
#define raw_cpu_cmpxchg_double_8 percpu_cmpxchg16b_double
#define this_cpu_cmpxchg_double_8 percpu_cmpxchg16b_double
#endif
/* This is not atomic against other CPUs -- CPU preemption needs to be off */
#define x86_test_and_clear_bit_percpu(bit, var) \
({ \
int old__; \
asm volatile("btr %2,"__percpu_arg(1)"\n\tsbbl %0,%0" \
: "=r" (old__), "+m" (var) \
: "dIr" (bit)); \
old__; \
})
static __always_inline int x86_this_cpu_constant_test_bit(unsigned int nr,
const unsigned long __percpu *addr)
{
unsigned long __percpu *a = (unsigned long *)addr + nr / BITS_PER_LONG;
#ifdef CONFIG_X86_64
return ((1UL << (nr % BITS_PER_LONG)) & raw_cpu_read_8(*a)) != 0;
#else
return ((1UL << (nr % BITS_PER_LONG)) & raw_cpu_read_4(*a)) != 0;
#endif
}
static inline int x86_this_cpu_variable_test_bit(int nr,
const unsigned long __percpu *addr)
{
int oldbit;
asm volatile("bt "__percpu_arg(2)",%1\n\t"
"sbb %0,%0"
: "=r" (oldbit)
: "m" (*(unsigned long *)addr), "Ir" (nr));
return oldbit;
}
#define x86_this_cpu_test_bit(nr, addr) \
(__builtin_constant_p((nr)) \
? x86_this_cpu_constant_test_bit((nr), (addr)) \
: x86_this_cpu_variable_test_bit((nr), (addr)))
#include <asm-generic/percpu.h>
/* We can use this directly for local CPU (faster). */
DECLARE_PER_CPU(unsigned long, this_cpu_off);
#endif /* !__ASSEMBLY__ */
#ifdef CONFIG_SMP
/*
* Define the "EARLY_PER_CPU" macros. These are used for some per_cpu
* variables that are initialized and accessed before there are per_cpu
* areas allocated.
*/
#define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \
DEFINE_PER_CPU(_type, _name) = _initvalue; \
__typeof__(_type) _name##_early_map[NR_CPUS] __initdata = \
{ [0 ... NR_CPUS-1] = _initvalue }; \
__typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
#define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue) \
DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue; \
__typeof__(_type) _name##_early_map[NR_CPUS] __initdata = \
{ [0 ... NR_CPUS-1] = _initvalue }; \
__typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
#define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \
EXPORT_PER_CPU_SYMBOL(_name)
#define DECLARE_EARLY_PER_CPU(_type, _name) \
DECLARE_PER_CPU(_type, _name); \
extern __typeof__(_type) *_name##_early_ptr; \
extern __typeof__(_type) _name##_early_map[]
#define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name) \
DECLARE_PER_CPU_READ_MOSTLY(_type, _name); \
extern __typeof__(_type) *_name##_early_ptr; \
extern __typeof__(_type) _name##_early_map[]
#define early_per_cpu_ptr(_name) (_name##_early_ptr)
#define early_per_cpu_map(_name, _idx) (_name##_early_map[_idx])
#define early_per_cpu(_name, _cpu) \
*(early_per_cpu_ptr(_name) ? \
&early_per_cpu_ptr(_name)[_cpu] : \
&per_cpu(_name, _cpu))
#else /* !CONFIG_SMP */
#define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \
DEFINE_PER_CPU(_type, _name) = _initvalue
#define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue) \
DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue
#define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \
EXPORT_PER_CPU_SYMBOL(_name)
#define DECLARE_EARLY_PER_CPU(_type, _name) \
DECLARE_PER_CPU(_type, _name)
#define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name) \
DECLARE_PER_CPU_READ_MOSTLY(_type, _name)
#define early_per_cpu(_name, _cpu) per_cpu(_name, _cpu)
#define early_per_cpu_ptr(_name) NULL
/* no early_per_cpu_map() */
#endif /* !CONFIG_SMP */
#endif /* _ASM_X86_PERCPU_H */
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