android_kernel_xiaomi_sm8350/include/asm-sparc64/system.h
Nick Piggin 4866cde064 [PATCH] sched: cleanup context switch locking
Instead of requiring architecture code to interact with the scheduler's
locking implementation, provide a couple of defines that can be used by the
architecture to request runqueue unlocked context switches, and ask for
interrupts to be enabled over the context switch.

Also replaces the "switch_lock" used by these architectures with an oncpu
flag (note, not a potentially slow bitflag).  This eliminates one bus
locked memory operation when context switching, and simplifies the
task_running function.

Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 16:24:43 -07:00

345 lines
9.7 KiB
C

/* $Id: system.h,v 1.69 2002/02/09 19:49:31 davem Exp $ */
#ifndef __SPARC64_SYSTEM_H
#define __SPARC64_SYSTEM_H
#include <linux/config.h>
#include <asm/ptrace.h>
#include <asm/processor.h>
#include <asm/visasm.h>
#ifndef __ASSEMBLY__
/*
* Sparc (general) CPU types
*/
enum sparc_cpu {
sun4 = 0x00,
sun4c = 0x01,
sun4m = 0x02,
sun4d = 0x03,
sun4e = 0x04,
sun4u = 0x05, /* V8 ploos ploos */
sun_unknown = 0x06,
ap1000 = 0x07, /* almost a sun4m */
};
#define sparc_cpu_model sun4u
/* This cannot ever be a sun4c nor sun4 :) That's just history. */
#define ARCH_SUN4C_SUN4 0
#define ARCH_SUN4 0
#endif
#define setipl(__new_ipl) \
__asm__ __volatile__("wrpr %0, %%pil" : : "r" (__new_ipl) : "memory")
#define local_irq_disable() \
__asm__ __volatile__("wrpr 15, %%pil" : : : "memory")
#define local_irq_enable() \
__asm__ __volatile__("wrpr 0, %%pil" : : : "memory")
#define getipl() \
({ unsigned long retval; __asm__ __volatile__("rdpr %%pil, %0" : "=r" (retval)); retval; })
#define swap_pil(__new_pil) \
({ unsigned long retval; \
__asm__ __volatile__("rdpr %%pil, %0\n\t" \
"wrpr %1, %%pil" \
: "=&r" (retval) \
: "r" (__new_pil) \
: "memory"); \
retval; \
})
#define read_pil_and_cli() \
({ unsigned long retval; \
__asm__ __volatile__("rdpr %%pil, %0\n\t" \
"wrpr 15, %%pil" \
: "=r" (retval) \
: : "memory"); \
retval; \
})
#define local_save_flags(flags) ((flags) = getipl())
#define local_irq_save(flags) ((flags) = read_pil_and_cli())
#define local_irq_restore(flags) setipl((flags))
/* On sparc64 IRQ flags are the PIL register. A value of zero
* means all interrupt levels are enabled, any other value means
* only IRQ levels greater than that value will be received.
* Consequently this means that the lowest IRQ level is one.
*/
#define irqs_disabled() \
({ unsigned long flags; \
local_save_flags(flags);\
(flags > 0); \
})
#define nop() __asm__ __volatile__ ("nop")
#define membar(type) __asm__ __volatile__ ("membar " type : : : "memory")
#define mb() \
membar("#LoadLoad | #LoadStore | #StoreStore | #StoreLoad")
#define rmb() membar("#LoadLoad")
#define wmb() membar("#StoreStore")
#define read_barrier_depends() do { } while(0)
#define set_mb(__var, __value) \
do { __var = __value; membar("#StoreLoad | #StoreStore"); } while(0)
#define set_wmb(__var, __value) \
do { __var = __value; membar("#StoreStore"); } while(0)
#ifdef CONFIG_SMP
#define smp_mb() mb()
#define smp_rmb() rmb()
#define smp_wmb() wmb()
#define smp_read_barrier_depends() read_barrier_depends()
#else
#define smp_mb() __asm__ __volatile__("":::"memory")
#define smp_rmb() __asm__ __volatile__("":::"memory")
#define smp_wmb() __asm__ __volatile__("":::"memory")
#define smp_read_barrier_depends() do { } while(0)
#endif
#define flushi(addr) __asm__ __volatile__ ("flush %0" : : "r" (addr) : "memory")
#define flushw_all() __asm__ __volatile__("flushw")
/* Performance counter register access. */
#define read_pcr(__p) __asm__ __volatile__("rd %%pcr, %0" : "=r" (__p))
#define write_pcr(__p) __asm__ __volatile__("wr %0, 0x0, %%pcr" : : "r" (__p))
#define read_pic(__p) __asm__ __volatile__("rd %%pic, %0" : "=r" (__p))
/* Blackbird errata workaround. See commentary in
* arch/sparc64/kernel/smp.c:smp_percpu_timer_interrupt()
* for more information.
*/
#define reset_pic() \
__asm__ __volatile__("ba,pt %xcc, 99f\n\t" \
".align 64\n" \
"99:wr %g0, 0x0, %pic\n\t" \
"rd %pic, %g0")
#ifndef __ASSEMBLY__
extern void sun_do_break(void);
extern int serial_console;
extern int stop_a_enabled;
static __inline__ int con_is_present(void)
{
return serial_console ? 0 : 1;
}
extern void synchronize_user_stack(void);
extern void __flushw_user(void);
#define flushw_user() __flushw_user()
#define flush_user_windows flushw_user
#define flush_register_windows flushw_all
/* Don't hold the runqueue lock over context switch */
#define __ARCH_WANT_UNLOCKED_CTXSW
#define prepare_arch_switch(next) \
do { \
flushw_all(); \
} while (0)
/* See what happens when you design the chip correctly?
*
* We tell gcc we clobber all non-fixed-usage registers except
* for l0/l1. It will use one for 'next' and the other to hold
* the output value of 'last'. 'next' is not referenced again
* past the invocation of switch_to in the scheduler, so we need
* not preserve it's value. Hairy, but it lets us remove 2 loads
* and 2 stores in this critical code path. -DaveM
*/
#if __GNUC__ >= 3
#define EXTRA_CLOBBER ,"%l1"
#else
#define EXTRA_CLOBBER
#endif
#define switch_to(prev, next, last) \
do { if (test_thread_flag(TIF_PERFCTR)) { \
unsigned long __tmp; \
read_pcr(__tmp); \
current_thread_info()->pcr_reg = __tmp; \
read_pic(__tmp); \
current_thread_info()->kernel_cntd0 += (unsigned int)(__tmp);\
current_thread_info()->kernel_cntd1 += ((__tmp) >> 32); \
} \
flush_tlb_pending(); \
save_and_clear_fpu(); \
/* If you are tempted to conditionalize the following */ \
/* so that ASI is only written if it changes, think again. */ \
__asm__ __volatile__("wr %%g0, %0, %%asi" \
: : "r" (__thread_flag_byte_ptr(next->thread_info)[TI_FLAG_BYTE_CURRENT_DS]));\
__asm__ __volatile__( \
"mov %%g4, %%g7\n\t" \
"wrpr %%g0, 0x95, %%pstate\n\t" \
"stx %%i6, [%%sp + 2047 + 0x70]\n\t" \
"stx %%i7, [%%sp + 2047 + 0x78]\n\t" \
"rdpr %%wstate, %%o5\n\t" \
"stx %%o6, [%%g6 + %3]\n\t" \
"stb %%o5, [%%g6 + %2]\n\t" \
"rdpr %%cwp, %%o5\n\t" \
"stb %%o5, [%%g6 + %5]\n\t" \
"mov %1, %%g6\n\t" \
"ldub [%1 + %5], %%g1\n\t" \
"wrpr %%g1, %%cwp\n\t" \
"ldx [%%g6 + %3], %%o6\n\t" \
"ldub [%%g6 + %2], %%o5\n\t" \
"ldx [%%g6 + %4], %%o7\n\t" \
"mov %%g6, %%l2\n\t" \
"wrpr %%o5, 0x0, %%wstate\n\t" \
"ldx [%%sp + 2047 + 0x70], %%i6\n\t" \
"ldx [%%sp + 2047 + 0x78], %%i7\n\t" \
"wrpr %%g0, 0x94, %%pstate\n\t" \
"mov %%l2, %%g6\n\t" \
"ldx [%%g6 + %7], %%g4\n\t" \
"wrpr %%g0, 0x96, %%pstate\n\t" \
"andcc %%o7, %6, %%g0\n\t" \
"beq,pt %%icc, 1f\n\t" \
" mov %%g7, %0\n\t" \
"b,a ret_from_syscall\n\t" \
"1:\n\t" \
: "=&r" (last) \
: "0" (next->thread_info), \
"i" (TI_WSTATE), "i" (TI_KSP), "i" (TI_FLAGS), "i" (TI_CWP), \
"i" (_TIF_NEWCHILD), "i" (TI_TASK) \
: "cc", \
"g1", "g2", "g3", "g7", \
"l2", "l3", "l4", "l5", "l6", "l7", \
"i0", "i1", "i2", "i3", "i4", "i5", \
"o0", "o1", "o2", "o3", "o4", "o5", "o7" EXTRA_CLOBBER);\
/* If you fuck with this, update ret_from_syscall code too. */ \
if (test_thread_flag(TIF_PERFCTR)) { \
write_pcr(current_thread_info()->pcr_reg); \
reset_pic(); \
} \
} while(0)
static inline unsigned long xchg32(__volatile__ unsigned int *m, unsigned int val)
{
unsigned long tmp1, tmp2;
__asm__ __volatile__(
" membar #StoreLoad | #LoadLoad\n"
" mov %0, %1\n"
"1: lduw [%4], %2\n"
" cas [%4], %2, %0\n"
" cmp %2, %0\n"
" bne,a,pn %%icc, 1b\n"
" mov %1, %0\n"
" membar #StoreLoad | #StoreStore\n"
: "=&r" (val), "=&r" (tmp1), "=&r" (tmp2)
: "0" (val), "r" (m)
: "cc", "memory");
return val;
}
static inline unsigned long xchg64(__volatile__ unsigned long *m, unsigned long val)
{
unsigned long tmp1, tmp2;
__asm__ __volatile__(
" membar #StoreLoad | #LoadLoad\n"
" mov %0, %1\n"
"1: ldx [%4], %2\n"
" casx [%4], %2, %0\n"
" cmp %2, %0\n"
" bne,a,pn %%xcc, 1b\n"
" mov %1, %0\n"
" membar #StoreLoad | #StoreStore\n"
: "=&r" (val), "=&r" (tmp1), "=&r" (tmp2)
: "0" (val), "r" (m)
: "cc", "memory");
return val;
}
#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
#define tas(ptr) (xchg((ptr),1))
extern void __xchg_called_with_bad_pointer(void);
static __inline__ unsigned long __xchg(unsigned long x, __volatile__ void * ptr,
int size)
{
switch (size) {
case 4:
return xchg32(ptr, x);
case 8:
return xchg64(ptr, x);
};
__xchg_called_with_bad_pointer();
return x;
}
extern void die_if_kernel(char *str, struct pt_regs *regs) __attribute__ ((noreturn));
/*
* Atomic compare and exchange. Compare OLD with MEM, if identical,
* store NEW in MEM. Return the initial value in MEM. Success is
* indicated by comparing RETURN with OLD.
*/
#define __HAVE_ARCH_CMPXCHG 1
static __inline__ unsigned long
__cmpxchg_u32(volatile int *m, int old, int new)
{
__asm__ __volatile__("membar #StoreLoad | #LoadLoad\n"
"cas [%2], %3, %0\n\t"
"membar #StoreLoad | #StoreStore"
: "=&r" (new)
: "0" (new), "r" (m), "r" (old)
: "memory");
return new;
}
static __inline__ unsigned long
__cmpxchg_u64(volatile long *m, unsigned long old, unsigned long new)
{
__asm__ __volatile__("membar #StoreLoad | #LoadLoad\n"
"casx [%2], %3, %0\n\t"
"membar #StoreLoad | #StoreStore"
: "=&r" (new)
: "0" (new), "r" (m), "r" (old)
: "memory");
return new;
}
/* This function doesn't exist, so you'll get a linker error
if something tries to do an invalid cmpxchg(). */
extern void __cmpxchg_called_with_bad_pointer(void);
static __inline__ unsigned long
__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
{
switch (size) {
case 4:
return __cmpxchg_u32(ptr, old, new);
case 8:
return __cmpxchg_u64(ptr, old, new);
}
__cmpxchg_called_with_bad_pointer();
return old;
}
#define cmpxchg(ptr,o,n) \
({ \
__typeof__(*(ptr)) _o_ = (o); \
__typeof__(*(ptr)) _n_ = (n); \
(__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
(unsigned long)_n_, sizeof(*(ptr))); \
})
#endif /* !(__ASSEMBLY__) */
#define arch_align_stack(x) (x)
#endif /* !(__SPARC64_SYSTEM_H) */