linux/include/asm-sparc64/system.h
David S. Miller 52eb053b71 [SPARC64]: Fix linkage of enormous kernels.
This was found by make randconfig

If the kernel .text is very large, the .fixup section branches
are too far away to be relocated correctly.

Use "sethi %hi(label), reg; jmpl reg + %lo(label); %g0" sequence
instead of the branch to fix this.

There is another case in switch_to() involving a branch, which
is fixed similarly.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-31 15:30:56 -07:00

323 lines
9.4 KiB
C

#ifndef __SPARC64_SYSTEM_H
#define __SPARC64_SYSTEM_H
#include <asm/ptrace.h>
#include <asm/processor.h>
#include <asm/visasm.h>
#ifndef __ASSEMBLY__
#include <linux/irqflags.h>
/*
* 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
/* These are here in an effort to more fully work around Spitfire Errata
* #51. Essentially, if a memory barrier occurs soon after a mispredicted
* branch, the chip can stop executing instructions until a trap occurs.
* Therefore, if interrupts are disabled, the chip can hang forever.
*
* It used to be believed that the memory barrier had to be right in the
* delay slot, but a case has been traced recently wherein the memory barrier
* was one instruction after the branch delay slot and the chip still hung.
* The offending sequence was the following in sym_wakeup_done() of the
* sym53c8xx_2 driver:
*
* call sym_ccb_from_dsa, 0
* movge %icc, 0, %l0
* brz,pn %o0, .LL1303
* mov %o0, %l2
* membar #LoadLoad
*
* The branch has to be mispredicted for the bug to occur. Therefore, we put
* the memory barrier explicitly into a "branch always, predicted taken"
* delay slot to avoid the problem case.
*/
#define membar_safe(type) \
do { __asm__ __volatile__("ba,pt %%xcc, 1f\n\t" \
" membar " type "\n" \
"1:\n" \
: : : "memory"); \
} while (0)
#define mb() \
membar_safe("#LoadLoad | #LoadStore | #StoreStore | #StoreLoad")
#define rmb() \
membar_safe("#LoadLoad")
#define wmb() \
membar_safe("#StoreStore")
#define membar_storeload() \
membar_safe("#StoreLoad")
#define membar_storeload_storestore() \
membar_safe("#StoreLoad | #StoreStore")
#define membar_storeload_loadload() \
membar_safe("#StoreLoad | #LoadLoad")
#define membar_storestore_loadstore() \
membar_safe("#StoreStore | #LoadStore")
#endif
#define nop() __asm__ __volatile__ ("nop")
#define read_barrier_depends() do { } while(0)
#define set_mb(__var, __value) \
do { __var = __value; membar_storeload_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 stop_a_enabled;
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
*/
#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(task_thread_info(next))[TI_FLAG_BYTE_CURRENT_DS]));\
trap_block[current_thread_info()->cpu].thread = \
task_thread_info(next); \
__asm__ __volatile__( \
"mov %%g4, %%g7\n\t" \
"stx %%i6, [%%sp + 2047 + 0x70]\n\t" \
"stx %%i7, [%%sp + 2047 + 0x78]\n\t" \
"rdpr %%wstate, %%o5\n\t" \
"stx %%o6, [%%g6 + %6]\n\t" \
"stb %%o5, [%%g6 + %5]\n\t" \
"rdpr %%cwp, %%o5\n\t" \
"stb %%o5, [%%g6 + %8]\n\t" \
"mov %4, %%g6\n\t" \
"ldub [%4 + %8], %%g1\n\t" \
"wrpr %%g1, %%cwp\n\t" \
"ldx [%%g6 + %6], %%o6\n\t" \
"ldub [%%g6 + %5], %%o5\n\t" \
"ldub [%%g6 + %7], %%o7\n\t" \
"wrpr %%o5, 0x0, %%wstate\n\t" \
"ldx [%%sp + 2047 + 0x70], %%i6\n\t" \
"ldx [%%sp + 2047 + 0x78], %%i7\n\t" \
"ldx [%%g6 + %9], %%g4\n\t" \
"brz,pt %%o7, 1f\n\t" \
" mov %%g7, %0\n\t" \
"sethi %%hi(ret_from_syscall), %%g1\n\t" \
"jmpl %%g1 + %%lo(ret_from_syscall), %%g0\n\t" \
" nop\n\t" \
"1:\n\t" \
: "=&r" (last), "=r" (current), "=r" (current_thread_info_reg), \
"=r" (__local_per_cpu_offset) \
: "0" (task_thread_info(next)), \
"i" (TI_WSTATE), "i" (TI_KSP), "i" (TI_NEW_CHILD), \
"i" (TI_CWP), "i" (TI_TASK) \
: "cc", \
"g1", "g2", "g3", "g7", \
"l1", "l2", "l3", "l4", "l5", "l6", "l7", \
"i0", "i1", "i2", "i3", "i4", "i5", \
"o0", "o1", "o2", "o3", "o4", "o5", "o7"); \
/* 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))))
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) */