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sparc64: add hot-patched and inlined get_tick()

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Add the new get_tick() function that is hot-patched during boot based on
processor we are booting on.

Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Pavel Tatashin
2017-06-12 16:41:47 -04:00
committed by David S. Miller
parent 83e8eb99d9
commit 4929c83a6c
3 changed files with 87 additions and 6 deletions
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60
arch/sparc/include/asm/timer_64.h
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@@ -34,4 +34,64 @@ unsigned long sparc64_get_clock_tick(unsigned int cpu);
void setup_sparc64_timer(void);
void __init time_init(void);
#define TICK_PRIV_BIT BIT(63)
#define TICKCMP_IRQ_BIT BIT(63)
#define HBIRD_STICKCMP_ADDR 0x1fe0000f060UL
#define HBIRD_STICK_ADDR 0x1fe0000f070UL
#define GET_TICK_NINSTR 13
struct get_tick_patch {
unsigned int addr;
unsigned int tick[GET_TICK_NINSTR];
unsigned int stick[GET_TICK_NINSTR];
};
extern struct get_tick_patch __get_tick_patch;
extern struct get_tick_patch __get_tick_patch_end;
static inline unsigned long get_tick(void)
{
unsigned long tick, tmp1, tmp2;
__asm__ __volatile__(
/* read hbtick 13 instructions */
"661:\n"
" mov 0x1fe, %1\n"
" sllx %1, 0x20, %1\n"
" sethi %%hi(0xf000), %2\n"
" or %2, 0x70, %2\n"
" or %1, %2, %1\n" /* %1 = HBIRD_STICK_ADDR */
" add %1, 8, %2\n"
" ldxa [%2]%3, %0\n"
" ldxa [%1]%3, %1\n"
" ldxa [%2]%3, %2\n"
" sub %2, %0, %0\n" /* don't modify %xcc */
" brnz,pn %0, 661b\n" /* restart to save one register */
" sllx %2, 32, %2\n"
" or %2, %1, %0\n"
/* Common/not patched code */
" sllx %0, 1, %0\n"
" srlx %0, 1, %0\n" /* Clear TICK_PRIV_BIT */
/* Beginning of patch section */
" .section .get_tick_patch, \"ax\"\n"
" .word 661b\n"
/* read tick 2 instructions and 11 skipped */
" ba 1f\n"
" rd %%tick, %0\n"
" .skip 4 * (%4 - 2)\n"
"1:\n"
/* read stick 2 instructions and 11 skipped */
" ba 1f\n"
" rd %%asr24, %0\n"
" .skip 4 * (%4 - 2)\n"
"1:\n"
/* End of patch section */
" .previous\n"
: "=&r" (tick), "=&r" (tmp1), "=&r" (tmp2)
: "i" (ASI_PHYS_BYPASS_EC_E), "i" (GET_TICK_NINSTR));
return tick;
}
#endif /* _SPARC64_TIMER_H */