Commit 4929c83a authored by Pavel Tatashin's avatar Pavel Tatashin Committed by David S. Miller
Browse files

sparc64: add hot-patched and inlined get_tick() 



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

Signed-off-by: default avatarPavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: default avatarSteven Sistare <steven.sistare@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 83e8eb99

arch/sparc/include/asm/timer_64.h

+60 −0
Original line number Diff line number Diff line
@@ -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 */

arch/sparc/kernel/time_64.c

+22 −6
Original line number Diff line number Diff line
@@ -47,15 +47,13 @@ 
#include <asm/cpudata.h>

#include <linux/uaccess.h>

#include <asm/irq_regs.h>

#include <asm/cacheflush.h>



#include "entry.h"

#include "kernel.h"



DEFINE_SPINLOCK(rtc_lock);



#define TICK_PRIV_BIT	(1UL << 63)

#define TICKCMP_IRQ_BIT	(1UL << 63)



#ifdef CONFIG_SMP

unsigned long profile_pc(struct pt_regs *regs)

{
@@ -290,9 +288,6 @@ static struct sparc64_tick_ops stick_operations __read_mostly = { 
 * 2) write high

 * 3) write low

 */

#define HBIRD_STICKCMP_ADDR	0x1fe0000f060UL

#define HBIRD_STICK_ADDR	0x1fe0000f070UL



static unsigned long __hbird_read_stick(void)

{

	unsigned long ret, tmp1, tmp2, tmp3;
@@ -777,6 +772,26 @@ static u64 clocksource_tick_read(struct clocksource *cs) 
	return tick_operations.get_tick();

}



static void __init get_tick_patch(void)

{

	unsigned int *addr, *instr, i;

	struct get_tick_patch *p;



	if (tlb_type == spitfire && is_hummingbird())

		return;



	for (p = &__get_tick_patch; p < &__get_tick_patch_end; p++) {

		instr = (tlb_type == spitfire) ? p->tick : p->stick;

		addr = (unsigned int *)(unsigned long)p->addr;

		for (i = 0; i < GET_TICK_NINSTR; i++) {

			addr[i] = instr[i];

			/* ensure that address is modified before flush */

			wmb();

			flushi(&addr[i]);

		}

	}

}



static void init_tick_ops(struct sparc64_tick_ops *ops)

{

	unsigned long freq, quotient, tick;
@@ -789,6 +804,7 @@ static void init_tick_ops(struct sparc64_tick_ops *ops) 
	ops->ticks_per_nsec_quotient = quotient;

	ops->frequency = freq;

	tick_operations = *ops;

	get_tick_patch();

}



void __init time_init_early(void)

arch/sparc/kernel/vmlinux.lds.S

+5 −0
Original line number Diff line number Diff line
@@ -149,6 +149,11 @@ SECTIONS 
		*(.sun_m7_2insn_patch)

		__sun_m7_2insn_patch_end = .;

	}

	.get_tick_patch : {

		__get_tick_patch = .;

		*(.get_tick_patch)

		__get_tick_patch_end = .;

	}

	PERCPU_SECTION(SMP_CACHE_BYTES)



#ifdef CONFIG_JUMP_LABEL