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[MIPS] R2: Implement shadow register allocation without spinlock.

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Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Ralf Baechle 2006-04-04 15:09:06 +01:00
parent 62a442155e
commit 193dd2ce2a
1 changed files with 18 additions and 23 deletions
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41
arch/mips/kernel/traps.c
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@ -961,15 +961,19 @@ void *set_except_vector(int n, void *addr)
#ifdef CONFIG_CPU_MIPSR2
/*
* Shadow register allocation
* MIPSR2 shadow register set allocation
* FIXME: SMP...
*/
/* MIPSR2 shadow register sets */
struct shadow_registers {
spinlock_t sr_lock; /* */
int sr_supported; /* Number of shadow register sets supported */
int sr_allocated; /* Bitmap of allocated shadow registers */
static struct shadow_registers {
/*
* Number of shadow register sets supported
*/
unsigned long sr_supported;
/*
* Bitmap of allocated shadow registers
*/
unsigned long sr_allocated;
} shadow_registers;
void mips_srs_init(void)
@ -980,7 +984,6 @@ void mips_srs_init(void)
shadow_registers.sr_supported);
#endif
shadow_registers.sr_allocated = 1; /* Set 0 used by kernel */
spin_lock_init(&shadow_registers.sr_lock);
}
int mips_srs_max(void)
@ -991,32 +994,24 @@ int mips_srs_max(void)
int mips_srs_alloc(void)
{
struct shadow_registers *sr = &shadow_registers;
unsigned long flags;
int set;
spin_lock_irqsave(&sr->sr_lock, flags);
again:
set = find_first_zero_bit(&sr->sr_allocated, sr->sr_supported);
if (set >= sr->sr_supported)
return -1;
for (set = 0; set < sr->sr_supported; set++) {
if ((sr->sr_allocated & (1 << set)) == 0) {
sr->sr_allocated |= 1 << set;
spin_unlock_irqrestore(&sr->sr_lock, flags);
return set;
}
}
if (test_and_set_bit(set, &sr->sr_allocated))
goto again;
/* None available */
spin_unlock_irqrestore(&sr->sr_lock, flags);
return -1;
return set;
}
void mips_srs_free (int set)
{
struct shadow_registers *sr = &shadow_registers;
unsigned long flags;
spin_lock_irqsave(&sr->sr_lock, flags);
sr->sr_allocated &= ~(1 << set);
spin_unlock_irqrestore(&sr->sr_lock, flags);
clear_bit(set, &sr->sr_allocated);
}
static void *set_vi_srs_handler(int n, void *addr, int srs)