Commit a5878691 authored by Bjorn Helgaas's avatar Bjorn Helgaas Committed by Tony Luck

[IA64] avoid broken SAL_CACHE_FLUSH implementations

If SAL_CACHE_FLUSH drops interrupts, complain about it and fall back to
using PAL_CACHE_FLUSH instead.

This is to work around a defect in HP rx5670 firmware: when an interrupt
occurs during SAL_CACHE_FLUSH, SAL drops the interrupt but leaves it marked
"in-service", which leaves the interrupt (and others of equal or lower
priority) masked.
Signed-off-by: default avatarBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent af14aca9
......@@ -14,6 +14,7 @@
#include <linux/spinlock.h>
#include <linux/string.h>
#include <asm/delay.h>
#include <asm/page.h>
#include <asm/sal.h>
#include <asm/pal.h>
......@@ -214,6 +215,78 @@ chk_nointroute_opt(void)
static void __init sal_desc_ap_wakeup(void *p) { }
#endif
/*
* HP rx5670 firmware polls for interrupts during SAL_CACHE_FLUSH by reading
* cr.ivr, but it never writes cr.eoi. This leaves any interrupt marked as
* "in-service" and masks other interrupts of equal or lower priority.
*
* HP internal defect reports: F1859, F2775, F3031.
*/
static int sal_cache_flush_drops_interrupts;
static void __init
check_sal_cache_flush (void)
{
unsigned long flags, itv;
int cpu;
u64 vector;
cpu = get_cpu();
local_irq_save(flags);
/*
* Schedule a timer interrupt, wait until it's reported, and see if
* SAL_CACHE_FLUSH drops it.
*/
itv = ia64_get_itv();
BUG_ON((itv & (1 << 16)) == 0);
ia64_set_itv(IA64_TIMER_VECTOR);
ia64_set_itm(ia64_get_itc() + 1000);
while (!ia64_get_irr(IA64_TIMER_VECTOR))
cpu_relax();
ia64_sal_cache_flush(3);
if (ia64_get_irr(IA64_TIMER_VECTOR)) {
vector = ia64_get_ivr();
ia64_eoi();
WARN_ON(vector != IA64_TIMER_VECTOR);
} else {
sal_cache_flush_drops_interrupts = 1;
printk(KERN_ERR "SAL: SAL_CACHE_FLUSH drops interrupts; "
"PAL_CACHE_FLUSH will be used instead\n");
ia64_eoi();
}
ia64_set_itv(itv);
local_irq_restore(flags);
put_cpu();
}
s64
ia64_sal_cache_flush (u64 cache_type)
{
struct ia64_sal_retval isrv;
if (sal_cache_flush_drops_interrupts) {
unsigned long flags;
u64 progress;
s64 rc;
progress = 0;
local_irq_save(flags);
rc = ia64_pal_cache_flush(cache_type,
PAL_CACHE_FLUSH_INVALIDATE, &progress, NULL);
local_irq_restore(flags);
return rc;
}
SAL_CALL(isrv, SAL_CACHE_FLUSH, cache_type, 0, 0, 0, 0, 0, 0);
return isrv.status;
}
void __init
ia64_sal_init (struct ia64_sal_systab *systab)
{
......@@ -262,6 +335,8 @@ ia64_sal_init (struct ia64_sal_systab *systab)
}
p += SAL_DESC_SIZE(*p);
}
check_sal_cache_flush();
}
int
......
......@@ -559,6 +559,23 @@ ia64_eoi (void)
#define cpu_relax() ia64_hint(ia64_hint_pause)
static inline int
ia64_get_irr(unsigned int vector)
{
unsigned int reg = vector / 64;
unsigned int bit = vector % 64;
u64 irr;
switch (reg) {
case 0: irr = ia64_getreg(_IA64_REG_CR_IRR0); break;
case 1: irr = ia64_getreg(_IA64_REG_CR_IRR1); break;
case 2: irr = ia64_getreg(_IA64_REG_CR_IRR2); break;
case 3: irr = ia64_getreg(_IA64_REG_CR_IRR3); break;
}
return test_bit(bit, &irr);
}
static inline void
ia64_set_lrr0 (unsigned long val)
{
......
......@@ -658,15 +658,7 @@ ia64_sal_freq_base (unsigned long which, unsigned long *ticks_per_second,
return isrv.status;
}
/* Flush all the processor and platform level instruction and/or data caches */
static inline s64
ia64_sal_cache_flush (u64 cache_type)
{
struct ia64_sal_retval isrv;
SAL_CALL(isrv, SAL_CACHE_FLUSH, cache_type, 0, 0, 0, 0, 0, 0);
return isrv.status;
}
extern s64 ia64_sal_cache_flush (u64 cache_type);
/* Initialize all the processor and platform level instruction and data caches */
static inline s64
......
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