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powerpc/xive: Add a debugfs toggle for StoreEOI

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It can be used to deactivate temporarily StoreEOI for tests or
performance on platforms supporting the feature (POWER10)

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211105102636.1016378-9-clg@kaod.org
This commit is contained in:
Cédric Le Goater 2021-11-05 11:26:33 +01:00 committed by Michael Ellerman
parent 08f3f61021
commit d7bc1e376c
1 changed files with 14 additions and 3 deletions
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17
arch/powerpc/sysdev/xive/common.c
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@ -84,6 +84,16 @@ static DEFINE_PER_CPU(struct xive_cpu *, xive_cpu);
/* An invalid CPU target */
#define XIVE_INVALID_TARGET (-1)
/*
* Global toggle to switch on/off StoreEOI
*/
static bool xive_store_eoi = true;
static bool xive_is_store_eoi(struct xive_irq_data *xd)
{
return xd->flags & XIVE_IRQ_FLAG_STORE_EOI && xive_store_eoi;
}
/*
* Read the next entry in a queue, return its content if it's valid
* or 0 if there is no new entry.
@ -208,7 +218,7 @@ static notrace u8 xive_esb_read(struct xive_irq_data *xd, u32 offset)
{
u64 val;
if (offset == XIVE_ESB_SET_PQ_10 && xd->flags & XIVE_IRQ_FLAG_STORE_EOI)
if (offset == XIVE_ESB_SET_PQ_10 && xive_is_store_eoi(xd))
offset |= XIVE_ESB_LD_ST_MO;
if ((xd->flags & XIVE_IRQ_FLAG_H_INT_ESB) && xive_ops->esb_rw)
@ -233,7 +243,7 @@ static void xive_irq_data_dump(struct xive_irq_data *xd, char *buffer, size_t si
u64 val = xive_esb_read(xd, XIVE_ESB_GET);
snprintf(buffer, size, "flags=%c%c%c PQ=%c%c 0x%016llx 0x%016llx",
xd->flags & XIVE_IRQ_FLAG_STORE_EOI ? 'S' : ' ',
xive_is_store_eoi(xd) ? 'S' : ' ',
xd->flags & XIVE_IRQ_FLAG_LSI ? 'L' : ' ',
xd->flags & XIVE_IRQ_FLAG_H_INT_ESB ? 'H' : ' ',
val & XIVE_ESB_VAL_P ? 'P' : '-',
@ -395,7 +405,7 @@ static void xive_do_source_eoi(struct xive_irq_data *xd)
xd->stale_p = false;
/* If the XIVE supports the new "store EOI facility, use it */
if (xd->flags & XIVE_IRQ_FLAG_STORE_EOI) {
if (xive_is_store_eoi(xd)) {
xive_esb_write(xd, XIVE_ESB_STORE_EOI, 0);
return;
}
@ -1823,6 +1833,7 @@ static void xive_core_debugfs_create(void)
debugfs_create_file(name, 0400, xive_eq_dir, (void *)cpu,
&xive_eq_debug_fops);
}
debugfs_create_bool("store-eoi", 0600, xive_dir, &xive_store_eoi);
}
#else
static inline void xive_core_debugfs_create(void) { }