diff options
Diffstat (limited to 'hw/xive.c')
| -rw-r--r-- | hw/xive.c | 57 |
1 files changed, 54 insertions, 3 deletions
@@ -1244,6 +1244,52 @@ static int64_t __xive_cache_watch(struct xive *x, enum xive_cache_type ctype, void *new_data, bool light_watch, bool synchronous); +static void xive_scrub_workaround_vp(struct xive *x, uint32_t block, uint32_t idx __unused) +{ + /* VP variant of the workaround described in __xive_cache_scrub(), + * we need to be careful to use for that workaround an NVT that + * sits on the same xive but isn NOT part of a donated indirect + * entry. + * + * The reason is that the dummy cache watch will re-create a + * dirty entry in the cache, even if the entry is marked + * invalid. + * + * Thus if we are about to dispose of the indirect entry backing + * it, we'll cause a checkstop later on when trying to write it + * out. + * + * Note: This means the workaround only works for block group + * mode. + */ +#ifdef USE_BLOCK_GROUP_MODE + __xive_cache_watch(x, xive_cache_vpc, block, INITIAL_VP_BASE, 0, + 0, NULL, true, false); +#else + /* WARNING: Some workarounds related to cache scrubs require us to + * have at least one firmware owned (permanent) indirect entry for + * each XIVE instance. This currently only happens in block group + * mode + */ +#warning Block group mode should not be disabled +#endif +} + +static void xive_scrub_workaround_eq(struct xive *x, uint32_t block __unused, uint32_t idx) +{ + void *mmio; + + /* EQ variant of the workaround described in __xive_cache_scrub(), + * a simple non-side effect load from ESn will do + */ + mmio = x->eq_mmio + idx * 0x20000; + + /* Ensure the above has returned before we do anything else + * the XIVE store queue is completely empty + */ + load_wait(in_be64(mmio + 0x800)); +} + static int64_t __xive_cache_scrub(struct xive *x, enum xive_cache_type ctype, uint64_t block, uint64_t idx, bool want_inval, bool want_disable) @@ -1263,6 +1309,9 @@ static int64_t __xive_cache_scrub(struct xive *x, enum xive_cache_type ctype, * invalidate, then after the scrub, we do a dummy cache * watch which will make the HW read the data back, which * should be ordered behind all the preceding stores. + * + * Update: For EQs we can do a non-side effect ESB load instead + * which is faster. */ want_inval = true; @@ -1324,9 +1373,11 @@ static int64_t __xive_cache_scrub(struct xive *x, enum xive_cache_type ctype, /* Workaround for HW bug described above (only applies to * EQC and VPC */ - if (ctype == xive_cache_eqc || ctype == xive_cache_vpc) - __xive_cache_watch(x, ctype, block, idx, 0, 0, NULL, - true, false); + if (ctype == xive_cache_eqc) + xive_scrub_workaround_eq(x, block, idx); + else if (ctype == xive_cache_vpc) + xive_scrub_workaround_vp(x, block, idx); + return 0; } |