git: 5567d6b4419b - main - arm64 pmap: Simplify logic around pv_chunk sizes.
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Date: Wed, 17 Aug 2022 19:11:07 UTC
The branch main has been updated by jhb: URL: https://cgit.FreeBSD.org/src/commit/?id=5567d6b4419b02a2099527228b1a51cc55a5b47d commit 5567d6b4419b02a2099527228b1a51cc55a5b47d Author: John Baldwin <jhb@FreeBSD.org> AuthorDate: 2022-08-17 19:10:12 +0000 Commit: John Baldwin <jhb@FreeBSD.org> CommitDate: 2022-08-17 19:10:12 +0000 arm64 pmap: Simplify logic around pv_chunk sizes. - Define PC_FREEL and _NPCM in terms of _NPCPV rather than via magic numbers. - Remove assertions about _NPC* values from pmap.c. This is less relevant now that PC_FREEL and _NPCM are derived from _NPCPV. - Add a helper inline function pc_is_full() which uses a loop to check if pc_map is all zeroes. Use this to replace three places that check for a full mask assuming there are only 3 entries in pc_map. Reviewed by: markj Sponsored by: DARPA Differential Revision: https://reviews.freebsd.org/D36217 --- sys/arm64/arm64/pmap.c | 30 +++++++++++++----------------- sys/arm64/include/pmap.h | 3 +-- 2 files changed, 14 insertions(+), 19 deletions(-) diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c index 62276c024212..9c47c043d251 100644 --- a/sys/arm64/arm64/pmap.c +++ b/sys/arm64/arm64/pmap.c @@ -2449,13 +2449,6 @@ pmap_growkernel(vm_offset_t addr) ***************************************************/ CTASSERT(sizeof(struct pv_chunk) == PAGE_SIZE); -#if PAGE_SIZE == PAGE_SIZE_4K -CTASSERT(_NPCM == 3); -CTASSERT(_NPCPV == 168); -#else -CTASSERT(_NPCM == 11); -CTASSERT(_NPCPV == 677); -#endif static __inline struct pv_chunk * pv_to_chunk(pv_entry_t pv) @@ -2467,11 +2460,7 @@ pv_to_chunk(pv_entry_t pv) #define PV_PMAP(pv) (pv_to_chunk(pv)->pc_pmap) #define PC_FREEN 0xfffffffffffffffful -#if _NPCM == 3 -#define PC_FREEL 0x000000fffffffffful -#elif _NPCM == 11 -#define PC_FREEL 0x0000001ffffffffful -#endif +#define PC_FREEL ((1ul << (_NPCPV % 64)) - 1) #if _NPCM == 3 #define PC_IS_FREE(pc) ((pc)->pc_map[0] == PC_FREEN && \ @@ -2491,6 +2480,15 @@ static const uint64_t pc_freemask[] = { PC_FREEN, PC_FREEN, CTASSERT(nitems(pc_freemask) == _NPCM); +static __inline bool +pc_is_full(struct pv_chunk *pc) +{ + for (u_int i = 0; i < _NPCM; i++) + if (pc->pc_map[i] != 0) + return (false); + return (true); +} + #ifdef PV_STATS static int pc_chunk_count, pc_chunk_allocs, pc_chunk_frees, pc_chunk_tryfail; @@ -2785,8 +2783,7 @@ retry: pv = &pc->pc_pventry[field * 64 + bit]; pc->pc_map[field] &= ~(1ul << bit); /* If this was the last item, move it to tail */ - if (pc->pc_map[0] == 0 && pc->pc_map[1] == 0 && - pc->pc_map[2] == 0) { + if (pc_is_full(pc)) { TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list); TAILQ_INSERT_TAIL(&pmap->pm_pvchunk, pc, pc_list); @@ -2953,8 +2950,7 @@ pmap_pv_demote_l2(pmap_t pmap, vm_offset_t va, vm_paddr_t pa, va_last = va + L2_SIZE - PAGE_SIZE; for (;;) { pc = TAILQ_FIRST(&pmap->pm_pvchunk); - KASSERT(pc->pc_map[0] != 0 || pc->pc_map[1] != 0 || - pc->pc_map[2] != 0, ("pmap_pv_demote_l2: missing spare")); + KASSERT(!pc_is_full(pc), ("pmap_pv_demote_l2: missing spare")); for (field = 0; field < _NPCM; field++) { while (pc->pc_map[field]) { bit = ffsl(pc->pc_map[field]) - 1; @@ -2975,7 +2971,7 @@ pmap_pv_demote_l2(pmap_t pmap, vm_offset_t va, vm_paddr_t pa, TAILQ_INSERT_TAIL(&pmap->pm_pvchunk, pc, pc_list); } out: - if (pc->pc_map[0] == 0 && pc->pc_map[1] == 0 && pc->pc_map[2] == 0) { + if (pc_is_full(pc)) { TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list); TAILQ_INSERT_TAIL(&pmap->pm_pvchunk, pc, pc_list); } diff --git a/sys/arm64/include/pmap.h b/sys/arm64/include/pmap.h index f36b081ea869..9605c813285b 100644 --- a/sys/arm64/include/pmap.h +++ b/sys/arm64/include/pmap.h @@ -107,16 +107,15 @@ typedef struct pv_entry { * need to track per-pmap assignments. */ #if PAGE_SIZE == PAGE_SIZE_4K -#define _NPCM 3 #define _NPCPV 168 #define _NPAD 0 #elif PAGE_SIZE == PAGE_SIZE_16K -#define _NPCM 11 #define _NPCPV 677 #define _NPAD 1 #else #error Unsupported page size #endif +#define _NPCM howmany(_NPCPV, 64) #define PV_CHUNK_HEADER \ pmap_t pc_pmap; \