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amd64: micro-optimize vptopte()/vtopde() further

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Eliminate shlq $3,address shift after masking of the va is done, which
is needed to convert pt_entry_t[] array index into byte offset.
Do it by preshifting the mask, and compensating the right shift of va.

Suggested by:	alc
Reviewed by:	markj
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D33786
This commit is contained in:
Konstantin Belousov 2022-01-08 07:09:09 +02:00
parent 0b8643eaf6
commit e7c5442162
1 changed files with 14 additions and 14 deletions
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28
sys/amd64/amd64/pmap.c
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@ -1516,28 +1516,28 @@ pmap_pt_page_count_adj(pmap_t pmap, int count)
} }
} }
pt_entry_t vtoptem __read_mostly = (1ul << (NPTEPGSHIFT + NPDEPGSHIFT + pt_entry_t vtoptem __read_mostly = ((1ul << (NPTEPGSHIFT + NPDEPGSHIFT +
NPDPEPGSHIFT + NPML4EPGSHIFT)) - 1; NPDPEPGSHIFT + NPML4EPGSHIFT)) - 1) << 3;
pt_entry_t *PTmap __read_mostly = P4Tmap; vm_offset_t PTmap __read_mostly = (vm_offset_t)P4Tmap;
PMAP_INLINE pt_entry_t * PMAP_INLINE pt_entry_t *
vtopte(vm_offset_t va) vtopte(vm_offset_t va)
{ {
KASSERT(va >= VM_MAXUSER_ADDRESS, ("vtopte on a uva/gpa 0x%0lx", va)); KASSERT(va >= VM_MAXUSER_ADDRESS, ("vtopte on a uva/gpa 0x%0lx", va));
return (PTmap + ((va >> PAGE_SHIFT) & vtoptem)); return ((pt_entry_t *)(PTmap + ((va >> (PAGE_SHIFT - 3)) & vtoptem)));
} }
pd_entry_t vtopdem __read_mostly = (1ul << (NPDEPGSHIFT + NPDPEPGSHIFT + pd_entry_t vtopdem __read_mostly = ((1ul << (NPDEPGSHIFT + NPDPEPGSHIFT +
NPML4EPGSHIFT)) - 1; NPML4EPGSHIFT)) - 1) << 3;
pd_entry_t *PDmap __read_mostly = P4Dmap; vm_offset_t PDmap __read_mostly = (vm_offset_t)P4Dmap;
static __inline pd_entry_t * static __inline pd_entry_t *
vtopde(vm_offset_t va) vtopde(vm_offset_t va)
{ {
KASSERT(va >= VM_MAXUSER_ADDRESS, ("vtopde on a uva/gpa 0x%0lx", va)); KASSERT(va >= VM_MAXUSER_ADDRESS, ("vtopde on a uva/gpa 0x%0lx", va));
return (PDmap + ((va >> PDRSHIFT) & vtopdem)); return ((pt_entry_t *)(PDmap + ((va >> (PDRSHIFT - 3)) & vtopdem)));
} }
static u_int64_t static u_int64_t
@ -2229,12 +2229,12 @@ pmap_bootstrap_la57(void *arg __unused)
*/ */
v_pml5[PML5PML5I] = KPML5phys | X86_PG_RW | X86_PG_V | pg_nx; v_pml5[PML5PML5I] = KPML5phys | X86_PG_RW | X86_PG_V | pg_nx;
vtoptem = (1ul << (NPTEPGSHIFT + NPDEPGSHIFT + NPDPEPGSHIFT + vtoptem = ((1ul << (NPTEPGSHIFT + NPDEPGSHIFT + NPDPEPGSHIFT +
NPML4EPGSHIFT + NPML5EPGSHIFT)) - 1; NPML4EPGSHIFT + NPML5EPGSHIFT)) - 1) << 3;
PTmap = P5Tmap; PTmap = (vm_offset_t)P5Tmap;
vtopdem = (1ul << (NPDEPGSHIFT + NPDPEPGSHIFT + vtopdem = ((1ul << (NPDEPGSHIFT + NPDPEPGSHIFT +
NPML4EPGSHIFT + NPML5EPGSHIFT)) - 1; NPML4EPGSHIFT + NPML5EPGSHIFT)) - 1) << 3;
PDmap = P5Dmap; PDmap = (vm_offset_t)P5Dmap;
kernel_pmap->pm_cr3 = KPML5phys; kernel_pmap->pm_cr3 = KPML5phys;
kernel_pmap->pm_pmltop = v_pml5; kernel_pmap->pm_pmltop = v_pml5;