- Make lazy I-sync a little safer -- always mark the pmap as needing
I-sync in pmap_remove_mapping() if the old mapping had PG_EXEC, and kick curcpu (IMB) or other CPUs (via an IPI) only if the pmap was the kernel pmap or active on other CPUs (curcpu is handled in userret()). - Use lazy I-sync everywhere, (hopefully) eliminating the last of the I-sync issues for multiprocessor support. - Eliminate some memory barriers added in a couple of previous revisions, after some discussion on port-alpha/tech-smp. Still some lazy I-sync optimization possibilites: - pmap_changebit() does not need to I-sync when only write-protecting a page. - pmap_asn_alloc() may be able to cancel a pending lazy I-sync when a new ASN is allocated. Need to double check against Green Book or Brown Book.
This commit is contained in:
thorpej
parent
33016f23e0
commit
c7b8439ec4
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@ -1,4 +1,4 @@
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/* $NetBSD: pmap.c,v 1.141 2000/08/13 22:43:42 thorpej Exp $ */
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/* $NetBSD: pmap.c,v 1.142 2000/08/15 05:21:20 thorpej Exp $ */
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/*-
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* Copyright (c) 1998, 1999, 2000 The NetBSD Foundation, Inc.
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@ -154,7 +154,7 @@
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#include <sys/cdefs.h> /* RCS ID & Copyright macro defns */
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__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.141 2000/08/13 22:43:42 thorpej Exp $");
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__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.142 2000/08/15 05:21:20 thorpej Exp $");
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#include <sys/param.h>
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#include <sys/systm.h>
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@ -624,6 +624,14 @@ do { \
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} \
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} while (0)
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/*
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* PMAP_SET_NEEDISYNC:
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*
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* Mark that a user pmap needs an I-stream synch on its
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* way back out to userspace.
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*/
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#define PMAP_SET_NEEDISYNC(pmap) (pmap)->pm_needisync = ~0UL
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/*
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* PMAP_SYNC_ISTREAM:
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*
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@ -640,13 +648,12 @@ do { \
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#define PMAP_SYNC_ISTREAM_USER(pmap) \
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do { \
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(pmap)->pm_needisync = ~0UL; \
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alpha_mb(); /* XXX alpha_wmb()? */ \
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alpha_multicast_ipi((pmap)->pm_cpus, ALPHA_IPI_AST); \
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/* for curcpu, will happen in userret() */ \
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} while (0)
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#else
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#define PMAP_SYNC_ISTREAM_KERNEL() alpha_pal_imb()
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#define PMAP_SYNC_ISTREAM_USER(pmap) (pmap)->pm_needisync = ~0UL
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#define PMAP_SYNC_ISTREAM_USER(pmap) /* will happen in userret() */
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#endif /* MULTIPROCESSOR */
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#define PMAP_SYNC_ISTREAM(pmap) \
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@ -742,15 +749,7 @@ do { \
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*
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* Set a PTE to a specified value.
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*/
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#if defined(MULTIPROCESSOR)
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#define PMAP_SET_PTE(ptep, val) \
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do { \
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*(ptep) = (val); \
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alpha_mb(); /* XXX alpha_wmb()? */ \
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} while (0)
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#else
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#define PMAP_SET_PTE(ptep, val) *(ptep) = (val)
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#endif
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/*
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* PMAP_STAT_{INCR,DECR}:
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@ -1639,7 +1638,8 @@ pmap_enter(pmap_t pmap, vaddr_t va, paddr_t pa, vm_prot_t prot, int flags)
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paddr_t opa;
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boolean_t tflush = TRUE;
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boolean_t hadasm = FALSE; /* XXX gcc -Wuninitialized */
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boolean_t needisync;
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boolean_t needisync = FALSE;
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boolean_t setisync = FALSE;
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boolean_t isactive;
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boolean_t wired;
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long cpu_id = cpu_number();
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@ -1655,10 +1655,23 @@ pmap_enter(pmap_t pmap, vaddr_t va, paddr_t pa, vm_prot_t prot, int flags)
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managed = PAGE_IS_MANAGED(pa);
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isactive = PMAP_ISACTIVE(pmap, cpu_id);
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needisync = ((prot & VM_PROT_EXECUTE) != 0) &&
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(pmap->pm_cpus != 0 || pmap == pmap_kernel());
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wired = (flags & PMAP_WIRED) != 0;
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/*
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* Determine what we need to do about the I-stream. If
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* VM_PROT_EXECUTE is set, we mark a user pmap as needing
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* an I-sync on the way back out to userspace. We always
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* need an immediate I-sync for the kernel pmap.
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*/
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if (prot & VM_PROT_EXECUTE) {
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if (pmap == pmap_kernel())
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needisync = TRUE;
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else {
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setisync = TRUE;
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needisync = (pmap->pm_cpus != 0);
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}
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}
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PMAP_MAP_TO_HEAD_LOCK();
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PMAP_LOCK(pmap);
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@ -1772,7 +1785,7 @@ pmap_enter(pmap_t pmap, vaddr_t va, paddr_t pa, vm_prot_t prot, int flags)
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* No need to synchronize the I-stream, either, for basically
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* the same reason.
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*/
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needisync = FALSE;
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setisync = needisync = FALSE;
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if (pmap != pmap_kernel()) {
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/*
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@ -1917,6 +1930,8 @@ pmap_enter(pmap_t pmap, vaddr_t va, paddr_t pa, vm_prot_t prot, int flags)
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pmap_tlb_shootdown(pmap, va, hadasm ? PG_ASM : 0);
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#endif
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}
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if (setisync)
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PMAP_SET_NEEDISYNC(pmap);
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if (needisync)
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PMAP_SYNC_ISTREAM(pmap);
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@ -1976,6 +1991,9 @@ pmap_kenter_pa(vaddr_t va, paddr_t pa, vm_prot_t prot)
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* Set the new PTE.
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*/
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PMAP_SET_PTE(pte, npte);
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#if defined(MULTIPROCESSOR)
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alpha_mb(); /* XXX alpha_wmb()? */
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#endif
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/*
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* Invalidate the TLB entry for this VA and any appropriate
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@ -2053,6 +2071,9 @@ pmap_kremove(vaddr_t va, vsize_t size)
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/* Zap the mapping. */
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PMAP_SET_PTE(pte, PG_NV);
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#if defined(MULTIPROCESSOR)
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alpha_mb(); /* XXX alpha_wmb()? */
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#endif
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PMAP_INVALIDATE_TLB(pmap, va, TRUE, TRUE, cpu_id);
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#if defined(MULTIPROCESSOR) && 0
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pmap_tlb_shootdown(pmap, va, PG_ASM);
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@ -2356,10 +2377,6 @@ pmap_zero_page(paddr_t phys)
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: "0" (p0), "1" (p1)
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: "memory");
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} while (p0 < pend);
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#if defined(MULTIPROCESSOR)
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/* Ensure the other CPUs see the correct data. */
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alpha_mb(); /* XXX alpha_wmb()? */
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#endif
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}
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/*
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@ -2383,10 +2400,6 @@ pmap_copy_page(paddr_t src, paddr_t dst)
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s = (caddr_t)ALPHA_PHYS_TO_K0SEG(src);
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d = (caddr_t)ALPHA_PHYS_TO_K0SEG(dst);
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memcpy(d, s, PAGE_SIZE);
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#if defined(MULTIPROCESSOR)
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/* Ensure the other CPUs see the correct data. */
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alpha_mb(); /* XXX alpha_wmb()? */
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#endif
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}
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/*
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@ -2592,8 +2605,8 @@ alpha_protection_init(void)
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* from beneath it. We assume that the pmap itself is already
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* locked; dolock applies only to the PV list.
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*
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* Returns TRUE or FALSE, indicating if the I-stream needs to
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* be synchronized.
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* Returns TRUE or FALSE, indicating if an I-stream sync needs
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* to be initiated (for this CPU or for other CPUs).
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*/
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boolean_t
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pmap_remove_mapping(pmap_t pmap, vaddr_t va, pt_entry_t *pte,
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@ -2603,7 +2616,7 @@ pmap_remove_mapping(pmap_t pmap, vaddr_t va, pt_entry_t *pte,
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boolean_t onpv;
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boolean_t hadasm;
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boolean_t isactive;
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boolean_t needisync;
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boolean_t needisync = FALSE;
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struct pv_entry **pvp;
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pt_entry_t **ptp;
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@ -2640,8 +2653,21 @@ pmap_remove_mapping(pmap_t pmap, vaddr_t va, pt_entry_t *pte,
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onpv = (pmap_pte_pv(pte) != 0);
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hadasm = (pmap_pte_asm(pte) != 0);
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isactive = PMAP_ISACTIVE(pmap, cpu_id);
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needisync = (pmap_pte_exec(pte) != 0) &&
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(pmap->pm_cpus != 0 || pmap == pmap_kernel());
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/*
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* Determine what we need to do about the I-stream. If
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* PG_EXEC was set, we mark a user pmap as needing an
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* I-sync on the way out to userspace. We always need
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* an immediate I-sync for the kernel pmap.
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*/
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if (pmap_pte_exec(pte)) {
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if (pmap == pmap_kernel())
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needisync = TRUE;
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else {
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PMAP_SET_NEEDISYNC(pmap);
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needisync = (pmap->pm_cpus != 0);
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}
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}
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/*
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* Update statistics
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@ -2751,16 +2777,25 @@ pmap_changebit(paddr_t pa, u_long set, u_long mask, long cpu_id)
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if (*pte != npte) {
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hadasm = (pmap_pte_asm(pte) != 0);
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isactive = PMAP_ISACTIVE(pv->pv_pmap, cpu_id);
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needisync = (pmap_pte_exec(pte) != 0) &&
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(pv->pv_pmap->pm_cpus != 0 ||
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pv->pv_pmap == pmap_kernel());
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PMAP_SET_PTE(pte, npte);
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if (needisync) {
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/*
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* Determine what we need to do about the I-stream.
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* If PG_EXEC was set, we mark a user pmap as needing
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* an I-sync on the way out to userspace. We always
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* need an immediate I-sync for the kernel pmap.
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*/
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needisync = FALSE;
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if (pmap_pte_exec(pte)) {
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if (pv->pv_pmap == pmap_kernel())
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needkisync |= TRUE;
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else
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PMAP_SYNC_ISTREAM_USER(pv->pv_pmap);
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needkisync = TRUE;
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else {
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PMAP_SET_NEEDISYNC(pv->pv_pmap);
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if (pv->pv_pmap->pm_cpus != 0)
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needisync = TRUE;
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}
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}
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PMAP_SET_PTE(pte, npte);
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if (needisync)
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PMAP_SYNC_ISTREAM_USER(pv->pv_pmap);
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PMAP_INVALIDATE_TLB(pv->pv_pmap, va, hadasm, isactive,
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cpu_id);
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#if defined(MULTIPROCESSOR) && 0
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@ -3111,11 +3146,6 @@ pmap_pv_alloc(void)
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if (pvpmap == pmap_kernel())
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continue;
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/*
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* XXX We know we're not going to try and
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* XXX lock the kernel pmap, so we don't
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* XXX have to block interrupts here.
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*/
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if (simple_lock_try(&pvpmap->pm_slock) == 0)
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continue;
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@ -3135,7 +3165,7 @@ pmap_pv_alloc(void)
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*/
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if (pmap_remove_mapping(pvpmap, pv->pv_va,
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pte, FALSE, cpu_id, &prmt))
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alpha_pal_imb(); /* XXXSMP */
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PMAP_SYNC_ISTREAM(pvpmap);
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/* Unlock everything and return. */
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simple_unlock(&pvpmap->pm_slock);
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@ -3627,14 +3657,10 @@ pmap_ptpage_steal(pmap_t pmap, int usage, paddr_t *pap)
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}
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}
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PMAP_UNLOCK(spmap);
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if (needisync)
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PMAP_SYNC_ISTREAM(pmap);
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if (needisync) { /* XXXSMP */
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alpha_pal_imb();
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#if defined(MULTIPROCESSOR) && 0
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alpha_broadcast_ipi(ALPHA_IPI_IMB);
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#endif
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}
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PMAP_UNLOCK(spmap);
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#ifdef DIAGNOSTIC
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if (prmt.prmt_ptp == NULL)
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