Revise pv_table_map(): to simplify calculations, pv_table[] now covers
all of physical memory, i.e. it conceptually is pv_table[0..avail_end]. The previous version could lead to an off-by-one error in the page allocation for pv_table[] in some memory configurations.
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pk
parent
c6bbb5288d
commit
3011e0816b
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@ -1,4 +1,4 @@
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/* $NetBSD: pmap.c,v 1.173 2000/06/29 07:40:11 mrg Exp $ */
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/* $NetBSD: pmap.c,v 1.174 2000/09/09 10:24:34 pk Exp $ */
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/*
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* Copyright (c) 1996
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@ -202,10 +202,9 @@ struct pvlist {
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struct pvlist *pv_table; /* array of entries, one per physical page */
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#define pvhead(pa) (&pv_table[((pa) - vm_first_phys) >> PGSHIFT])
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#define pvhead(pa) (&pv_table[(pa) >> PGSHIFT])
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static vsize_t pv_table_map __P((paddr_t, int));
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static paddr_t pv_physmem;
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static psize_t pv_table_map __P((paddr_t));
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static struct pool pv_pool;
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@ -2180,7 +2179,7 @@ pv_link4_4c(pv, pm, va, nc)
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"pv_link: badalias: pid %d, 0x%lx<=>0x%lx, pa 0x%lx\n",
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curproc ? curproc->p_pid : -1,
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va, npv->pv_va,
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vm_first_phys + (pv-pv_table)*NBPG);
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(pv-pv_table)*PAGE_SIZE);
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#endif
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/* Mark list head `uncached due to aliases' */
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pv->pv_flags |= PV_ANC;
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@ -2490,7 +2489,7 @@ pv_link4m(pv, pm, va, nc)
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"pv_link: badalias: pid %d, 0x%lx<=>0x%lx, pa 0x%lx\n",
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curproc ? curproc->p_pid : -1,
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va, npv->pv_va,
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vm_first_phys + (pv-pv_table)*NBPG);
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(pv-pv_table)*PAGE_SIZE);
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#endif
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/* Mark list head `uncached due to aliases' */
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pv->pv_flags |= PV_ANC;
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@ -2547,32 +2546,47 @@ pv_flushcache(pv)
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splx(s);
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}
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vsize_t
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pv_table_map(base, mapit)
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psize_t
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pv_table_map(base)
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paddr_t base;
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int mapit;
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{
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int nmem;
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struct memarr *mp;
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int mapit;
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vsize_t s;
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vaddr_t sva, va, eva;
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paddr_t pa;
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static paddr_t pv_physbase;
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/*
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* Map pv_table[] as a `sparse' array. pv_table_map() is called
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* twice: the first time `mapit' is 0, and the number of
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* physical pages needed to map the used pieces of pv_table[]
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* is computed; the second time those pages are used to
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* actually map pv_table[].
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* In both cases, this function returns the amount of physical
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* memory needed.
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* Map pv_table[] as a `sparse' array. Virtual memory for pv_table
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* will cover the entire range of physical memory in the machine,
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* i.e. the array is used as pv_table[0..avail_end]. However,
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* depending on the configuration and wiring of the machine's
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* memory banks, there may be large sections in that index range
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* which will not be used. Therefore, we calculate the ranges of
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* pv_table[]'s virtual address extent that will get used and
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* proceed to only map those extents to actual physical memory.
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*
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* pv_table_map() is called twice: the first time `base' is the start
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* of physical memory that needs to be mapped by pv_table[].
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* `base' is also the location from which physical memory is taken
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* to map pv_table[] itself. pv_table_map() will return the amount
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* of physical memory needed.
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*
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* The second time pv_table_map() is called, `base' will be zero
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* and the phyical memory allocated in the first round will be
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* used to actually map pv_table[].
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*/
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if (!mapit)
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/* Mark physical pages for pv_table[] */
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pv_physmem = base;
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pa = pv_physmem; /* XXX - always init `pa' to appease gcc */
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if (base != 0) {
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/* Mark start of physical pages for pv_table[] */
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pv_physbase = base;
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mapit = 0;
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} else {
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pa = pv_physbase;
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mapit = 1;
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}
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s = 0;
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sva = eva = 0;
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@ -2581,17 +2595,17 @@ pv_table_map(base, mapit)
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paddr_t addr;
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len = mp->len;
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if ((addr = mp->addr) < base) {
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if ((addr = mp->addr) < pv_physbase) {
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/*
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* pv_table[] covers everything above `avail_start'.
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* pv_table[] covers everything above `pv_physbase'.
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*/
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addr = base;
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len -= base;
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addr = pv_physbase;
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len -= pv_physbase;
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}
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/* Calculate stretch of pv_table */
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/* Calculate stretch of pv_table[] that needs to be mapped */
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len = sizeof(struct pvlist) * btoc(len);
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va = (vaddr_t)&pv_table[btoc(addr - base)];
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va = (vaddr_t)&pv_table[btoc(addr)];
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sva = trunc_page(va);
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if (sva < eva) {
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@ -2837,7 +2851,7 @@ pmap_bootstrap4_4c(nctx, nregion, nsegment)
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get_phys_mem();
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/* Allocate physical memory for pv_table[] */
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p += pv_table_map((paddr_t)p - KERNBASE, 0);
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p += pv_table_map((paddr_t)p - KERNBASE);
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avail_start = (paddr_t)p - KERNBASE;
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i = (int)p;
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@ -2848,7 +2862,7 @@ pmap_bootstrap4_4c(nctx, nregion, nsegment)
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/* Allocate virtual memory for pv_table[]. */
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pv_table = (struct pvlist *)p;
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p += round_page(sizeof(struct pvlist) * atop(avail_end - avail_start));
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p += round_page(sizeof(struct pvlist) * atop(avail_end));
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virtual_avail = (vaddr_t)p;
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virtual_end = VM_MAX_KERNEL_ADDRESS;
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@ -3152,9 +3166,6 @@ pmap_bootstrap4m(void)
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*/
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get_phys_mem();
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/* Allocate physical memory for pv_table[] */
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p += pv_table_map((paddr_t)(p - KERNBASE), 0);
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/*
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* Reserve memory for MMU pagetables. Some of these have severe
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* alignment restrictions. We allocate in a sequence that
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@ -3198,6 +3209,9 @@ pmap_bootstrap4m(void)
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/* Round to next page and mark end of pre-wired kernel space */
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p = (caddr_t)(((u_int)p + NBPG - 1) & ~PGOFSET);
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pagetables_end = p;
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/* Allocate physical memory for pv_table[] */
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p += pv_table_map((paddr_t)(p - KERNBASE));
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avail_start = (paddr_t)(p - KERNBASE);
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/*
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@ -3275,7 +3289,7 @@ pmap_bootstrap4m(void)
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/* Allocate virtual memory for pv_table[]. */
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pv_table = (struct pvlist *)p;
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p += round_page(sizeof(struct pvlist) * atop(avail_end - avail_start));
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p += round_page(sizeof(struct pvlist) * atop(avail_end));
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virtual_avail = (vaddr_t)p;
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virtual_end = VM_MAX_KERNEL_ADDRESS;
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@ -3552,7 +3566,7 @@ pmap_init()
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panic("pmap_init: CLSIZE!=1");
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/* Map pv_table[] */
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(void)pv_table_map(avail_start, 1);
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(void)pv_table_map(0);
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vm_first_phys = avail_start;
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vm_num_phys = avail_end - avail_start;
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