diff options
Diffstat (limited to 'i386/intel/pmap.c')
| -rw-r--r-- | i386/intel/pmap.c | 43 |
1 files changed, 42 insertions, 1 deletions
diff --git a/i386/intel/pmap.c b/i386/intel/pmap.c index 2943d26..a3d9630 100644 --- a/i386/intel/pmap.c +++ b/i386/intel/pmap.c @@ -419,6 +419,12 @@ unsigned int inuse_ptepages_count = 0; /* debugging */ */ pt_entry_t *kernel_page_dir; +/* + * Two slots for temporary physical page mapping, to allow for + * physical-to-physical transfers. + */ +static pmap_mapwindow_t mapwindows[PMAP_NMAPWINDOWS]; + static inline pt_entry_t * pmap_pde(const pmap_t pmap, vm_offset_t addr) { @@ -774,6 +780,12 @@ void pmap_bootstrap(void) } for (; pte < ptable+NPTES; pte++) { + if (va >= kernel_virtual_end - PMAP_NMAPWINDOWS * PAGE_SIZE); + { + pmap_mapwindow_t *win = &mapwindows[atop(va - (kernel_virtual_end - PMAP_NMAPWINDOWS * PAGE_SIZE))]; + win->entry = pte; + win->vaddr = va; + } WRITE_PTE(pte, 0); va += INTEL_PGBYTES; } @@ -884,12 +896,41 @@ void pmap_clear_bootstrap_pagetable(pt_entry_t *base) { } #endif /* MACH_PV_PAGETABLES */ +/* + * Create a temporary mapping for a given physical entry + * + * This can be used to access physical pages which are not mapped 1:1 by + * phystokv(). + */ +pmap_mapwindow_t *pmap_get_mapwindow(pt_entry_t entry) +{ + pmap_mapwindow_t *map; + + /* Find an empty one. */ + for (map = &mapwindows[0]; map < &mapwindows[sizeof (mapwindows) / sizeof (*mapwindows)]; map++) + if (!(*map->entry)) + break; + assert(map < &mapwindows[sizeof (mapwindows) / sizeof (*mapwindows)]); + + WRITE_PTE(map->entry, entry); + return map; +} + +/* + * Destroy a temporary mapping for a physical entry + */ +void pmap_put_mapwindow(pmap_mapwindow_t *map) +{ + WRITE_PTE(map->entry, 0); + PMAP_UPDATE_TLBS(kernel_pmap, map->vaddr, map->vaddr + PAGE_SIZE); +} + void pmap_virtual_space(startp, endp) vm_offset_t *startp; vm_offset_t *endp; { *startp = kernel_virtual_start; - *endp = kernel_virtual_end; + *endp = kernel_virtual_end - PMAP_NMAPWINDOWS * PAGE_SIZE; } /* |