diff options
Diffstat (limited to 'kernel/vm/vmmap.c')
| -rw-r--r-- | kernel/vm/vmmap.c | 556 |
1 files changed, 537 insertions, 19 deletions
diff --git a/kernel/vm/vmmap.c b/kernel/vm/vmmap.c index 0e2dad6..fd99c55 100644 --- a/kernel/vm/vmmap.c +++ b/kernel/vm/vmmap.c @@ -16,6 +16,7 @@ #include "mm/mm.h" #include "mm/mman.h" #include "mm/slab.h" +#include "mm/tlb.h" static slab_allocator_t *vmmap_allocator; static slab_allocator_t *vmarea_allocator; @@ -32,8 +33,27 @@ void vmmap_init(void) */ vmarea_t *vmarea_alloc(void) { - NOT_YET_IMPLEMENTED("VM: vmarea_alloc"); - return NULL; + // NOT_YET_IMPLEMENTED("VM: vmarea_alloc"); + + // Allocate a new vmarea + vmarea_t *new_vmarea = (vmarea_t *)slab_obj_alloc(vmarea_allocator); + if (new_vmarea == NULL) + { + return NULL; + } + + // Initialize the fields of the vmarea + new_vmarea->vma_start = 0; + new_vmarea->vma_end = 0; + new_vmarea->vma_off = 0; + new_vmarea->vma_prot = 0; + new_vmarea->vma_flags = 0; + new_vmarea->vma_obj = NULL; + new_vmarea->vma_obj = NULL; + list_link_init(&new_vmarea->vma_plink); + + // Return the new vmarea + return new_vmarea; } /* @@ -42,7 +62,22 @@ vmarea_t *vmarea_alloc(void) */ void vmarea_free(vmarea_t *vma) { - NOT_YET_IMPLEMENTED("VM: vmarea_free"); + // NOT_YET_IMPLEMENTED("VM: vmarea_free"); + + // Remove the vmarea from any lists it may be on + if (list_link_is_linked(&vma->vma_plink)) + { + list_remove(&vma->vma_plink); + } + + // Put the vma_obj if it exists + if (vma->vma_obj != NULL) + { + mobj_put(&vma->vma_obj); + } + + // Free the vmarea + slab_obj_free(vmarea_allocator, vma); } /* @@ -50,8 +85,20 @@ void vmarea_free(vmarea_t *vma) */ vmmap_t *vmmap_create(void) { - NOT_YET_IMPLEMENTED("VM: vmmap_create"); - return NULL; + // NOT_YET_IMPLEMENTED("VM: vmmap_create"); + + // Allocate a new vmmap + vmmap_t *new_vmmap = (vmmap_t *)slab_obj_alloc(vmmap_allocator); + if (new_vmmap == NULL) + { + return NULL; + } + + // Initialize the fields of the vmmap + list_init(&new_vmmap->vmm_list); + new_vmmap->vmm_proc = curproc; + + return new_vmmap; } /* @@ -60,7 +107,22 @@ vmmap_t *vmmap_create(void) */ void vmmap_destroy(vmmap_t **mapp) { - NOT_YET_IMPLEMENTED("VM: vmmap_destroy"); + // NOT_YET_IMPLEMENTED("VM: vmmap_destroy"); + + vmmap_t *map = *mapp; + + // Iterate through the list of vmareas and free each one + list_iterate(&(map)->vmm_list, vma, vmarea_t, vma_plink) + { + list_remove(&vma->vma_plink); + vmarea_free(vma); + } + + // Free the map + slab_obj_free(vmmap_allocator, map); + + // Set the map to NULL + *mapp = NULL; } /* @@ -70,7 +132,22 @@ void vmmap_destroy(vmmap_t **mapp) */ void vmmap_insert(vmmap_t *map, vmarea_t *new_vma) { - NOT_YET_IMPLEMENTED("VM: vmmap_insert*"); + // NOT_YET_IMPLEMENTED("VM: vmmap_insert*"); + + // iterate over the list of vmareas + list_iterate(&map->vmm_list, vma, vmarea_t, vma_plink) + { + // if the new vmarea is after the current vmarea + if (vma->vma_start > new_vma->vma_end) + { + // insert the new vmarea before the current vmarea + list_insert_before(&vma->vma_plink, &new_vma->vma_plink); + return; + } + } + + // insert this map to the tail + list_insert_tail(&map->vmm_list, &new_vma->vma_plink); } /* @@ -90,7 +167,51 @@ void vmmap_insert(vmmap_t *map, vmarea_t *new_vma) */ ssize_t vmmap_find_range(vmmap_t *map, size_t npages, int dir) { - NOT_YET_IMPLEMENTED("VM: vmmap_find_range"); + // NOT_YET_IMPLEMENTED("VM: vmmap_find_range"); + + // case 1: dir is VMMAP_DIR_LOHI + if (dir == VMMAP_DIR_LOHI) + { + // iterate over the page numbers + size_t vfn = ADDR_TO_PN(USER_MEM_LOW); + while (vfn <= ADDR_TO_PN(USER_MEM_HIGH) - npages) + { + // Lookup the vmarea for this page number + vmarea_t *vma = vmmap_lookup(map, vfn); + + // if the vmarea is NULL, return the page number + if (vma == NULL) + { + return vfn; + } + + // if the vmarea is not NULL, set the page number to the end of the vmarea + vfn = vma->vma_end; + } + } + + // case 2: dir is VMMAP_DIR_HILO + else if (dir == VMMAP_DIR_HILO) + { + // iterate over the page numbers + size_t vfn = ADDR_TO_PN(USER_MEM_HIGH) - npages; + while (vfn >= ADDR_TO_PN(USER_MEM_LOW)) + { + // Lookup the vmarea for this page number + vmarea_t *vma = vmmap_lookup(map, vfn); + + // if the vmarea is NULL, return the page number + if (vma == NULL) + { + return vfn; + } + + // if the vmarea is not NULL, set the page number to the start of the vmarea + vfn = vma->vma_start - npages; + } + } + + // if no range exists, return -1 return -1; } @@ -100,7 +221,19 @@ ssize_t vmmap_find_range(vmmap_t *map, size_t npages, int dir) */ vmarea_t *vmmap_lookup(vmmap_t *map, size_t vfn) { - NOT_YET_IMPLEMENTED("VM: vmmap_lookup"); + // NOT_YET_IMPLEMENTED("VM: vmmap_lookup"); + + // iterate over the list of vmareas + list_iterate(&map->vmm_list, vma, vmarea_t, vma_plink) + { + // if the vfn lies within the range of the current vmarea + if (vfn >= vma->vma_start && vfn < vma->vma_end) + { + return vma; + } + } + + // if the page is unmapped, return NULL return NULL; } @@ -140,8 +273,83 @@ void vmmap_collapse(vmmap_t *map) */ vmmap_t *vmmap_clone(vmmap_t *map) { - NOT_YET_IMPLEMENTED("VM: vmmap_clone"); - return NULL; + // NOT_YET_IMPLEMENTED("VM: vmmap_clone"); + + // Create a new vmmap + vmmap_t *new_vmmap = vmmap_create(); + if (new_vmmap == NULL) + { + return NULL; + } + + // Iterate over the list of vmareas + list_iterate(&map->vmm_list, vma, vmarea_t, vma_plink) + { + // Create a new vmarea + vmarea_t *new_vmarea = vmarea_alloc(); + if (new_vmarea == NULL) + { + vmmap_destroy(&new_vmmap); + return NULL; + } + + // Clone the fields of the vmarea + new_vmarea->vma_start = vma->vma_start; + new_vmarea->vma_end = vma->vma_end; + new_vmarea->vma_off = vma->vma_off; + new_vmarea->vma_prot = vma->vma_prot; + new_vmarea->vma_flags = vma->vma_flags; + + // If the vmarea is share-mapped + if (vma->vma_flags & MAP_SHARED) + { + new_vmarea->vma_obj = vma->vma_obj; + mobj_ref(new_vmarea->vma_obj); + } + + // If the vmarea is not share-mapped + else + { + // Create two shadow objects + mobj_lock(vma->vma_obj); + mobj_t *shadow_obj_map = shadow_create(vma->vma_obj); + mobj_unlock(vma->vma_obj); + + mobj_unlock(shadow_obj_map); // unlock the map before use + if (shadow_obj_map == NULL) + { + vmarea_free(new_vmarea); + vmmap_destroy(&new_vmmap); + return NULL; + } + + mobj_lock(vma->vma_obj); + mobj_t *shadow_obj_new = shadow_create(vma->vma_obj); + mobj_unlock(vma->vma_obj); + + mobj_unlock(shadow_obj_new); // unlock the new before use + if (shadow_obj_new == NULL) + { + mobj_put(&shadow_obj_map); + vmarea_free(new_vmarea); + vmmap_destroy(&new_vmmap); + return NULL; + } + + // Put the original vma_obj + mobj_put(&vma->vma_obj); + + // Insert the shadow objects into their respective vmareas + new_vmarea->vma_obj = shadow_obj_new; + vma->vma_obj = shadow_obj_map; + } + + // Insert the new vmarea into the new vmmap + vmmap_insert(new_vmmap, new_vmarea); + } + + // Return the new vmmap + return new_vmmap; } /* @@ -182,8 +390,98 @@ vmmap_t *vmmap_clone(vmmap_t *map) long vmmap_map(vmmap_t *map, vnode_t *file, size_t lopage, size_t npages, int prot, int flags, off_t off, int dir, vmarea_t **new_vma) { - NOT_YET_IMPLEMENTED("VM: vmmap_map"); - return -1; + // NOT_YET_IMPLEMENTED("VM: vmmap_map"); + + // Create a new vmarea + // see if lopage is 0. if so, use vmmap_find_range() to get a valid range + if (lopage == 0) + { + lopage = vmmap_find_range(map, npages, dir); + if (lopage == -1) + { + return -ENOMEM; + } + } + + // Alloc the new vmarea + vmarea_t *new_vmarea = vmarea_alloc(); + if (new_vmarea == NULL) + { + return -ENOMEM; + } + // Set the fields of the new vmarea + new_vmarea->vma_start = lopage; + new_vmarea->vma_end = lopage + npages; + new_vmarea->vma_off = ADDR_TO_PN(off); + new_vmarea->vma_prot = prot; + new_vmarea->vma_flags = flags; + new_vmarea->vma_vmmap = map; + new_vmarea->vma_obj = NULL; + + // If file is NULL, create an anon object + if (file == NULL) + { + new_vmarea->vma_obj = anon_create(); + mobj_unlock(new_vmarea->vma_obj); // unlock the anon object before use + if (new_vmarea->vma_obj == NULL) + { + vmarea_free(new_vmarea); + return -ENOMEM; + } + } + else + { + // If file is non-NULL, use the vnode's mmap operation to get the mobj + long ret = file->vn_ops->mmap(file, &new_vmarea->vma_obj); + if (ret < 0) + { + // on fail, free the new vmarea and return the error + vmarea_free(new_vmarea); + return ret; + } + } + + // If MAP_PRIVATE is specified, set up a shadow object + if (flags & MAP_PRIVATE) + { + mobj_lock(new_vmarea->vma_obj); + mobj_t *shadow_obj = shadow_create(new_vmarea->vma_obj); + mobj_unlock(new_vmarea->vma_obj); + mobj_unlock(shadow_obj); // unlock the shadow object before use + if (shadow_obj == NULL) + { + vmarea_free(new_vmarea); + return -ENOMEM; + } + new_vmarea->vma_obj = shadow_obj; + } + + // If MAP_FIXED is specified and the given range overlaps with any preexisting mappings, remove the preexisting mappings + if (lopage != 0 && (flags & MAP_FIXED)) + { + long ret = vmmap_remove(map, lopage, npages); + if (ret < 0) + { + vmarea_free(new_vmarea); + // remove/put the shadow/annon object if it exists + if (new_vmarea->vma_obj) + { + mobj_put(&new_vmarea->vma_obj); // FIXME: is this correct! + } + + return ret; + } + } + + // Insert the new vmarea into the map + vmmap_insert(map, new_vmarea); + + // set ret val and return 0 + if (new_vma) + { + *new_vma = new_vmarea; + } + return 0; } /* @@ -219,8 +517,107 @@ long vmmap_map(vmmap_t *map, vnode_t *file, size_t lopage, size_t npages, */ long vmmap_remove(vmmap_t *map, size_t lopage, size_t npages) { - NOT_YET_IMPLEMENTED("VM: vmmap_remove"); - return -1; + // NOT_YET_IMPLEMENTED("VM: vmmap_remove"); + + // Iterate over the list of vmareas + list_iterate(&map->vmm_list, vma, vmarea_t, vma_plink) + { + // if the vmarea is completely inside the region to be unmapped + if (vma->vma_start < lopage && vma->vma_end > lopage + npages) + { + // split the old vmarea into two vmareas + vmarea_t *new_vmarea = vmarea_alloc(); + if (new_vmarea == NULL) + { + return -ENOMEM; + } + + // Set the fields of the new vmarea + new_vmarea->vma_start = lopage + npages; + new_vmarea->vma_end = vma->vma_end; + new_vmarea->vma_off = vma->vma_off + (new_vmarea->vma_start - vma->vma_start); + new_vmarea->vma_prot = vma->vma_prot; + new_vmarea->vma_flags = vma->vma_flags; + new_vmarea->vma_vmmap = map; + new_vmarea->vma_obj = vma->vma_obj; + // increment the refcount of the object associated with the vmarea + mobj_ref(new_vmarea->vma_obj); + + // Shorten the length of the old vmarea + vma->vma_end = lopage; + + // Insert the new vmarea into the map + vmmap_insert(map, new_vmarea); + + // call pt_unmap_range() and tlb_flush_range() to clean the pagetables and TLB + pt_unmap_range( + map->vmm_proc->p_pml4, + PN_TO_ADDR(lopage), + PN_TO_ADDR(lopage + npages) + ); + tlb_flush_range( + map->vmm_proc->p_pml4, + PN_TO_ADDR(lopage + npages) - PN_TO_ADDR(lopage) + ); + } + + // if the region overlaps the end of the vmarea + else if (vma->vma_start < lopage && vma->vma_end > lopage && vma->vma_end <= lopage + npages) + { + // shorten the length of the mapping + vma->vma_end = lopage; + // call pt_unmap_range() and tlb_flush_range() to clean the pagetables and TLB + pt_unmap_range( + map->vmm_proc->p_pml4, + PN_TO_ADDR(lopage), + PN_TO_ADDR(lopage + npages) + ); + tlb_flush_range( + map->vmm_proc->p_pml4, + PN_TO_ADDR(lopage + npages) - PN_TO_ADDR(lopage) + ); + } + + // if the region overlaps the beginning of the vmarea + else if (vma->vma_start >= lopage && vma->vma_end > lopage + npages && vma->vma_start < lopage + npages) + { + // move the beginning of the mapping and shorten its length + vma->vma_off += (lopage + npages - vma->vma_start); + vma->vma_start = lopage + npages; + + // call pt_unmap_range() and tlb_flush_range() to clean the pagetables and TLB + pt_unmap_range( + map->vmm_proc->p_pml4, + PN_TO_ADDR(lopage), + PN_TO_ADDR(lopage + npages) + ); + tlb_flush_range( + map->vmm_proc->p_pml4, + PN_TO_ADDR(lopage + npages) - PN_TO_ADDR(lopage) + ); + } + + // if the region completely contains the vmarea + else if (vma->vma_start >= lopage && vma->vma_end <= lopage + npages) + { + // remove the vmarea from the list + list_remove(&vma->vma_plink); + vmarea_free(vma); + + // call pt_unmap_range() and tlb_flush_range() to clean the pagetables and TLB + pt_unmap_range( + map->vmm_proc->p_pml4, + PN_TO_ADDR(lopage), + PN_TO_ADDR(lopage + npages) + ); + tlb_flush_range( + map->vmm_proc->p_pml4, + PN_TO_ADDR(lopage + npages) - PN_TO_ADDR(lopage) + ); + } + } + + return 0; } /* @@ -229,8 +626,29 @@ long vmmap_remove(vmmap_t *map, size_t lopage, size_t npages) */ long vmmap_is_range_empty(vmmap_t *map, size_t startvfn, size_t npages) { - NOT_YET_IMPLEMENTED("VM: vmmap_is_range_empty"); - return 0; + // NOT_YET_IMPLEMENTED("VM: vmmap_is_range_empty"); + + // Iterate over the list of vmareas + list_iterate(&map->vmm_list, vma, vmarea_t, vma_plink) + { + // if the range completely contains the vmarea + if (vma->vma_start <= startvfn && vma->vma_end >= startvfn + npages) + { + return 0; + } + // if the start of the vmarea is greater than or equal to the start of the range + if (vma->vma_start < startvfn + npages && vma->vma_start >= startvfn) + { + return 0; + } + // check if the end of the vmarea is greater than the start of the range + if (vma->vma_end > startvfn && vma->vma_end <= startvfn + npages) + { + return 0; + } + } + + return 1; } /* @@ -250,7 +668,55 @@ long vmmap_is_range_empty(vmmap_t *map, size_t startvfn, size_t npages) */ long vmmap_read(vmmap_t *map, const void *vaddr, void *buf, size_t count) { - NOT_YET_IMPLEMENTED("VM: vmmap_read"); + // NOT_YET_IMPLEMENTED("VM: vmmap_read"); + + // Iterate over the page numbers + size_t vfn = ADDR_TO_PN(vaddr); + size_t end_vfn = ADDR_TO_PN(vaddr + count); + size_t bytes_read = 0; + while (vfn < end_vfn) + { + // Lookup the vmarea for this page number + vmarea_t *vma = vmmap_lookup(map, vfn); + if (vma == NULL) + { + return -EFAULT; + } + + // Find the pframe for this page number + pframe_t *pf; + mobj_lock(vma->vma_obj); + long ret = mobj_get_pframe(vma->vma_obj, vfn - vma->vma_start + vma->vma_off, 0, &pf); + mobj_unlock(vma->vma_obj); + if (ret < 0) + { + return ret; + } + + // Read from the pframe and copy it into buf + void *cursor = (void *)(bytes_read + vaddr); + size_t bytes_this_iteration = MIN(PAGE_SIZE - PAGE_OFFSET(cursor), count - bytes_read); + memcpy( + buf + bytes_read, + (void *)pf->pf_addr + PAGE_OFFSET(cursor), + bytes_this_iteration + ); + + // Unlock the pframe + pframe_release(&pf); + + // Increment the bytes read + bytes_read += bytes_this_iteration; + + // check if we have read enough + if (bytes_read >= count) + { + return 0; + } + + // Increment the page number + vfn++; + } return 0; } @@ -272,7 +738,59 @@ long vmmap_read(vmmap_t *map, const void *vaddr, void *buf, size_t count) */ long vmmap_write(vmmap_t *map, void *vaddr, const void *buf, size_t count) { - NOT_YET_IMPLEMENTED("VM: vmmap_write"); + // NOT_YET_IMPLEMENTED("VM: vmmap_write"); + + // Iterate over the page numbers + size_t vfn = ADDR_TO_PN(vaddr); + size_t end_vfn = ADDR_TO_PN(vaddr + count); + size_t bytes_written = 0; + while(vfn < end_vfn) + { + // Lookup the vmarea for this page number + vmarea_t *vma = vmmap_lookup(map, vfn); + if (vma == NULL) + { + return -EFAULT; + } + + // Find the pframe for this page number + pframe_t *pf; + mobj_lock(vma->vma_obj); + long ret = mobj_get_pframe(vma->vma_obj, vfn - vma->vma_start + vma->vma_off, 1, &pf); + mobj_unlock(vma->vma_obj); + if (ret < 0) + { + return ret; + } + + // Write to the pframe, copying data from buf + void *cursor = (void *)(bytes_written + vaddr); + size_t bytes_this_iteration = MIN(PAGE_SIZE - PAGE_OFFSET(cursor), count - bytes_written); + memcpy( + (void *)pf->pf_addr + PAGE_OFFSET(cursor), + buf + bytes_written, + bytes_this_iteration + ); + + // Dirty the page + pf->pf_dirty = 1; + + // Unlock the pframe + pframe_release(&pf); + + // Increment the bytes written + bytes_written += bytes_this_iteration; + + // check if we have written enough + if (bytes_written >= count) + { + return 0; + } + + // Increment the page number + vfn++; + } + return 0; } |