kernel: add header files

include/kernel/vm-region.h

@@ -0,0 +1,146 @@
+#ifndef KERNEL_VM_REGION_H_
+#define KERNEL_VM_REGION_H_
+
+#include <kernel/object.h>
+#include <kernel/pmap.h>
+#include <kernel/vm.h>
+
+#define VM_REGION_NAME_MAX 64
+#define VM_REGION_COPY_ALL ((size_t)-1)
+
+struct vm_region;
+struct vm_object;
+
+enum vm_region_entry_type {
+	VM_REGION_ENTRY_NONE = 0,
+	VM_REGION_ENTRY_REGION,
+	VM_REGION_ENTRY_MAPPING,
+};
+
+struct vm_region_entry {
+	struct btree_node e_node;
+	struct vm_region_entry *e_parent;
+	enum vm_region_entry_type e_type;
+	/* offset in bytes of this entry within its immediate parent. */
+	off_t e_offset;
+	/* size of the entry in bytes */
+	size_t e_size;
+};
+
+struct vm_region_mapping {
+	struct vm_region_entry m_entry;
+	struct vm_object *m_object;
+
+	/* used to link to  vm_object->vo_mappings */
+	struct queue_entry m_object_entry;
+
+	vm_prot_t m_prot;
+	/* offset in bytes to the start of the object data that was mapped */
+	off_t m_object_offset;
+};
+
+struct vm_region {
+	struct object vr_base;
+	struct vm_region_entry vr_entry;
+
+	char vr_name[VM_REGION_NAME_MAX];
+
+	/* btree of struct vm_region_entry.
+	 * sibling entries cannot overlap each other, and child entries must
+	 * be entirely contained within their immediate parent entry. */
+	struct btree vr_entries;
+
+	/* memory protection restriction mask.
+	 * any mapping in this region, or any of its children, cannot use
+	 * protection flags that are not set in this mask.
+	 * for example, if VM_PROT_EXEC is /not/ set here, no mapping
+	 * can be created in this region or any child region with VM_PROT_EXEC
+	 * set. */
+	vm_prot_t vr_prot;
+
+	/* the physical address space in which mappings in this region (and
+	 * its children) are created */
+	pmap_t vr_pmap;
+};
+
+extern kern_status_t vm_region_type_init(void);
+extern struct vm_region *vm_region_cast(struct object *obj);
+
+/* create a new vm-region, optionally within a parent region.
+ * `offset` is the byte offset within the parent region where the new region
+ * should start.
+ * if no parent is specified, `offset` is the absolute virtual address of the
+ * start of the region.
+ * in both cases, `len` is the length of the new region in bytes. */
+extern kern_status_t vm_region_create(
+	struct vm_region *parent,
+	const char *name,
+	size_t name_len,
+	off_t offset,
+	size_t region_len,
+	vm_prot_t prot,
+	struct vm_region **out);
+
+/* map a vm-object into a vm-region.
+ * [region_offset,length] must fall within exactly one region, and cannot span
+ * multiple sibling regions.
+ * if [region_offset,length] falls within a child region, the map operation
+ * will be transparently redirected to the relevant region.
+ * `prot` must be allowed both by the region into which the mapping is being
+ * created AND the vm-object being mapped. */
+extern kern_status_t vm_region_map_object(
+	struct vm_region *region,
+	off_t region_offset,
+	struct vm_object *object,
+	off_t object_offset,
+	size_t length,
+	vm_prot_t prot,
+	virt_addr_t *out);
+
+extern kern_status_t vm_region_unmap(
+	struct vm_region *region,
+	off_t region_offset,
+	size_t length);
+
+extern bool vm_region_validate_access(
+	struct vm_region *region,
+	off_t offset,
+	size_t len,
+	vm_prot_t prot);
+
+/* find the mapping corresponding to the given virtual address, and page-in the
+ * necessary vm_page to allow the memory access to succeed. if the relevant
+ * vm-object page hasn't been allocated yet, it will be allocated here. */
+extern kern_status_t vm_region_demand_map(
+	struct vm_region *region,
+	virt_addr_t addr,
+	enum pmap_fault_flags flags);
+
+/* get the absolute base virtual address of a region within its
+ * parent/ancestors. */
+extern virt_addr_t vm_region_get_base_address(const struct vm_region *region);
+
+extern void vm_region_dump(struct vm_region *region);
+
+extern kern_status_t vm_region_memmove(
+	struct vm_region *dest_region,
+	virt_addr_t dest_ptr,
+	struct vm_region *src_region,
+	virt_addr_t src_ptr,
+	size_t count,
+	size_t *nr_moved);
+
+extern kern_status_t vm_region_memmove_v(
+	struct vm_region *dest_region,
+	size_t dest_offset,
+	struct iovec *dest,
+	size_t nr_dest,
+	struct vm_region *src_region,
+	size_t src_offset,
+	const struct iovec *src,
+	size_t nr_src,
+	size_t bytes_to_move);
+
+DEFINE_OBJECT_LOCK_FUNCTION(vm_region, vr_base)
+
+#endif