merge yamt-km-doc branch.
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@ -1,4 +1,4 @@
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.\" $NetBSD: uvm.9,v 1.61 2005/03/11 19:40:47 rumble Exp $
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.\" $NetBSD: uvm.9,v 1.62 2005/04/01 12:03:26 yamt Exp $
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.\"
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.\" Copyright (c) 1998 Matthew R. Green
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.\" All rights reserved.
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@ -516,142 +516,102 @@ on the memory described in
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.Sh ALLOCATION OF KERNEL MEMORY
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.Ft vaddr_t
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.br
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.Fn uvm_km_alloc "struct vm_map *map" "vsize_t size" ;
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.Fn uvm_km_alloc "struct vm_map *map" "vsize_t size" "vsize_t align" "uvm_flag_t flags";
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.Pp
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.Ft vaddr_t
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.Ft void
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.br
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.Fn uvm_km_zalloc "struct vm_map *map" "vsize_t size" ;
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.Pp
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.Ft vaddr_t
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.br
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.Fn uvm_km_alloc1 "struct vm_map *map" "vsize_t size" "boolean_t zeroit" ;
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.Pp
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.Ft vaddr_t
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.br
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.Fn uvm_km_kmemalloc1 "struct vm_map *map" "struct uvm_object *obj" "vsize_t size" "vsize_t align" "voff_t preferred offset" "int flags" ;
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.Pp
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.Ft vaddr_t
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.br
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.Fn uvm_km_kmemalloc "struct vm_map *map" "struct uvm_object *obj" "vsize_t size" "int flags" ;
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.Pp
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.Ft vaddr_t
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.br
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.Fn uvm_km_valloc "struct vm_map *map" "vsize_t size" ;
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.Pp
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.Ft vaddr_t
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.br
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.Fn uvm_km_valloc_wait "struct vm_map *map" "vsize_t size" ;
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.Fn uvm_km_free "struct vm_map *map" "vaddr_t addr" "vsize_t size" "uvm_flag_t flags";
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.Pp
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.Ft struct vm_map *
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.br
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.Fn uvm_km_suballoc "struct vm_map *map" "vaddr_t *min" "vaddr_t *max " "vsize_t size" "boolean_t pageable" "boolean_t fixed" "struct vm_map *submap" ;
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.Pp
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.Ft void
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.br
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.Fn uvm_km_free "struct vm_map *map" "vaddr_t addr" "vsize_t size" ;
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.Pp
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.Ft void
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.br
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.Fn uvm_km_free_wakeup "struct vm_map *map" "vaddr_t addr" "vsize_t size" ;
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.Pp
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.Fn uvm_km_alloc
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and
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.Fn uvm_km_zalloc
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allocate
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allocates
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.Fa size
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bytes of wired kernel memory in map
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bytes of kernel memory in map
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.Fa map .
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In addition to allocation,
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.Fn uvm_km_zalloc
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zeros the memory.
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Both of these functions are defined as macros in terms of
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.Fn uvm_km_alloc1 ,
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and should almost always be used in preference to
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.Fn uvm_km_alloc1 .
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.Pp
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.Fn uvm_km_alloc1
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allocates and returns
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.Fa size
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bytes of wired memory in the kernel map, zeroing the memory if the
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.Fa zeroit
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argument is non-zero.
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.Pp
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.Fn uvm_km_kmemalloc1
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allocates and returns
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.Fa size
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bytes of wired kernel memory into
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.Fa obj .
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The first address of the allocated memory range will be aligned according to the
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.Fa align
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argument
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.Pq specify 0 if no alignment is necessary .
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The flags can be any of:
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.Bd -literal
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#define UVM_KMF_NOWAIT 0x1 /* matches M_NOWAIT */
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#define UVM_KMF_VALLOC 0x2 /* allocate VA only */
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#define UVM_KMF_CANFAIL 0x4 /* caller handles failure */
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#define UVM_KMF_TRYLOCK UVM_FLAG_TRYLOCK /* try locking only */
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.Ed
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The alignment must be a multiple of page size.
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The
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.Fa flags
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is a bitwise inclusive OR of the allocation type and operation flags.
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.Pp
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The allocation type should be one of:
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.Bl -tag -width UVM_KMF_PAGEABLE
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.It UVM_KMF_WIRED
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Wired memory.
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.It UVM_KMF_PAGEABLE
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Demand-paged zero-filled memory.
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.It UVM_KMF_VAONLY
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Virtuall address only.
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No physical pages are mapped in the allocated region.
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If necessary, it's caller's responsibility to enter page mappings.
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It's also caller's responsibility to clean up the mappings before freeing
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the address range.
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.El
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.Pp
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The following operation flags are available:
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.Bl -tag -width UVM_KMF_PAGEABLE
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.It UVM_KMF_CANFAIL
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Can fail even if
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.Dv UVM_KMF_NOWAIT
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causes
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.Fn uvm_km_kmemalloc1
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to return immediately if no memory is available.
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.Dv UVM_KMF_VALLOC
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causes no physical pages to be allocated, only virtual space.
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.Dv UVM_KMF_TRYLOCK
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causes
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.Fn uvm_km_kmemalloc1
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to use
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.Fn simple_lock_try
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when locking maps.
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.Dv UVM_KMF_CANFAIL
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indicates that
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.Fn uvm_km_kmemalloc1
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can return 0 even if
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.Dv UVM_KMF_NOWAIT
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is not specified.
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is not specified and
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.Dv UVM_KMF_WAITVA
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is specified.
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.It UVM_KMF_ZERO
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Request zero-filled memory.
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Only supported for
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.Dv UVM_KMF_WIRED .
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Shouldn't be used with other types.
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.It UVM_KMF_TRYLOCK
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Fail if we can't lock the map.
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.It UVM_KMF_NOWAIT
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Fail immediately if no memory is available.
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.It UVM_KMF_WAITVA
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Sleep to wait for the virtual address resources if needed.
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.El
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.Pp
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(If neither
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.Dv UVM_KMF_NOWAIT
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nor
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.Dv UVM_KMF_CANFAIL
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are specified,
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.Fn uvm_km_kmemalloc1
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are specified and
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.Dv UVM_KMF_WAITVA
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is specified,
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.Fn uvm_km_alloc
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will never fail, but rather sleep indefinitely until the allocation succeeds.)
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.Pp
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.Fn uvm_km_kmemalloc
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allocates kernel memory like
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.Fn uvm_km_kmemalloc1
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but uses the default values
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.Dv 0
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for the
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.Fa align ,
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and
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.Dv UVM_UNKNOWN_OFFSET
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for the
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.Fa prefer
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arguments.
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.Pp
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.Fn uvm_km_valloc
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and
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.Fn uvm_km_valloc_wait
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return a newly allocated zero-filled address in the kernel map of size
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.Fa size .
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.Fn uvm_km_valloc_wait
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will also wait for kernel memory to become available, if there is a
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memory shortage.
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Pageability of the pages allocated with
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.Dv UVM_KMF_PAGEABLE
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can be changed by
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.Fn uvm_map_pageable .
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In that case, the entire range must be changed atomically.
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Changing a part of the range is not supported.
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.Pp
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.Fn uvm_km_free
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frees the memory range allocated by
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.Fn uvm_km_alloc .
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.Fa addr
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must be an address returned by
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.Fn uvm_km_alloc .
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.Fa map
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and
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.Fn uvm_km_free_wakeup
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free
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.Fa size
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bytes of memory in the kernel map, starting at address
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.Fa addr .
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.Fn uvm_km_free_wakeup
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calls
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.Fn wakeup
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on the map before unlocking the map.
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must be the same as the ones used for the corresponding
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.Fn uvm_km_alloc .
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.Fa flags
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must be the allocation type used for the corresponding
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.Fn uvm_km_alloc .
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.Pp
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.Fn uvm_km_free
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is the only way to free memory ranges allocated by
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.Fn uvm_km_alloc .
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.Fn uvm_unmap
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must not be used.
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.Pp
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.Fn uvm_km_suballoc
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allocates submap from
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