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subr_kmem.c revision 1.1 
      1 /*	$NetBSD: subr_kmem.c,v 1.1 2006/06/25 08:00:01 yamt Exp $	*/
      2 
      3 /*-
      4  * Copyright (c)2006 YAMAMOTO Takashi,
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 /*
     30  * allocator of kernel wired memory.
     31  *
     32  * TODO:
     33  * -	worth to have "intrsafe" version?  maybe..
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 __KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.1 2006/06/25 08:00:01 yamt Exp $");
     38 
     39 #include <sys/param.h>
     40 #include <sys/kmem.h>
     41 #include <sys/vmem.h>
     42 
     43 #include <lib/libkern/libkern.h>
     44 
     45 #define	KMEM_QUANTUM_SIZE	sizeof(void *)	/* XXX */
     46 
     47 static vmem_t *kmem_arena;
     48 
     49 static vmem_addr_t kmem_backend_alloc(vmem_t *, vmem_size_t, vmem_size_t *,
     50     vm_flag_t);
     51 static void kmem_backend_free(vmem_t *, vmem_addr_t, vmem_size_t);
     52 
     53 static inline vm_flag_t
     54 kmf_to_vmf(km_flag_t kmflags)
     55 {
     56 	vm_flag_t vmflags;
     57 
     58 	KASSERT((kmflags & (KM_SLEEP|KM_NOSLEEP)) != 0);
     59 	KASSERT((~kmflags & (KM_SLEEP|KM_NOSLEEP)) != 0);
     60 
     61 	vmflags = 0;
     62 	if ((kmflags & KM_SLEEP) != 0) {
     63 		vmflags |= VM_SLEEP;
     64 	}
     65 	if ((kmflags & KM_NOSLEEP) != 0) {
     66 		vmflags |= VM_NOSLEEP;
     67 	}
     68 
     69 	return vmflags;
     70 }
     71 
     72 /* ---- kmem API */
     73 
     74 /*
     75  * kmem_alloc: allocate wired memory.
     76  *
     77  * => must not be called from interrupt context.
     78  */
     79 
     80 void *
     81 kmem_alloc(size_t size, km_flag_t kmflags)
     82 {
     83 
     84 	return (void *)vmem_alloc(kmem_arena, size,
     85 	    kmf_to_vmf(kmflags) | VM_INSTANTFIT);
     86 }
     87 
     88 /*
     89  * kmem_free: free wired memory allocated by kmem_alloc.
     90  *
     91  * => must not be called from interrupt context.
     92  */
     93 
     94 void
     95 kmem_free(void *p, size_t size)
     96 {
     97 
     98 	vmem_free(kmem_arena, (vmem_addr_t)p, size);
     99 }
    100 
    101 void
    102 kmem_init(void)
    103 {
    104 
    105 	kmem_arena = vmem_create("kmem", 0, 0, KMEM_QUANTUM_SIZE,
    106 	    kmem_backend_alloc, kmem_backend_free, NULL, 0, VM_SLEEP);
    107 }
    108 
    109 size_t
    110 kmem_roundup_size(size_t size)
    111 {
    112 
    113 	return vmem_roundup_size(kmem_arena, size);
    114 }
    115 
    116 /* ---- uvm glue */
    117 
    118 #include <uvm/uvm_extern.h>
    119 
    120 static vmem_addr_t
    121 kmem_backend_alloc(vmem_t *dummy, vmem_size_t size, vmem_size_t *resultsize,
    122     vm_flag_t vmflags)
    123 {
    124 	uvm_flag_t uflags;
    125 
    126 	KASSERT(dummy == NULL);
    127 	KASSERT(size != 0);
    128 	KASSERT((vmflags & (VM_SLEEP|VM_NOSLEEP)) != 0);
    129 	KASSERT((~vmflags & (VM_SLEEP|VM_NOSLEEP)) != 0);
    130 
    131 	if ((vmflags & VM_NOSLEEP) != 0) {
    132 		uflags = UVM_KMF_TRYLOCK | UVM_KMF_NOWAIT;
    133 	} else {
    134 		uflags = UVM_KMF_WAITVA;
    135 	}
    136 	*resultsize = size = round_page(size);
    137 	return (vmem_addr_t)uvm_km_alloc(kernel_map, size, 0,
    138 	    uflags | UVM_KMF_WIRED | UVM_KMF_CANFAIL);
    139 }
    140 
    141 static void
    142 kmem_backend_free(vmem_t *dummy, vmem_addr_t addr, vmem_size_t size)
    143 {
    144 
    145 	KASSERT(dummy == NULL);
    146 	KASSERT(addr != 0);
    147 	KASSERT(size != 0);
    148 	KASSERT(size == round_page(size));
    149 
    150 	uvm_km_free(kernel_map, (vaddr_t)addr, size, UVM_KMF_WIRED);
    151 }
    152