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subr_kmem.c revision 1.3 
      1 /*	$NetBSD: subr_kmem.c,v 1.3 2006/07/03 09:18:35 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 1.3 2006/07/03 09:18:35 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	(ALIGNBYTES + 1)
     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_zalloc: allocate wired memory.
     90  *
     91  * => must not be called from interrupt context.
     92  */
     93 
     94 void *
     95 kmem_zalloc(size_t size, km_flag_t kmflags)
     96 {
     97 	void *p;
     98 
     99 	p = kmem_alloc(size, kmflags);
    100 	if (p != NULL) {
    101 		memset(p, 0, size);
    102 	}
    103 	return p;
    104 }
    105 
    106 /*
    107  * kmem_free: free wired memory allocated by kmem_alloc.
    108  *
    109  * => must not be called from interrupt context.
    110  */
    111 
    112 void
    113 kmem_free(void *p, size_t size)
    114 {
    115 
    116 	vmem_free(kmem_arena, (vmem_addr_t)p, size);
    117 }
    118 
    119 void
    120 kmem_init(void)
    121 {
    122 
    123 	kmem_arena = vmem_create("kmem", 0, 0, KMEM_QUANTUM_SIZE,
    124 	    kmem_backend_alloc, kmem_backend_free, NULL, 0, VM_SLEEP);
    125 }
    126 
    127 size_t
    128 kmem_roundup_size(size_t size)
    129 {
    130 
    131 	return vmem_roundup_size(kmem_arena, size);
    132 }
    133 
    134 /* ---- uvm glue */
    135 
    136 #include <uvm/uvm_extern.h>
    137 
    138 static vmem_addr_t
    139 kmem_backend_alloc(vmem_t *dummy, vmem_size_t size, vmem_size_t *resultsize,
    140     vm_flag_t vmflags)
    141 {
    142 	uvm_flag_t uflags;
    143 
    144 	KASSERT(dummy == NULL);
    145 	KASSERT(size != 0);
    146 	KASSERT((vmflags & (VM_SLEEP|VM_NOSLEEP)) != 0);
    147 	KASSERT((~vmflags & (VM_SLEEP|VM_NOSLEEP)) != 0);
    148 
    149 	if ((vmflags & VM_NOSLEEP) != 0) {
    150 		uflags = UVM_KMF_TRYLOCK | UVM_KMF_NOWAIT;
    151 	} else {
    152 		uflags = UVM_KMF_WAITVA;
    153 	}
    154 	*resultsize = size = round_page(size);
    155 	return (vmem_addr_t)uvm_km_alloc(kernel_map, size, 0,
    156 	    uflags | UVM_KMF_WIRED | UVM_KMF_CANFAIL);
    157 }
    158 
    159 static void
    160 kmem_backend_free(vmem_t *dummy, vmem_addr_t addr, vmem_size_t size)
    161 {
    162 
    163 	KASSERT(dummy == NULL);
    164 	KASSERT(addr != 0);
    165 	KASSERT(size != 0);
    166 	KASSERT(size == round_page(size));
    167 
    168 	uvm_km_free(kernel_map, (vaddr_t)addr, size, UVM_KMF_WIRED);
    169 }
    170