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vmalloc.h revision 1.10 
      1 /*	$NetBSD: vmalloc.h,v 1.10 2021/12/19 10:51:24 riastradh Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2013, 2018 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Taylor R. Campbell.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #ifndef _LINUX_VMALLOC_H_
     33 #define _LINUX_VMALLOC_H_
     34 
     35 #include <sys/malloc.h>
     36 
     37 #include <uvm/uvm_extern.h>
     38 
     39 #include <linux/mm.h>
     40 #include <linux/mm_types.h>
     41 #include <linux/overflow.h>
     42 
     43 #include <asm/page.h>
     44 
     45 struct notifier_block;
     46 
     47 /*
     48  * XXX vmalloc and kmalloc both use malloc(9).  If you change this, be
     49  * sure to update kmalloc in <linux/slab.h> and kvfree in <linux/mm.h>.
     50  */
     51 
     52 static inline bool
     53 is_vmalloc_addr(void *addr)
     54 {
     55 	return true;
     56 }
     57 
     58 static inline void *
     59 vmalloc(unsigned long size)
     60 {
     61 	return malloc(size, M_TEMP, M_WAITOK);
     62 }
     63 
     64 static inline void *
     65 vmalloc_user(unsigned long size)
     66 {
     67 	return malloc(size, M_TEMP, (M_WAITOK | M_ZERO));
     68 }
     69 
     70 static inline void *
     71 vzalloc(unsigned long size)
     72 {
     73 	return malloc(size, M_TEMP, (M_WAITOK | M_ZERO));
     74 }
     75 
     76 static inline void
     77 vfree(void *ptr)
     78 {
     79 	if (ptr == NULL)
     80 		return;
     81 	return free(ptr, M_TEMP);
     82 }
     83 
     84 #define	PAGE_KERNEL	UVM_PROT_RW
     85 
     86 /*
     87  * vmap(pages, npages, flags, prot)
     88  *
     89  *	Map pages[0], pages[1], ..., pages[npages-1] into contiguous
     90  *	kernel virtual address space with the specified protection, and
     91  *	return a KVA pointer to the start.
     92  *
     93  *	prot may be a bitwise ior of UVM_PROT_READ/WRITE/EXEC and
     94  *	PMAP_* cache flags accepted by pmap_enter().
     95  */
     96 static inline void *
     97 vmap(struct page **pages, unsigned npages, unsigned long flags,
     98     pgprot_t protflags)
     99 {
    100 	vm_prot_t justprot = protflags & UVM_PROT_ALL;
    101 	vaddr_t va;
    102 	unsigned i;
    103 
    104 	/* Allocate some KVA, or return NULL if we can't.  */
    105 	va = uvm_km_alloc(kernel_map, (vsize_t)npages << PAGE_SHIFT, PAGE_SIZE,
    106 	    UVM_KMF_VAONLY|UVM_KMF_NOWAIT);
    107 	if (va == 0)
    108 		return NULL;
    109 
    110 	/* Ask pmap to map the KVA to the specified page addresses.  */
    111 	for (i = 0; i < npages; i++) {
    112 		pmap_kenter_pa(va + i*PAGE_SIZE, page_to_phys(pages[i]),
    113 		    justprot, protflags);
    114 	}
    115 
    116 	/* Commit the pmap updates.  */
    117 	pmap_update(pmap_kernel());
    118 
    119 	return (void *)va;
    120 }
    121 
    122 /*
    123  * vunmap(ptr, npages)
    124  *
    125  *	Unmap the KVA pages starting at ptr that were mapped by a call
    126  *	to vmap with the same npages parameter.
    127  */
    128 static inline void
    129 vunmap(void *ptr, unsigned npages)
    130 {
    131 	vaddr_t va = (vaddr_t)ptr;
    132 
    133 	/* Ask pmap to unmap the KVA.  */
    134 	pmap_kremove(va, (vsize_t)npages << PAGE_SHIFT);
    135 
    136 	/* Commit the pmap updates.  */
    137 	pmap_update(pmap_kernel());
    138 
    139 	/*
    140 	 * Now that the pmap is no longer mapping the KVA we allocated
    141 	 * on any CPU, it is safe to free the KVA.
    142 	 */
    143 	uvm_km_free(kernel_map, va, (vsize_t)npages << PAGE_SHIFT,
    144 	    UVM_KMF_VAONLY);
    145 }
    146 
    147 static inline int
    148 register_vmap_purge_notifier(struct notifier_block *nb __unused)
    149 {
    150 	return 0;
    151 }
    152 
    153 static inline int
    154 unregister_vmap_purge_notifier(struct notifier_block *nb __unused)
    155 {
    156 	return 0;
    157 }
    158 
    159 #endif  /* _LINUX_VMALLOC_H_ */
    160