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      1 /*	$NetBSD: vmalloc.h,v 1.12 2022/02/26 15:57:22 rillig 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 <uvm/uvm_extern.h>
     36 
     37 #include <linux/mm.h>
     38 #include <linux/mm_types.h>
     39 #include <linux/overflow.h>
     40 #include <linux/slab.h>
     41 
     42 #include <asm/page.h>
     43 
     44 struct notifier_block;
     45 
     46 /*
     47  * XXX vmalloc and kvmalloc both use kmalloc.  If you change that, be
     48  * sure to update this so kvfree in <linux/mm.h> still works on vmalloc
     49  * addresses.
     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 kmalloc(size, GFP_KERNEL);
     62 }
     63 
     64 static inline void *
     65 vmalloc_user(unsigned long size)
     66 {
     67 	return kzalloc(size, GFP_KERNEL);
     68 }
     69 
     70 static inline void *
     71 vzalloc(unsigned long size)
     72 {
     73 	return kzalloc(size, GFP_KERNEL);
     74 }
     75 
     76 static inline void
     77 vfree(void *ptr)
     78 {
     79 	kfree(ptr);
     80 }
     81 
     82 #define	PAGE_KERNEL	UVM_PROT_RW
     83 
     84 /*
     85  * vmap(pages, npages, flags, prot)
     86  *
     87  *	Map pages[0], pages[1], ..., pages[npages-1] into contiguous
     88  *	kernel virtual address space with the specified protection, and
     89  *	return a KVA pointer to the start.
     90  *
     91  *	prot may be a bitwise ior of UVM_PROT_READ/WRITE/EXEC and
     92  *	PMAP_* cache flags accepted by pmap_enter().
     93  */
     94 static inline void *
     95 vmap(struct page **pages, unsigned npages, unsigned long flags,
     96     pgprot_t protflags)
     97 {
     98 	vm_prot_t justprot = protflags & UVM_PROT_ALL;
     99 	vaddr_t va;
    100 	unsigned i;
    101 
    102 	/* Allocate some KVA, or return NULL if we can't.  */
    103 	va = uvm_km_alloc(kernel_map, (vsize_t)npages << PAGE_SHIFT, PAGE_SIZE,
    104 	    UVM_KMF_VAONLY|UVM_KMF_NOWAIT);
    105 	if (va == 0)
    106 		return NULL;
    107 
    108 	/* Ask pmap to map the KVA to the specified page addresses.  */
    109 	for (i = 0; i < npages; i++) {
    110 		pmap_kenter_pa(va + i*PAGE_SIZE, page_to_phys(pages[i]),
    111 		    justprot, protflags);
    112 	}
    113 
    114 	/* Commit the pmap updates.  */
    115 	pmap_update(pmap_kernel());
    116 
    117 	return (void *)va;
    118 }
    119 
    120 /*
    121  * vunmap(ptr, npages)
    122  *
    123  *	Unmap the KVA pages starting at ptr that were mapped by a call
    124  *	to vmap with the same npages parameter.
    125  */
    126 static inline void
    127 vunmap(void *ptr, unsigned npages)
    128 {
    129 	vaddr_t va = (vaddr_t)ptr;
    130 
    131 	/* Ask pmap to unmap the KVA.  */
    132 	pmap_kremove(va, (vsize_t)npages << PAGE_SHIFT);
    133 
    134 	/* Commit the pmap updates.  */
    135 	pmap_update(pmap_kernel());
    136 
    137 	/*
    138 	 * Now that the pmap is no longer mapping the KVA we allocated
    139 	 * on any CPU, it is safe to free the KVA.
    140 	 */
    141 	uvm_km_free(kernel_map, va, (vsize_t)npages << PAGE_SHIFT,
    142 	    UVM_KMF_VAONLY);
    143 }
    144 
    145 static inline int
    146 register_vmap_purge_notifier(struct notifier_block *nb __unused)
    147 {
    148 	return 0;
    149 }
    150 
    151 static inline int
    152 unregister_vmap_purge_notifier(struct notifier_block *nb __unused)
    153 {
    154 	return 0;
    155 }
    156 
    157 #endif  /* _LINUX_VMALLOC_H_ */
    158