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authorDan Williams <dan.j.williams@intel.com>2018-03-29 22:07:13 -0400
committerDan Williams <dan.j.williams@intel.com>2018-05-16 02:08:33 -0400
commit5981690ddb8f72f9546a2d017a914cf56095fc1f (patch)
tree0f7b9d0f919cf9eef997d8905bc79063ec30cc3e
parent6d08b06e67cd117f6992c46611dfb4ce267cd71e (diff)
memremap: split devm_memremap_pages() and memremap() infrastructure
Currently, kernel/memremap.c contains generic code for supporting memremap() (CONFIG_HAS_IOMEM) and devm_memremap_pages() (CONFIG_ZONE_DEVICE). This causes ongoing build maintenance problems as additions to memremap.c, especially for the ZONE_DEVICE case, need to be careful about being placed in ifdef guards. Remove the need for these ifdef guards by moving the ZONE_DEVICE support functions to their own compilation unit. Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat
-rw-r--r--kernel/Makefile3
-rw-r--r--kernel/iomem.c167
-rw-r--r--kernel/memremap.c178
3 files changed, 171 insertions, 177 deletions
diff --git a/kernel/Makefile b/kernel/Makefile
index f85ae5dfa474..9b9241361311 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -112,7 +112,8 @@ obj-$(CONFIG_JUMP_LABEL) += jump_label.o
112obj-$(CONFIG_CONTEXT_TRACKING) += context_tracking.o 112obj-$(CONFIG_CONTEXT_TRACKING) += context_tracking.o
113obj-$(CONFIG_TORTURE_TEST) += torture.o 113obj-$(CONFIG_TORTURE_TEST) += torture.o
114 114
115obj-$(CONFIG_HAS_IOMEM) += memremap.o 115obj-$(CONFIG_HAS_IOMEM) += iomem.o
116obj-$(CONFIG_ZONE_DEVICE) += memremap.o
116 117
117$(obj)/configs.o: $(obj)/config_data.h 118$(obj)/configs.o: $(obj)/config_data.h
118 119
diff --git a/kernel/iomem.c b/kernel/iomem.c
new file mode 100644
index 000000000000..f7525e14ebc6
--- /dev/null
+++ b/kernel/iomem.c
@@ -0,0 +1,167 @@
1/* SPDX-License-Identifier: GPL-2.0 */
2#include <linux/device.h>
3#include <linux/types.h>
4#include <linux/io.h>
5#include <linux/mm.h>
6
7#ifndef ioremap_cache
8/* temporary while we convert existing ioremap_cache users to memremap */
9__weak void __iomem *ioremap_cache(resource_size_t offset, unsigned long size)
10{
11 return ioremap(offset, size);
12}
13#endif
14
15#ifndef arch_memremap_wb
16static void *arch_memremap_wb(resource_size_t offset, unsigned long size)
17{
18 return (__force void *)ioremap_cache(offset, size);
19}
20#endif
21
22#ifndef arch_memremap_can_ram_remap
23static bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size,
24 unsigned long flags)
25{
26 return true;
27}
28#endif
29
30static void *try_ram_remap(resource_size_t offset, size_t size,
31 unsigned long flags)
32{
33 unsigned long pfn = PHYS_PFN(offset);
34
35 /* In the simple case just return the existing linear address */
36 if (pfn_valid(pfn) && !PageHighMem(pfn_to_page(pfn)) &&
37 arch_memremap_can_ram_remap(offset, size, flags))
38 return __va(offset);
39
40 return NULL; /* fallback to arch_memremap_wb */
41}
42
43/**
44 * memremap() - remap an iomem_resource as cacheable memory
45 * @offset: iomem resource start address
46 * @size: size of remap
47 * @flags: any of MEMREMAP_WB, MEMREMAP_WT, MEMREMAP_WC,
48 * MEMREMAP_ENC, MEMREMAP_DEC
49 *
50 * memremap() is "ioremap" for cases where it is known that the resource
51 * being mapped does not have i/o side effects and the __iomem
52 * annotation is not applicable. In the case of multiple flags, the different
53 * mapping types will be attempted in the order listed below until one of
54 * them succeeds.
55 *
56 * MEMREMAP_WB - matches the default mapping for System RAM on
57 * the architecture. This is usually a read-allocate write-back cache.
58 * Morever, if MEMREMAP_WB is specified and the requested remap region is RAM
59 * memremap() will bypass establishing a new mapping and instead return
60 * a pointer into the direct map.
61 *
62 * MEMREMAP_WT - establish a mapping whereby writes either bypass the
63 * cache or are written through to memory and never exist in a
64 * cache-dirty state with respect to program visibility. Attempts to
65 * map System RAM with this mapping type will fail.
66 *
67 * MEMREMAP_WC - establish a writecombine mapping, whereby writes may
68 * be coalesced together (e.g. in the CPU's write buffers), but is otherwise
69 * uncached. Attempts to map System RAM with this mapping type will fail.
70 */
71void *memremap(resource_size_t offset, size_t size, unsigned long flags)
72{
73 int is_ram = region_intersects(offset, size,
74 IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE);
75 void *addr = NULL;
76
77 if (!flags)
78 return NULL;
79
80 if (is_ram == REGION_MIXED) {
81 WARN_ONCE(1, "memremap attempted on mixed range %pa size: %#lx\n",
82 &offset, (unsigned long) size);
83 return NULL;
84 }
85
86 /* Try all mapping types requested until one returns non-NULL */
87 if (flags & MEMREMAP_WB) {
88 /*
89 * MEMREMAP_WB is special in that it can be satisifed
90 * from the direct map. Some archs depend on the
91 * capability of memremap() to autodetect cases where
92 * the requested range is potentially in System RAM.
93 */
94 if (is_ram == REGION_INTERSECTS)
95 addr = try_ram_remap(offset, size, flags);
96 if (!addr)
97 addr = arch_memremap_wb(offset, size);
98 }
99
100 /*
101 * If we don't have a mapping yet and other request flags are
102 * present then we will be attempting to establish a new virtual
103 * address mapping. Enforce that this mapping is not aliasing
104 * System RAM.
105 */
106 if (!addr && is_ram == REGION_INTERSECTS && flags != MEMREMAP_WB) {
107 WARN_ONCE(1, "memremap attempted on ram %pa size: %#lx\n",
108 &offset, (unsigned long) size);
109 return NULL;
110 }
111
112 if (!addr && (flags & MEMREMAP_WT))
113 addr = ioremap_wt(offset, size);
114
115 if (!addr && (flags & MEMREMAP_WC))
116 addr = ioremap_wc(offset, size);
117
118 return addr;
119}
120EXPORT_SYMBOL(memremap);
121
122void memunmap(void *addr)
123{
124 if (is_vmalloc_addr(addr))
125 iounmap((void __iomem *) addr);
126}
127EXPORT_SYMBOL(memunmap);
128
129static void devm_memremap_release(struct device *dev, void *res)
130{
131 memunmap(*(void **)res);
132}
133
134static int devm_memremap_match(struct device *dev, void *res, void *match_data)
135{
136 return *(void **)res == match_data;
137}
138
139void *devm_memremap(struct device *dev, resource_size_t offset,
140 size_t size, unsigned long flags)
141{
142 void **ptr, *addr;
143
144 ptr = devres_alloc_node(devm_memremap_release, sizeof(*ptr), GFP_KERNEL,
145 dev_to_node(dev));
146 if (!ptr)
147 return ERR_PTR(-ENOMEM);
148
149 addr = memremap(offset, size, flags);
150 if (addr) {
151 *ptr = addr;
152 devres_add(dev, ptr);
153 } else {
154 devres_free(ptr);
155 return ERR_PTR(-ENXIO);
156 }
157
158 return addr;
159}
160EXPORT_SYMBOL(devm_memremap);
161
162void devm_memunmap(struct device *dev, void *addr)
163{
164 WARN_ON(devres_release(dev, devm_memremap_release,
165 devm_memremap_match, addr));
166}
167EXPORT_SYMBOL(devm_memunmap);
diff --git a/kernel/memremap.c b/kernel/memremap.c
index 895e6b76b25e..37a9604133f6 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -1,15 +1,5 @@
1/* 1/* SPDX-License-Identifier: GPL-2.0 */
2 * Copyright(c) 2015 Intel Corporation. All rights reserved. 2/* Copyright(c) 2015 Intel Corporation. All rights reserved. */
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of version 2 of the GNU General Public License as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 */
13#include <linux/radix-tree.h> 3#include <linux/radix-tree.h>
14#include <linux/device.h> 4#include <linux/device.h>
15#include <linux/types.h> 5#include <linux/types.h>
@@ -20,169 +10,6 @@
20#include <linux/swap.h> 10#include <linux/swap.h>
21#include <linux/swapops.h> 11#include <linux/swapops.h>
22 12
23#ifndef ioremap_cache
24/* temporary while we convert existing ioremap_cache users to memremap */
25__weak void __iomem *ioremap_cache(resource_size_t offset, unsigned long size)
26{
27 return ioremap(offset, size);
28}
29#endif
30
31#ifndef arch_memremap_wb
32static void *arch_memremap_wb(resource_size_t offset, unsigned long size)
33{
34 return (__force void *)ioremap_cache(offset, size);
35}
36#endif
37
38#ifndef arch_memremap_can_ram_remap
39static bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size,
40 unsigned long flags)
41{
42 return true;
43}
44#endif
45
46static void *try_ram_remap(resource_size_t offset, size_t size,
47 unsigned long flags)
48{
49 unsigned long pfn = PHYS_PFN(offset);
50
51 /* In the simple case just return the existing linear address */
52 if (pfn_valid(pfn) && !PageHighMem(pfn_to_page(pfn)) &&
53 arch_memremap_can_ram_remap(offset, size, flags))
54 return __va(offset);
55
56 return NULL; /* fallback to arch_memremap_wb */
57}
58
59/**
60 * memremap() - remap an iomem_resource as cacheable memory
61 * @offset: iomem resource start address
62 * @size: size of remap
63 * @flags: any of MEMREMAP_WB, MEMREMAP_WT, MEMREMAP_WC,
64 * MEMREMAP_ENC, MEMREMAP_DEC
65 *
66 * memremap() is "ioremap" for cases where it is known that the resource
67 * being mapped does not have i/o side effects and the __iomem
68 * annotation is not applicable. In the case of multiple flags, the different
69 * mapping types will be attempted in the order listed below until one of
70 * them succeeds.
71 *
72 * MEMREMAP_WB - matches the default mapping for System RAM on
73 * the architecture. This is usually a read-allocate write-back cache.
74 * Morever, if MEMREMAP_WB is specified and the requested remap region is RAM
75 * memremap() will bypass establishing a new mapping and instead return
76 * a pointer into the direct map.
77 *
78 * MEMREMAP_WT - establish a mapping whereby writes either bypass the
79 * cache or are written through to memory and never exist in a
80 * cache-dirty state with respect to program visibility. Attempts to
81 * map System RAM with this mapping type will fail.
82 *
83 * MEMREMAP_WC - establish a writecombine mapping, whereby writes may
84 * be coalesced together (e.g. in the CPU's write buffers), but is otherwise
85 * uncached. Attempts to map System RAM with this mapping type will fail.
86 */
87void *memremap(resource_size_t offset, size_t size, unsigned long flags)
88{
89 int is_ram = region_intersects(offset, size,
90 IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE);
91 void *addr = NULL;
92
93 if (!flags)
94 return NULL;
95
96 if (is_ram == REGION_MIXED) {
97 WARN_ONCE(1, "memremap attempted on mixed range %pa size: %#lx\n",
98 &offset, (unsigned long) size);
99 return NULL;
100 }
101
102 /* Try all mapping types requested until one returns non-NULL */
103 if (flags & MEMREMAP_WB) {
104 /*
105 * MEMREMAP_WB is special in that it can be satisifed
106 * from the direct map. Some archs depend on the
107 * capability of memremap() to autodetect cases where
108 * the requested range is potentially in System RAM.
109 */
110 if (is_ram == REGION_INTERSECTS)
111 addr = try_ram_remap(offset, size, flags);
112 if (!addr)
113 addr = arch_memremap_wb(offset, size);
114 }
115
116 /*
117 * If we don't have a mapping yet and other request flags are
118 * present then we will be attempting to establish a new virtual
119 * address mapping. Enforce that this mapping is not aliasing
120 * System RAM.
121 */
122 if (!addr && is_ram == REGION_INTERSECTS && flags != MEMREMAP_WB) {
123 WARN_ONCE(1, "memremap attempted on ram %pa size: %#lx\n",
124 &offset, (unsigned long) size);
125 return NULL;
126 }
127
128 if (!addr && (flags & MEMREMAP_WT))
129 addr = ioremap_wt(offset, size);
130
131 if (!addr && (flags & MEMREMAP_WC))
132 addr = ioremap_wc(offset, size);
133
134 return addr;
135}
136EXPORT_SYMBOL(memremap);
137
138void memunmap(void *addr)
139{
140 if (is_vmalloc_addr(addr))
141 iounmap((void __iomem *) addr);
142}
143EXPORT_SYMBOL(memunmap);
144
145static void devm_memremap_release(struct device *dev, void *res)
146{
147 memunmap(*(void **)res);
148}
149
150static int devm_memremap_match(struct device *dev, void *res, void *match_data)
151{
152 return *(void **)res == match_data;
153}
154
155void *devm_memremap(struct device *dev, resource_size_t offset,
156 size_t size, unsigned long flags)
157{
158 void **ptr, *addr;
159
160 ptr = devres_alloc_node(devm_memremap_release, sizeof(*ptr), GFP_KERNEL,
161 dev_to_node(dev));
162 if (!ptr)
163 return ERR_PTR(-ENOMEM);
164
165 addr = memremap(offset, size, flags);
166 if (addr) {
167 *ptr = addr;
168 devres_add(dev, ptr);
169 } else {
170 devres_free(ptr);
171 return ERR_PTR(-ENXIO);
172 }
173
174 return addr;
175}
176EXPORT_SYMBOL(devm_memremap);
177
178void devm_memunmap(struct device *dev, void *addr)
179{
180 WARN_ON(devres_release(dev, devm_memremap_release,
181 devm_memremap_match, addr));
182}
183EXPORT_SYMBOL(devm_memunmap);
184
185#ifdef CONFIG_ZONE_DEVICE
186static DEFINE_MUTEX(pgmap_lock); 13static DEFINE_MUTEX(pgmap_lock);
187static RADIX_TREE(pgmap_radix, GFP_KERNEL); 14static RADIX_TREE(pgmap_radix, GFP_KERNEL);
188#define SECTION_MASK ~((1UL << PA_SECTION_SHIFT) - 1) 15#define SECTION_MASK ~((1UL << PA_SECTION_SHIFT) - 1)
@@ -473,7 +300,6 @@ struct dev_pagemap *get_dev_pagemap(unsigned long pfn,
473 300
474 return pgmap; 301 return pgmap;
475} 302}
476#endif /* CONFIG_ZONE_DEVICE */
477 303
478#if IS_ENABLED(CONFIG_DEVICE_PRIVATE) || IS_ENABLED(CONFIG_DEVICE_PUBLIC) 304#if IS_ENABLED(CONFIG_DEVICE_PRIVATE) || IS_ENABLED(CONFIG_DEVICE_PUBLIC)
479void put_zone_device_private_or_public_page(struct page *page) 305void put_zone_device_private_or_public_page(struct page *page)
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