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1976ca32 GKH |
1 | From ae86cbfef3818300f1972e52f67a93211acb0e24 Mon Sep 17 00:00:00 2001 |
2 | From: Dan Williams <dan.j.williams@intel.com> | |
3 | Date: Sat, 24 Nov 2018 10:47:04 -0800 | |
4 | Subject: libnvdimm, pfn: Pad pfn namespaces relative to other regions | |
5 | ||
6 | From: Dan Williams <dan.j.williams@intel.com> | |
7 | ||
8 | commit ae86cbfef3818300f1972e52f67a93211acb0e24 upstream. | |
9 | ||
10 | Commit cfe30b872058 "libnvdimm, pmem: adjust for section collisions with | |
11 | 'System RAM'" enabled Linux to workaround occasions where platform | |
12 | firmware arranges for "System RAM" and "Persistent Memory" to collide | |
13 | within a single section boundary. Unfortunately, as reported in this | |
14 | issue [1], platform firmware can inflict the same collision between | |
15 | persistent memory regions. | |
16 | ||
17 | The approach of interrogating iomem_resource does not work in this | |
18 | case because platform firmware may merge multiple regions into a single | |
19 | iomem_resource range. Instead provide a method to interrogate regions | |
20 | that share the same parent bus. | |
21 | ||
22 | This is a stop-gap until the core-MM can grow support for hotplug on | |
23 | sub-section boundaries. | |
24 | ||
25 | [1]: https://github.com/pmem/ndctl/issues/76 | |
26 | ||
27 | Fixes: cfe30b872058 ("libnvdimm, pmem: adjust for section collisions with...") | |
28 | Cc: <stable@vger.kernel.org> | |
29 | Reported-by: Patrick Geary <patrickg@supermicro.com> | |
30 | Tested-by: Patrick Geary <patrickg@supermicro.com> | |
31 | Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> | |
32 | Signed-off-by: Dan Williams <dan.j.williams@intel.com> | |
33 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
34 | ||
35 | --- | |
36 | drivers/nvdimm/nd-core.h | 2 + | |
37 | drivers/nvdimm/pfn_devs.c | 64 ++++++++++++++++++++++++------------------- | |
38 | drivers/nvdimm/region_devs.c | 41 +++++++++++++++++++++++++++ | |
39 | 3 files changed, 80 insertions(+), 27 deletions(-) | |
40 | ||
41 | --- a/drivers/nvdimm/nd-core.h | |
42 | +++ b/drivers/nvdimm/nd-core.h | |
43 | @@ -112,6 +112,8 @@ resource_size_t nd_pmem_available_dpa(st | |
44 | struct nd_mapping *nd_mapping, resource_size_t *overlap); | |
45 | resource_size_t nd_blk_available_dpa(struct nd_region *nd_region); | |
46 | resource_size_t nd_region_available_dpa(struct nd_region *nd_region); | |
47 | +int nd_region_conflict(struct nd_region *nd_region, resource_size_t start, | |
48 | + resource_size_t size); | |
49 | resource_size_t nvdimm_allocated_dpa(struct nvdimm_drvdata *ndd, | |
50 | struct nd_label_id *label_id); | |
51 | int alias_dpa_busy(struct device *dev, void *data); | |
52 | --- a/drivers/nvdimm/pfn_devs.c | |
53 | +++ b/drivers/nvdimm/pfn_devs.c | |
54 | @@ -590,14 +590,47 @@ static u64 phys_pmem_align_down(struct n | |
55 | ALIGN_DOWN(phys, nd_pfn->align)); | |
56 | } | |
57 | ||
58 | +/* | |
59 | + * Check if pmem collides with 'System RAM', or other regions when | |
60 | + * section aligned. Trim it accordingly. | |
61 | + */ | |
62 | +static void trim_pfn_device(struct nd_pfn *nd_pfn, u32 *start_pad, u32 *end_trunc) | |
63 | +{ | |
64 | + struct nd_namespace_common *ndns = nd_pfn->ndns; | |
65 | + struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev); | |
66 | + struct nd_region *nd_region = to_nd_region(nd_pfn->dev.parent); | |
67 | + const resource_size_t start = nsio->res.start; | |
68 | + const resource_size_t end = start + resource_size(&nsio->res); | |
69 | + resource_size_t adjust, size; | |
70 | + | |
71 | + *start_pad = 0; | |
72 | + *end_trunc = 0; | |
73 | + | |
74 | + adjust = start - PHYS_SECTION_ALIGN_DOWN(start); | |
75 | + size = resource_size(&nsio->res) + adjust; | |
76 | + if (region_intersects(start - adjust, size, IORESOURCE_SYSTEM_RAM, | |
77 | + IORES_DESC_NONE) == REGION_MIXED | |
78 | + || nd_region_conflict(nd_region, start - adjust, size)) | |
79 | + *start_pad = PHYS_SECTION_ALIGN_UP(start) - start; | |
80 | + | |
81 | + /* Now check that end of the range does not collide. */ | |
82 | + adjust = PHYS_SECTION_ALIGN_UP(end) - end; | |
83 | + size = resource_size(&nsio->res) + adjust; | |
84 | + if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM, | |
85 | + IORES_DESC_NONE) == REGION_MIXED | |
86 | + || !IS_ALIGNED(end, nd_pfn->align) | |
87 | + || nd_region_conflict(nd_region, start, size + adjust)) | |
88 | + *end_trunc = end - phys_pmem_align_down(nd_pfn, end); | |
89 | +} | |
90 | + | |
91 | static int nd_pfn_init(struct nd_pfn *nd_pfn) | |
92 | { | |
93 | u32 dax_label_reserve = is_nd_dax(&nd_pfn->dev) ? SZ_128K : 0; | |
94 | struct nd_namespace_common *ndns = nd_pfn->ndns; | |
95 | - u32 start_pad = 0, end_trunc = 0; | |
96 | + struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev); | |
97 | resource_size_t start, size; | |
98 | - struct nd_namespace_io *nsio; | |
99 | struct nd_region *nd_region; | |
100 | + u32 start_pad, end_trunc; | |
101 | struct nd_pfn_sb *pfn_sb; | |
102 | unsigned long npfns; | |
103 | phys_addr_t offset; | |
104 | @@ -629,30 +662,7 @@ static int nd_pfn_init(struct nd_pfn *nd | |
105 | ||
106 | memset(pfn_sb, 0, sizeof(*pfn_sb)); | |
107 | ||
108 | - /* | |
109 | - * Check if pmem collides with 'System RAM' when section aligned and | |
110 | - * trim it accordingly | |
111 | - */ | |
112 | - nsio = to_nd_namespace_io(&ndns->dev); | |
113 | - start = PHYS_SECTION_ALIGN_DOWN(nsio->res.start); | |
114 | - size = resource_size(&nsio->res); | |
115 | - if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM, | |
116 | - IORES_DESC_NONE) == REGION_MIXED) { | |
117 | - start = nsio->res.start; | |
118 | - start_pad = PHYS_SECTION_ALIGN_UP(start) - start; | |
119 | - } | |
120 | - | |
121 | - start = nsio->res.start; | |
122 | - size = PHYS_SECTION_ALIGN_UP(start + size) - start; | |
123 | - if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM, | |
124 | - IORES_DESC_NONE) == REGION_MIXED | |
125 | - || !IS_ALIGNED(start + resource_size(&nsio->res), | |
126 | - nd_pfn->align)) { | |
127 | - size = resource_size(&nsio->res); | |
128 | - end_trunc = start + size - phys_pmem_align_down(nd_pfn, | |
129 | - start + size); | |
130 | - } | |
131 | - | |
132 | + trim_pfn_device(nd_pfn, &start_pad, &end_trunc); | |
133 | if (start_pad + end_trunc) | |
134 | dev_info(&nd_pfn->dev, "%s alignment collision, truncate %d bytes\n", | |
135 | dev_name(&ndns->dev), start_pad + end_trunc); | |
136 | @@ -663,7 +673,7 @@ static int nd_pfn_init(struct nd_pfn *nd | |
137 | * implementation will limit the pfns advertised through | |
138 | * ->direct_access() to those that are included in the memmap. | |
139 | */ | |
140 | - start += start_pad; | |
141 | + start = nsio->res.start + start_pad; | |
142 | size = resource_size(&nsio->res); | |
143 | npfns = PFN_SECTION_ALIGN_UP((size - start_pad - end_trunc - SZ_8K) | |
144 | / PAGE_SIZE); | |
145 | --- a/drivers/nvdimm/region_devs.c | |
146 | +++ b/drivers/nvdimm/region_devs.c | |
147 | @@ -1184,6 +1184,47 @@ int nvdimm_has_cache(struct nd_region *n | |
148 | } | |
149 | EXPORT_SYMBOL_GPL(nvdimm_has_cache); | |
150 | ||
151 | +struct conflict_context { | |
152 | + struct nd_region *nd_region; | |
153 | + resource_size_t start, size; | |
154 | +}; | |
155 | + | |
156 | +static int region_conflict(struct device *dev, void *data) | |
157 | +{ | |
158 | + struct nd_region *nd_region; | |
159 | + struct conflict_context *ctx = data; | |
160 | + resource_size_t res_end, region_end, region_start; | |
161 | + | |
162 | + if (!is_memory(dev)) | |
163 | + return 0; | |
164 | + | |
165 | + nd_region = to_nd_region(dev); | |
166 | + if (nd_region == ctx->nd_region) | |
167 | + return 0; | |
168 | + | |
169 | + res_end = ctx->start + ctx->size; | |
170 | + region_start = nd_region->ndr_start; | |
171 | + region_end = region_start + nd_region->ndr_size; | |
172 | + if (ctx->start >= region_start && ctx->start < region_end) | |
173 | + return -EBUSY; | |
174 | + if (res_end > region_start && res_end <= region_end) | |
175 | + return -EBUSY; | |
176 | + return 0; | |
177 | +} | |
178 | + | |
179 | +int nd_region_conflict(struct nd_region *nd_region, resource_size_t start, | |
180 | + resource_size_t size) | |
181 | +{ | |
182 | + struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev); | |
183 | + struct conflict_context ctx = { | |
184 | + .nd_region = nd_region, | |
185 | + .start = start, | |
186 | + .size = size, | |
187 | + }; | |
188 | + | |
189 | + return device_for_each_child(&nvdimm_bus->dev, &ctx, region_conflict); | |
190 | +} | |
191 | + | |
192 | void __exit nd_region_devs_exit(void) | |
193 | { | |
194 | ida_destroy(®ion_ida); |