* [PATCH 1/2] libnvdimm, pmem: fix 'pfn' support for section-misaligned namespaces
2016-03-01 2:56 [PATCH 0/2] devm_memremap_pages vs section-misaligned pmem Dan Williams
@ 2016-03-01 2:56 ` Dan Williams
2016-03-01 3:16 ` kbuild test robot
2016-03-01 2:56 ` [PATCH 2/2] mm: fix mixed zone detection in devm_memremap_pages Dan Williams
1 sibling, 1 reply; 4+ messages in thread
From: Dan Williams @ 2016-03-01 2:56 UTC (permalink / raw)
To: linux-nvdimm; +Cc: linux-mm, akpm, linux-kernel
The altmap for a section-misaligned namespace needs to arrange for the
base_pfn to be section-aligned. As a result the 'reserve' region (pfns
from base that do not have a struct page) must be increased. Otherwise
we trip the altmap validation check in __add_pages:
if (altmap->base_pfn != phys_start_pfn
|| vmem_altmap_offset(altmap) > nr_pages) {
pr_warn_once("memory add fail, invalid altmap\n");
return -EINVAL;
}
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/nvdimm/pmem.c | 29 +++++++++++++++++++++++++++--
1 file changed, 27 insertions(+), 2 deletions(-)
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index efc2a5e671c6..6a6283ab974c 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -356,6 +356,31 @@ static int nvdimm_namespace_detach_pfn(struct nd_namespace_common *ndns)
return 0;
}
+/*
+ * We hotplug memory at section granularity, pad the reserved area from
+ * the previous section base to the namespace base address.
+ */
+static unsigned long init_altmap_base(resource_size_t base)
+{
+ unsigned long base_pfn = __phys_to_pfn(base);
+
+#ifdef CONFIG_SPARSEMEM
+ base_pfn = SECTION_ALIGN_DOWN(base_pfn);
+#endif
+ return base_pfn;
+}
+
+static unsigned long init_altmap_reserve(resource_size_t base)
+{
+ unsigned long base_pfn = __phys_to_pfn(base);
+ unsigned long reserve = __phys_to_pfn(SZ_8K);
+
+#ifdef CONFIG_SPARSEMEM
+ reserve += base_pfn - SECTION_ALIGN_DOWN(base_pfn);
+#endif
+ return reserve;
+}
+
static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
{
struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
@@ -369,8 +394,8 @@ static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
phys_addr_t offset;
int rc;
struct vmem_altmap __altmap = {
- .base_pfn = __phys_to_pfn(nsio->res.start),
- .reserve = __phys_to_pfn(SZ_8K),
+ .base_pfn = init_altmap_base(nsio->res.start),
+ .reserve = init_altmap_reserve(nsio->res.start),
};
if (!nd_pfn->uuid || !nd_pfn->ndns)
--
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^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 2/2] mm: fix mixed zone detection in devm_memremap_pages
2016-03-01 2:56 [PATCH 0/2] devm_memremap_pages vs section-misaligned pmem Dan Williams
2016-03-01 2:56 ` [PATCH 1/2] libnvdimm, pmem: fix 'pfn' support for section-misaligned namespaces Dan Williams
@ 2016-03-01 2:56 ` Dan Williams
1 sibling, 0 replies; 4+ messages in thread
From: Dan Williams @ 2016-03-01 2:56 UTC (permalink / raw)
To: linux-nvdimm; +Cc: linux-mm, akpm, linux-kernel
The check for whether we overlap "System RAM" needs to be done at
section granularity. For example a system with the following mapping:
100000000-37bffffff : System RAM
37c000000-837ffffff : Persistent Memory
...is unable to use devm_memremap_pages() as it would result in two
zones colliding within a given section.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
kernel/memremap.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/kernel/memremap.c b/kernel/memremap.c
index b981a7b023f0..4c7d08339f62 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -270,9 +270,10 @@ struct dev_pagemap *find_dev_pagemap(resource_size_t phys)
void *devm_memremap_pages(struct device *dev, struct resource *res,
struct percpu_ref *ref, struct vmem_altmap *altmap)
{
- int is_ram = region_intersects(res->start, resource_size(res),
- "System RAM");
- resource_size_t key, align_start, align_size, align_end;
+ resource_size_t align_start = res->start & ~(SECTION_SIZE - 1);
+ resource_size_t align_size = ALIGN(resource_size(res), SECTION_SIZE);
+ int is_ram = region_intersects(align_start, align_size, "System RAM");
+ resource_size_t key, align_end;
struct dev_pagemap *pgmap;
struct page_map *page_map;
unsigned long pfn;
@@ -314,8 +315,6 @@ void *devm_memremap_pages(struct device *dev, struct resource *res,
mutex_lock(&pgmap_lock);
error = 0;
- align_start = res->start & ~(SECTION_SIZE - 1);
- align_size = ALIGN(resource_size(res), SECTION_SIZE);
align_end = align_start + align_size - 1;
for (key = align_start; key <= align_end; key += SECTION_SIZE) {
struct dev_pagemap *dup;
--
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^ permalink raw reply related [flat|nested] 4+ messages in thread