summaryrefslogtreecommitdiffstats
path: root/drivers/nvdimm
diff options
context:
space:
mode:
authorIngo Molnar <mingo@kernel.org>2023-02-23 09:16:39 +0100
committerIngo Molnar <mingo@kernel.org>2023-02-23 09:16:39 +0100
commit585a78c1f77be305b1f6adad392f16047fb66ffd (patch)
tree765143b487d582832c7695c9fbcae141c35baa4c /drivers/nvdimm
parentx86/entry: Fix unwinding from kprobe on PUSH/POP instruction (diff)
parentMerge tag 'platform-drivers-x86-v6.3-1' of git://git.kernel.org/pub/scm/linux... (diff)
downloadlinux-585a78c1f77be305b1f6adad392f16047fb66ffd.tar.xz
linux-585a78c1f77be305b1f6adad392f16047fb66ffd.zip
Merge branch 'linus' into objtool/core, to pick up Xen dependencies
Pick up dependencies - freshly merged upstream via xen-next - before applying dependent objtool changes. Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/nvdimm')
-rw-r--r--drivers/nvdimm/Kconfig19
-rw-r--r--drivers/nvdimm/nd.h2
-rw-r--r--drivers/nvdimm/pfn_devs.c42
3 files changed, 47 insertions, 16 deletions
diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig
index 79d93126453d..77b06d54cc62 100644
--- a/drivers/nvdimm/Kconfig
+++ b/drivers/nvdimm/Kconfig
@@ -102,6 +102,25 @@ config NVDIMM_KEYS
depends on ENCRYPTED_KEYS
depends on (LIBNVDIMM=ENCRYPTED_KEYS) || LIBNVDIMM=m
+config NVDIMM_KMSAN
+ bool
+ depends on KMSAN
+ help
+ KMSAN, and other memory debug facilities, increase the size of
+ 'struct page' to contain extra metadata. This collides with
+ the NVDIMM capability to store a potentially
+ larger-than-"System RAM" size 'struct page' array in a
+ reservation of persistent memory rather than limited /
+ precious DRAM. However, that reservation needs to persist for
+ the life of the given NVDIMM namespace. If you are using KMSAN
+ to debug an issue unrelated to NVDIMMs or DAX then say N to this
+ option. Otherwise, say Y but understand that any namespaces
+ (with the page array stored pmem) created with this build of
+ the kernel will permanently reserve and strand excess
+ capacity compared to the CONFIG_KMSAN=n case.
+
+ Select N if unsure.
+
config NVDIMM_TEST_BUILD
tristate "Build the unit test core"
depends on m
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index 85ca5b4da3cf..ec5219680092 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -652,7 +652,7 @@ void devm_namespace_disable(struct device *dev,
struct nd_namespace_common *ndns);
#if IS_ENABLED(CONFIG_ND_CLAIM)
/* max struct page size independent of kernel config */
-#define MAX_STRUCT_PAGE_SIZE 128
+#define MAX_STRUCT_PAGE_SIZE 64
int nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap);
#else
static inline int nvdimm_setup_pfn(struct nd_pfn *nd_pfn,
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 61af072ac98f..af7d9301520c 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -13,6 +13,8 @@
#include "pfn.h"
#include "nd.h"
+static const bool page_struct_override = IS_ENABLED(CONFIG_NVDIMM_KMSAN);
+
static void nd_pfn_release(struct device *dev)
{
struct nd_region *nd_region = to_nd_region(dev->parent);
@@ -758,12 +760,6 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
return -ENXIO;
}
- /*
- * Note, we use 64 here for the standard size of struct page,
- * debugging options may cause it to be larger in which case the
- * implementation will limit the pfns advertised through
- * ->direct_access() to those that are included in the memmap.
- */
start = nsio->res.start;
size = resource_size(&nsio->res);
npfns = PHYS_PFN(size - SZ_8K);
@@ -782,20 +778,33 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
}
end_trunc = start + size - ALIGN_DOWN(start + size, align);
if (nd_pfn->mode == PFN_MODE_PMEM) {
+ unsigned long page_map_size = MAX_STRUCT_PAGE_SIZE * npfns;
+
/*
* The altmap should be padded out to the block size used
* when populating the vmemmap. This *should* be equal to
* PMD_SIZE for most architectures.
*
- * Also make sure size of struct page is less than 128. We
- * want to make sure we use large enough size here so that
- * we don't have a dynamic reserve space depending on
- * struct page size. But we also want to make sure we notice
- * when we end up adding new elements to struct page.
+ * Also make sure size of struct page is less than
+ * MAX_STRUCT_PAGE_SIZE. The goal here is compatibility in the
+ * face of production kernel configurations that reduce the
+ * 'struct page' size below MAX_STRUCT_PAGE_SIZE. For debug
+ * kernel configurations that increase the 'struct page' size
+ * above MAX_STRUCT_PAGE_SIZE, the page_struct_override allows
+ * for continuing with the capacity that will be wasted when
+ * reverting to a production kernel configuration. Otherwise,
+ * those configurations are blocked by default.
*/
- BUILD_BUG_ON(sizeof(struct page) > MAX_STRUCT_PAGE_SIZE);
- offset = ALIGN(start + SZ_8K + MAX_STRUCT_PAGE_SIZE * npfns, align)
- - start;
+ if (sizeof(struct page) > MAX_STRUCT_PAGE_SIZE) {
+ if (page_struct_override)
+ page_map_size = sizeof(struct page) * npfns;
+ else {
+ dev_err(&nd_pfn->dev,
+ "Memory debug options prevent using pmem for the page map\n");
+ return -EINVAL;
+ }
+ }
+ offset = ALIGN(start + SZ_8K + page_map_size, align) - start;
} else if (nd_pfn->mode == PFN_MODE_RAM)
offset = ALIGN(start + SZ_8K, align) - start;
else
@@ -818,7 +827,10 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
pfn_sb->version_minor = cpu_to_le16(4);
pfn_sb->end_trunc = cpu_to_le32(end_trunc);
pfn_sb->align = cpu_to_le32(nd_pfn->align);
- pfn_sb->page_struct_size = cpu_to_le16(MAX_STRUCT_PAGE_SIZE);
+ if (sizeof(struct page) > MAX_STRUCT_PAGE_SIZE && page_struct_override)
+ pfn_sb->page_struct_size = cpu_to_le16(sizeof(struct page));
+ else
+ pfn_sb->page_struct_size = cpu_to_le16(MAX_STRUCT_PAGE_SIZE);
pfn_sb->page_size = cpu_to_le32(PAGE_SIZE);
checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
pfn_sb->checksum = cpu_to_le64(checksum);