@@ -422,6 +422,19 @@ config BLK_DEV_PMEM
Most normal users won't need this functionality, and can thus say N
here.
+config BLK_DEV_PMEM_USE_PAGES
+ bool "Enable use of page struct pages with pmem"
+ depends on BLK_DEV_PMEM
+ depends on PERSISTENT_MEMORY_DEPENDENCY
+ select DRIVER_NEEDS_PERSISTENT_MEMORY
+ default y
+ help
+ If a user of PMEM device needs "struct page" associated
+ with its memory, so this memory can be sent to other
+ block devices, or sent on the network, or be DMA transferred
+ to other devices in the system, then you must say "Yes" here.
+ If unsure leave as Yes.
+
config CDROM_PKTCDVD
tristate "Packet writing on CD/DVD media"
depends on !UML
@@ -20,6 +20,7 @@
#include <linux/blkdev.h>
#include <linux/hdreg.h>
#include <linux/init.h>
+#include <linux/memory_hotplug.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
@@ -141,6 +142,24 @@ MODULE_PARM_DESC(map,
static LIST_HEAD(pmem_devices);
+#ifdef CONFIG_BLK_DEV_PMEM_USE_PAGES
+/* pmem->phys_addr and pmem->size need to be set.
+ * Will then set pmem->virt_addr if successful.
+ */
+int pmem_mapmem(struct pmem_device *pmem)
+{
+ return add_persistent_memory(pmem->phys_addr, pmem->size,
+ &pmem->virt_addr);
+}
+
+static void pmem_unmapmem(struct pmem_device *pmem)
+{
+ remove_persistent_memory(pmem->phys_addr, pmem->size);
+}
+
+#define PMEM_ALIGNMEM (1UL << SECTION_SIZE_BITS)
+#else /* !CONFIG_BLK_DEV_PMEM_USE_PAGES */
+
/* pmem->phys_addr and pmem->size need to be set.
* Will then set virt_addr if successful.
*/
@@ -180,6 +199,7 @@ void pmem_unmapmem(struct pmem_device *pmem)
}
#define PMEM_ALIGNMEM PAGE_SIZE
+#endif /* ! CONFIG_BLK_DEV_PMEM_USE_PAGES */
static struct pmem_device *pmem_alloc(phys_addr_t phys_addr, size_t disk_size,
int i)
One of the current shortcomings of the NVDIMM/PMEM support is that this memory does not have a page-struct(s) associated with its memory and therefor cannot be passed to a block-device or network or DMAed in any way through another device in the system. The use of add_persistent_memory() fixes all this. After this patch an FS can do: bdev_direct_access(,&pfn,); page = pfn_to_page(pfn); And use that page for a lock_page(), set_page_dirty(), and/or anything else one might do with a page *. (Note that with brd one can already do this) [pmem-pages-ref-count] pmem will serve it's pages with ref==0. Once an FS does an blkdev_get_XXX(,FMODE_EXCL,), that memory is own by the FS. The FS needs to manage its allocation, just as it already does for its disk blocks. The fs should set page->count = 2, before submission to any Kernel subsystem so when it returns it will never be released to the Kernel's page-allocators. (page_freeze) Signed-off-by: Boaz Harrosh <boaz@plexistor.com> --- drivers/block/Kconfig | 13 +++++++++++++ drivers/block/pmem.c | 20 ++++++++++++++++++++ 2 files changed, 33 insertions(+)