@@ -69,6 +69,7 @@ struct resource {
#define IORESOURCE_UNSET 0x20000000 /* No address assigned yet */
#define IORESOURCE_AUTO 0x40000000
#define IORESOURCE_BUSY 0x80000000 /* Driver has marked this resource busy */
+#define IORESOURCE_DEVICE_BACKED_VMEMMAP 0xa0000000 /* device backed vmemmap resource */
/* I/O resource extended types */
#define IORESOURCE_SYSTEM_RAM (IORESOURCE_MEM|IORESOURCE_SYSRAM)
@@ -17,6 +17,8 @@ struct device;
* @free: free pages set aside in the mapping for memmap storage
* @align: pages reserved to meet allocation alignments
* @alloc: track pages consumed, private to vmemmap_populate()
+ * @parent: the parent resource that altmap region belongs to
+ * @res: altmap region resource
*/
struct vmem_altmap {
unsigned long base_pfn;
@@ -25,6 +27,7 @@ struct vmem_altmap {
unsigned long free;
unsigned long align;
unsigned long alloc;
+ struct resource *parent, *res;
};
/*
@@ -157,7 +157,17 @@ EXPORT_SYMBOL_GPL(memunmap_pages);
static void devm_memremap_pages_release(void *data)
{
- memunmap_pages(data);
+ struct dev_pagemap *pgmap = data;
+
+ if (pgmap->flags & PGMAP_ALTMAP_VALID && pgmap->altmap.res) {
+ resource_size_t start = pgmap->altmap.res->start;
+ resource_size_t size = pgmap->altmap.res->end -
+ pgmap->altmap.res->start + 1;
+
+ __release_region(pgmap->altmap.parent, start, size);
+ }
+
+ memunmap_pages(pgmap);
}
static void dev_pagemap_percpu_release(struct percpu_ref *ref)
@@ -404,11 +414,22 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
{
int error;
void *ret;
+ struct vmem_altmap *altmap = &pgmap->altmap;
ret = memremap_pages(pgmap, dev_to_node(dev));
if (IS_ERR(ret))
return ret;
+ if (pgmap->flags & PGMAP_ALTMAP_VALID && altmap->parent) {
+ unsigned long start = altmap->base_pfn << PAGE_SHIFT;
+ unsigned long size = vmem_altmap_offset(altmap) << PAGE_SHIFT;
+ int flags = IORESOURCE_DEVICE_BACKED_VMEMMAP | IORESOURCE_BUSY;
+
+ altmap->res = __request_region(altmap->parent, start, size,
+ "Device Backed Vmemmap", flags);
+ pr_debug("Insert a separate resource for altmap, %lx-%lx\n",
+ start, start + size);
+ }
error = devm_add_action_or_reset(dev, devm_memremap_pages_release,
pgmap);
if (error)
The elfcorehdr descirbes the dumpable region in PT_LOADs. Generally, an iomem resource registered with flags (IORESOURCE_SYSTEM_RAM | IORESOUCE_BUSY) will be added to PT_LOADs by kexe_file_load(2). An iomem resource with name prefix "System RAM" will be added to PT_LOADs in kexec-tools by calling kexe_load(2). So a simple way to make the altmap dumpable is to register altmap region as a separate resource with the proper name and resource flags. Here naming it as "Device Backed Vmemmap" plus resource flags (IORESOURCE_DEVICE_BACKED_VMEMMAP and IORESOUCE_BUSY) to make it work first. A /proc/iomem example is as following: $ sudo cat /proc/iomem ... fffc0000-ffffffff : Reserved 100000000-13fffffff : Persistent Memory 100000000-10fffffff : namespace0.0 100000000-1005fffff : Device Backed Vmemmap # fsdax a80000000-b7fffffff : CXL Window 0 a80000000-affffffff : Persistent Memory a80000000-affffffff : region1 a80000000-a811fffff : namespace1.0 a80000000-a811fffff : Device Backed Vmemmap # devdax a81200000-abfffffff : dax1.0 b80000000-c7fffffff : CXL Window 1 c80000000-147fffffff : PCI Bus 0000:00 c80000000-c801fffff : PCI Bus 0000:01 ... CC: Andrew Morton <akpm@linux-foundation.org> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> CC: Baoquan He <bhe@redhat.com> CC: Dan Williams <dan.j.williams@intel.com> CC: linux-mm@kvack.org Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> --- include/linux/ioport.h | 1 + include/linux/memremap.h | 3 +++ mm/memremap.c | 23 ++++++++++++++++++++++- 3 files changed, 26 insertions(+), 1 deletion(-)