From: Li Zhijian <lizhijian@fujitsu.com>
To: linux-kernel@vger.kernel.org
Cc: y-goto@fujitsu.com, Alison Schofield <alison.schofield@intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
Baoquan He <bhe@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dan Williams <dan.j.williams@intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Dave Jiang <dave.jiang@intel.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
hpa@zytor.com, Ingo Molnar <mingo@redhat.com>,
Ira Weiny <ira.weiny@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Vishal Verma <vishal.l.verma@intel.com>,
linux-cxl@vger.kernel.org, linux-mm@kvack.org,
nvdimm@lists.linux.dev, x86@kernel.org,
kexec@lists.infradead.org, Li Zhijian <lizhijian@fujitsu.com>
Subject: [PATCH v3 1/7] mm: memremap: register/unregister altmap region to a separate resource
Date: Wed, 6 Mar 2024 18:28:40 +0800 [thread overview]
Message-ID: <20240306102846.1020868-2-lizhijian@fujitsu.com> (raw)
In-Reply-To: <20240306102846.1020868-1-lizhijian@fujitsu.com>
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(-)
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index db7fe25f3370..3b59e924f531 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -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)
diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index 744c830f4b13..ca1f12353008 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -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;
};
/*
diff --git a/mm/memremap.c b/mm/memremap.c
index 9e9fb1972fff..78047157b0ee 100644
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -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)
--
2.29.2
next prev parent reply other threads:[~2024-03-06 10:29 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-06 10:28 [RFC PATCH v3 0/7] device backed vmemmap crash dump support Li Zhijian
2024-03-06 10:28 ` Li Zhijian [this message]
2024-03-06 10:28 ` [PATCH v3 2/7] mm: memremap: add pgmap_parent_resource() helper Li Zhijian
2024-03-06 10:28 ` [PATCH v3 3/7] nvdimm: pmem: assign a parent resource for vmemmap region for the fsdax Li Zhijian
2024-03-07 8:07 ` kernel test robot
2024-03-07 11:08 ` kernel test robot
2024-03-06 10:28 ` [PATCH v3 4/7] dax: pmem: assign a parent resource for vmemmap region for the devdax Li Zhijian
2024-03-06 10:28 ` [PATCH v3 5/7] resource: Introduce walk device_backed_vmemmap res() helper Li Zhijian
2024-03-06 10:28 ` [PATCH v3 6/7] x86/crash: make device backed vmemmap dumpable for kexec_file_load Li Zhijian
2024-03-06 10:28 ` [PATCH v3 7/7] nvdimm: set force_raw=1 in kdump kernel Li Zhijian
2024-03-21 5:40 ` [RFC PATCH v3 0/7] device backed vmemmap crash dump support Zhijian Li (Fujitsu)
2024-03-21 6:17 ` Baoquan He
2024-03-21 6:57 ` Zhijian Li (Fujitsu)
2024-04-19 2:05 ` Zhijian Li (Fujitsu)
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