From: Dan Williams <dan.j.williams@intel.com>
To: linux-kernel@vger.kernel.org
Cc: x86@kernel.org, kbuild test robot <lkp@intel.com>,
ard.biesheuvel@linaro.org, peterz@infradead.org,
dave.hansen@linux.intel.com, linux-nvdimm@lists.01.org,
linux-efi@vger.kernel.org
Subject: [PATCH v3 08/10] device-dax: Add a driver for "hmem" devices
Date: Fri, 07 Jun 2019 12:27:55 -0700 [thread overview]
Message-ID: <155993567538.3036719.16306480832003017141.stgit@dwillia2-desk3.amr.corp.intel.com> (raw)
In-Reply-To: <155993563277.3036719.17400338098057706494.stgit@dwillia2-desk3.amr.corp.intel.com>
Platform firmware like EFI/ACPI may publish "hmem" platform devices.
Such a device is a performance differentiated memory range likely
reserved for an application specific use case. The driver gives access
to 100% of the capacity via a device-dax mmap instance by default.
However, if over-subscription and other kernel memory management is
desired the resulting dax device can be assigned to the core-mm via the
kmem driver.
This consumes "hmem" devices the producer of "hmem" devices is saved for
a follow-on patch so that it can reference the new CONFIG_DEV_DAX_HMEM
symbol to gate performing the enumeration work.
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/dax/Kconfig | 27 +++++++++++++++++----
drivers/dax/Makefile | 2 ++
drivers/dax/hmem.c | 58 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/memregion.h | 3 ++
4 files changed, 85 insertions(+), 5 deletions(-)
create mode 100644 drivers/dax/hmem.c
diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig
index f33c73e4af41..1a59ef86f148 100644
--- a/drivers/dax/Kconfig
+++ b/drivers/dax/Kconfig
@@ -32,19 +32,36 @@ config DEV_DAX_PMEM
Say M if unsure
+config DEV_DAX_HMEM
+ tristate "HMEM DAX: direct access to 'specific purpose' memory"
+ depends on EFI_APPLICATION_RESERVED
+ default DEV_DAX
+ help
+ EFI 2.8 platforms, and others, may advertise 'specific purpose'
+ memory. For example, a high bandwidth memory pool. The
+ indication from platform firmware is meant to reserve the
+ memory from typical usage by default. This driver creates
+ device-dax instances for these memory ranges, and that also
+ enables the possibility to assign them to the DEV_DAX_KMEM
+ driver to override the reservation and add them to kernel
+ "System RAM" pool.
+
+ Say M if unsure.
+
config DEV_DAX_KMEM
tristate "KMEM DAX: volatile-use of persistent memory"
default DEV_DAX
depends on DEV_DAX
depends on MEMORY_HOTPLUG # for add_memory() and friends
help
- Support access to persistent memory as if it were RAM. This
- allows easier use of persistent memory by unmodified
- applications.
+ Support access to persistent, or other performance
+ differentiated memory as if it were System RAM. This allows
+ easier use of persistent memory by unmodified applications, or
+ adds core kernel memory services to heterogeneous memory types
+ (HMEM) marked "reserved" by platform firmware.
To use this feature, a DAX device must be unbound from the
- device_dax driver (PMEM DAX) and bound to this kmem driver
- on each boot.
+ device_dax driver and bound to this kmem driver on each boot.
Say N if unsure.
diff --git a/drivers/dax/Makefile b/drivers/dax/Makefile
index 81f7d54dadfb..80065b38b3c4 100644
--- a/drivers/dax/Makefile
+++ b/drivers/dax/Makefile
@@ -2,9 +2,11 @@
obj-$(CONFIG_DAX) += dax.o
obj-$(CONFIG_DEV_DAX) += device_dax.o
obj-$(CONFIG_DEV_DAX_KMEM) += kmem.o
+obj-$(CONFIG_DEV_DAX_HMEM) += dax_hmem.o
dax-y := super.o
dax-y += bus.o
device_dax-y := device.o
+dax_hmem-y := hmem.o
obj-y += pmem/
diff --git a/drivers/dax/hmem.c b/drivers/dax/hmem.c
new file mode 100644
index 000000000000..741f2c222271
--- /dev/null
+++ b/drivers/dax/hmem.c
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/platform_device.h>
+#include <linux/memregion.h>
+#include <linux/memremap.h>
+#include <linux/module.h>
+#include <linux/pfn_t.h>
+#include "bus.h"
+
+static int dax_hmem_probe(struct platform_device *pdev)
+{
+ struct dev_pagemap pgmap = { NULL };
+ struct device *dev = &pdev->dev;
+ struct dax_region *dax_region;
+ struct memregion_info *mri;
+ struct dev_dax *dev_dax;
+ struct resource *res;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENOMEM;
+
+ mri = dev->platform_data;
+ pgmap.dev = dev;
+ memcpy(&pgmap.res, res, sizeof(*res));
+
+ dax_region = alloc_dax_region(dev, pdev->id, res, mri->target_node,
+ PMD_SIZE, PFN_DEV|PFN_MAP);
+ if (!dax_region)
+ return -ENOMEM;
+
+ dev_dax = devm_create_dev_dax(dax_region, 0, &pgmap);
+ if (IS_ERR(dev_dax))
+ return PTR_ERR(dev_dax);
+
+ /* child dev_dax instances now own the lifetime of the dax_region */
+ dax_region_put(dax_region);
+ return 0;
+}
+
+static int dax_hmem_remove(struct platform_device *pdev)
+{
+ /* devm handles teardown */
+ return 0;
+}
+
+static struct platform_driver dax_hmem_driver = {
+ .probe = dax_hmem_probe,
+ .remove = dax_hmem_remove,
+ .driver = {
+ .name = "hmem",
+ },
+};
+
+module_platform_driver(dax_hmem_driver);
+
+MODULE_ALIAS("platform:hmem*");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Intel Corporation");
diff --git a/include/linux/memregion.h b/include/linux/memregion.h
index ba03c70f98d2..920fb300a98b 100644
--- a/include/linux/memregion.h
+++ b/include/linux/memregion.h
@@ -3,6 +3,9 @@
#define _MEMREGION_H_
#include <linux/types.h>
+struct memregion_info {
+ int target_node;
+};
int memregion_alloc(gfp_t gfp);
void memregion_free(int id);
#endif /* _MEMREGION_H_ */
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
next prev parent reply other threads:[~2019-06-07 19:42 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-07 19:27 [PATCH v3 00/10] EFI Specific Purpose Memory Support Dan Williams
2019-06-07 19:27 ` [PATCH v3 01/10] acpi/numa: Establish a new drivers/acpi/numa/ directory Dan Williams
2019-06-10 11:02 ` Rafael J. Wysocki
2019-06-07 19:27 ` [PATCH v3 02/10] acpi/numa/hmat: Skip publishing target info for nodes with no online memory Dan Williams
2019-06-07 19:27 ` [PATCH v3 03/10] efi: Enumerate EFI_MEMORY_SP Dan Williams
2019-06-07 19:53 ` Dave Hansen
2019-06-07 20:03 ` Dan Williams
2019-06-07 21:12 ` Dave Hansen
2019-06-07 22:07 ` Dan Williams
2019-06-07 19:27 ` [PATCH v3 04/10] x86, efi: Push EFI_MEMMAP check into leaf routines Dan Williams
2019-06-07 19:27 ` [PATCH v3 05/10] x86, efi: Reserve UEFI 2.8 Specific Purpose Memory for dax Dan Williams
2019-06-07 19:27 ` [PATCH v3 06/10] x86, efi: Add efi_fake_mem support for EFI_MEMORY_SP Dan Williams
2019-06-07 19:27 ` [PATCH v3 07/10] lib/memregion: Uplevel the pmem "region" ida to a global allocator Dan Williams
2019-06-07 20:23 ` Matthew Wilcox
2019-06-21 20:35 ` Dan Williams
2019-08-27 5:48 ` Dan Williams
2019-06-07 19:27 ` Dan Williams [this message]
2019-06-07 19:54 ` [PATCH v3 08/10] device-dax: Add a driver for "hmem" devices Dave Hansen
2019-06-07 20:07 ` Dan Williams
2019-06-07 19:28 ` [PATCH v3 09/10] acpi/numa/hmat: Register HMAT at device_initcall level Dan Williams
2019-06-07 19:28 ` [PATCH v3 10/10] acpi/numa/hmat: Register "specific purpose" memory as an "hmem" device Dan Williams
2019-06-07 19:57 ` [PATCH v3 00/10] EFI Specific Purpose Memory Support Dave Hansen
2019-06-07 20:37 ` Dan Williams
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=155993567538.3036719.16306480832003017141.stgit@dwillia2-desk3.amr.corp.intel.com \
--to=dan.j.williams@intel.com \
--cc=ard.biesheuvel@linaro.org \
--cc=dave.hansen@linux.intel.com \
--cc=linux-efi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nvdimm@lists.01.org \
--cc=lkp@intel.com \
--cc=peterz@infradead.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).