0f3da14a4f
Add a seed device concept for dynamic dax regions to be able to split the region amongst multiple sub-instances. The seed device, similar to libnvdimm seed devices, is a device that starts with zero capacity allocated and unbound to a driver. In contrast to libnvdimm seed devices explicit 'create' and 'delete' interfaces are added to the region to trigger seeds to be created and unused devices to be reclaimed. The explicit create and delete replaces implicit create as a side effect of probe and implicit delete when writing 0 to the size that libnvdimm implements. Delete can be performed on any 0-sized and idle device. This avoids the gymnastics of needing to move device_unregister() to its own async context. Specifically, it avoids the deadlock of deleting a device via one of its own attributes. It is also less surprising to userspace which never sees an extra device it did not request. For now just add the device creation, teardown, and ->probe() prevention. A later patch will arrange for the 'dax/size' attribute to be writable to allocate capacity from the region. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Brice Goglin <Brice.Goglin@inria.fr> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jia He <justin.he@arm.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: David Airlie <airlied@linux.ie> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hulk Robot <hulkci@huawei.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Jason Yan <yanaijie@huawei.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: kernel test robot <lkp@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Will Deacon <will@kernel.org> Link: https://lkml.kernel.org/r/159643101583.4062302.12255093902950754962.stgit@dwillia2-desk3.amr.corp.intel.com Link: https://lkml.kernel.org/r/160106113873.30709.15168756050631539431.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
60 lines
1.3 KiB
C
60 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
#include <linux/platform_device.h>
|
|
#include <linux/memregion.h>
|
|
#include <linux/module.h>
|
|
#include <linux/pfn_t.h>
|
|
#include "../bus.h"
|
|
|
|
static int dax_hmem_probe(struct platform_device *pdev)
|
|
{
|
|
struct device *dev = &pdev->dev;
|
|
struct dax_region *dax_region;
|
|
struct memregion_info *mri;
|
|
struct dev_dax_data data;
|
|
struct dev_dax *dev_dax;
|
|
struct resource *res;
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
if (!res)
|
|
return -ENOMEM;
|
|
|
|
mri = dev->platform_data;
|
|
dax_region = alloc_dax_region(dev, pdev->id, res, mri->target_node,
|
|
PMD_SIZE, 0);
|
|
if (!dax_region)
|
|
return -ENOMEM;
|
|
|
|
data = (struct dev_dax_data) {
|
|
.dax_region = dax_region,
|
|
.id = -1,
|
|
.size = resource_size(res),
|
|
};
|
|
dev_dax = devm_create_dev_dax(&data);
|
|
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");
|