linux/drivers/xen/unpopulated-alloc.c
Dan Williams b7b3c01b19 mm/memremap_pages: support multiple ranges per invocation
In support of device-dax growing the ability to front physically
dis-contiguous ranges of memory, update devm_memremap_pages() to track
multiple ranges with a single reference counter and devm instance.

Convert all [devm_]memremap_pages() users to specify the number of ranges
they are mapping in their 'struct dev_pagemap' instance.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: "Jérôme Glisse" <jglisse@redhat.co
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brice Goglin <Brice.Goglin@inria.fr>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
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: Jia He <justin.he@arm.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
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: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lkml.kernel.org/r/159643103789.4062302.18426128170217903785.stgit@dwillia2-desk3.amr.corp.intel.com
Link: https://lkml.kernel.org/r/160106116293.30709.13350662794915396198.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:28 -07:00

201 lines
4.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/errno.h>
#include <linux/gfp.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/memremap.h>
#include <linux/slab.h>
#include <asm/page.h>
#include <xen/page.h>
#include <xen/xen.h>
static DEFINE_MUTEX(list_lock);
static LIST_HEAD(page_list);
static unsigned int list_count;
static int fill_list(unsigned int nr_pages)
{
struct dev_pagemap *pgmap;
struct resource *res;
void *vaddr;
unsigned int i, alloc_pages = round_up(nr_pages, PAGES_PER_SECTION);
int ret = -ENOMEM;
res = kzalloc(sizeof(*res), GFP_KERNEL);
if (!res)
return -ENOMEM;
pgmap = kzalloc(sizeof(*pgmap), GFP_KERNEL);
if (!pgmap)
goto err_pgmap;
pgmap->type = MEMORY_DEVICE_GENERIC;
res->name = "Xen scratch";
res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
ret = allocate_resource(&iomem_resource, res,
alloc_pages * PAGE_SIZE, 0, -1,
PAGES_PER_SECTION * PAGE_SIZE, NULL, NULL);
if (ret < 0) {
pr_err("Cannot allocate new IOMEM resource\n");
goto err_resource;
}
pgmap->range = (struct range) {
.start = res->start,
.end = res->end,
};
pgmap->nr_range = 1;
pgmap->owner = res;
#ifdef CONFIG_XEN_HAVE_PVMMU
/*
* memremap will build page tables for the new memory so
* the p2m must contain invalid entries so the correct
* non-present PTEs will be written.
*
* If a failure occurs, the original (identity) p2m entries
* are not restored since this region is now known not to
* conflict with any devices.
*/
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
xen_pfn_t pfn = PFN_DOWN(res->start);
for (i = 0; i < alloc_pages; i++) {
if (!set_phys_to_machine(pfn + i, INVALID_P2M_ENTRY)) {
pr_warn("set_phys_to_machine() failed, no memory added\n");
ret = -ENOMEM;
goto err_memremap;
}
}
}
#endif
vaddr = memremap_pages(pgmap, NUMA_NO_NODE);
if (IS_ERR(vaddr)) {
pr_err("Cannot remap memory range\n");
ret = PTR_ERR(vaddr);
goto err_memremap;
}
for (i = 0; i < alloc_pages; i++) {
struct page *pg = virt_to_page(vaddr + PAGE_SIZE * i);
BUG_ON(!virt_addr_valid(vaddr + PAGE_SIZE * i));
list_add(&pg->lru, &page_list);
list_count++;
}
return 0;
err_memremap:
release_resource(res);
err_resource:
kfree(pgmap);
err_pgmap:
kfree(res);
return ret;
}
/**
* xen_alloc_unpopulated_pages - alloc unpopulated pages
* @nr_pages: Number of pages
* @pages: pages returned
* @return 0 on success, error otherwise
*/
int xen_alloc_unpopulated_pages(unsigned int nr_pages, struct page **pages)
{
unsigned int i;
int ret = 0;
mutex_lock(&list_lock);
if (list_count < nr_pages) {
ret = fill_list(nr_pages - list_count);
if (ret)
goto out;
}
for (i = 0; i < nr_pages; i++) {
struct page *pg = list_first_entry_or_null(&page_list,
struct page,
lru);
BUG_ON(!pg);
list_del(&pg->lru);
list_count--;
pages[i] = pg;
#ifdef CONFIG_XEN_HAVE_PVMMU
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
ret = xen_alloc_p2m_entry(page_to_pfn(pg));
if (ret < 0) {
unsigned int j;
for (j = 0; j <= i; j++) {
list_add(&pages[j]->lru, &page_list);
list_count++;
}
goto out;
}
}
#endif
}
out:
mutex_unlock(&list_lock);
return ret;
}
EXPORT_SYMBOL(xen_alloc_unpopulated_pages);
/**
* xen_free_unpopulated_pages - return unpopulated pages
* @nr_pages: Number of pages
* @pages: pages to return
*/
void xen_free_unpopulated_pages(unsigned int nr_pages, struct page **pages)
{
unsigned int i;
mutex_lock(&list_lock);
for (i = 0; i < nr_pages; i++) {
list_add(&pages[i]->lru, &page_list);
list_count++;
}
mutex_unlock(&list_lock);
}
EXPORT_SYMBOL(xen_free_unpopulated_pages);
#ifdef CONFIG_XEN_PV
static int __init init(void)
{
unsigned int i;
if (!xen_domain())
return -ENODEV;
if (!xen_pv_domain())
return 0;
/*
* Initialize with pages from the extra memory regions (see
* arch/x86/xen/setup.c).
*/
for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
unsigned int j;
for (j = 0; j < xen_extra_mem[i].n_pfns; j++) {
struct page *pg =
pfn_to_page(xen_extra_mem[i].start_pfn + j);
list_add(&pg->lru, &page_list);
list_count++;
}
}
return 0;
}
subsys_initcall(init);
#endif