@@ -927,9 +927,10 @@ int track_pfn_copy(struct vm_area_struct *vma)
}
/*
- * prot is passed in as a parameter for the new mapping. If the vma has a
- * linear pfn mapping for the entire range reserve the entire vma range with
- * single reserve_pfn_range call.
+ * prot is passed in as a parameter for the new mapping. If the vma has
+ * a linear pfn mapping for the entire range, or no vma is provided,
+ * reserve the entire pfn + size range with single reserve_pfn_range
+ * call.
*/
int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
unsigned long pfn, unsigned long addr, unsigned long size)
@@ -938,11 +939,12 @@ int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
enum page_cache_mode pcm;
/* reserve the whole chunk starting from paddr */
- if (addr == vma->vm_start && size == (vma->vm_end - vma->vm_start)) {
+ if (!vma || (addr == vma->vm_start
+ && size == (vma->vm_end - vma->vm_start))) {
int ret;
ret = reserve_pfn_range(paddr, size, prot, 0);
- if (!ret)
+ if (ret == 0 && vma)
vma->vm_flags |= VM_PAT;
return ret;
}
@@ -997,7 +999,7 @@ void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
resource_size_t paddr;
unsigned long prot;
- if (!(vma->vm_flags & VM_PAT))
+ if (vma && !(vma->vm_flags & VM_PAT))
return;
/* free the chunk starting from pfn or the whole chunk */
@@ -1011,7 +1013,8 @@ void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
size = vma->vm_end - vma->vm_start;
}
free_pfn_range(paddr, size);
- vma->vm_flags &= ~VM_PAT;
+ if (vma)
+ vma->vm_flags &= ~VM_PAT;
}
/*
@@ -247,6 +247,7 @@ static void devm_memremap_pages_release(struct device *dev, void *data)
align_start = res->start & ~(SECTION_SIZE - 1);
align_size = ALIGN(resource_size(res), SECTION_SIZE);
arch_remove_memory(align_start, align_size);
+ untrack_pfn(NULL, PHYS_PFN(align_start), align_size);
pgmap_radix_release(res);
dev_WARN_ONCE(dev, pgmap->altmap && pgmap->altmap->alloc,
"%s: failed to free all reserved pages\n", __func__);
@@ -282,6 +283,7 @@ void *devm_memremap_pages(struct device *dev, struct resource *res,
struct percpu_ref *ref, struct vmem_altmap *altmap)
{
resource_size_t key, align_start, align_size, align_end;
+ pgprot_t pgprot = PAGE_KERNEL;
struct dev_pagemap *pgmap;
struct page_map *page_map;
int error, nid, is_ram;
@@ -351,6 +353,11 @@ void *devm_memremap_pages(struct device *dev, struct resource *res,
if (nid < 0)
nid = numa_mem_id();
+ error = track_pfn_remap(NULL, &pgprot, PHYS_PFN(align_start), 0,
+ align_size);
+ if (error)
+ goto err_pfn_remap;
+
error = arch_add_memory(nid, align_start, align_size, true);
if (error)
goto err_add_memory;
@@ -371,6 +378,8 @@ void *devm_memremap_pages(struct device *dev, struct resource *res,
return __va(res->start);
err_add_memory:
+ untrack_pfn(NULL, PHYS_PFN(align_start), align_size);
+ err_pfn_remap:
err_radix:
pgmap_radix_release(res);
devres_free(page_map);
track_pfn_insert() in vmf_insert_pfn_pmd() is marking dax mappings as uncacheable rendering them impractical for application usage. DAX-pte mappings are cached and the goal of establishing DAX-pmd mappings is to attain more performance, not dramatically less (3 orders of magnitude). track_pfn_insert() relies on a previous call to reserve_memtype() to establish the expected page_cache_mode for the range. While memremap() arranges for reserve_memtype() to be called, devm_memremap_pages() does not. So, teach track_pfn_insert() and untrack_pfn() how to handle tracking without a vma, and arrange for devm_memremap_pages() to establish the write-back-cache reservation in the memtype tree. Cc: <stable@vger.kernel.org> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Nilesh Choudhury <nilesh.choudhury@oracle.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Toshi Kani <toshi.kani@hpe.com> Reported-by: Kai Zhang <kai.ka.zhang@oracle.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- arch/x86/mm/pat.c | 17 ++++++++++------- kernel/memremap.c | 9 +++++++++ 2 files changed, 19 insertions(+), 7 deletions(-)