@@ -1063,7 +1063,8 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
if (pmd_none(READ_ONCE(*pmdp))) {
void *p = NULL;
- p = vmemmap_alloc_block_buf(PMD_SIZE, node);
+ p = vmemmap_alloc_block_buf(PMD_SIZE, node,
+ NULL, false);
if (!p)
return -ENOMEM;
@@ -226,12 +226,12 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
* fall back to system memory if the altmap allocation fail.
*/
if (altmap && !altmap_cross_boundary(altmap, start, page_size)) {
- p = altmap_alloc_block_buf(page_size, altmap);
- if (!p)
- pr_debug("altmap block allocation failed, falling back to system memory");
+ p = vmemmap_alloc_block_buf(page_size, node,
+ altmap, true);
+ } else {
+ p = vmemmap_alloc_block_buf(page_size, node,
+ NULL, false);
}
- if (!p)
- p = vmemmap_alloc_block_buf(page_size, node);
if (!p)
return -ENOMEM;
@@ -1444,10 +1444,8 @@ static int __meminit vmemmap_populate_hugepages(unsigned long start,
if (pmd_none(*pmd)) {
void *p;
- if (altmap)
- p = altmap_alloc_block_buf(PMD_SIZE, altmap);
- else
- p = vmemmap_alloc_block_buf(PMD_SIZE, node);
+ p = vmemmap_alloc_block_buf(PMD_SIZE, node,
+ altmap, false);
if (p) {
pte_t entry;
@@ -2991,7 +2991,8 @@ pte_t *vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node,
struct vmem_altmap *altmap);
void *vmemmap_alloc_block(unsigned long size, int node);
struct vmem_altmap;
-void *vmemmap_alloc_block_buf(unsigned long size, int node);
+void *vmemmap_alloc_block_buf(unsigned long size, int node,
+ struct vmem_altmap *altmap, bool sysram_fallback);
void *altmap_alloc_block_buf(unsigned long size, struct vmem_altmap *altmap);
void vmemmap_verify(pte_t *, int, unsigned long, unsigned long);
int vmemmap_populate_basepages(unsigned long start, unsigned long end,
@@ -71,10 +71,31 @@ void * __meminit vmemmap_alloc_block(unsigned long size, int node)
}
/* need to make sure size is all the same during early stage */
-void * __meminit vmemmap_alloc_block_buf(unsigned long size, int node)
+void * __meminit vmemmap_alloc_block_buf(unsigned long size, int node,
+ struct vmem_altmap *altmap,
+ bool sysram_fallback)
{
- void *ptr = sparse_buffer_alloc(size);
+ void *ptr;
+ /*
+ * There is no point in asking for sysram fallback
+ * without an altmap request to begin with. So just
+ * warn here to catch potential call sites that may
+ * be violating this.
+ */
+ WARN_ON(!altmap && sysram_fallback);
+
+ if (altmap) {
+ ptr = altmap_alloc_block_buf(size, altmap);
+ if (ptr)
+ return ptr;
+ pr_debug("altmap block allocation failed\n");
+ if (!sysram_fallback)
+ return NULL;
+ pr_debug("falling back to system memory\n");
+ }
+
+ ptr = sparse_buffer_alloc(size);
if (!ptr)
ptr = vmemmap_alloc_block(size, node);
return ptr;
@@ -148,10 +169,7 @@ pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node,
pte_t entry;
void *p;
- if (altmap)
- p = altmap_alloc_block_buf(PAGE_SIZE, altmap);
- else
- p = vmemmap_alloc_block_buf(PAGE_SIZE, node);
+ p = vmemmap_alloc_block_buf(PAGE_SIZE, node, altmap, false);
if (!p)
return NULL;
entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
There are many instances where vmemap allocation is often switched between regular memory and device memory just based on whether altmap is available or not. vmemmap_alloc_block_buf() is used in various platforms to allocate vmemmap mappings. Lets also enable it to handle altmap based device memory allocation along with existing regular memory allocations. This will help in avoiding the altmap based allocation switch in many places. While here also implement a regular memory allocation fallback mechanism when the first preferred device memory allocation fails. This will ensure preserving the existing semantics on powerpc platform. To summarize there are three different methods to call vmemmap_alloc_block_buf(). (., NULL, false) /* Allocate from system RAM */ (., altmap, false) /* Allocate from altmap without any fallback */ (., altmap, true) /* Allocate from altmap with fallback (system RAM) */ Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: x86@kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Suggested-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> --- arch/arm64/mm/mmu.c | 3 ++- arch/powerpc/mm/init_64.c | 10 +++++----- arch/x86/mm/init_64.c | 6 ++---- include/linux/mm.h | 3 ++- mm/sparse-vmemmap.c | 30 ++++++++++++++++++++++++------ 5 files changed, 35 insertions(+), 17 deletions(-)