From: "Barry Song (Xiaomi)" <[email protected]>

Try to align the vmap virtual address to PMD_SHIFT or a
larger PTE mapping size hinted by the architecture, so
contiguous pages can be batch-mapped when setting PMD or
PTE entries. We do not expect any significant overhead for
this.

Add __get_vm_area_node_aligned_caller() as a wrapper over
__get_vm_area_node() to simplify repeated calls with fixed
arguments.

Signed-off-by: Barry Song (Xiaomi) <[email protected]>
Signed-off-by: Wen Jiang <[email protected]>
Tested-by: Xueyuan Chen <[email protected]>
Tested-by: Leo Yan <[email protected]>
Reviewed-by: Uladzislau Rezki (Sony) <[email protected]>
Reviewed-by: Dev Jain <[email protected]>
---
 mm/vmalloc.c | 35 ++++++++++++++++++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index bce2d2c09f546..84413def1d771 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -3306,6 +3306,14 @@ struct vm_struct *get_vm_area_caller(unsigned long size, 
unsigned long flags,
                                  NUMA_NO_NODE, GFP_KERNEL, caller);
 }
 
+static struct vm_struct *__get_vm_area_node_aligned_caller(unsigned long size,
+               unsigned long align, unsigned long flags, const void *caller)
+{
+       return __get_vm_area_node(size, align, PAGE_SHIFT, flags,
+                                 VMALLOC_START, VMALLOC_END,
+                                 NUMA_NO_NODE, GFP_KERNEL, caller);
+}
+
 /**
  * find_vm_area - find a continuous kernel virtual area
  * @addr:        base address
@@ -3619,6 +3627,30 @@ static int vmap_pages_range_batched(unsigned long addr, 
unsigned long end,
        return err;
 }
 
+static struct vm_struct *vmap_get_aligned_vm_area(unsigned long size,
+               unsigned long flags, pgprot_t prot, const void *caller)
+{
+       struct vm_struct *vm_area;
+       unsigned int shift;
+
+       if (arch_vmap_pmd_supported(prot) && size >= PMD_SIZE) {
+               vm_area = __get_vm_area_node_aligned_caller(size, PMD_SIZE,
+                               flags, caller);
+               if (vm_area)
+                       return vm_area;
+       }
+
+       shift = arch_vmap_pte_supported_shift(size);
+       if (shift > PAGE_SHIFT) {
+               vm_area = __get_vm_area_node_aligned_caller(size, 1UL << shift,
+                               flags, caller);
+               if (vm_area)
+                       return vm_area;
+       }
+
+       return __get_vm_area_node_aligned_caller(size, PAGE_SIZE, flags, 
caller);
+}
+
 /**
  * vmap - map an array of pages into virtually contiguous space
  * @pages: array of page pointers
@@ -3657,7 +3689,8 @@ void *vmap(struct page **pages, unsigned int count,
                return NULL;
 
        size = (unsigned long)count << PAGE_SHIFT;
-       area = get_vm_area_caller(size, flags, __builtin_return_address(0));
+       area = vmap_get_aligned_vm_area(size, flags, prot,
+                               __builtin_return_address(0));
        if (!area)
                return NULL;
 
-- 
2.34.1


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