From: Arjun Roy <arjunroy@xxxxxxxxxx>
Subject: mm: define pte_index as macro for x86
pte_index() is either defined as a macro (e.g. sparc64) or as an inlined
function (e.g. x86). vm_insert_pages() depends on pte_index but it is
not defined on all platforms (e.g. m68k).
To fix compilation of vm_insert_pages() on architectures not providing
pte_index(), we perform the following fix:
0. For platforms where it is meaningful, and defined as a macro, no
change is needed.
1. For platforms where it is meaningful and defined as an inlined
function, and we want to use it with vm_insert_pages(), we define
a degenerate macro of the form: #define pte_index pte_index
2. vm_insert_pages() checks for the existence of a pte_index macro
definition. If found, it implements a batched insert. If not found,
it devolves to calling vm_insert_page() in a loop.
This patch implements step 1 for x86.
v3 of this patch fixes a compilation warning for an unused method.
v2 of this patch moved a macro definition to a more readable location.
Link: http://lkml.kernel.org/r/20200228054714.204424-1-arjunroy.kdev@xxxxxxxxx
Signed-off-by: Arjun Roy <arjunroy@xxxxxxxxxx>
Cc: David Miller <davem@xxxxxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Soheil Hassas Yeganeh <soheil@xxxxxxxxxx>
Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/pgtable.h | 3 +++
1 file changed, 3 insertions(+)
--- a/arch/x86/include/asm/pgtable.h~mm-define-pte_index-as-macro-for-x86
+++ a/arch/x86/include/asm/pgtable.h
@@ -860,7 +860,10 @@ static inline unsigned long pmd_index(un
*
* this function returns the index of the entry in the pte page which would
* control the given virtual address
+ *
+ * Also define macro so we can test if pte_index is defined for arch.
*/
+#define pte_index pte_index
static inline unsigned long pte_index(unsigned long address)
{
return (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
_
