sparse-vmemmap: specify vmemmap population range in bytes

The sparse code, when asking the architecture to populate the vmemmap,
specifies the section range as a starting page and a number of pages.

This is an awkward interface, because none of the arch-specific code
actually thinks of the range in terms of 'struct page' units and always
translates it to bytes first.

In addition, later patches mix huge page and regular page backing for
the vmemmap.  For this, they need to call vmemmap_populate_basepages()
on sub-section ranges with PAGE_SIZE and PMD_SIZE in mind.  But these
are not necessarily multiples of the 'struct page' size and so this unit
is too coarse.

Just translate the section range into bytes once in the generic sparse
code, then pass byte ranges down the stack.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Bernhard Schmidt <Bernhard.Schmidt@lrz.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: David S. Miller <davem@davemloft.net>
Tested-by: David S. Miller <davem@davemloft.net>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 10 deletions

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 2ef81f19bd6c..528c143f467c 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1011,11 +1011,8 @@ remove_pagetable(unsigned long start, unsigned long end, bool direct)
         flush_tlb_all();
 }
 
-void __ref vmemmap_free(struct page *memmap, unsigned long nr_pages)
+void __ref vmemmap_free(unsigned long start, unsigned long end)
 {
-        unsigned long start = (unsigned long)memmap;
-        unsigned long end = (unsigned long)(memmap + nr_pages);
-
         remove_pagetable(start, end, false);
 }
 
@@ -1284,17 +1281,15 @@ static long __meminitdata addr_start, addr_end;
 static void __meminitdata *p_start, *p_end;
 static int __meminitdata node_start;
 
-int __meminit
-vmemmap_populate(struct page *start_page, unsigned long size, int node)
+int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
 {
-        unsigned long addr = (unsigned long)start_page;
-        unsigned long end = (unsigned long)(start_page + size);
+        unsigned long addr;
         unsigned long next;
         pgd_t *pgd;
         pud_t *pud;
         pmd_t *pmd;
 
-        for (; addr < end; addr = next) {
+        for (addr = start; addr < end; addr = next) {
                 void *p = NULL;
 
                 pgd = vmemmap_pgd_populate(addr, node);
@@ -1351,7 +1346,7 @@ vmemmap_populate(struct page *start_page, unsigned long size, int node)
                 }
 
         }
-        sync_global_pgds((unsigned long)start_page, end - 1);
+        sync_global_pgds(start, end - 1);
         return 0;
 }