Re: [PATCH] Revert "arm64: vmemmap: use virtual projection of linear region"

[David Daney]

On 03/08/2016 11:26 AM, Laura Abbott wrote:

On 03/08/2016 11:03 AM, David Daney wrote:

From: David Daney <david.da...@cavium.com>

This reverts commit dfd55ad85e4a7fbaa82df12467515ac3c81e8a3e.

Commit dfd55ad85e4a ("arm64: vmemmap: use virtual projection of linear
region") causes this failure on Cavium Thunder systems:

[...]

See http://article.gmane.org/gmane.linux.ports.arm.kernel/484866 for a
proposed fix.

Yes, that patch fixes it for me.  I withdraw my patch to revert.

Thanks,
David Daney

Signed-off-by: David Daney <david.da...@cavium.com>
---
  arch/arm64/include/asm/pgtable.h | 7 +++----
  arch/arm64/mm/init.c             | 4 ++--
  2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h
b/arch/arm64/include/asm/pgtable.h
index f506086..bf464de 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -34,13 +34,13 @@
  /*
   * VMALLOC and SPARSEMEM_VMEMMAP ranges.
   *
- * VMEMAP_SIZE: allows the whole linear region to be covered by a
struct page array
+ * VMEMAP_SIZE: allows the whole VA space to be covered by a struct
page array
   *    (rounded up to PUD_SIZE).
   * VMALLOC_START: beginning of the kernel VA space
   * VMALLOC_END: extends to the available space below vmmemmap, PCI
I/O space,
   *    fixed mappings and modules
   */
-#define VMEMMAP_SIZE        ALIGN((1UL << (VA_BITS - PAGE_SHIFT - 1))
* sizeof(struct page), PUD_SIZE)
+#define VMEMMAP_SIZE        ALIGN((1UL << (VA_BITS - PAGE_SHIFT)) *
sizeof(struct page), PUD_SIZE)

  #ifndef CONFIG_KASAN
  #define VMALLOC_START        (VA_START)
@@ -51,8 +51,7 @@

  #define VMALLOC_END        (PAGE_OFFSET - PUD_SIZE - VMEMMAP_SIZE -
SZ_64K)

-#define VMEMMAP_START        (VMALLOC_END + SZ_64K)
-#define vmemmap            ((struct page *)VMEMMAP_START -
(memstart_addr >> PAGE_SHIFT))
+#define vmemmap            ((struct page *)(VMALLOC_END + SZ_64K))

  #define FIRST_USER_ADDRESS    0UL

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 7802f21..f3b061e 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -319,8 +319,8 @@ void __init mem_init(void)
  #endif
            MLG(VMALLOC_START, VMALLOC_END),
  #ifdef CONFIG_SPARSEMEM_VMEMMAP
-          MLG(VMEMMAP_START,
-              VMEMMAP_START + VMEMMAP_SIZE),
+          MLG((unsigned long)vmemmap,
+              (unsigned long)vmemmap + VMEMMAP_SIZE),
            MLM((unsigned long)virt_to_page(PAGE_OFFSET),
                (unsigned long)virt_to_page(high_memory)),
  #endif