[Crash-utility] [PATCH] arm64: handle 1GB block

[Johan.Erlandsson at sony.com]

With enough continuous physical memory we can have 1GB block. This have
been seen only in linear mapping region in kernel space. I have only
verified this for VM_L3_4K.

reference: alloc_init_pud(), use_1G_block() [arch/arm64/mm/mmu.c]

This problem can for instance be seen with vtop command, example:

crash> vtop ffffffd988008000
VIRTUAL           PHYSICAL
ffffffd988008000  148008000

PAGE DIRECTORY: ffffff9188c6c000
PGD: ffffff9188c6cb30 => 68000140000711
PMD: ffffffd980000200 => aa0003e2b9402fe1
PAGE: 3e2b9400000  (2MB)

PTE               PHYSICAL     FLAGS
aa0003e2b9402fe1  3e2b9402000  (VALID|USER|RDONLY|SHARED|AF|NG)
---
 arm64.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arm64.c b/arm64.c
index 37aed07..4787fa6 100644
--- a/arm64.c
+++ b/arm64.c
@@ -1260,11 +1260,14 @@ arm64_uvtop(struct task_context *tc, ulong uvaddr, physaddr_t *paddr, int verbos
 #define PTE_TO_PHYS(pteval)  (machdep->max_physmem_bits == 52 ? \
        (((pteval & PTE_ADDR_LOW) | ((pteval & PTE_ADDR_HIGH) << 36))) : (pteval & PTE_ADDR_LOW))
 
+#define PUD_TYPE_MASK   3
+#define PUD_TYPE_SECT   1
 #define PMD_TYPE_MASK   3
 #define PMD_TYPE_SECT   1
 #define PMD_TYPE_TABLE  2
 #define SECTION_PAGE_MASK_2MB    ((long)(~((MEGABYTES(2))-1)))
 #define SECTION_PAGE_MASK_512MB  ((long)(~((MEGABYTES(512))-1)))
+#define SECTION_PAGE_MASK_1GB    ((long)(~((GIGABYTES(1))-1)))
 
 static int 
 arm64_vtop_2level_64k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose)
@@ -1420,6 +1423,15 @@ arm64_vtop_3level_4k(ulong pgd, ulong vaddr, physaddr_t *paddr, int verbose)
        if (!pgd_val)
                goto no_page;
 
+       if ((pgd_val & PUD_TYPE_MASK) == PUD_TYPE_SECT) {
+               ulong sectionbase = (pgd_val & SECTION_PAGE_MASK_1GB) & PHYS_MASK;
+               if (verbose) {
+                       fprintf(fp, "  PAGE: %lx  (1GB)\n\n", sectionbase);
+                       arm64_translate_pte(pgd_val, 0, 0);
+               }
+               *paddr = sectionbase + (vaddr & ~SECTION_PAGE_MASK_1GB);
+               return TRUE;
+       }
        /* 
         * #define __PAGETABLE_PUD_FOLDED 
         */
-- 
2.17.1