[PATCHv4 2/4] arm64/crashdump: unify routine to get page_offset

[Pingfan Liu]

There are two funcs to get page_offset:
  get_kernel_page_offset()
  get_page_offset()

Since get_kernel_page_offset() does not observe the kernel formula, and
remove it. Unify them in order to introduce 52-bits VA kernel more
easily in the coming patch.

Signed-off-by: Pingfan Liu <piliu at redhat.com>
Cc: Kairui Song <kasong at tencent.com>
Cc: Simon Horman <horms at verge.net.au>
Cc: Philipp Rudo <prudo at redhat.com>
To: kexec at lists.infradead.org
---
 kexec/arch/arm64/crashdump-arm64.c | 23 +----------------------
 kexec/arch/arm64/kexec-arm64.c     |  8 ++++----
 kexec/arch/arm64/kexec-arm64.h     |  1 +
 3 files changed, 6 insertions(+), 26 deletions(-)

diff --git a/kexec/arch/arm64/crashdump-arm64.c b/kexec/arch/arm64/crashdump-arm64.c
index a02019a..0a8d44c 100644
--- a/kexec/arch/arm64/crashdump-arm64.c
+++ b/kexec/arch/arm64/crashdump-arm64.c
@@ -46,27 +46,6 @@ static struct crash_elf_info elf_info = {
 	.machine	= EM_AARCH64,
 };
 
-/*
- * Note: The returned value is correct only if !CONFIG_RANDOMIZE_BASE.
- */
-static uint64_t get_kernel_page_offset(void)
-{
-	int i;
-
-	if (elf_info.kern_vaddr_start == UINT64_MAX)
-		return UINT64_MAX;
-
-	/* Current max virtual memory range is 48-bits. */
-	for (i = 48; i > 0; i--)
-		if (!(elf_info.kern_vaddr_start & (1UL << i)))
-			break;
-
-	if (i <= 0)
-		return UINT64_MAX;
-	else
-		return UINT64_MAX << i;
-}
-
 /*
  * iomem_range_callback() - callback called for each iomem region
  * @data: not used
@@ -198,7 +177,7 @@ int load_crashdump_segments(struct kexec_info *info)
 	if (err)
 		return EFAILED;
 
-	elf_info.page_offset = get_kernel_page_offset();
+	get_page_offset(&elf_info.page_offset);
 	dbgprintf("%s: page_offset:   %016llx\n", __func__,
 			elf_info.page_offset);
 
diff --git a/kexec/arch/arm64/kexec-arm64.c b/kexec/arch/arm64/kexec-arm64.c
index c6c67e8..33cc258 100644
--- a/kexec/arch/arm64/kexec-arm64.c
+++ b/kexec/arch/arm64/kexec-arm64.c
@@ -909,7 +909,7 @@ static int get_va_bits(void)
  * get_page_offset - Helper for getting PAGE_OFFSET
  */
 
-static int get_page_offset(void)
+int get_page_offset(unsigned long *page_offset)
 {
 	int ret;
 
@@ -917,8 +917,8 @@ static int get_page_offset(void)
 	if (ret < 0)
 		return ret;
 
-	page_offset = (0xffffffffffffffffUL) << (va_bits - 1);
-	dbgprintf("page_offset : %lx\n", page_offset);
+	*page_offset = UINT64_MAX << (va_bits - 1);
+	dbgprintf("page_offset : %lx\n", *page_offset);
 
 	return 0;
 }
@@ -954,7 +954,7 @@ int get_phys_base_from_pt_load(long *phys_offset)
 	unsigned long long phys_start;
 	unsigned long long virt_start;
 
-	ret = get_page_offset();
+	ret = get_page_offset(&page_offset);
 	if (ret < 0)
 		return ret;
 
diff --git a/kexec/arch/arm64/kexec-arm64.h b/kexec/arch/arm64/kexec-arm64.h
index 1844b67..ed99d9d 100644
--- a/kexec/arch/arm64/kexec-arm64.h
+++ b/kexec/arch/arm64/kexec-arm64.h
@@ -69,6 +69,7 @@ extern struct arm64_mem arm64_mem;
 
 uint64_t get_phys_offset(void);
 uint64_t get_vp_offset(void);
+int get_page_offset(unsigned long *offset);
 
 static inline void reset_vp_offset(void)
 {
-- 
2.31.1