[PATCH 3/5] x86/boot/64: Change add_identity_map() to take size for ease of use

[Arvind Sankar]

Change back the arguments of add_identity_map() to (start, size) instead
of (start, end). This reverts

  21cf2372618e ("x86/boot/compressed/64: Change add_identity_map() to take 
start and end")

since we will soon have more callers that know the size rather than the
end address.

This also makes the #PF handler print the original CR2 value in case of
error, instead of after aligning to PMD_SIZE.

Signed-off-by: Arvind Sankar <nived...@alum.mit.edu>
---
 arch/x86/boot/compressed/ident_map_64.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/arch/x86/boot/compressed/ident_map_64.c 
b/arch/x86/boot/compressed/ident_map_64.c
index 063a60edcf99..070cda70aef3 100644
--- a/arch/x86/boot/compressed/ident_map_64.c
+++ b/arch/x86/boot/compressed/ident_map_64.c
@@ -90,8 +90,9 @@ static struct x86_mapping_info mapping_info;
 /*
  * Adds the specified range to the identity mappings.
  */
-static void add_identity_map(unsigned long start, unsigned long end)
+static void add_identity_map(unsigned long start, unsigned long size)
 {
+       unsigned long end = start + size;
        int ret;
 
        /* Align boundary to 2M. */
@@ -152,7 +153,7 @@ void initialize_identity_maps(void)
         * New page-table is set up - map the kernel image and load it
         * into cr3.
         */
-       add_identity_map((unsigned long)_head, (unsigned long)_end);
+       add_identity_map((unsigned long)_head, (unsigned long)_end - (unsigned 
long)_head);
        write_cr3(top_level_pgt);
 }
 
@@ -322,14 +323,10 @@ static void do_pf_error(const char *msg, unsigned long 
error_code,
 void do_boot_page_fault(struct pt_regs *regs, unsigned long error_code)
 {
        unsigned long address = native_read_cr2();
-       unsigned long end;
        bool ghcb_fault;
 
        ghcb_fault = sev_es_check_ghcb_fault(address);
 
-       address   &= PMD_MASK;
-       end        = address + PMD_SIZE;
-
        /*
         * Check for unexpected error codes. Unexpected are:
         *      - Faults on present pages
@@ -345,5 +342,5 @@ void do_boot_page_fault(struct pt_regs *regs, unsigned long 
error_code)
         * Error code is sane - now identity map the 2M region around
         * the faulting address.
         */
-       add_identity_map(address, end);
+       add_identity_map(address & PMD_MASK, PMD_SIZE);
 }
-- 
2.26.2