[PATCH v2 3/5] x86/boot: Remove hardcoded boot_param constants

[Brian Gerst]

Use generated constants or sizeof() instead of hardcoded values.

No functional change.

Signed-off-by: Brian Gerst <brgerst@xxxxxxxxx>
---
 arch/x86/include/asm/setup.h            | 3 ---
 arch/x86/kernel/asm-offsets.c           | 2 ++
 arch/x86/kernel/head_32.S               | 4 ++--
 drivers/firmware/efi/libstub/x86-stub.c | 6 +++---
 4 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h
index 5534f4aaf73b..d23f4272d930 100644
--- a/arch/x86/include/asm/setup.h
+++ b/arch/x86/include/asm/setup.h
@@ -21,11 +21,8 @@
 
 #endif /* __i386__ */
 
-#define PARAM_SIZE 4096		/* sizeof(struct boot_params) */
-
 #define OLD_CL_MAGIC		0xA33F
 #define OLD_CL_ADDRESS		0x020	/* Relative to real mode data */
-#define NEW_CL_POINTER		0x228	/* Relative to real mode data */
 
 #ifndef __ASSEMBLER__
 #include <linux/cache.h>
diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c
index 081816888f7a..0c49bb50188d 100644
--- a/arch/x86/kernel/asm-offsets.c
+++ b/arch/x86/kernel/asm-offsets.c
@@ -105,6 +105,8 @@ static void __used common(void)
 	OFFSET(BP_kernel_alignment, boot_params, hdr.kernel_alignment);
 	OFFSET(BP_init_size, boot_params, hdr.init_size);
 	OFFSET(BP_pref_address, boot_params, hdr.pref_address);
+	OFFSET(BP_cmd_line_ptr, boot_params, hdr.cmd_line_ptr);
+	DEFINE(SIZEOF_boot_params, sizeof(struct boot_params));
 
 	BLANK();
 	DEFINE(PTREGS_SIZE, sizeof(struct pt_regs));
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index 5171cb746444..1f66ccc36fe8 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -96,10 +96,10 @@ SYM_CODE_START(startup_32)
  * page tables.
  */
 	movl $pa(boot_params),%edi
-	movl $(PARAM_SIZE/4),%ecx
+	movl $(SIZEOF_boot_params/4),%ecx
 	cld
 	rep movsl
-	movl pa(boot_params) + NEW_CL_POINTER,%esi
+	movl pa(boot_params) + BP_cmd_line_ptr,%esi
 	andl %esi,%esi
 	jz 1f			# No command line
 	movl $pa(boot_command_line),%edi
diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index cef32e2c82d8..9ec19e9a79ff 100644
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -520,11 +520,11 @@ static efi_status_t efi_allocate_bootparams(efi_handle_t handle,
 		return status;
 	}
 
-	status = efi_allocate_pages(PARAM_SIZE, &alloc, ULONG_MAX);
+	status = efi_allocate_pages(sizeof(*boot_params), &alloc, ULONG_MAX);
 	if (status != EFI_SUCCESS)
 		return status;
 
-	boot_params = memset((void *)alloc, 0x0, PARAM_SIZE);
+	boot_params = memset((void *)alloc, 0x0, sizeof(*boot_params));
 	hdr	    = &boot_params->hdr;
 
 	/* Assign the setup_header fields that the kernel actually cares about */
@@ -537,7 +537,7 @@ static efi_status_t efi_allocate_bootparams(efi_handle_t handle,
 	/* Convert unicode cmdline to ascii */
 	cmdline_ptr = efi_convert_cmdline(image);
 	if (!cmdline_ptr) {
-		efi_free(PARAM_SIZE, alloc);
+		efi_free(sizeof(*boot_params), alloc);
 		return EFI_OUT_OF_RESOURCES;
 	}
 
-- 
2.55.0