diff mbox series

[3/8] efi/x86: Factor GDT setup code into a function

Message ID 20200130200440.1796058-4-nivedita@alum.mit.edu
State New
Headers show
Series None | expand

Commit Message

Arvind Sankar Jan. 30, 2020, 8:04 p.m. UTC 
Move GDT allocation and definition code into a function in preparation
to cleaning it up a bit.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
---
 arch/x86/boot/compressed/eboot.c | 191 ++++++++++++++++---------------
 1 file changed, 101 insertions(+), 90 deletions(-)
diff mbox series

Patch

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index a0a2fd0528af..066125a18391 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -344,6 +344,105 @@  void setup_graphics(struct boot_params *boot_params)
 	}
 }
 
+static efi_status_t setup_gdt(struct desc_ptr *gdt)
+{
+	efi_status_t status;
+	struct desc_struct *desc;
+
+	gdt->size = 0x800;
+	status = efi_low_alloc(gdt->size, 8, (unsigned long *)&gdt->address);
+	if (status != EFI_SUCCESS) {
+		efi_printk("Failed to allocate memory for 'gdt'\n");
+		return status;
+	}
+
+	memset((char *)gdt->address, 0x0, gdt->size);
+	desc = (struct desc_struct *)gdt->address;
+
+	/* The first GDT is a dummy. */
+	desc++;
+
+	if (IS_ENABLED(CONFIG_X86_64)) {
+		/* __KERNEL32_CS */
+		desc->limit0	= 0xffff;
+		desc->base0	= 0x0000;
+		desc->base1	= 0x0000;
+		desc->type	= SEG_TYPE_CODE | SEG_TYPE_EXEC_READ;
+		desc->s		= DESC_TYPE_CODE_DATA;
+		desc->dpl	= 0;
+		desc->p		= 1;
+		desc->limit1	= 0xf;
+		desc->avl	= 0;
+		desc->l		= 0;
+		desc->d		= SEG_OP_SIZE_32BIT;
+		desc->g		= SEG_GRANULARITY_4KB;
+		desc->base2	= 0x00;
+
+		desc++;
+	} else {
+		/* Second entry is unused on 32-bit */
+		desc++;
+	}
+
+	/* __KERNEL_CS */
+	desc->limit0	= 0xffff;
+	desc->base0	= 0x0000;
+	desc->base1	= 0x0000;
+	desc->type	= SEG_TYPE_CODE | SEG_TYPE_EXEC_READ;
+	desc->s		= DESC_TYPE_CODE_DATA;
+	desc->dpl	= 0;
+	desc->p		= 1;
+	desc->limit1	= 0xf;
+	desc->avl	= 0;
+
+	if (IS_ENABLED(CONFIG_X86_64)) {
+		desc->l = 1;
+		desc->d = 0;
+	} else {
+		desc->l = 0;
+		desc->d = SEG_OP_SIZE_32BIT;
+	}
+	desc->g		= SEG_GRANULARITY_4KB;
+	desc->base2	= 0x00;
+	desc++;
+
+	/* __KERNEL_DS */
+	desc->limit0	= 0xffff;
+	desc->base0	= 0x0000;
+	desc->base1	= 0x0000;
+	desc->type	= SEG_TYPE_DATA | SEG_TYPE_READ_WRITE;
+	desc->s		= DESC_TYPE_CODE_DATA;
+	desc->dpl	= 0;
+	desc->p		= 1;
+	desc->limit1	= 0xf;
+	desc->avl	= 0;
+	desc->l		= 0;
+	desc->d		= SEG_OP_SIZE_32BIT;
+	desc->g		= SEG_GRANULARITY_4KB;
+	desc->base2	= 0x00;
+	desc++;
+
+	if (IS_ENABLED(CONFIG_X86_64)) {
+		/* Task segment value */
+		desc->limit0	= 0x0000;
+		desc->base0	= 0x0000;
+		desc->base1	= 0x0000;
+		desc->type	= SEG_TYPE_TSS;
+		desc->s		= 0;
+		desc->dpl	= 0;
+		desc->p		= 1;
+		desc->limit1	= 0x0;
+		desc->avl	= 0;
+		desc->l		= 0;
+		desc->d		= 0;
+		desc->g		= SEG_GRANULARITY_4KB;
+		desc->base2	= 0x00;
+		desc++;
+	}
+
+	return EFI_SUCCESS;
+}
+
 void startup_32(struct boot_params *boot_params);
 
 void __noreturn efi_stub_entry(efi_handle_t handle,
@@ -716,7 +815,6 @@  struct boot_params *efi_main(efi_handle_t handle,
 	struct desc_ptr gdt;
 	struct setup_header *hdr = &boot_params->hdr;
 	efi_status_t status;
-	struct desc_struct *desc;
 	unsigned long cmdline_paddr;
 
 	sys_table = sys_table_arg;
@@ -754,12 +852,9 @@  struct boot_params *efi_main(efi_handle_t handle,
 
 	setup_quirks(boot_params);
 
-	gdt.size = 0x800;
-	status = efi_low_alloc(gdt.size, 8, (unsigned long *)&gdt.address);
-	if (status != EFI_SUCCESS) {
-		efi_printk("Failed to allocate memory for 'gdt'\n");
+	status = setup_gdt(&gdt);
+	if (status != EFI_SUCCESS)
 		goto fail;
-	}
 
 	/*
 	 * If the kernel isn't already loaded at the preferred load
@@ -787,90 +882,6 @@  struct boot_params *efi_main(efi_handle_t handle,
 		goto fail;
 	}
 
-	memset((char *)gdt.address, 0x0, gdt.size);
-	desc = (struct desc_struct *)gdt.address;
-
-	/* The first GDT is a dummy. */
-	desc++;
-
-	if (IS_ENABLED(CONFIG_X86_64)) {
-		/* __KERNEL32_CS */
-		desc->limit0	= 0xffff;
-		desc->base0	= 0x0000;
-		desc->base1	= 0x0000;
-		desc->type	= SEG_TYPE_CODE | SEG_TYPE_EXEC_READ;
-		desc->s		= DESC_TYPE_CODE_DATA;
-		desc->dpl	= 0;
-		desc->p		= 1;
-		desc->limit1	= 0xf;
-		desc->avl	= 0;
-		desc->l		= 0;
-		desc->d		= SEG_OP_SIZE_32BIT;
-		desc->g		= SEG_GRANULARITY_4KB;
-		desc->base2	= 0x00;
-
-		desc++;
-	} else {
-		/* Second entry is unused on 32-bit */
-		desc++;
-	}
-
-	/* __KERNEL_CS */
-	desc->limit0	= 0xffff;
-	desc->base0	= 0x0000;
-	desc->base1	= 0x0000;
-	desc->type	= SEG_TYPE_CODE | SEG_TYPE_EXEC_READ;
-	desc->s		= DESC_TYPE_CODE_DATA;
-	desc->dpl	= 0;
-	desc->p		= 1;
-	desc->limit1	= 0xf;
-	desc->avl	= 0;
-
-	if (IS_ENABLED(CONFIG_X86_64)) {
-		desc->l = 1;
-		desc->d = 0;
-	} else {
-		desc->l = 0;
-		desc->d = SEG_OP_SIZE_32BIT;
-	}
-	desc->g		= SEG_GRANULARITY_4KB;
-	desc->base2	= 0x00;
-	desc++;
-
-	/* __KERNEL_DS */
-	desc->limit0	= 0xffff;
-	desc->base0	= 0x0000;
-	desc->base1	= 0x0000;
-	desc->type	= SEG_TYPE_DATA | SEG_TYPE_READ_WRITE;
-	desc->s		= DESC_TYPE_CODE_DATA;
-	desc->dpl	= 0;
-	desc->p		= 1;
-	desc->limit1	= 0xf;
-	desc->avl	= 0;
-	desc->l		= 0;
-	desc->d		= SEG_OP_SIZE_32BIT;
-	desc->g		= SEG_GRANULARITY_4KB;
-	desc->base2	= 0x00;
-	desc++;
-
-	if (IS_ENABLED(CONFIG_X86_64)) {
-		/* Task segment value */
-		desc->limit0	= 0x0000;
-		desc->base0	= 0x0000;
-		desc->base1	= 0x0000;
-		desc->type	= SEG_TYPE_TSS;
-		desc->s		= 0;
-		desc->dpl	= 0;
-		desc->p		= 1;
-		desc->limit1	= 0x0;
-		desc->avl	= 0;
-		desc->l		= 0;
-		desc->d		= 0;
-		desc->g		= SEG_GRANULARITY_4KB;
-		desc->base2	= 0x00;
-		desc++;
-	}
-
 	raw_local_irq_disable();
 	native_load_gdt(&gdt);