1 files changed, 88 insertions, 33 deletions

diff --git a/arch/x86/kernel/head32.c b/arch/x86/kernel/head32.c
index ec6fefbfd3c0..de001b2146ab 100644
--- a/arch/x86/kernel/head32.c
+++ b/arch/x86/kernel/head32.c
@@ -19,6 +19,7 @@
 #include <asm/apic.h>
 #include <asm/io_apic.h>
 #include <asm/bios_ebda.h>
+#include <asm/microcode.h>
 #include <asm/tlbflush.h>
 #include <asm/bootparam_utils.h>
 
@@ -29,11 +30,33 @@ static void __init i386_default_early_setup(void)
 	x86_init.mpparse.setup_ioapic_ids = setup_ioapic_ids_from_mpc;
 }
 
-asmlinkage __visible void __init i386_start_kernel(void)
+#ifdef CONFIG_MICROCODE_INITRD32
+unsigned long __initdata initrd_start_early;
+static pte_t __initdata *initrd_pl2p_start, *initrd_pl2p_end;
+
+static void zap_early_initrd_mapping(void)
+{
+	pte_t *pl2p = initrd_pl2p_start;
+
+	for (; pl2p < initrd_pl2p_end; pl2p++) {
+		*pl2p = (pte_t){ .pte = 0 };
+
+		if (!IS_ENABLED(CONFIG_X86_PAE))
+			*(pl2p + ((PAGE_OFFSET >> PGDIR_SHIFT))) = (pte_t) {.pte = 0};
+	}
+}
+#else
+static inline void zap_early_initrd_mapping(void) { }
+#endif
+
+asmlinkage __visible void __init __noreturn i386_start_kernel(void)
 {
 	/* Make sure IDT is set up before any exception happens */
 	idt_setup_early_handler();
 
+	load_ucode_bsp();
+	zap_early_initrd_mapping();
+
 	cr4_init_shadow();
 
 	sanitize_boot_params(&boot_params);
@@ -69,51 +92,83 @@ asmlinkage __visible void __init i386_start_kernel(void)
  * to the first kernel PMD. Note the upper half of each PMD or PTE are
  * always zero at this stage.
  */
-void __init mk_early_pgtbl_32(void)
-{
-#ifdef __pa
-#undef __pa
-#endif
-#define __pa(x)  ((unsigned long)(x) - PAGE_OFFSET)
-	pte_t pte, *ptep;
-	int i;
-	unsigned long *ptr;
-	/* Enough space to fit pagetables for the low memory linear map */
-	const unsigned long limit = __pa(_end) +
-		(PAGE_TABLE_SIZE(LOWMEM_PAGES) << PAGE_SHIFT);
 #ifdef CONFIG_X86_PAE
-	pmd_t pl2, *pl2p = (pmd_t *)__pa(initial_pg_pmd);
-#define SET_PL2(pl2, val)    { (pl2).pmd = (val); }
+typedef pmd_t			pl2_t;
+#define pl2_base		initial_pg_pmd
+#define SET_PL2(val)		{ .pmd = (val), }
 #else
-	pgd_t pl2, *pl2p = (pgd_t *)__pa(initial_page_table);
-#define SET_PL2(pl2, val)   { (pl2).pgd = (val); }
+typedef pgd_t			pl2_t;
+#define pl2_base		initial_page_table
+#define SET_PL2(val)		{ .pgd = (val), }
 #endif
 
-	ptep = (pte_t *)__pa(__brk_base);
-	pte.pte = PTE_IDENT_ATTR;
-
+static __init __no_stack_protector pte_t init_map(pte_t pte, pte_t **ptep, pl2_t **pl2p,
+						  const unsigned long limit)
+{
 	while ((pte.pte & PTE_PFN_MASK) < limit) {
+		pl2_t pl2 = SET_PL2((unsigned long)*ptep | PDE_IDENT_ATTR);
+		int i;
+
+		**pl2p = pl2;
+		if (!IS_ENABLED(CONFIG_X86_PAE)) {
+			/* Kernel PDE entry */
+			*(*pl2p + ((PAGE_OFFSET >> PGDIR_SHIFT))) = pl2;
+		}
 
-		SET_PL2(pl2, (unsigned long)ptep | PDE_IDENT_ATTR);
-		*pl2p = pl2;
-#ifndef CONFIG_X86_PAE
-		/* Kernel PDE entry */
-		*(pl2p +  ((PAGE_OFFSET >> PGDIR_SHIFT))) = pl2;
-#endif
 		for (i = 0; i < PTRS_PER_PTE; i++) {
-			*ptep = pte;
+			**ptep = pte;
 			pte.pte += PAGE_SIZE;
-			ptep++;
+			(*ptep)++;
 		}
-
-		pl2p++;
+		(*pl2p)++;
 	}
+	return pte;
+}
+
+void __init __no_stack_protector mk_early_pgtbl_32(void)
+{
+	/* Enough space to fit pagetables for the low memory linear map */
+	unsigned long limit = __pa_nodebug(_end) + (PAGE_TABLE_SIZE(LOWMEM_PAGES) << PAGE_SHIFT);
+	pte_t pte, *ptep = (pte_t *)__pa_nodebug(__brk_base);
+	struct boot_params __maybe_unused *params;
+	pl2_t *pl2p = (pl2_t *)__pa_nodebug(pl2_base);
+	unsigned long *ptr;
+
+	pte.pte = PTE_IDENT_ATTR;
+	pte = init_map(pte, &ptep, &pl2p, limit);
 
-	ptr = (unsigned long *)__pa(&max_pfn_mapped);
+	ptr = (unsigned long *)__pa_nodebug(&max_pfn_mapped);
 	/* Can't use pte_pfn() since it's a call with CONFIG_PARAVIRT */
 	*ptr = (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;
 
-	ptr = (unsigned long *)__pa(&_brk_end);
+	ptr = (unsigned long *)__pa_nodebug(&_brk_end);
 	*ptr = (unsigned long)ptep + PAGE_OFFSET;
-}
 
+#ifdef CONFIG_MICROCODE_INITRD32
+	/* Running on a hypervisor? */
+	if (native_cpuid_ecx(1) & BIT(31))
+		return;
+
+	params = (struct boot_params *)__pa_nodebug(&boot_params);
+	if (!params->hdr.ramdisk_size || !params->hdr.ramdisk_image)
+		return;
+
+	/* Save the virtual start address */
+	ptr = (unsigned long *)__pa_nodebug(&initrd_start_early);
+	*ptr = (pte.pte & PTE_PFN_MASK) + PAGE_OFFSET;
+	*ptr += ((unsigned long)params->hdr.ramdisk_image) & ~PAGE_MASK;
+
+	/* Save PLP2 for cleanup */
+	ptr = (unsigned long *)__pa_nodebug(&initrd_pl2p_start);
+	*ptr = (unsigned long)pl2p + PAGE_OFFSET;
+
+	limit = (unsigned long)params->hdr.ramdisk_image;
+	pte.pte = PTE_IDENT_ATTR | PFN_ALIGN(limit);
+	limit = (unsigned long)params->hdr.ramdisk_image + params->hdr.ramdisk_size;
+
+	init_map(pte, &ptep, &pl2p, limit);
+
+	ptr = (unsigned long *)__pa_nodebug(&initrd_pl2p_end);
+	*ptr = (unsigned long)pl2p + PAGE_OFFSET;
+#endif
+}