arm64: head: pass ID map root table address to __enable_mmu()

We will be adding an initial ID map that covers the entire kernel image,
so we will pass the actual ID map root table to use to __enable_mmu(),
rather than hard code it.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220624150651.1358849-10-ardb@kernel.orgSigned-off-by: Will Deacon <will@kernel.org>

arch/arm64/kernel/head.S

@@ -595,6 +595,7 @@ SYM_FUNC_START_LOCAL(secondary_startup)
 	bl	__cpu_secondary_check52bitva
 	bl	__cpu_setup			// initialise processor
 	adrp	x1, swapper_pg_dir
+	adrp	x2, idmap_pg_dir
 	bl	__enable_mmu
 	ldr	x8, =__secondary_switched
 	br	x8
@@ -648,6 +649,7 @@ SYM_FUNC_END(__secondary_too_slow)
  *
  *  x0  = SCTLR_EL1 value for turning on the MMU.
  *  x1  = TTBR1_EL1 value
+ *  x2  = ID map root table address
  *
  * Returns to the caller via x30/lr. This requires the caller to be covered
  * by the .idmap.text section.
@@ -656,14 +658,13 @@ SYM_FUNC_END(__secondary_too_slow)
  * If it isn't, park the CPU
  */
 SYM_FUNC_START(__enable_mmu)
-	mrs	x2, ID_AA64MMFR0_EL1
-	ubfx	x2, x2, #ID_AA64MMFR0_TGRAN_SHIFT, 4
-	cmp     x2, #ID_AA64MMFR0_TGRAN_SUPPORTED_MIN
+	mrs	x3, ID_AA64MMFR0_EL1
+	ubfx	x3, x3, #ID_AA64MMFR0_TGRAN_SHIFT, 4
+	cmp     x3, #ID_AA64MMFR0_TGRAN_SUPPORTED_MIN
 	b.lt    __no_granule_support
-	cmp     x2, #ID_AA64MMFR0_TGRAN_SUPPORTED_MAX
+	cmp     x3, #ID_AA64MMFR0_TGRAN_SUPPORTED_MAX
 	b.gt    __no_granule_support
-	update_early_cpu_boot_status 0, x2, x3
-	adrp	x2, idmap_pg_dir
+	update_early_cpu_boot_status 0, x3, x4
 	phys_to_ttbr x1, x1
 	phys_to_ttbr x2, x2
 	msr	ttbr0_el1, x2			// load TTBR0
@@ -819,6 +820,7 @@ SYM_FUNC_START_LOCAL(__primary_switch)
 #endif
 
 	adrp	x1, init_pg_dir
+	adrp	x2, idmap_pg_dir
 	bl	__enable_mmu
 #ifdef CONFIG_RELOCATABLE
 #ifdef CONFIG_RELR

arch/arm64/kernel/sleep.S

@@ -104,6 +104,7 @@ SYM_CODE_START(cpu_resume)
 	bl	__cpu_setup
 	/* enable the MMU early - so we can access sleep_save_stash by va */
 	adrp	x1, swapper_pg_dir
+	adrp	x2, idmap_pg_dir
 	bl	__enable_mmu
 	ldr	x8, =_cpu_resume
 	br	x8