Commit 828e9834 authored by Matthew Leach's avatar Matthew Leach Committed by Catalin Marinas
Browse files

arm64: head: create a new function for setting the boot_cpu_mode flag

Currently, the code for setting the __cpu_boot_mode flag is munged in
with el2_setup. This makes things difficult on a BE bringup as a
memory access has to have occurred before el2_setup which is the place
that we'd like to set the endianess on the current EL.

Create a new function for setting __cpu_boot_mode and have el2_setup
return the mode the CPU. Also define a new constant in virt.h,
BOOT_CPU_MODE_EL1, for readability.
Acked-by: default avatarMarc Zyngier <>
Acked-by: default avatarWill Deacon <>
Signed-off-by: default avatarMatthew Leach <>
Signed-off-by: default avatarCatalin Marinas <>
parent e68bedaa
......@@ -18,7 +18,8 @@
#ifndef __ASM__VIRT_H
#define __ASM__VIRT_H
#define BOOT_CPU_MODE_EL2 (0x0e12b007)
#define BOOT_CPU_MODE_EL1 (0xe11)
#define BOOT_CPU_MODE_EL2 (0xe12)
#ifndef __ASSEMBLY__
#include <asm/cacheflush.h>
......@@ -123,8 +123,9 @@
mov x21, x0 // x21=FDT
bl el2_setup // Drop to EL1, w20=cpu_boot_mode
bl __calc_phys_offset // x24=PHYS_OFFSET, x28=PHYS_OFFSET-PAGE_OFFSET
bl el2_setup // Drop to EL1
bl set_cpu_boot_mode_flag
mrs x22, midr_el1 // x22=cpuid
mov x0, x22
bl lookup_processor_type
......@@ -150,21 +151,20 @@ ENDPROC(stext)
* If we're fortunate enough to boot at EL2, ensure that the world is
* sane before dropping to EL1.
* Returns either BOOT_CPU_MODE_EL1 or BOOT_CPU_MODE_EL2 in x20 if
* booted in EL1 or EL2 respectively.
mrs x0, CurrentEL
cmp x0, #PSR_MODE_EL2t
ccmp x0, #PSR_MODE_EL2h, #0x4, ne
ldr x0, =__boot_cpu_mode // Compute __boot_cpu_mode
add x0, x0, x28
b.eq 1f
str wzr, [x0] // Remember we don't have EL2...
mov w20, #BOOT_CPU_MODE_EL1 // This cpu booted in EL1
/* Hyp configuration. */
1: ldr w1, =BOOT_CPU_MODE_EL2
str w1, [x0, #4] // This CPU has EL2
mov x0, #(1 << 31) // 64-bit EL1
1: mov x0, #(1 << 31) // 64-bit EL1
msr hcr_el2, x0
/* Generic timers. */
......@@ -204,9 +204,24 @@ ENTRY(el2_setup)
msr spsr_el2, x0
msr elr_el2, lr
mov w20, #BOOT_CPU_MODE_EL2 // This CPU booted in EL2
* Sets the __boot_cpu_mode flag depending on the CPU boot mode passed
* in x20. See arch/arm64/include/asm/virt.h for more info.
ldr x1, =__boot_cpu_mode // Compute __boot_cpu_mode
add x1, x1, x28
cmp w20, #BOOT_CPU_MODE_EL2 1f
add x1, x1, #4
1: str w20, [x1] // This CPU has booted in EL1
* We need to find out the CPU boot mode long after boot, so we need to
* store it in a writable variable.
......@@ -234,8 +249,9 @@ ENTRY(__boot_cpu_mode)
* cores are held until we're ready for them to initialise.
bl __calc_phys_offset // x24=phys offset
bl el2_setup // Drop to EL1
bl el2_setup // Drop to EL1, w20=cpu_boot_mode
bl __calc_phys_offset // x24=PHYS_OFFSET, x28=PHYS_OFFSET-PAGE_OFFSET
bl set_cpu_boot_mode_flag
mrs x0, mpidr_el1
and x0, x0, x1
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