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authorMatthew Leach <matthew.leach@arm.com>2013-10-11 14:52:16 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2013-10-25 15:59:39 +0100
commit828e9834e9a5b7e61046aa3c5f603a4fecba2fb4 (patch)
tree0a0e3cd11b88f88b718e71fcb7990152486cf1a7 /arch/arm64/kernel/head.S
parente68bedaa03c950ae8045e7899e7a6b2a97d1bf41 (diff)
downloadlinux-linaro-stable-828e9834e9a5b7e61046aa3c5f603a4fecba2fb4.tar.gz
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: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Matthew Leach <matthew.leach@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/head.S')
-rw-r--r--arch/arm64/kernel/head.S34
1 files changed, 25 insertions, 9 deletions
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index bf7efdf2d7e7..775ecb313ee7 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -123,8 +123,9 @@
ENTRY(stext)
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.
*/
ENTRY(el2_setup)
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
ret
/* 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. */
@@ -204,10 +204,25 @@ ENTRY(el2_setup)
PSR_MODE_EL1h)
msr spsr_el2, x0
msr elr_el2, lr
+ mov w20, #BOOT_CPU_MODE_EL2 // This CPU booted in EL2
eret
ENDPROC(el2_setup)
/*
+ * 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.
+ */
+ENTRY(set_cpu_boot_mode_flag)
+ ldr x1, =__boot_cpu_mode // Compute __boot_cpu_mode
+ add x1, x1, x28
+ cmp w20, #BOOT_CPU_MODE_EL2
+ b.ne 1f
+ add x1, x1, #4
+1: str w20, [x1] // This CPU has booted in EL1
+ ret
+ENDPROC(set_cpu_boot_mode_flag)
+
+/*
* 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.
*/
ENTRY(secondary_holding_pen)
- 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
ldr x1, =MPIDR_HWID_BITMASK
and x0, x0, x1