[PATCHv3 03/17] arm64: head.S: rename el2_setup -> init_kernel_el

Mark Rutland
2020-10-26T13:34:37Z

For a while now el2_setup has performed some basic initialization of EL1
even when the kernel is booted at EL1, so the name is a little
misleading. Further, some comments are stale as with VHE it doesn't drop
the CPU to EL1.

To clarify things, rename el2_setup to init_kernel_el, and update
comments to be clearer as to the function's purpose.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
---
arch/arm64/kernel/head.S | 15 ++++++++-------
arch/arm64/kernel/sleep.S | 2 +-
2 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index d8d9caf02834e..5a31086e8e85b 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -104,7 +104,7 @@ pe_header:
*/
SYM_CODE_START(primary_entry)
bl preserve_boot_args
- bl el2_setup // Drop to EL1, w0=cpu_boot_mode
+ bl init_kernel_el // w0=cpu_boot_mode
adrp x23, __PHYS_OFFSET
and x23, x23, MIN_KIMG_ALIGN - 1 // KASLR offset, defaults to 0
bl set_cpu_boot_mode_flag
@@ -482,13 +482,14 @@ EXPORT_SYMBOL(kimage_vaddr)
.section ".idmap.text","awx"

/*
- * If we're fortunate enough to boot at EL2, ensure that the world is
- * sane before dropping to EL1.
+ * Starting from EL2 or EL1, configure the CPU to execute at the highest
+ * reachable EL supported by the kernel in a chosen default state. If dropping
+ * from EL2 to EL1, configure EL2 before configuring EL1.
*
* Returns either BOOT_CPU_MODE_EL1 or BOOT_CPU_MODE_EL2 in w0 if
* booted in EL1 or EL2 respectively.
*/
-SYM_FUNC_START(el2_setup)
+SYM_FUNC_START(init_kernel_el)
msr SPsel, #1 // We want to use SP_EL{1,2}
mrs x0, CurrentEL
cmp x0, #CurrentEL_EL2
@@ -649,7 +650,7 @@ SYM_INNER_LABEL(install_el2_stub, SYM_L_LOCAL)
msr elr_el2, lr
mov w0, #BOOT_CPU_MODE_EL2 // This CPU booted in EL2
eret
-SYM_FUNC_END(el2_setup)
+SYM_FUNC_END(init_kernel_el)

/*
* Sets the __boot_cpu_mode flag depending on the CPU boot mode passed
@@ -699,7 +700,7 @@ SYM_DATA_END(__early_cpu_boot_status)
* cores are held until we're ready for them to initialise.
*/
SYM_FUNC_START(secondary_holding_pen)
- bl el2_setup // Drop to EL1, w0=cpu_boot_mode
+ bl init_kernel_el // w0=cpu_boot_mode
bl set_cpu_boot_mode_flag
mrs x0, mpidr_el1
mov_q x1, MPIDR_HWID_BITMASK
@@ -717,7 +718,7 @@ SYM_FUNC_END(secondary_holding_pen)
* be used where CPUs are brought online dynamically by the kernel.
*/
SYM_FUNC_START(secondary_entry)
- bl el2_setup // Drop to EL1
+ bl init_kernel_el // w0=cpu_boot_mode
bl set_cpu_boot_mode_flag
b secondary_startup
SYM_FUNC_END(secondary_entry)
diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S
index ba40d57757d63..4be7f7eed8750 100644
--- a/arch/arm64/kernel/sleep.S
+++ b/arch/arm64/kernel/sleep.S
@@ -99,7 +99,7 @@ SYM_FUNC_END(__cpu_suspend_enter)

.pushsection ".idmap.text", "awx"
SYM_CODE_START(cpu_resume)
- bl el2_setup // if in EL2 drop to EL1 cleanly
+ bl init_kernel_el
bl __cpu_setup
/* enable the MMU early - so we can access sleep_save_stash by va */
adrp x1, swapper_pg_dir