From mboxrd@z Thu Jan 1 00:00:00 1970 From: ard.biesheuvel@linaro.org (Ard Biesheuvel) Date: Mon, 4 Apr 2016 16:52:20 +0200 Subject: [PATCH 4/8] arm64/kernel: use ordinary calling convention for EL2 setup In-Reply-To: <1459781544-14310-1-git-send-email-ard.biesheuvel@linaro.org> References: <1459781544-14310-1-git-send-email-ard.biesheuvel@linaro.org> Message-ID: <1459781544-14310-5-git-send-email-ard.biesheuvel@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Since the return value of el2_setup() is almost immediately passed to set_cpu_boot_mode_flag() in all cases, there is no need to use a callee saved register w20, but we can use simply use w0 instead. Signed-off-by: Ard Biesheuvel --- arch/arm64/kernel/head.S | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index f441fc73a7a2..2a1b3ba1d81c 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -211,7 +211,7 @@ section_table: ENTRY(stext) bl preserve_boot_args - bl el2_setup // Drop to EL1, w20=cpu_boot_mode + bl el2_setup // Drop to EL1, w0=cpu_boot_mode mov x23, xzr // KASLR offset, defaults to 0 adrp x24, __PHYS_OFFSET bl set_cpu_boot_mode_flag @@ -530,7 +530,7 @@ CPU_LE( bic x0, x0, #(1 << 25) ) // Clear the EE bit for EL2 CPU_BE( orr x0, x0, #(3 << 24) ) // Set the EE and E0E bits for EL1 CPU_LE( bic x0, x0, #(3 << 24) ) // Clear the EE and E0E bits for EL1 msr sctlr_el1, x0 - mov w20, #BOOT_CPU_MODE_EL1 // This cpu booted in EL1 + mov w0, #BOOT_CPU_MODE_EL1 // This cpu booted in EL1 isb ret @@ -616,7 +616,7 @@ CPU_LE( movk x0, #0x30d0, lsl #16 ) // Clear EE and E0E on LE systems cbz x2, install_el2_stub - mov w20, #BOOT_CPU_MODE_EL2 // This CPU booted in EL2 + mov w0, #BOOT_CPU_MODE_EL2 // This CPU booted in EL2 isb ret @@ -631,20 +631,20 @@ install_el2_stub: PSR_MODE_EL1h) msr spsr_el2, x0 msr elr_el2, lr - mov w20, #BOOT_CPU_MODE_EL2 // This CPU booted in EL2 + mov w0, #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. + * in x0. See arch/arm64/include/asm/virt.h for more info. */ ENTRY(set_cpu_boot_mode_flag) adr_l x1, __boot_cpu_mode - cmp w20, #BOOT_CPU_MODE_EL2 + cmp w0, #BOOT_CPU_MODE_EL2 b.ne 1f add x1, x1, #4 -1: str w20, [x1] // This CPU has booted in EL1 +1: str w0, [x1] // This CPU has booted in EL1 dmb sy dc ivac, x1 // Invalidate potentially stale cache line ret @@ -669,7 +669,7 @@ ENTRY(__boot_cpu_mode) * cores are held until we're ready for them to initialise. */ ENTRY(secondary_holding_pen) - bl el2_setup // Drop to EL1, w20=cpu_boot_mode + bl el2_setup // Drop to EL1, w0=cpu_boot_mode bl set_cpu_boot_mode_flag mrs x0, mpidr_el1 ldr x1, =MPIDR_HWID_BITMASK -- 2.5.0