From mboxrd@z Thu Jan 1 00:00:00 1970 From: james.morse@arm.com (James Morse) Date: Tue, 16 Feb 2016 15:49:24 +0000 Subject: [PATCH v5 12/15] arm64: head.S: el2_setup() to accept sctlr_el1 as an argument In-Reply-To: <1455637767-31561-1-git-send-email-james.morse@arm.com> References: <1455637767-31561-1-git-send-email-james.morse@arm.com> Message-ID: <1455637767-31561-13-git-send-email-james.morse@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org el2_setup() doesn't just configure el2, it configures el1 too. This means we can't use it to re-configure el2 after resume from hibernate, as we will be returned to el1 with the MMU turned off. Split the sctlr_el1 setting code up, so that el2_setup() accepts an initial value as an argument. This value will be ignored if el2_setup() is called at el1: the running value will be preserved with endian correction. Hibernate can now call el2_setup() to re-configure el2, passing the current sctlr_el1 as an argument. Signed-off-by: James Morse --- arch/arm64/include/asm/assembler.h | 9 +++++++++ arch/arm64/include/asm/processor.h | 2 +- arch/arm64/kernel/head.S | 19 ++++++++++++------- arch/arm64/kernel/sleep.S | 1 + 4 files changed, 23 insertions(+), 8 deletions(-) diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index f3854d9b5e31..9a4746302d8d 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -304,6 +304,15 @@ lr .req x30 // link register .endm /* + * Generate the initial sctlr_el1 value for el2_setup to set if we boot at EL2. + */ + .macro init_sctlr_el1 reg + mov \reg, #0x0800 // Set/clear RES{1,0} bits +CPU_BE( movk \reg, #0x33d0, lsl #16) // Set EE and E0E on BE systems +CPU_LE( movk \reg, #0x30d0, lsl #16) // Clear EE and E0E on LE systems + .endm + +/* * Annotate a function as position independent, i.e., safe to be called before * the kernel virtual mapping is activated. */ diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index 07ac4351538e..8973715e582e 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -188,6 +188,6 @@ static inline void spin_lock_prefetch(const void *x) void cpu_enable_pan(void *__unused); -int el2_setup(void); +int el2_setup(unsigned long init_sctlr_el1); #endif /* __ASM_PROCESSOR_H */ diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 5894c7e91e6b..4926093461e9 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -206,6 +206,7 @@ section_table: ENTRY(stext) bl preserve_boot_args + init_sctlr_el1 x0 bl el2_setup // Drop to EL1, w0=cpu_boot_mode adrp x24, __PHYS_OFFSET bl set_cpu_boot_mode_flag @@ -448,8 +449,12 @@ ENDPROC(__mmap_switched) * * Returns either BOOT_CPU_MODE_EL1 or BOOT_CPU_MODE_EL2 if booted in * EL1 or EL2 respectively. + * + * If booted in EL2, SCTLR_EL1 will be initialised with the value in x0 + * (otherwise the existing value will be preserved, with endian correction). */ ENTRY(el2_setup) + mov x1, x0 // preserve passed-in sctlr_el1 mrs x0, CurrentEL cmp x0, #CurrentEL_EL2 b.ne 1f @@ -458,7 +463,7 @@ CPU_BE( orr x0, x0, #(1 << 25) ) // Set the EE bit for EL2 CPU_LE( bic x0, x0, #(1 << 25) ) // Clear the EE bit for EL2 msr sctlr_el2, x0 b 2f -1: mrs x0, sctlr_el1 +1: mrs x0, sctlr_el1 // ignore passed-in sctlr_el1 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 @@ -494,6 +499,10 @@ CPU_LE( bic x0, x0, #(3 << 24) ) // Clear the EE and E0E bits for EL1 3: #endif + /* use sctlr_el1 value we were provided with */ +CPU_BE( orr x1, x1, #(3 << 24) ) // Set the EE and E0E bits for EL1 +CPU_LE( bic x1, x1, #(3 << 24) ) // Clear the EE and E0E bits for EL1 + msr sctlr_el1, x1 /* Populate ID registers. */ mrs x0, midr_el1 @@ -501,12 +510,6 @@ CPU_LE( bic x0, x0, #(3 << 24) ) // Clear the EE and E0E bits for EL1 msr vpidr_el2, x0 msr vmpidr_el2, x1 - /* sctlr_el1 */ - mov x0, #0x0800 // Set/clear RES{1,0} bits -CPU_BE( movk x0, #0x33d0, lsl #16 ) // Set EE and E0E on BE systems -CPU_LE( movk x0, #0x30d0, lsl #16 ) // Clear EE and E0E on LE systems - msr sctlr_el1, x0 - /* Coprocessor traps. */ mov x0, #0x33ff msr cptr_el2, x0 // Disable copro. traps to EL2 @@ -576,6 +579,7 @@ ENTRY(__boot_cpu_mode) * cores are held until we're ready for them to initialise. */ ENTRY(secondary_holding_pen) + init_sctlr_el1 x0 bl el2_setup // Drop to EL1, w0=cpu_boot_mode bl set_cpu_boot_mode_flag mrs x0, mpidr_el1 @@ -594,6 +598,7 @@ ENDPROC(secondary_holding_pen) * be used where CPUs are brought online dynamically by the kernel. */ ENTRY(secondary_entry) + init_sctlr_el1 x0 bl el2_setup // Drop to EL1 bl set_cpu_boot_mode_flag b secondary_startup diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S index 0e2b36f1fb44..5c66252d2b9f 100644 --- a/arch/arm64/kernel/sleep.S +++ b/arch/arm64/kernel/sleep.S @@ -98,6 +98,7 @@ ENDPROC(__cpu_suspend_enter) .ltorg ENTRY(cpu_resume) + init_sctlr_el1 x0 bl el2_setup // if in EL2 drop to EL1 cleanly /* enable the MMU early - so we can access sleep_save_stash by va */ adr_l lr, __enable_mmu /* __cpu_setup will return here */ -- 2.6.2