Hi,
On Mon, Jan 12, 2015 at 08:56:45PM +0000, Arnab Basu wrote:
Implement core support for PSCI. As this is generic code, it doesn't implement anything really useful (all the functions are returning Not Implemented).
This is largely ported from the similar code that exists for ARMv7
Signed-off-by: Arnab Basu arnab_basu@rocketmail.com Cc: Bhupesh Sharma bhupesh.sharma@freescale.com Cc: Marc Zyngier marc.zyngier@arm.com
arch/arm/cpu/armv8/Makefile | 3 +- arch/arm/cpu/armv8/psci.S | 162 +++++++++++++++++++++++++++++++++++++++ arch/arm/include/asm/armv8/esr.h | 12 +++ 3 files changed, 176 insertions(+), 1 deletion(-) create mode 100644 arch/arm/cpu/armv8/psci.S create mode 100644 arch/arm/include/asm/armv8/esr.h
diff --git a/arch/arm/cpu/armv8/Makefile b/arch/arm/cpu/armv8/Makefile index 74c32b2..1c696ea 100644 --- a/arch/arm/cpu/armv8/Makefile +++ b/arch/arm/cpu/armv8/Makefile @@ -16,4 +16,5 @@ obj-y += tlb.o obj-y += transition.o obj-y += cpu-dt.o
-obj-$(CONFIG_FSL_LSCH3) += fsl-lsch3/ +obj-$(CONFIG_ARMV8_PSCI) += psci.o +obj-$(CONFIG_FSL_LSCH3) += fsl-lsch3/ diff --git a/arch/arm/cpu/armv8/psci.S b/arch/arm/cpu/armv8/psci.S new file mode 100644 index 0000000..6028020 --- /dev/null +++ b/arch/arm/cpu/armv8/psci.S @@ -0,0 +1,162 @@ +/*
- (C) Copyright 2014
- Arnab Basu arnab.basu@freescale.com
- (C) Copyright 2015
- Arnab Basu arnab_basu@rocketmail.com
- Based on arch/arm/cpu/armv7/psci.S
- SPDX-License-Identifier: GPL-2.0+
- */
+#include <linux/linkage.h> +#include <asm/psci.h> +#include <asm/armv8/esr.h>
+#define PSCI_FN(__id, __fn) \
.quad __id; \.quad __fn+.pushsection ._secure.text, "ax"
+ENTRY(psci_0_2_cpu_suspend_64) +ENTRY(psci_0_2_cpu_on_64) +ENTRY(psci_0_2_affinity_info_64) +ENTRY(psci_0_2_migrate_64) +ENTRY(psci_0_2_migrate_info_up_cpu_64)
- mov x0, #ARM_PSCI_RET_NI /* Return -1 (Not Implemented) */
- ret
+ENDPROC(psci_0_2_cpu_suspend_64) +ENDPROC(psci_0_2_cpu_on_64) +ENDPROC(psci_0_2_affinity_info_64) +ENDPROC(psci_0_2_migrate_64) +ENDPROC(psci_0_2_migrate_info_up_cpu_64) +.weak psci_0_2_cpu_suspend_64 +.weak psci_0_2_cpu_on_64 +.weak psci_0_2_affinity_info_64 +.weak psci_0_2_migrate_64 +.weak psci_0_2_migrate_info_up_cpu_64
You also need to have MIGRATE_INFO_TYPE, which I didn't spot here or elsewhere in this patch.
We need that to be able to detect and handle UP Trusted OSs (i.e. firmware) which requires a particular CPU to remain enabled at all times. While mainline Linux doesn't have that yet, it's coming shortly.
Do you require that a particular CPU remains online? If so you will need to have MIGRATE_INFO_TYPE return 1, and MIGRATE_INFO_UP_CPU return the MPIDR.Aff* fields for the CPU which must remain on.
If any arbitrary CPU can be disabled, it should return 2 (Trusted OS is either not present or does not require migration).
Thanks, Mark
+ENTRY(psci_0_2_psci_version)
- mov x0, #2 /* Return Major = 0, Minor = 2*/
- ret
+ENDPROC(psci_0_2_psci_version)
+.align 4 +_psci_0_2_table:
- PSCI_FN(PSCI_0_2_FN_PSCI_VERSION, psci_0_2_psci_version)
- PSCI_FN(PSCI_0_2_FN64_CPU_SUSPEND, psci_0_2_cpu_suspend_64)
- PSCI_FN(PSCI_0_2_FN64_CPU_ON, psci_0_2_cpu_on_64)
- PSCI_FN(PSCI_0_2_FN64_AFFINITY_INFO, psci_0_2_affinity_info_64)
- PSCI_FN(PSCI_0_2_FN64_MIGRATE, psci_0_2_migrate_64)
- PSCI_FN(PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU, psci_0_2_migrate_info_up_cpu_64)
- PSCI_FN(0, 0)
+.macro psci_enter
- stp x29, x30, [sp, #-16]!
- stp x27, x28, [sp, #-16]!
- stp x25, x26, [sp, #-16]!
- stp x23, x24, [sp, #-16]!
- stp x21, x22, [sp, #-16]!
- stp x19, x20, [sp, #-16]!
str x18, [sp, #-8]!mrs x16, sp_el0mrs x15, elr_el3- stp x15, x16, [sp, #-16]!
- /* Switching to Secure State to Execute U-Boot */
- mrs x4, scr_el3
- bic x4, x4, #1
- msr scr_el3, x4
+.endm
+.macro psci_return
- /* Switching to Non-Secure State to Execute OS */
- mrs x4, scr_el3
- orr x4, x4, #1
- msr scr_el3, x4
ldp x15, x16, [sp], #16msr elr_el3, x15msr sp_el0, x16ldr x18, [sp], #8- ldp x19, x20, [sp], #16
- ldp x21, x22, [sp], #16
- ldp x23, x24, [sp], #16
- ldp x25, x26, [sp], #16
- ldp x27, x28, [sp], #16
- ldp x29, x30, [sp], #16
- eret
+.endm
+ENTRY(_smc_psci)
- psci_enter
- adr x4, _psci_0_2_table
+1: ldp x5, x6, [x4] /* Load PSCI function ID and target PC */
- cbz x5, fn_not_found /* If reach the end, bail out */
- cmp x0, x5 /* If not matching, try next entry */
- b.eq fn_call
- add x4, x4, #16
- b 1b
+fn_call:
- blr x6
- psci_return
+fn_not_found:
- mov x0, #ARM_PSCI_RET_NI /* Return -1 (Not Supported) */
- psci_return
+ENDPROC(_smc_psci)
+ENTRY(unhandled_exception) +/* Returning to the place that caused the exception has the potential to cause
- an endless loop of taking the same exception over and over again. Looping
- here seems marginally better
- */
+1: b 1b +ENDPROC(unhandled_exception)
+__handle_sync:
- str x4, [sp, #-8]!
- mrs x4, esr_el3
- ubfx x4, x4, #26, #6
- cmp x4, #ESR_EC_SMC64
- b.eq smc_found
- ldr x4, [sp], #8
- b unhandled_exception
+smc_found:
- ldr x4, [sp], #8
- b _smc_psci
+/*
- PSCI Exception vectors.
- */
- .align 11
- .globl psci_vectors
+psci_vectors:
- .align 7
- b unhandled_exception /* Current EL Synchronous Thread */
- .align 7
- b unhandled_exception /* Current EL IRQ Thread */
- .align 7
- b unhandled_exception /* Current EL FIQ Thread */
- .align 7
- b unhandled_exception /* Current EL Error Thread */
- .align 7
- b unhandled_exception /* Current EL Synchronous Handler */
- .align 7
- b unhandled_exception /* Current EL IRQ Handler */
- .align 7
- b unhandled_exception /* Current EL FIQ Handler */
- .align 7
- b unhandled_exception /* Current EL Error Handler */
- .align 7
- b __handle_sync /* Lower EL Synchronous (64b) */
- .align 7
- b unhandled_exception /* Lower EL IRQ (64b) */
- .align 7
- b unhandled_exception /* Lower EL FIQ (64b) */
- .align 7
- b unhandled_exception /* Lower EL Error (64b) */
+.popsection diff --git a/arch/arm/include/asm/armv8/esr.h b/arch/arm/include/asm/armv8/esr.h new file mode 100644 index 0000000..59d4289 --- /dev/null +++ b/arch/arm/include/asm/armv8/esr.h @@ -0,0 +1,12 @@ +/*
- Copyright 2015, Arnab Basu arnab_basu@rocketmail.com
- SPDX-License-Identifier: GPL-2.0+
- */
+#ifndef _ARMV8_ESR_H +#define _ARMV8_ESR_H
+#define ESR_EC_SMC64 (0x17)
+#endif /* _ARMV8_ESR_H */
1.9.1