arm-trusted-firmware/services/std_svc/psci/psci_entry.S
Achin Gupta 0c8d4fef28 Unmask SError interrupt and clear SCR_EL3.EA bit
This patch disables routing of external aborts from lower exception levels to
EL3 and ensures that a SError interrupt generated as a result of execution in
EL3 is taken locally instead of a lower exception level.

The SError interrupt is enabled in the TSP code only when the operation has not
been directly initiated by the normal world. This is to prevent the possibility
of an asynchronous external abort which originated in normal world from being
taken when execution is in S-EL1.

Fixes ARM-software/tf-issues#153

Change-Id: I157b996c75996d12fd86d27e98bc73dd8bce6cd5
2014-08-15 10:21:50 +01:00

164 lines
5.4 KiB
ArmAsm

/*
* Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of ARM nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <arch.h>
#include <asm_macros.S>
#include <psci.h>
#include <xlat_tables.h>
.globl psci_aff_on_finish_entry
.globl psci_aff_suspend_finish_entry
.globl __psci_cpu_off
.globl __psci_cpu_suspend
.globl psci_power_down_wfi
/* -----------------------------------------------------
* This cpu has been physically powered up. Depending
* upon whether it was resumed from suspend or simply
* turned on, call the common power on finisher with
* the handlers (chosen depending upon original state).
* -----------------------------------------------------
*/
func psci_aff_on_finish_entry
adr x23, psci_afflvl_on_finishers
b psci_aff_common_finish_entry
psci_aff_suspend_finish_entry:
adr x23, psci_afflvl_suspend_finishers
psci_aff_common_finish_entry:
#if !RESET_TO_BL31
/* ---------------------------------------------
* Enable the instruction cache, stack pointer
* and data access alignment checks. Also, set
* the EL3 exception endianess to little-endian.
* It can be assumed that BL3-1 entrypoint code
* will do this when RESET_TO_BL31 is set. The
* same assumption cannot be made when another
* boot loader executes before BL3-1 in the warm
* boot path e.g. BL1.
* ---------------------------------------------
*/
mov x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT)
mrs x0, sctlr_el3
orr x0, x0, x1
msr sctlr_el3, x0
isb
#endif
/* ---------------------------------------------
* Initialise the pcpu cache pointer for the CPU
* ---------------------------------------------
*/
bl init_cpu_data_ptr
/* ---------------------------------------------
* Set the exception vectors
* ---------------------------------------------
*/
adr x0, runtime_exceptions
msr vbar_el3, x0
isb
/* ---------------------------------------------
* Enable the SError interrupt now that the
* exception vectors have been setup.
* ---------------------------------------------
*/
msr daifclr, #DAIF_ABT_BIT
/* ---------------------------------------------
* Use SP_EL0 for the C runtime stack.
* ---------------------------------------------
*/
msr spsel, #0
/* --------------------------------------------
* Give ourselves a stack whose memory will be
* marked as Normal-IS-WBWA when the MMU is
* enabled.
* --------------------------------------------
*/
mrs x0, mpidr_el1
bl platform_set_stack
/* --------------------------------------------
* Enable the MMU with the DCache disabled. It
* is safe to use stacks allocated in normal
* memory as a result. All memory accesses are
* marked nGnRnE when the MMU is disabled. So
* all the stack writes will make it to memory.
* All memory accesses are marked Non-cacheable
* when the MMU is enabled but D$ is disabled.
* So used stack memory is guaranteed to be
* visible immediately after the MMU is enabled
* Enabling the DCache at the same time as the
* MMU can lead to speculatively fetched and
* possibly stale stack memory being read from
* other caches. This can lead to coherency
* issues.
* --------------------------------------------
*/
mov x0, #DISABLE_DCACHE
bl bl31_plat_enable_mmu
/* ---------------------------------------------
* Call the finishers starting from affinity
* level 0.
* ---------------------------------------------
*/
mrs x0, mpidr_el1
bl get_power_on_target_afflvl
cmp x0, xzr
b.lt _panic
mov x2, x23
mov x1, x0
mov x0, #MPIDR_AFFLVL0
bl psci_afflvl_power_on_finish
b el3_exit
_panic:
b _panic
/* --------------------------------------------
* This function is called to indicate to the
* power controller that it is safe to power
* down this cpu. It should not exit the wfi
* and will be released from reset upon power
* up. 'wfi_spill' is used to catch erroneous
* exits from wfi.
* --------------------------------------------
*/
func psci_power_down_wfi
dsb sy // ensure write buffer empty
wfi
wfi_spill:
b wfi_spill