arm-trusted-firmware/lib/psci/aarch64/psci_helpers.S
Jeenu Viswambharan 5dd9dbb5bf Add provision to extend CPU operations at more levels
Various CPU drivers in ARM Trusted Firmware register functions to handle
power-down operations. At present, separate functions are registered to
power down individual cores and clusters.

This scheme operates on the basis of core and cluster, and doesn't cater
for extending the hierarchy for power-down operations. For example,
future CPUs might support multiple threads which might need powering
down individually.

This patch therefore reworks the CPU operations framework to allow for
registering power down handlers on specific level basis. Henceforth:

  - Generic code invokes CPU power down operations by the level
    required.

  - CPU drivers explicitly mention CPU_NO_RESET_FUNC when the CPU has no
    reset function.

  - CPU drivers register power down handlers as a list: a mandatory
    handler for level 0, and optional handlers for higher levels.

All existing CPU drivers are adapted to the new CPU operations framework
without needing any functional changes within.

Also update firmware design guide.

Change-Id: I1826842d37a9e60a9e85fdcee7b4b8f6bc1ad043
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
2016-12-15 15:41:40 +00:00

166 lines
5.6 KiB
ArmAsm

/*
* Copyright (c) 2014-2016, 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 <asm_macros.S>
#include <assert_macros.S>
#include <platform_def.h>
#include <psci.h>
.globl psci_do_pwrdown_cache_maintenance
.globl psci_do_pwrup_cache_maintenance
.globl psci_power_down_wfi
#if !ERROR_DEPRECATED
.globl psci_entrypoint
#endif
/* -----------------------------------------------------------------------
* void psci_do_pwrdown_cache_maintenance(unsigned int power level);
*
* This function performs cache maintenance for the specified power
* level. The levels of cache affected are determined by the power
* level which is passed as the argument i.e. level 0 results
* in a flush of the L1 cache. Both the L1 and L2 caches are flushed
* for a higher power level.
*
* Additionally, this function also ensures that stack memory is correctly
* flushed out to avoid coherency issues due to a change in its memory
* attributes after the data cache is disabled.
* -----------------------------------------------------------------------
*/
func psci_do_pwrdown_cache_maintenance
stp x29, x30, [sp,#-16]!
stp x19, x20, [sp,#-16]!
/* ---------------------------------------------
* Invoke CPU-specific power down operations for
* the appropriate level
* ---------------------------------------------
*/
bl prepare_cpu_pwr_dwn
/* ---------------------------------------------
* Do stack maintenance by flushing the used
* stack to the main memory and invalidating the
* remainder.
* ---------------------------------------------
*/
bl plat_get_my_stack
/* ---------------------------------------------
* Calculate and store the size of the used
* stack memory in x1.
* ---------------------------------------------
*/
mov x19, x0
mov x1, sp
sub x1, x0, x1
mov x0, sp
bl flush_dcache_range
/* ---------------------------------------------
* Calculate and store the size of the unused
* stack memory in x1. Calculate and store the
* stack base address in x0.
* ---------------------------------------------
*/
sub x0, x19, #PLATFORM_STACK_SIZE
sub x1, sp, x0
bl inv_dcache_range
ldp x19, x20, [sp], #16
ldp x29, x30, [sp], #16
ret
endfunc psci_do_pwrdown_cache_maintenance
/* -----------------------------------------------------------------------
* void psci_do_pwrup_cache_maintenance(void);
*
* This function performs cache maintenance after this cpu is powered up.
* Currently, this involves managing the used stack memory before turning
* on the data cache.
* -----------------------------------------------------------------------
*/
func psci_do_pwrup_cache_maintenance
stp x29, x30, [sp,#-16]!
/* ---------------------------------------------
* Ensure any inflight stack writes have made it
* to main memory.
* ---------------------------------------------
*/
dmb st
/* ---------------------------------------------
* Calculate and store the size of the used
* stack memory in x1. Calculate and store the
* stack base address in x0.
* ---------------------------------------------
*/
bl plat_get_my_stack
mov x1, sp
sub x1, x0, x1
mov x0, sp
bl inv_dcache_range
/* ---------------------------------------------
* Enable the data cache.
* ---------------------------------------------
*/
mrs x0, sctlr_el3
orr x0, x0, #SCTLR_C_BIT
msr sctlr_el3, x0
isb
ldp x29, x30, [sp], #16
ret
endfunc psci_do_pwrup_cache_maintenance
/* -----------------------------------------------------------------------
* void psci_power_down_wfi(void);
* 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.
* -----------------------------------------------------------------------
*/
func psci_power_down_wfi
dsb sy // ensure write buffer empty
wfi
no_ret plat_panic_handler
endfunc psci_power_down_wfi
/* -----------------------------------------------------------------------
* void psci_entrypoint(void);
* The deprecated entry point for PSCI on warm boot for AArch64.
* -----------------------------------------------------------------------
*/
func_deprecated psci_entrypoint
b bl31_warm_entrypoint
endfunc_deprecated psci_entrypoint