| /* |
| * Copyright (c) 2013, ARM Limited. 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 <stdio.h> |
| #include <string.h> |
| #include <assert.h> |
| #include <arch_helpers.h> |
| #include <console.h> |
| #include <platform.h> |
| #include <psci.h> |
| #include <psci_private.h> |
| |
| typedef int (*afflvl_off_handler)(unsigned long, aff_map_node *); |
| |
| /******************************************************************************* |
| * The next three functions implement a handler for each supported affinity |
| * level which is called when that affinity level is turned off. |
| ******************************************************************************/ |
| static int psci_afflvl0_off(unsigned long mpidr, aff_map_node *cpu_node) |
| { |
| unsigned int index, plat_state; |
| int rc = PSCI_E_SUCCESS; |
| unsigned long sctlr = read_sctlr(); |
| |
| assert(cpu_node->level == MPIDR_AFFLVL0); |
| |
| /* |
| * Generic management: Get the index for clearing any |
| * lingering re-entry information |
| */ |
| index = cpu_node->data; |
| memset(&psci_ns_entry_info[index], 0, sizeof(psci_ns_entry_info[index])); |
| |
| /* |
| * Arch. management. Perform the necessary steps to flush all |
| * cpu caches. |
| * |
| * TODO: This power down sequence varies across cpus so it needs to be |
| * abstracted out on the basis of the MIDR like in cpu_reset_handler(). |
| * Do the bare minimal for the time being. Fix this before porting to |
| * Cortex models. |
| */ |
| sctlr &= ~SCTLR_C_BIT; |
| write_sctlr(sctlr); |
| |
| /* |
| * CAUTION: This flush to the level of unification makes an assumption |
| * about the cache hierarchy at affinity level 0 (cpu) in the platform. |
| * Ideally the platform should tell psci which levels to flush to exit |
| * coherency. |
| */ |
| dcsw_op_louis(DCCISW); |
| |
| /* |
| * Plat. management: Perform platform specific actions to turn this |
| * cpu off e.g. exit cpu coherency, program the power controller etc. |
| */ |
| if (psci_plat_pm_ops->affinst_off) { |
| |
| /* Get the current physical state of this cpu */ |
| plat_state = psci_get_aff_phys_state(cpu_node); |
| rc = psci_plat_pm_ops->affinst_off(mpidr, |
| cpu_node->level, |
| plat_state); |
| } |
| |
| /* |
| * The only error cpu_off can return is E_DENIED. So check if that's |
| * indeed the case. The caller will simply 'eret' in case of an error. |
| */ |
| if (rc != PSCI_E_SUCCESS) |
| assert(rc == PSCI_E_DENIED); |
| |
| return rc; |
| } |
| |
| static int psci_afflvl1_off(unsigned long mpidr, aff_map_node *cluster_node) |
| { |
| int rc = PSCI_E_SUCCESS; |
| unsigned int plat_state; |
| |
| /* Sanity check the cluster level */ |
| assert(cluster_node->level == MPIDR_AFFLVL1); |
| |
| /* |
| * Keep the physical state of this cluster handy to decide |
| * what action needs to be taken |
| */ |
| plat_state = psci_get_aff_phys_state(cluster_node); |
| |
| /* |
| * Arch. Management. Flush all levels of caches to PoC if |
| * the cluster is to be shutdown |
| */ |
| if (plat_state == PSCI_STATE_OFF) |
| dcsw_op_all(DCCISW); |
| |
| /* |
| * Plat. Management. Allow the platform to do it's cluster |
| * specific bookeeping e.g. turn off interconnect coherency, |
| * program the power controller etc. |
| */ |
| if (psci_plat_pm_ops->affinst_off) |
| rc = psci_plat_pm_ops->affinst_off(mpidr, |
| cluster_node->level, |
| plat_state); |
| |
| return rc; |
| } |
| |
| static int psci_afflvl2_off(unsigned long mpidr, aff_map_node *system_node) |
| { |
| int rc = PSCI_E_SUCCESS; |
| unsigned int plat_state; |
| |
| /* Cannot go beyond this level */ |
| assert(system_node->level == MPIDR_AFFLVL2); |
| |
| /* |
| * Keep the physical state of the system handy to decide what |
| * action needs to be taken |
| */ |
| plat_state = psci_get_aff_phys_state(system_node); |
| |
| /* No arch. and generic bookeeping to do here currently */ |
| |
| /* |
| * Plat. Management : Allow the platform to do it's bookeeping |
| * at this affinity level |
| */ |
| if (psci_plat_pm_ops->affinst_off) |
| rc = psci_plat_pm_ops->affinst_off(mpidr, |
| system_node->level, |
| plat_state); |
| return rc; |
| } |
| |
| static const afflvl_off_handler psci_afflvl_off_handlers[] = { |
| psci_afflvl0_off, |
| psci_afflvl1_off, |
| psci_afflvl2_off, |
| }; |
| |
| /******************************************************************************* |
| * This function implements the core of the processing required to turn a cpu |
| * off. It's assumed that along with turning the cpu off, higher affinity levels |
| * will be turned off as far as possible. We first need to determine the new |
| * state off all the affinity instances in the mpidr corresponding to the target |
| * cpu. Action will be taken on the basis of this new state. To do the state |
| * change we first need to acquire the locks for all the implemented affinity |
| * level to be able to snapshot the system state. Then we need to start turning |
| * affinity levels off from the lowest to the highest (e.g. a cpu needs to be |
| * off before a cluster can be turned off). To achieve this flow, we start |
| * acquiring the locks from the highest to the lowest affinity level. Once we |
| * reach affinity level 0, we do the state change followed by the actions |
| * corresponding to the new state for affinity level 0. Actions as per the |
| * updated state for higher affinity levels are performed as we unwind back to |
| * highest affinity level. |
| ******************************************************************************/ |
| int psci_afflvl_off(unsigned long mpidr, |
| int cur_afflvl, |
| int tgt_afflvl) |
| { |
| int rc = PSCI_E_SUCCESS, level; |
| unsigned int next_state, prev_state; |
| aff_map_node *aff_node; |
| |
| mpidr &= MPIDR_AFFINITY_MASK;; |
| |
| /* |
| * Some affinity instances at levels between the current and |
| * target levels could be absent in the mpidr. Skip them and |
| * start from the first present instance. |
| */ |
| level = psci_get_first_present_afflvl(mpidr, |
| cur_afflvl, |
| tgt_afflvl, |
| &aff_node); |
| /* |
| * Return if there are no more affinity instances beyond this |
| * level to process. Else ensure that the returned affinity |
| * node makes sense. |
| */ |
| if (aff_node == NULL) |
| return rc; |
| |
| assert(level == aff_node->level); |
| |
| /* |
| * This function acquires the lock corresponding to each |
| * affinity level so that state management can be done safely. |
| */ |
| bakery_lock_get(mpidr, &aff_node->lock); |
| |
| /* Keep the old state and the next one handy */ |
| prev_state = psci_get_state(aff_node->state); |
| next_state = PSCI_STATE_OFF; |
| |
| /* |
| * We start from the highest affinity level and work our way |
| * downwards to the lowest i.e. MPIDR_AFFLVL0. |
| */ |
| if (aff_node->level == tgt_afflvl) { |
| psci_change_state(mpidr, |
| tgt_afflvl, |
| get_max_afflvl(), |
| next_state); |
| } else { |
| rc = psci_afflvl_off(mpidr, level - 1, tgt_afflvl); |
| if (rc != PSCI_E_SUCCESS) { |
| psci_set_state(aff_node->state, prev_state); |
| goto exit; |
| } |
| } |
| |
| /* |
| * Perform generic, architecture and platform specific |
| * handling |
| */ |
| rc = psci_afflvl_off_handlers[level](mpidr, aff_node); |
| if (rc != PSCI_E_SUCCESS) { |
| psci_set_state(aff_node->state, prev_state); |
| goto exit; |
| } |
| |
| /* |
| * If all has gone as per plan then this cpu should be |
| * marked as OFF |
| */ |
| if (level == MPIDR_AFFLVL0) { |
| next_state = psci_get_state(aff_node->state); |
| assert(next_state == PSCI_STATE_OFF); |
| } |
| |
| exit: |
| bakery_lock_release(mpidr, &aff_node->lock); |
| return rc; |
| } |