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Diffstat (limited to 'plat/fvp/fvp_topology.c')
| -rw-r--r-- | plat/fvp/fvp_topology.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/plat/fvp/fvp_topology.c b/plat/fvp/fvp_topology.c new file mode 100644 index 0000000..cf21503 --- /dev/null +++ b/plat/fvp/fvp_topology.c @@ -0,0 +1,240 @@ +/* + * 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 <assert.h> +#include <platform_def.h> +/* TODO: Reusing psci error codes & state information. Get our own! */ +#include <psci.h> +#include "drivers/pwrc/fvp_pwrc.h" + +/* We treat '255' as an invalid affinity instance */ +#define AFFINST_INVAL 0xff + +/******************************************************************************* + * We support 3 flavours of the FVP: Foundation, Base AEM & Base Cortex. Each + * flavour has a different topology. The common bit is that there can be a max. + * of 2 clusters (affinity 1) and 4 cpus (affinity 0) per cluster. So we define + * a tree like data structure which caters to these maximum bounds. It simply + * marks the absent affinity level instances as PSCI_AFF_ABSENT e.g. there is no + * cluster 1 on the Foundation FVP. The 'data' field is currently unused. + ******************************************************************************/ +typedef struct affinity_info { + unsigned char sibling; + unsigned char child; + unsigned char state; + unsigned int data; +} affinity_info_t; + +/******************************************************************************* + * The following two data structures store the topology tree for the fvp. There + * is a separate array for each affinity level i.e. cpus and clusters. The child + * and sibling references allow traversal inside and in between the two arrays. + ******************************************************************************/ +static affinity_info_t fvp_aff1_topology_map[PLATFORM_CLUSTER_COUNT]; +static affinity_info_t fvp_aff0_topology_map[PLATFORM_CORE_COUNT]; + +/* Simple global variable to safeguard us from stupidity */ +static unsigned int topology_setup_done; + +/******************************************************************************* + * This function implements a part of the critical interface between the psci + * generic layer and the platform to allow the former to detect the platform + * topology. psci queries the platform to determine how many affinity instances + * are present at a particular level for a given mpidr e.g. consider a dual + * cluster platform where each cluster has 4 cpus. A call to this function with + * (0, 0x100) will return the number of cpus implemented under cluster 1 i.e. 4. + * Similarly a call with (1, 0x100) will return 2 i.e. the number of clusters. + * This is 'cause we are effectively asking how many affinity level 1 instances + * are implemented under affinity level 2 instance 0. + ******************************************************************************/ +unsigned int plat_get_aff_count(unsigned int aff_lvl, + unsigned long mpidr) +{ + unsigned int aff_count = 1, ctr; + unsigned char parent_aff_id; + + assert(topology_setup_done == 1); + + switch (aff_lvl) { + case 3: + case 2: + /* + * Assert if the parent affinity instance is not 0. + * This also takes care of level 3 in an obfuscated way + */ + parent_aff_id = (mpidr >> MPIDR_AFF3_SHIFT) & MPIDR_AFFLVL_MASK; + assert(parent_aff_id == 0); + + /* + * Report that we implement a single instance of + * affinity levels 2 & 3 which are AFF_ABSENT + */ + break; + case 1: + /* Assert if the parent affinity instance is not 0. */ + parent_aff_id = (mpidr >> MPIDR_AFF2_SHIFT) & MPIDR_AFFLVL_MASK; + assert(parent_aff_id == 0); + + /* Fetch the starting index in the aff1 array */ + for (ctr = 0; + fvp_aff1_topology_map[ctr].sibling != AFFINST_INVAL; + ctr = fvp_aff1_topology_map[ctr].sibling) { + aff_count++; + } + + break; + case 0: + /* Assert if the cluster id is anything apart from 0 or 1 */ + parent_aff_id = (mpidr >> MPIDR_AFF1_SHIFT) & MPIDR_AFFLVL_MASK; + assert(parent_aff_id < PLATFORM_CLUSTER_COUNT); + + /* Fetch the starting index in the aff0 array */ + for (ctr = fvp_aff1_topology_map[parent_aff_id].child; + fvp_aff0_topology_map[ctr].sibling != AFFINST_INVAL; + ctr = fvp_aff0_topology_map[ctr].sibling) { + aff_count++; + } + + break; + default: + assert(0); + } + + return aff_count; +} + +/******************************************************************************* + * This function implements a part of the critical interface between the psci + * generic layer and the platform to allow the former to detect the state of a + * affinity instance in the platform topology. psci queries the platform to + * determine whether an affinity instance is present or absent. This caters for + * topologies where an intermediate affinity level instance is missing e.g. + * consider a platform which implements a single cluster with 4 cpus and there + * is another cpu sitting directly on the interconnect along with the cluster. + * The mpidrs of the cluster would range from 0x0-0x3. The mpidr of the single + * cpu would be 0x100 to highlight that it does not belong to cluster 0. Cluster + * 1 is however missing but needs to be accounted to reach this single cpu in + * the topology tree. Hence it will be marked as PSCI_AFF_ABSENT. This is not + * applicable to the FVP but depicted as an example. + ******************************************************************************/ +unsigned int plat_get_aff_state(unsigned int aff_lvl, + unsigned long mpidr) +{ + unsigned int aff_state = PSCI_AFF_ABSENT, idx; + idx = (mpidr >> MPIDR_AFF1_SHIFT) & MPIDR_AFFLVL_MASK; + + assert(topology_setup_done == 1); + + switch (aff_lvl) { + case 3: + case 2: + /* Report affinity levels 2 & 3 as absent */ + break; + case 1: + aff_state = fvp_aff1_topology_map[idx].state; + break; + case 0: + /* + * First get start index of the aff0 in its array & then add + * to it the affinity id that we want the state of + */ + idx = fvp_aff1_topology_map[idx].child; + idx += (mpidr >> MPIDR_AFF0_SHIFT) & MPIDR_AFFLVL_MASK; + aff_state = fvp_aff0_topology_map[idx].state; + break; + default: + assert(0); + } + + return aff_state; +} + +/******************************************************************************* + * Handy optimization to prevent the psci implementation from traversing through + * affinity levels which are not present while detecting the platform topology. + ******************************************************************************/ +int plat_get_max_afflvl() +{ + return MPIDR_AFFLVL1; +} + +/******************************************************************************* + * This function populates the FVP specific topology information depending upon + * the FVP flavour its running on. We construct all the mpidrs we can handle + * and rely on the PWRC.PSYSR to flag absent cpus when their status is queried. + ******************************************************************************/ +int fvp_setup_topology() +{ + unsigned char aff0, aff1, aff_state, aff0_offset = 0; + unsigned long mpidr; + + topology_setup_done = 0; + + for (aff1 = 0; aff1 < PLATFORM_CLUSTER_COUNT; aff1++) { + + fvp_aff1_topology_map[aff1].child = aff0_offset; + fvp_aff1_topology_map[aff1].sibling = aff1 + 1; + + for (aff0 = 0; aff0 < PLATFORM_MAX_CPUS_PER_CLUSTER; aff0++) { + + mpidr = aff1 << MPIDR_AFF1_SHIFT; + mpidr |= aff0 << MPIDR_AFF0_SHIFT; + + if (fvp_pwrc_read_psysr(mpidr) != PSYSR_INVALID) { + /* + * Presence of even a single aff0 indicates + * presence of parent aff1 on the FVP. + */ + aff_state = PSCI_AFF_PRESENT; + fvp_aff1_topology_map[aff1].state = + PSCI_AFF_PRESENT; + } else { + aff_state = PSCI_AFF_ABSENT; + } + + fvp_aff0_topology_map[aff0_offset].child = AFFINST_INVAL; + fvp_aff0_topology_map[aff0_offset].state = aff_state; + fvp_aff0_topology_map[aff0_offset].sibling = + aff0_offset + 1; + + /* Increment the absolute number of aff0s traversed */ + aff0_offset++; + } + + /* Tie-off the last aff0 sibling to -1 to avoid overflow */ + fvp_aff0_topology_map[aff0_offset - 1].sibling = AFFINST_INVAL; + } + + /* Tie-off the last aff1 sibling to AFFINST_INVAL to avoid overflow */ + fvp_aff1_topology_map[aff1 - 1].sibling = AFFINST_INVAL; + + topology_setup_done = 1; + return 0; +} |