arm64: psci: add node hierarchy

In order to properly support more arm64 SoCs PSCI needs
to handle the hierarchy of cpus/clusters within the SoC.
The nodes within PSCI are kept in a tree as well as
a depth-first ordered array of same tree. Additionally,
the PSCI states are now maintained in a hierachal manner.
OFF propogates up the tree as long as all siblings are
set to OFF. ON propogates up the tree until a node is
not already set to OFF.

The SoC provides the operations for determining how many
children are at a given affinity level. Lastly, the
secmon startup has been reworked in that all non-BSP CPUs
wait for instructions from the BSP.

BUG=chrome-os-partner:32136
BRANCH=None
TEST=Can still boot into kernel with SMP.

Change-Id: I036fabaf0f1cefa2841264c47e4092c75a2ff4dc
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 721d408cd110e1b56d38789177b740aa0e54ca33
Original-Change-Id: I520a9726e283bee7edcb514cda28ec1eb31b5ea0
Original-Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/226480
Original-Reviewed-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: http://review.coreboot.org/9390
Tested-by: build bot (Jenkins)
Reviewed-by: Furquan Shaikh <furquan@google.com>
This commit is contained in:
Aaron Durbin 2014-10-28 15:38:17 -05:00 committed by Patrick Georgi
parent 7d62ad05fb
commit b777f3e3d1
6 changed files with 530 additions and 86 deletions

View File

@ -28,23 +28,14 @@
#include <console/console.h>
#include "secmon.h"
enum {
PSCI_CPU_STATE_OFF = 0,
PSCI_CPU_STATE_ON_PENDING,
PSCI_CPU_STATE_ON,
};
struct psci_cpu_state {
uint64_t mpidr;
void *entry;
void *arg;
int state;
};
DECLARE_SPIN_LOCK(psci_spinlock);
static struct psci_cpu_state psci_state[CONFIG_MAX_CPUS];
/* Root of PSCI node tree. */
static struct psci_node psci_root;
/* Array of all the psci_nodes in system. */
static size_t psci_num_nodes;
static struct psci_node **psci_nodes;
static inline void psci_lock(void)
{
@ -56,33 +47,173 @@ static inline void psci_unlock(void)
spin_unlock(&psci_spinlock);
}
static inline int psci_cpu_state_locked(int i)
static inline int psci_state_locked(const struct psci_node *e)
{
return psci_state[i].state;
return e->state;
}
static inline void psci_cpu_set_state_locked(int i, int s)
static inline void psci_set_state_locked(struct psci_node *e, int s)
{
psci_state[i].state = s;
e->state = s;
}
static struct cpu_info *mpidr_to_cpu_info(uint64_t mpidr)
static struct psci_node *psci_node_lookup(uint64_t mpidr, int level)
{
int i;
size_t i;
for (i = 0; i < ARRAY_SIZE(psci_state); i++) {
if (mpidr == psci_state[i].mpidr)
return cpu_info_for_cpu(i);
/* The array of node pointers are in depth-first order of the tree. */
for (i = 0; i < psci_num_nodes; i++) {
struct psci_node *current = psci_nodes[i];
if (current->mpidr > mpidr)
break;
if (current->mpidr < mpidr)
continue;
if (current->level == level)
return current;
}
return NULL;
}
static inline struct psci_node *node_self(void)
{
return psci_node_lookup(cpu_info()->mpidr, PSCI_AFFINITY_LEVEL_0);
}
/* Find the ancestor of node affected by a state transition limited by level. */
static struct psci_node *psci_find_ancestor(struct psci_node *e, int level,
int state)
{
struct psci_node *p;
/* If all siblings of the node are already off then parent can be
* set to off as well. */
if (state == PSCI_STATE_OFF) {
while (1) {
size_t i;
struct psci_node *s;
if (psci_root_node(e))
return e;
p = psci_node_parent(e);
if (p->level > level)
return e;
for (i = 0; i < p->children.num; i++) {
s = &p->children.nodes[i];
/* Don't check target. */
if (s == e)
continue;
if (psci_state_locked(s) != PSCI_STATE_OFF)
return e;
}
return NULL;
e = p;
}
}
/* All ancestors in state OFF are affected. */
if (state == PSCI_STATE_ON_PENDING) {
while (1) {
/* At the root. Return last affected node. */
if (psci_root_node(e))
return e;
p = psci_node_parent(e);
if (p->level > level)
return e;
/* This parent is already ON. */
if (psci_state_locked(p) != PSCI_STATE_OFF)
return e;
e = p;
}
}
/* Default to returning node passed in. */
return e;
}
static void psci_set_hierarchy_state(struct psci_node *from,
struct psci_node *to,
int state)
{
struct psci_node *end;
end = psci_node_parent(to);
while (from != end) {
/* Raced with another CPU as state is already set. */
if (psci_state_locked(from) == state)
break;
psci_set_state_locked(from, state);
from = psci_node_parent(from);
}
}
static void psci_cpu_on_callback(void *arg)
{
struct psci_cpu_state *s = arg;
struct exc_state state;
int target_el;
struct psci_node *e = arg;
psci_turn_on_self(s->entry, s->arg);
psci_lock();
psci_set_hierarchy_state(e, e->cpu_state.ancestor, PSCI_STATE_ON);
psci_unlock();
/* Target EL is determined if HVC is enabled or not. */
target_el = (raw_read_scr_el3() & SCR_HVC_ENABLE) ? EL2 : EL1;
memset(&state, 0, sizeof(state));
state.elx.spsr = get_eret_el(target_el, SPSR_USE_H);
transition_with_entry(e->cpu_state.entry, e->cpu_state.arg, &state);
}
static void psci_cpu_on_prepare(struct psci_node *e,
void *entry, void *arg)
{
struct psci_node *ancestor;
int state = PSCI_STATE_ON_PENDING;
e->cpu_state.entry = entry;
e->cpu_state.arg = arg;
ancestor = psci_find_ancestor(e, PSCI_AFFINITY_LEVEL_HIGHEST, state);
e->cpu_state.ancestor = ancestor;
psci_set_hierarchy_state(e, ancestor, state);
}
static int psci_schedule_cpu_on(struct psci_node *e)
{
struct cpu_action action = {
.run = &psci_cpu_on_callback,
.arg = e,
};
if (arch_run_on_cpu_async(e->cpu_state.ci->id, &action))
return PSCI_RET_INTERNAL_FAILURE;
return PSCI_RET_SUCCESS;
}
void psci_turn_on_self(void *entry, void *arg)
{
struct psci_node *e = node_self();
if (e == NULL) {
printk(BIOS_ERR, "Couldn't turn on self: mpidr %llx\n",
cpu_info()->mpidr);
return;
}
psci_lock();
psci_cpu_on_prepare(e, entry, arg);
psci_unlock();
psci_schedule_cpu_on(e);
}
static void psci_cpu_on(struct psci_func *pf)
@ -90,60 +221,68 @@ static void psci_cpu_on(struct psci_func *pf)
uint64_t entry;
uint64_t target_mpidr;
uint64_t context_id;
struct cpu_info *ci;
int cpu_state;
struct cpu_action action;
struct psci_node *e;
target_mpidr = psci64_arg(pf, PSCI_PARAM_0);
entry = psci64_arg(pf, PSCI_PARAM_1);
context_id = psci64_arg(pf, PSCI_PARAM_2);
ci = mpidr_to_cpu_info(target_mpidr);
e = psci_node_lookup(target_mpidr, PSCI_AFFINITY_LEVEL_0);
if (ci == NULL) {
if (e == NULL) {
psci32_return(pf, PSCI_RET_INVALID_PARAMETERS);
return;
}
psci_lock();
cpu_state = psci_cpu_state_locked(ci->id);
cpu_state = psci_state_locked(e);
if (cpu_state == PSCI_CPU_STATE_ON_PENDING) {
if (cpu_state == PSCI_STATE_ON_PENDING) {
psci32_return(pf, PSCI_RET_ON_PENDING);
psci_unlock();
return;
} else if (cpu_state == PSCI_CPU_STATE_ON) {
} else if (cpu_state == PSCI_STATE_ON) {
psci32_return(pf, PSCI_RET_ALREADY_ON);
psci_unlock();
return;
}
psci_cpu_set_state_locked(ci->id, PSCI_CPU_STATE_ON_PENDING);
/* Set the parameters and initialize the action. */
psci_state[ci->id].entry = (void *)(uintptr_t)entry;
psci_state[ci->id].arg = (void *)(uintptr_t)context_id;
action.run = &psci_cpu_on_callback;
action.arg = &psci_state[ci->id];
if (arch_run_on_cpu_async(ci->id, &action)) {
psci32_return(pf, PSCI_RET_INTERNAL_FAILURE);
psci_unlock();
return;
}
psci_cpu_on_prepare(e, (void *)entry, (void *)context_id);
psci_unlock();
psci32_return(pf, PSCI_RET_SUCCESS);
psci32_return(pf, psci_schedule_cpu_on(e));
}
static void psci_cpu_off(struct psci_func *pf)
static int psci_turn_off_node(struct psci_node *e, int level,
int state_id)
{
struct psci_node *ancestor;
psci_lock();
psci_cpu_set_state_locked(cpu_info()->id, PSCI_CPU_STATE_OFF);
ancestor = psci_find_ancestor(e, level, PSCI_STATE_OFF);
psci_set_hierarchy_state(e, ancestor, PSCI_STATE_OFF);
psci_unlock();
/* TODO(adurbin): writeback cache and actually turn off CPU. */
secmon_trampoline(&secmon_wait_for_action, NULL);
return PSCI_RET_SUCCESS;
}
int psci_turn_off_self(void)
{
struct psci_node *e = node_self();
if (e == NULL) {
printk(BIOS_ERR, "No PSCI node for MPIDR %llx.\n",
cpu_info()->mpidr);
return PSCI_RET_INTERNAL_FAILURE;
}
/* -1 state id indicates to SoC to make its own decision for
* internal state when powering off the node. */
return psci_turn_off_node(e, PSCI_AFFINITY_LEVEL_HIGHEST, -1);
}
static int psci_handler(struct smc_call *smc)
@ -158,7 +297,7 @@ static int psci_handler(struct smc_call *smc)
psci_cpu_on(pf);
break;
case PSCI_CPU_OFF64:
psci_cpu_off(pf);
psci32_return(pf, psci_turn_off_self());
break;
default:
psci32_return(pf, PSCI_RET_NOT_SUPPORTED);
@ -168,41 +307,190 @@ static int psci_handler(struct smc_call *smc)
return 0;
}
static void psci_link_cpu_info(void *arg)
{
struct psci_node *e = node_self();
if (e == NULL) {
printk(BIOS_ERR, "No PSCI node for MPIDR %llx.\n",
cpu_info()->mpidr);
return;
}
e->cpu_state.ci = cpu_info();
}
static int psci_init_node(struct psci_node *e,
struct psci_node *parent,
int level, uint64_t mpidr)
{
size_t i;
uint64_t mpidr_inc;
struct psci_node_group *ng;
size_t num_children;
memset(e, 0, sizeof(*e));
e->mpidr = mpidr;
psci_set_state_locked(e, PSCI_STATE_OFF);
e->parent = parent;
e->level = level;
if (level == PSCI_AFFINITY_LEVEL_0)
return 0;
num_children = soc_psci_ops.children_at_level(level, mpidr);
if (num_children == 0)
return 0;
ng = &e->children;
ng->num = num_children;
ng->nodes = malloc(ng->num * sizeof(struct psci_node));
if (ng->nodes == NULL) {
printk(BIOS_DEBUG, "PSCI: Allocation failure at level %d\n",
level);
return -1;
}
/* Switch to next level below. */
level = psci_level_below(level);
mpidr_inc = mpidr_mask(!!(level == PSCI_AFFINITY_LEVEL_3),
!!(level == PSCI_AFFINITY_LEVEL_2),
!!(level == PSCI_AFFINITY_LEVEL_1),
!!(level == PSCI_AFFINITY_LEVEL_0));
for (i = 0; i < ng->num; i++) {
struct psci_node *c = &ng->nodes[i];
/* Recursively initialize the nodes. */
if (psci_init_node(c, e, level, mpidr))
return -1;
mpidr += mpidr_inc;
}
return 0;
}
static size_t psci_count_children(struct psci_node *e)
{
size_t i;
size_t count;
if (e->level == PSCI_AFFINITY_LEVEL_0)
return 0;
count = e->children.num;
for (i = 0; i < e->children.num; i++)
count += psci_count_children(&e->children.nodes[i]);
return count;
}
static size_t psci_write_nodes(struct psci_node *e, size_t index)
{
size_t i;
/*
* Recursively save node pointers in array. Node pointers are
* ordered in ascending mpidr and descending level within same mpidr.
* i.e. each node is saved in depth-first order of the tree.
*/
if (e->level != PSCI_AFFINITY_ROOT) {
psci_nodes[index] = e;
index++;
}
if (e->level == PSCI_AFFINITY_LEVEL_0)
return index;
for (i = 0; i < e->children.num; i++)
index = psci_write_nodes(&e->children.nodes[i], index);
return index;
}
static int psci_allocate_nodes(void)
{
int level;
size_t num_children;
uint64_t mpidr;
struct psci_node *e;
mpidr = 0;
level = PSCI_AFFINITY_ROOT;
/* Find where the root should start. */
while (psci_level_below(level) >= PSCI_AFFINITY_LEVEL_0) {
num_children = soc_psci_ops.children_at_level(level, mpidr);
if (num_children == 0) {
printk(BIOS_ERR, "PSCI: No children at level %d!\n",
level);
return -1;
}
/* The root starts where the affinity levels branch. */
if (num_children > 1)
break;
level = psci_level_below(level);
}
if (psci_init_node(&psci_root, NULL, level, mpidr)) {
printk(BIOS_ERR, "PSCI init node failure.\n");
return -1;
}
num_children = psci_count_children(&psci_root);
/* Count the root node if isn't a fake node. */
if (psci_root.level != PSCI_AFFINITY_ROOT)
num_children++;
psci_nodes = malloc(num_children * sizeof(void *));
psci_num_nodes = num_children;
if (psci_nodes == NULL) {
printk(BIOS_ERR, "PSCI node pointer array failure.\n");
return -1;
}
num_children = psci_write_nodes(&psci_root, 0);
if (num_children != psci_num_nodes) {
printk(BIOS_ERR, "Wrong nodes written: %zd vs %zd.\n",
num_children, psci_num_nodes);
return -1;
}
/*
* By default all nodes are set to PSCI_STATE_OFF. In order not
* to race with other CPUs turning themselves off set the BSPs
* affinity node to ON.
*/
e = node_self();
if (e == NULL) {
printk(BIOS_ERR, "No PSCI node for BSP.\n");
return -1;
}
psci_set_state_locked(e, PSCI_STATE_ON);
return 0;
}
void psci_init(void)
{
struct cpu_info *ci;
uint64_t mpidr;
struct cpu_action action = {
.run = &psci_link_cpu_info,
};
/* Set this CPUs MPIDR clearing the bits that are not per-cpu. */
ci = cpu_info();
mpidr = raw_read_mpidr_el1();
mpidr &= ~(1ULL << 31); /* RES1 */
mpidr &= ~(1ULL << 30); /* U */
mpidr &= ~(1ULL << 24); /* MT */
psci_state[ci->id].mpidr = mpidr;
if (!cpu_is_bsp())
if (psci_allocate_nodes()) {
printk(BIOS_ERR, "PSCI support not enabled.\n");
return;
}
if (arch_run_on_all_cpus_async(&action))
printk(BIOS_ERR, "Error linking cpu_info to PSCI nodes.\n");
/* Register PSCI handlers. */
if (smc_register_range(PSCI_CPU_OFF64, PSCI_CPU_ON64, &psci_handler))
printk(BIOS_ERR, "Couldn't register PSCI handler.\n");
}
void psci_turn_on_self(void *entry, void *arg)
{
struct exc_state state;
int target_el;
struct cpu_info *ci = cpu_info();
psci_lock();
psci_cpu_set_state_locked(ci->id, PSCI_CPU_STATE_ON);
psci_unlock();
/* Target EL is determined if HVC is enabled or not. */
target_el = (raw_read_scr_el3() & SCR_HVC_ENABLE) ? EL2 : EL1;
memset(&state, 0, sizeof(state));
state.elx.spsr = get_eret_el(target_el, SPSR_USE_H);
transition_with_entry(entry, arg, &state);
}

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@ -30,6 +30,18 @@
#include <stddef.h>
#include "secmon.h"
/* Save initial secmon params per CPU to handle turn up. */
static struct secmon_params *init_params[CONFIG_MAX_CPUS];
static void start_up_cpu(void *arg)
{
struct secmon_params *params = init_params[cpu_info()->id];
if (params == NULL)
psci_turn_off_self();
psci_turn_on_self(params->entry, params->arg);
}
static void cpu_init(int bsp)
{
struct cpu_info *ci = cpu_info();
@ -43,17 +55,26 @@ static void cpu_init(int bsp)
static void secmon_init(struct secmon_params *params, int bsp)
{
struct cpu_action action = {
.run = start_up_cpu,
};
exception_hwinit();
cpu_init(bsp);
init_params[cpu_info()->id] = params;
if (!cpu_is_bsp())
secmon_wait_for_action();
smc_init();
psci_init();
/* Turn on CPU if params are not NULL. */
if (params != NULL)
psci_turn_on_self(params->entry, params->arg);
arch_run_on_all_cpus_async(&action);
secmon_wait_for_action();
printk(BIOS_ERR, "CPU turn on failed for BSP.\n");
while (1)
;
}
void secmon_wait_for_action(void)

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@ -140,7 +140,7 @@ static struct exception_handler smc_handler32 = {
.handler = &smc_handler,
};
void smc_init(void)
static void enable_smc(void *arg)
{
uint32_t scr;
@ -149,9 +149,15 @@ void smc_init(void)
scr &= ~(SCR_SMC_MASK);
scr |= SCR_SMC_ENABLE;
raw_write_scr_el3(scr);
}
if (!cpu_is_bsp())
return;
void smc_init(void)
{
struct cpu_action action = {
.run = enable_smc,
};
arch_run_on_all_cpus_async(&action);
/* Register SMC handlers. */
exception_handler_register(EXC_VID_LOW64_SYNC, &smc_handler64);

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@ -20,6 +20,8 @@
#ifndef __ARCH_PSCI_H__
#define __ARCH_PSCI_H__
#include <stdint.h>
#include <arch/cpu.h>
#include <arch/smc.h>
/* Return Values */
@ -35,6 +37,85 @@ enum {
PSCI_RET_DISABLED = -8,
};
/* Generic PSCI state. */
enum {
PSCI_STATE_OFF = 0,
PSCI_STATE_ON_PENDING,
PSCI_STATE_ON,
};
/* Affinity level support. */
enum {
PSCI_AFFINITY_LEVEL_0,
PSCI_AFFINITY_LEVEL_1,
PSCI_AFFINITY_LEVEL_2,
PSCI_AFFINITY_LEVEL_3,
PSCI_AFFINITY_ROOT,
PSCI_AFFINITY_LEVEL_HIGHEST = PSCI_AFFINITY_ROOT,
};
static inline int psci_level_below(int level)
{
return level - 1;
}
struct psci_node;
struct psci_cpu_state {
struct cpu_info *ci;
void *entry;
void *arg;
/* Ancestor of target to update state in CPU_ON case. */
struct psci_node *ancestor;
};
struct psci_node_group {
size_t num;
struct psci_node *nodes;
};
struct psci_node {
uint64_t mpidr;
/* Affinity level of node. */
int level;
/* Generic power state of this entity. */
int state;
/* The SoC can stash its own state accounting in here. */
int soc_state;
/* Parent of curernt entity. */
struct psci_node *parent;
/*
* CPUs are leaves in the tree. They don't have children. The
* CPU-specific bits of storage can be shared with the children
* storage.
*/
union {
struct psci_node_group children;
struct psci_cpu_state cpu_state;
};
};
static inline struct psci_node *psci_node_parent(const struct psci_node *n)
{
return n->parent;
}
static inline int psci_root_node(const struct psci_node *n)
{
return psci_node_parent(n) == NULL;
}
struct psci_soc_ops {
/*
* Return number of entities one level below given parent affinitly
* level and mpidr.
*/
size_t (*children_at_level)(int parent_level, uint64_t mpidr);
};
/* Each SoC needs to provide the functions in the psci_soc_ops structure. */
extern struct psci_soc_ops soc_psci_ops;
/* PSCI Functions. */
enum {
/* 32-bit System level functions. */
@ -111,5 +192,6 @@ void psci_init(void);
/* Turn on the current CPU within the PSCI subsystem. */
void psci_turn_on_self(void *entry, void *arg);
int psci_turn_off_self(void);
#endif /* __ARCH_PSCI_H__ */

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@ -88,6 +88,7 @@ ramstage-y += ../tegra/usb.c
ramstage-$(CONFIG_ARCH_USE_SECURE_MONITOR) += secmon.c
secmon-$(CONFIG_ARCH_USE_SECURE_MONITOR) += cpu_lib.S
secmon-$(CONFIG_ARCH_USE_SECURE_MONITOR) += psci.c
secmon-$(CONFIG_ARCH_USE_SECURE_MONITOR) += uart.c
modules_arm-y += monotonic_timer.c

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@ -0,0 +1,46 @@
/*
* This file is part of the coreboot project.
*
* Copyright 2014 Google Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA
*/
#include <arch/psci.h>
static size_t children_at_level(int parent_level, uint64_t mpidr)
{
if (mpidr != 0)
return 0;
/* T132 just has 2 cores. 0. Level 1 has 2 children at level 0. */
switch (parent_level) {
case PSCI_AFFINITY_ROOT:
return 1;
case PSCI_AFFINITY_LEVEL_3:
return 1;
case PSCI_AFFINITY_LEVEL_2:
return 1;
case PSCI_AFFINITY_LEVEL_1:
return 2;
case PSCI_AFFINITY_LEVEL_0:
return 0;
default:
return 0;
}
}
struct psci_soc_ops soc_psci_ops = {
.children_at_level = &children_at_level,
};