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linux-next/arch/arm/mach-vexpress/spc.c
Sudeep Holla 2a76352ad2 ARM: vexpress: Set-up shared OPP table instead of individual for each CPU
Currently we add individual copy of same OPP table for each CPU within
the cluster. This is redundant and doesn't reflect the reality.

We can't use core cpumask to set policy->cpus in ve_spc_cpufreq_init()
anymore as it gets called via cpuhp_cpufreq_online()->cpufreq_online()
->cpufreq_driver->init() and the cpumask gets updated upon CPU hotplug
operations. It also may cause issues when the vexpress_spc_cpufreq
driver is built as a module.

Since ve_spc_clk_init is built-in device initcall, we should be able to
use the same topology_core_cpumask to set the opp sharing cpumask via
dev_pm_opp_set_sharing_cpus and use the same later in the driver via
dev_pm_opp_get_sharing_cpus.

Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-12-09 11:52:50 +00:00

599 lines
14 KiB
C

/*
* Versatile Express Serial Power Controller (SPC) support
*
* Copyright (C) 2013 ARM Ltd.
*
* Authors: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
* Achin Gupta <achin.gupta@arm.com>
* Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/pm_opp.h>
#include <linux/slab.h>
#include <linux/semaphore.h>
#include <asm/cacheflush.h>
#include "spc.h"
#define SPCLOG "vexpress-spc: "
#define PERF_LVL_A15 0x00
#define PERF_REQ_A15 0x04
#define PERF_LVL_A7 0x08
#define PERF_REQ_A7 0x0c
#define COMMS 0x10
#define COMMS_REQ 0x14
#define PWC_STATUS 0x18
#define PWC_FLAG 0x1c
/* SPC wake-up IRQs status and mask */
#define WAKE_INT_MASK 0x24
#define WAKE_INT_RAW 0x28
#define WAKE_INT_STAT 0x2c
/* SPC power down registers */
#define A15_PWRDN_EN 0x30
#define A7_PWRDN_EN 0x34
/* SPC per-CPU mailboxes */
#define A15_BX_ADDR0 0x68
#define A7_BX_ADDR0 0x78
/* SPC CPU/cluster reset statue */
#define STANDBYWFI_STAT 0x3c
#define STANDBYWFI_STAT_A15_CPU_MASK(cpu) (1 << (cpu))
#define STANDBYWFI_STAT_A7_CPU_MASK(cpu) (1 << (3 + (cpu)))
/* SPC system config interface registers */
#define SYSCFG_WDATA 0x70
#define SYSCFG_RDATA 0x74
/* A15/A7 OPP virtual register base */
#define A15_PERFVAL_BASE 0xC10
#define A7_PERFVAL_BASE 0xC30
/* Config interface control bits */
#define SYSCFG_START BIT(31)
#define SYSCFG_SCC (6 << 20)
#define SYSCFG_STAT (14 << 20)
/* wake-up interrupt masks */
#define GBL_WAKEUP_INT_MSK (0x3 << 10)
/* TC2 static dual-cluster configuration */
#define MAX_CLUSTERS 2
/*
* Even though the SPC takes max 3-5 ms to complete any OPP/COMMS
* operation, the operation could start just before jiffie is about
* to be incremented. So setting timeout value of 20ms = 2jiffies@100Hz
*/
#define TIMEOUT_US 20000
#define MAX_OPPS 8
#define CA15_DVFS 0
#define CA7_DVFS 1
#define SPC_SYS_CFG 2
#define STAT_COMPLETE(type) ((1 << 0) << (type << 2))
#define STAT_ERR(type) ((1 << 1) << (type << 2))
#define RESPONSE_MASK(type) (STAT_COMPLETE(type) | STAT_ERR(type))
struct ve_spc_opp {
unsigned long freq;
unsigned long u_volt;
};
struct ve_spc_drvdata {
void __iomem *baseaddr;
/*
* A15s cluster identifier
* It corresponds to A15 processors MPIDR[15:8] bitfield
*/
u32 a15_clusid;
uint32_t cur_rsp_mask;
uint32_t cur_rsp_stat;
struct semaphore sem;
struct completion done;
struct ve_spc_opp *opps[MAX_CLUSTERS];
int num_opps[MAX_CLUSTERS];
};
static struct ve_spc_drvdata *info;
static inline bool cluster_is_a15(u32 cluster)
{
return cluster == info->a15_clusid;
}
/**
* ve_spc_global_wakeup_irq()
*
* Function to set/clear global wakeup IRQs. Not protected by locking since
* it might be used in code paths where normal cacheable locks are not
* working. Locking must be provided by the caller to ensure atomicity.
*
* @set: if true, global wake-up IRQs are set, if false they are cleared
*/
void ve_spc_global_wakeup_irq(bool set)
{
u32 reg;
reg = readl_relaxed(info->baseaddr + WAKE_INT_MASK);
if (set)
reg |= GBL_WAKEUP_INT_MSK;
else
reg &= ~GBL_WAKEUP_INT_MSK;
writel_relaxed(reg, info->baseaddr + WAKE_INT_MASK);
}
/**
* ve_spc_cpu_wakeup_irq()
*
* Function to set/clear per-CPU wake-up IRQs. Not protected by locking since
* it might be used in code paths where normal cacheable locks are not
* working. Locking must be provided by the caller to ensure atomicity.
*
* @cluster: mpidr[15:8] bitfield describing cluster affinity level
* @cpu: mpidr[7:0] bitfield describing cpu affinity level
* @set: if true, wake-up IRQs are set, if false they are cleared
*/
void ve_spc_cpu_wakeup_irq(u32 cluster, u32 cpu, bool set)
{
u32 mask, reg;
if (cluster >= MAX_CLUSTERS)
return;
mask = BIT(cpu);
if (!cluster_is_a15(cluster))
mask <<= 4;
reg = readl_relaxed(info->baseaddr + WAKE_INT_MASK);
if (set)
reg |= mask;
else
reg &= ~mask;
writel_relaxed(reg, info->baseaddr + WAKE_INT_MASK);
}
/**
* ve_spc_set_resume_addr() - set the jump address used for warm boot
*
* @cluster: mpidr[15:8] bitfield describing cluster affinity level
* @cpu: mpidr[7:0] bitfield describing cpu affinity level
* @addr: physical resume address
*/
void ve_spc_set_resume_addr(u32 cluster, u32 cpu, u32 addr)
{
void __iomem *baseaddr;
if (cluster >= MAX_CLUSTERS)
return;
if (cluster_is_a15(cluster))
baseaddr = info->baseaddr + A15_BX_ADDR0 + (cpu << 2);
else
baseaddr = info->baseaddr + A7_BX_ADDR0 + (cpu << 2);
writel_relaxed(addr, baseaddr);
}
/**
* ve_spc_powerdown()
*
* Function to enable/disable cluster powerdown. Not protected by locking
* since it might be used in code paths where normal cacheable locks are not
* working. Locking must be provided by the caller to ensure atomicity.
*
* @cluster: mpidr[15:8] bitfield describing cluster affinity level
* @enable: if true enables powerdown, if false disables it
*/
void ve_spc_powerdown(u32 cluster, bool enable)
{
u32 pwdrn_reg;
if (cluster >= MAX_CLUSTERS)
return;
pwdrn_reg = cluster_is_a15(cluster) ? A15_PWRDN_EN : A7_PWRDN_EN;
writel_relaxed(enable, info->baseaddr + pwdrn_reg);
}
static u32 standbywfi_cpu_mask(u32 cpu, u32 cluster)
{
return cluster_is_a15(cluster) ?
STANDBYWFI_STAT_A15_CPU_MASK(cpu)
: STANDBYWFI_STAT_A7_CPU_MASK(cpu);
}
/**
* ve_spc_cpu_in_wfi(u32 cpu, u32 cluster)
*
* @cpu: mpidr[7:0] bitfield describing CPU affinity level within cluster
* @cluster: mpidr[15:8] bitfield describing cluster affinity level
*
* @return: non-zero if and only if the specified CPU is in WFI
*
* Take care when interpreting the result of this function: a CPU might
* be in WFI temporarily due to idle, and is not necessarily safely
* parked.
*/
int ve_spc_cpu_in_wfi(u32 cpu, u32 cluster)
{
int ret;
u32 mask = standbywfi_cpu_mask(cpu, cluster);
if (cluster >= MAX_CLUSTERS)
return 1;
ret = readl_relaxed(info->baseaddr + STANDBYWFI_STAT);
pr_debug("%s: PCFGREG[0x%X] = 0x%08X, mask = 0x%X\n",
__func__, STANDBYWFI_STAT, ret, mask);
return ret & mask;
}
static int ve_spc_get_performance(int cluster, u32 *freq)
{
struct ve_spc_opp *opps = info->opps[cluster];
u32 perf_cfg_reg = 0;
u32 perf;
perf_cfg_reg = cluster_is_a15(cluster) ? PERF_LVL_A15 : PERF_LVL_A7;
perf = readl_relaxed(info->baseaddr + perf_cfg_reg);
if (perf >= info->num_opps[cluster])
return -EINVAL;
opps += perf;
*freq = opps->freq;
return 0;
}
/* find closest match to given frequency in OPP table */
static int ve_spc_round_performance(int cluster, u32 freq)
{
int idx, max_opp = info->num_opps[cluster];
struct ve_spc_opp *opps = info->opps[cluster];
u32 fmin = 0, fmax = ~0, ftmp;
freq /= 1000; /* OPP entries in kHz */
for (idx = 0; idx < max_opp; idx++, opps++) {
ftmp = opps->freq;
if (ftmp >= freq) {
if (ftmp <= fmax)
fmax = ftmp;
} else {
if (ftmp >= fmin)
fmin = ftmp;
}
}
if (fmax != ~0)
return fmax * 1000;
else
return fmin * 1000;
}
static int ve_spc_find_performance_index(int cluster, u32 freq)
{
int idx, max_opp = info->num_opps[cluster];
struct ve_spc_opp *opps = info->opps[cluster];
for (idx = 0; idx < max_opp; idx++, opps++)
if (opps->freq == freq)
break;
return (idx == max_opp) ? -EINVAL : idx;
}
static int ve_spc_waitforcompletion(int req_type)
{
int ret = wait_for_completion_interruptible_timeout(
&info->done, usecs_to_jiffies(TIMEOUT_US));
if (ret == 0)
ret = -ETIMEDOUT;
else if (ret > 0)
ret = info->cur_rsp_stat & STAT_COMPLETE(req_type) ? 0 : -EIO;
return ret;
}
static int ve_spc_set_performance(int cluster, u32 freq)
{
u32 perf_cfg_reg;
int ret, perf, req_type;
if (cluster_is_a15(cluster)) {
req_type = CA15_DVFS;
perf_cfg_reg = PERF_LVL_A15;
} else {
req_type = CA7_DVFS;
perf_cfg_reg = PERF_LVL_A7;
}
perf = ve_spc_find_performance_index(cluster, freq);
if (perf < 0)
return perf;
if (down_timeout(&info->sem, usecs_to_jiffies(TIMEOUT_US)))
return -ETIME;
init_completion(&info->done);
info->cur_rsp_mask = RESPONSE_MASK(req_type);
writel(perf, info->baseaddr + perf_cfg_reg);
ret = ve_spc_waitforcompletion(req_type);
info->cur_rsp_mask = 0;
up(&info->sem);
return ret;
}
static int ve_spc_read_sys_cfg(int func, int offset, uint32_t *data)
{
int ret;
if (down_timeout(&info->sem, usecs_to_jiffies(TIMEOUT_US)))
return -ETIME;
init_completion(&info->done);
info->cur_rsp_mask = RESPONSE_MASK(SPC_SYS_CFG);
/* Set the control value */
writel(SYSCFG_START | func | offset >> 2, info->baseaddr + COMMS);
ret = ve_spc_waitforcompletion(SPC_SYS_CFG);
if (ret == 0)
*data = readl(info->baseaddr + SYSCFG_RDATA);
info->cur_rsp_mask = 0;
up(&info->sem);
return ret;
}
static irqreturn_t ve_spc_irq_handler(int irq, void *data)
{
struct ve_spc_drvdata *drv_data = data;
uint32_t status = readl_relaxed(drv_data->baseaddr + PWC_STATUS);
if (info->cur_rsp_mask & status) {
info->cur_rsp_stat = status;
complete(&drv_data->done);
}
return IRQ_HANDLED;
}
/*
* +--------------------------+
* | 31 20 | 19 0 |
* +--------------------------+
* | m_volt | freq(kHz) |
* +--------------------------+
*/
#define MULT_FACTOR 20
#define VOLT_SHIFT 20
#define FREQ_MASK (0xFFFFF)
static int ve_spc_populate_opps(uint32_t cluster)
{
uint32_t data = 0, off, ret, idx;
struct ve_spc_opp *opps;
opps = kcalloc(MAX_OPPS, sizeof(*opps), GFP_KERNEL);
if (!opps)
return -ENOMEM;
info->opps[cluster] = opps;
off = cluster_is_a15(cluster) ? A15_PERFVAL_BASE : A7_PERFVAL_BASE;
for (idx = 0; idx < MAX_OPPS; idx++, off += 4, opps++) {
ret = ve_spc_read_sys_cfg(SYSCFG_SCC, off, &data);
if (!ret) {
opps->freq = (data & FREQ_MASK) * MULT_FACTOR;
opps->u_volt = (data >> VOLT_SHIFT) * 1000;
} else {
break;
}
}
info->num_opps[cluster] = idx;
return ret;
}
static int ve_init_opp_table(struct device *cpu_dev)
{
int cluster;
int idx, ret = 0, max_opp;
struct ve_spc_opp *opps;
cluster = topology_physical_package_id(cpu_dev->id);
cluster = cluster < 0 ? 0 : cluster;
max_opp = info->num_opps[cluster];
opps = info->opps[cluster];
for (idx = 0; idx < max_opp; idx++, opps++) {
ret = dev_pm_opp_add(cpu_dev, opps->freq * 1000, opps->u_volt);
if (ret) {
dev_warn(cpu_dev, "failed to add opp %lu %lu\n",
opps->freq, opps->u_volt);
return ret;
}
}
return ret;
}
int __init ve_spc_init(void __iomem *baseaddr, u32 a15_clusid, int irq)
{
int ret;
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info)
return -ENOMEM;
info->baseaddr = baseaddr;
info->a15_clusid = a15_clusid;
if (irq <= 0) {
pr_err(SPCLOG "Invalid IRQ %d\n", irq);
kfree(info);
return -EINVAL;
}
init_completion(&info->done);
readl_relaxed(info->baseaddr + PWC_STATUS);
ret = request_irq(irq, ve_spc_irq_handler, IRQF_TRIGGER_HIGH
| IRQF_ONESHOT, "vexpress-spc", info);
if (ret) {
pr_err(SPCLOG "IRQ %d request failed\n", irq);
kfree(info);
return -ENODEV;
}
sema_init(&info->sem, 1);
/*
* Multi-cluster systems may need this data when non-coherent, during
* cluster power-up/power-down. Make sure driver info reaches main
* memory.
*/
sync_cache_w(info);
sync_cache_w(&info);
return 0;
}
struct clk_spc {
struct clk_hw hw;
int cluster;
};
#define to_clk_spc(spc) container_of(spc, struct clk_spc, hw)
static unsigned long spc_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_spc *spc = to_clk_spc(hw);
u32 freq;
if (ve_spc_get_performance(spc->cluster, &freq))
return -EIO;
return freq * 1000;
}
static long spc_round_rate(struct clk_hw *hw, unsigned long drate,
unsigned long *parent_rate)
{
struct clk_spc *spc = to_clk_spc(hw);
return ve_spc_round_performance(spc->cluster, drate);
}
static int spc_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_spc *spc = to_clk_spc(hw);
return ve_spc_set_performance(spc->cluster, rate / 1000);
}
static struct clk_ops clk_spc_ops = {
.recalc_rate = spc_recalc_rate,
.round_rate = spc_round_rate,
.set_rate = spc_set_rate,
};
static struct clk *ve_spc_clk_register(struct device *cpu_dev)
{
struct clk_init_data init;
struct clk_spc *spc;
spc = kzalloc(sizeof(*spc), GFP_KERNEL);
if (!spc)
return ERR_PTR(-ENOMEM);
spc->hw.init = &init;
spc->cluster = topology_physical_package_id(cpu_dev->id);
spc->cluster = spc->cluster < 0 ? 0 : spc->cluster;
init.name = dev_name(cpu_dev);
init.ops = &clk_spc_ops;
init.flags = CLK_GET_RATE_NOCACHE;
init.num_parents = 0;
return devm_clk_register(cpu_dev, &spc->hw);
}
static int __init ve_spc_clk_init(void)
{
int cpu, cluster;
struct clk *clk;
bool init_opp_table[MAX_CLUSTERS] = { false };
if (!info)
return 0; /* Continue only if SPC is initialised */
if (ve_spc_populate_opps(0) || ve_spc_populate_opps(1)) {
pr_err("failed to build OPP table\n");
return -ENODEV;
}
for_each_possible_cpu(cpu) {
struct device *cpu_dev = get_cpu_device(cpu);
if (!cpu_dev) {
pr_warn("failed to get cpu%d device\n", cpu);
continue;
}
clk = ve_spc_clk_register(cpu_dev);
if (IS_ERR(clk)) {
pr_warn("failed to register cpu%d clock\n", cpu);
continue;
}
if (clk_register_clkdev(clk, NULL, dev_name(cpu_dev))) {
pr_warn("failed to register cpu%d clock lookup\n", cpu);
continue;
}
cluster = topology_physical_package_id(cpu_dev->id);
if (init_opp_table[cluster])
continue;
if (ve_init_opp_table(cpu_dev))
pr_warn("failed to initialise cpu%d opp table\n", cpu);
else if (dev_pm_opp_set_sharing_cpus(cpu_dev,
topology_core_cpumask(cpu_dev->id)))
pr_warn("failed to mark OPPs shared for cpu%d\n", cpu);
else
init_opp_table[cluster] = true;
}
platform_device_register_simple("vexpress-spc-cpufreq", -1, NULL, 0);
return 0;
}
device_initcall(ve_spc_clk_init);