Re: [RFC PATCH 5/5] arm64: qcom: add cpu operations
From: Lorenzo Pieralisi
Date: Fri Apr 10 2015 - 06:39:40 EST
On Thu, Apr 09, 2015 at 06:37:11PM +0100, Kumar Gala wrote:
> From: Abhimanyu Kapur <abhimany@xxxxxxxxxxxxxx>
>
> Add qcom cpu operations for arm-v8 cpus. Implement secondary cpu boot ops
> As a part of this change update device tree documentation for:
>
> 1. Arm cortex-a ACC device which provides percpu reg
> 2. Armv8 cortex-a compatible string in arm/cpus.txt
I am pretty sure you heard about a standard FW interface called PSCI,
please implement it and drop this patch, thanks.
Lorenzo
> Signed-off-by: Abhimanyu Kapur <abhimany@xxxxxxxxxxxxxx>
> Signed-off-by: Kumar Gala <galak@xxxxxxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/arm/cpus.txt | 2 +
> Documentation/devicetree/bindings/arm/msm/acc.txt | 19 ++
> drivers/soc/qcom/Makefile | 1 +
> drivers/soc/qcom/cpu_ops.c | 343 ++++++++++++++++++++++
> 4 files changed, 365 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/arm/msm/acc.txt
> create mode 100644 drivers/soc/qcom/cpu_ops.c
>
> diff --git a/Documentation/devicetree/bindings/arm/cpus.txt b/Documentation/devicetree/bindings/arm/cpus.txt
> index 8b9e0a9..35cabe5 100644
> --- a/Documentation/devicetree/bindings/arm/cpus.txt
> +++ b/Documentation/devicetree/bindings/arm/cpus.txt
> @@ -185,6 +185,8 @@ nodes to be present and contain the properties described below.
> be one of:
> "psci"
> "spin-table"
> + "qcom,arm-cortex-acc"
> +
> # On ARM 32-bit systems this property is optional and
> can be one of:
> "allwinner,sun6i-a31"
> diff --git a/Documentation/devicetree/bindings/arm/msm/acc.txt b/Documentation/devicetree/bindings/arm/msm/acc.txt
> new file mode 100644
> index 0000000..ae2d725
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/msm/acc.txt
> @@ -0,0 +1,19 @@
> +Application Processor Sub-system (APSS) Application Clock Controller (ACC)
> +
> +The ACC provides clock, power domain, and reset control to a CPU. There is one ACC
> +register region per CPU within the APSS remapped region as well as an alias register
> +region that remaps accesses to the ACC associated with the CPU accessing the region.
> +
> +Required properties:
> +- compatible: Must be "qcom,arm-cortex-acc"
> +- reg: The first element specifies the base address and size of
> + the register region. An optional second element specifies
> + the base address and size of the alias register region.
> +
> +Example:
> +
> + clock-controller@b088000 {
> + compatible = "qcom,arm-cortex-acc";
> + reg = <0x0b088000 0x1000>,
> + <0x0b008000 0x1000>;
> + }
> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
> index 4389012..bb6030a 100644
> --- a/drivers/soc/qcom/Makefile
> +++ b/drivers/soc/qcom/Makefile
> @@ -1 +1,2 @@
> +obj-$(CONFIG_ARM64) += cpu_ops.o
> obj-$(CONFIG_QCOM_GSBI) += qcom_gsbi.o
> diff --git a/drivers/soc/qcom/cpu_ops.c b/drivers/soc/qcom/cpu_ops.c
> new file mode 100644
> index 0000000..d831cb0
> --- /dev/null
> +++ b/drivers/soc/qcom/cpu_ops.c
> @@ -0,0 +1,343 @@
> +/* Copyright (c) 2014, The Linux Foundation. All rights reserved.
> + * Copyright (c) 2013 ARM Ltd.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * 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.
> + */
> +
> +/* MSM ARMv8 CPU Operations
> + * Based on arch/arm64/kernel/smp_spin_table.c
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/cpu.h>
> +#include <linux/cpumask.h>
> +#include <linux/delay.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/smp.h>
> +#include <linux/qcom_scm.h>
> +
> +#include <asm/barrier.h>
> +#include <asm/cacheflush.h>
> +#include <asm/cpu_ops.h>
> +#include <asm/cputype.h>
> +#include <asm/smp_plat.h>
> +
> +static DEFINE_RAW_SPINLOCK(boot_lock);
> +
> +DEFINE_PER_CPU(int, cold_boot_done);
> +
> +#if 0
> +static int cold_boot_flags[] = {
> + 0,
> + QCOM_SCM_FLAG_COLDBOOT_CPU1,
> + QCOM_SCM_FLAG_COLDBOOT_CPU2,
> + QCOM_SCM_FLAG_COLDBOOT_CPU3,
> +};
> +#endif
> +
> +/* CPU power domain register offsets */
> +#define CPU_PWR_CTL 0x4
> +#define CPU_PWR_GATE_CTL 0x14
> +#define LDO_BHS_PWR_CTL 0x28
> +
> +/* L2 power domain register offsets */
> +#define L2_PWR_CTL_OVERRIDE 0xc
> +#define L2_PWR_CTL 0x14
> +#define L2_PWR_STATUS 0x18
> +#define L2_CORE_CBCR 0x58
> +#define L1_RST_DIS 0x284
> +
> +#define L2_SPM_STS 0xc
> +#define L2_VREG_CTL 0x1c
> +
> +#define SCM_IO_READ 1
> +#define SCM_IO_WRITE 2
> +
> +/*
> + * struct msm_l2ccc_of_info: represents of data for l2 cache clock controller.
> + * @compat: compat string for l2 cache clock controller
> + * @l2_pon: l2 cache power on routine
> + */
> +struct msm_l2ccc_of_info {
> + const char *compat;
> + int (*l2_power_on) (struct device_node *dn, u32 l2_mask, int cpu);
> + u32 l2_power_on_mask;
> +};
> +
> +
> +static int power_on_l2_msm8916(struct device_node *l2ccc_node, u32 pon_mask,
> + int cpu)
> +{
> + u32 pon_status;
> + void __iomem *l2_base;
> +
> + l2_base = of_iomap(l2ccc_node, 0);
> + if (!l2_base)
> + return -ENOMEM;
> +
> + /* Skip power-on sequence if l2 cache is already powered up*/
> + pon_status = (__raw_readl(l2_base + L2_PWR_STATUS) & pon_mask)
> + == pon_mask;
> + if (pon_status) {
> + iounmap(l2_base);
> + return 0;
> + }
> +
> + /* Close L2/SCU Logic GDHS and power up the cache */
> + writel_relaxed(0x10D700, l2_base + L2_PWR_CTL);
> +
> + /* Assert PRESETDBGn */
> + writel_relaxed(0x400000, l2_base + L2_PWR_CTL_OVERRIDE);
> + mb();
> + udelay(2);
> +
> + /* De-assert L2/SCU memory Clamp */
> + writel_relaxed(0x101700, l2_base + L2_PWR_CTL);
> +
> + /* Wakeup L2/SCU RAMs by deasserting sleep signals */
> + writel_relaxed(0x101703, l2_base + L2_PWR_CTL);
> + mb();
> + udelay(2);
> +
> + /* Enable clocks via SW_CLK_EN */
> + writel_relaxed(0x01, l2_base + L2_CORE_CBCR);
> +
> + /* De-assert L2/SCU logic clamp */
> + writel_relaxed(0x101603, l2_base + L2_PWR_CTL);
> + mb();
> + udelay(2);
> +
> + /* De-assert PRESSETDBg */
> + writel_relaxed(0x0, l2_base + L2_PWR_CTL_OVERRIDE);
> +
> + /* De-assert L2/SCU Logic reset */
> + writel_relaxed(0x100203, l2_base + L2_PWR_CTL);
> + mb();
> + udelay(54);
> +
> + /* Turn on the PMIC_APC */
> + writel_relaxed(0x10100203, l2_base + L2_PWR_CTL);
> +
> + /* Set H/W clock control for the cpu CBC block */
> + writel_relaxed(0x03, l2_base + L2_CORE_CBCR);
> + mb();
> + iounmap(l2_base);
> +
> + return 0;
> +}
> +
> +static const struct msm_l2ccc_of_info l2ccc_info[] = {
> + {
> + .compat = "qcom,8916-l2ccc",
> + .l2_power_on = power_on_l2_msm8916,
> + .l2_power_on_mask = BIT(9),
> + },
> +};
> +
> +static int power_on_l2_cache(struct device_node *l2ccc_node, int cpu)
> +{
> + int ret, i;
> + const char *compat;
> +
> + ret = of_property_read_string(l2ccc_node, "compatible", &compat);
> + if (ret)
> + return ret;
> +
> + for (i = 0; i < ARRAY_SIZE(l2ccc_info); i++) {
> + const struct msm_l2ccc_of_info *ptr = &l2ccc_info[i];
> +
> + if (!of_compat_cmp(ptr->compat, compat, strlen(compat)))
> + return ptr->l2_power_on(l2ccc_node,
> + ptr->l2_power_on_mask, cpu);
> + }
> + pr_err("Compat string not found for L2CCC node\n");
> + return -EIO;
> +}
> +
> +static int msm_unclamp_secondary_arm_cpu(unsigned int cpu)
> +{
> +
> + int ret = 0;
> + struct device_node *cpu_node, *acc_node, *l2_node, *l2ccc_node;
> + void __iomem *reg;
> +
> + cpu_node = of_get_cpu_node(cpu, NULL);
> + if (!cpu_node)
> + return -ENODEV;
> +
> + acc_node = of_parse_phandle(cpu_node, "qcom,acc", 0);
> + if (!acc_node) {
> + ret = -ENODEV;
> + goto out_acc;
> + }
> +
> + l2_node = of_parse_phandle(cpu_node, "next-level-cache", 0);
> + if (!l2_node) {
> + ret = -ENODEV;
> + goto out_l2;
> + }
> +
> + l2ccc_node = of_parse_phandle(l2_node, "power-domain", 0);
> + if (!l2ccc_node) {
> + ret = -ENODEV;
> + goto out_l2;
> + }
> +
> + /* Ensure L2-cache of the CPU is powered on before
> + * unclamping cpu power rails.
> + */
> + ret = power_on_l2_cache(l2ccc_node, cpu);
> + if (ret) {
> + pr_err("L2 cache power up failed for CPU%d\n", cpu);
> + goto out_l2ccc;
> + }
> +
> + reg = of_iomap(acc_node, 0);
> + if (!reg) {
> + ret = -ENOMEM;
> + goto out_acc_reg;
> + }
> +
> + /* Assert Reset on cpu-n */
> + writel_relaxed(0x00000033, reg + CPU_PWR_CTL);
> + mb();
> +
> + /*Program skew to 16 X0 clock cycles*/
> + writel_relaxed(0x10000001, reg + CPU_PWR_GATE_CTL);
> + mb();
> + udelay(2);
> +
> + /* De-assert coremem clamp */
> + writel_relaxed(0x00000031, reg + CPU_PWR_CTL);
> + mb();
> +
> + /* Close coremem array gdhs */
> + writel_relaxed(0x00000039, reg + CPU_PWR_CTL);
> + mb();
> + udelay(2);
> +
> + /* De-assert cpu-n clamp */
> + writel_relaxed(0x00020038, reg + CPU_PWR_CTL);
> + mb();
> + udelay(2);
> +
> + /* De-assert cpu-n reset */
> + writel_relaxed(0x00020008, reg + CPU_PWR_CTL);
> + mb();
> +
> + /* Assert PWRDUP signal on core-n */
> + writel_relaxed(0x00020088, reg + CPU_PWR_CTL);
> + mb();
> +
> + /* Secondary CPU-N is now alive */
> + iounmap(reg);
> +out_acc_reg:
> + of_node_put(l2ccc_node);
> +out_l2ccc:
> + of_node_put(l2_node);
> +out_l2:
> + of_node_put(acc_node);
> +out_acc:
> + of_node_put(cpu_node);
> +
> + return ret;
> +}
> +
> +static void write_pen_release(u64 val)
> +{
> + void *start = (void *)&secondary_holding_pen_release;
> + unsigned long size = sizeof(secondary_holding_pen_release);
> +
> + secondary_holding_pen_release = val;
> + smp_wmb();
> + __flush_dcache_area(start, size);
> +}
> +
> +static int secondary_pen_release(unsigned int cpu)
> +{
> + unsigned long timeout;
> +
> + /*
> + * Set synchronisation state between this boot processor
> + * and the secondary one
> + */
> + raw_spin_lock(&boot_lock);
> + write_pen_release(cpu_logical_map(cpu));
> +
> + timeout = jiffies + (1 * HZ);
> + while (time_before(jiffies, timeout)) {
> + if (secondary_holding_pen_release == INVALID_HWID)
> + break;
> + udelay(10);
> + }
> + raw_spin_unlock(&boot_lock);
> +
> + return secondary_holding_pen_release != INVALID_HWID ? -ENOSYS : 0;
> +}
> +
> +static int __init msm_cpu_init(struct device_node *dn, unsigned int cpu)
> +{
> + /* Mark CPU0 cold boot flag as done */
> + if (!cpu && !per_cpu(cold_boot_done, cpu))
> + per_cpu(cold_boot_done, cpu) = true;
> +
> + return 0;
> +}
> +
> +static int __init msm_cpu_prepare(unsigned int cpu)
> +{
> + const cpumask_t *mask = cpumask_of(cpu);
> +
> + if (qcom_scm_set_cold_boot_addr(secondary_holding_pen, mask)) {
> + pr_warn("CPU%d:Failed to set boot address\n", cpu);
> + return -ENOSYS;
> + }
> +
> + return 0;
> +}
> +
> +static int msm_cpu_boot(unsigned int cpu)
> +{
> + int ret = 0;
> +
> + if (per_cpu(cold_boot_done, cpu) == false) {
> + ret = msm_unclamp_secondary_arm_cpu(cpu);
> + if (ret)
> + return ret;
> + per_cpu(cold_boot_done, cpu) = true;
> + }
> + return secondary_pen_release(cpu);
> +}
> +
> +void msm_cpu_postboot(void)
> +{
> + /*
> + * Let the primary processor know we're out of the pen.
> + */
> + write_pen_release(INVALID_HWID);
> +
> + /*
> + * Synchronise with the boot thread.
> + */
> + raw_spin_lock(&boot_lock);
> + raw_spin_unlock(&boot_lock);
> +}
> +
> +static const struct cpu_operations msm_cortex_a_ops = {
> + .name = "qcom,arm-cortex-acc",
> + .cpu_init = msm_cpu_init,
> + .cpu_prepare = msm_cpu_prepare,
> + .cpu_boot = msm_cpu_boot,
> + .cpu_postboot = msm_cpu_postboot,
> +};
> +CPU_METHOD_OF_DECLARE(msm_cortex_a_ops, &msm_cortex_a_ops);
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