Re: [PATCH v3 6/8] ARM: rockchip: add support smp for rk3036

Heiko Stübner
2015-10-02T09:19:56Z

Hi,

Am Dienstag, 29. September 2015, 10:13:51 schrieb Xing Zheng:
> The rk3036 is dual-core soc, we can use this patch to enable cpu1
> enter boot secondary, and hotplug(online/offline).
>
> Signed-off-by: Xing Zheng <zhengxing@rock-chips.com>
> Reviewed-by: Heiko Stuebner <heiko@sntech.de>
> ---
>
> Changes in v3: None
>
> arch/arm/mach-rockchip/platsmp.c | 142
> ++++++++++++++++++++++++++++++++++++++ 1 file changed, 142 insertions(+)
>
> diff --git a/arch/arm/mach-rockchip/platsmp.c
> b/arch/arm/mach-rockchip/platsmp.c index 3e7a4b7..7864bf3 100644
> --- a/arch/arm/mach-rockchip/platsmp.c
> +++ b/arch/arm/mach-rockchip/platsmp.c
> @@ -34,6 +34,8 @@
>
> static void __iomem *scu_base_addr;
> static void __iomem *sram_base_addr;
> +static void __iomem *cru_base_addr;
> +
> static int ncores;
>
> #define PMU_PWRDN_CON 0x08
> @@ -41,6 +43,8 @@ static int ncores;
>
> #define PMU_PWRDN_SCU 4
>
> +#define RK3036_SOFTRST_CON(x) ((x) * 0x4 + 0x110)
> +
> static struct regmap *pmu;
>
> static int pmu_power_domain_is_on(int pd)
> @@ -350,3 +354,141 @@ static struct smp_operations rockchip_smp_ops
> __initdata = { };
>
> CPU_METHOD_OF_DECLARE(rk3066_smp, "rockchip,rk3066-smp",
> &rockchip_smp_ops); +
> +/* for RK3036 */
> +
> +static int rk3036_set_power_domain(int pd, bool on)
> +{
> + struct reset_control *rstc = rockchip_get_core_reset(pd);
> + u32 val;
> +
> + /* there are 2cpus on rk3036 soc, we just need to be care cpu1 */
> + if (pd != 1)
> + return 0;
> +
> + if (IS_ERR(rstc) && read_cpuid_part() != ARM_CPU_PART_CORTEX_A9) {
> + pr_err("%s: could not get reset control for core %d\n",
> + __func__, pd);
> + return PTR_ERR(rstc);
> + }
> +
> + /*
> + * We need to soft reset the cpu when we turn off the cpu power domain,
> + * or else the active processors might be stalled when the individual
> + * processor is powered down.
> + */
> + if (!IS_ERR(rstc) && !on)
> + reset_control_assert(rstc);
> +
> + val = (on) ? 0 : 1;
> + val = (val << pd) | BIT(pd + 16);
> + writel_relaxed(val, cru_base_addr + RK3036_SOFTRST_CON(0));

simply mapping the CRU in some arbitary part and then writing to the raw
reset register is just a no-go. Even more, as it also conflicts with the
reset-control handling directly above and below.

> +
> + dsb();
> +
> + if (!IS_ERR(rstc)) {
> + if (on)
> + reset_control_deassert(rstc);
> + reset_control_put(rstc);
> + }
> +
> + return 0;
> +}

In general you are duplicating a lot of code for the simple case of not being
able to control the power domains. The following should do the trick as well
I'd think and produce a lot less code duplication?
[of course adapting the dts slightly for the sram now old name]

Heiko

-------------- 8< --------------
>From 3b3910db3a783f625dcc1f05c547680c61c9c818 Mon Sep 17 00:00:00 2001
From: Heiko Stuebner <heiko@sntech.de>
Date: Fri, 2 Oct 2015 10:24:08 +0200
Subject: [PATCH] ARM: rockchip: add support smp for rk3036

The dual-core Cortex A7 rk3036 is a bit special in that it does not allow
to control the actual powerdomain of the cpu cores, while the rest of the
smp-bringup like reset control and entry address handling stays the same.
Its bigger sibling, the quad-core rk3128 again allows powerdomain control.

So allow that case by introducing a separate smp-enable-method, that simply
disables powerdomain handling in the common code.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
Documentation/devicetree/bindings/arm/cpus.txt | 1 +
arch/arm/mach-rockchip/platsmp.c | 45 +++++++++++++++++++-------
2 files changed, 34 insertions(+), 12 deletions(-)

diff --git a/Documentation/devicetree/bindings/arm/cpus.txt b/Documentation/devicetree/bindings/arm/cpus.txt
index 91e6e5c..261cc27 100644
--- a/Documentation/devicetree/bindings/arm/cpus.txt
+++ b/Documentation/devicetree/bindings/arm/cpus.txt
@@ -198,6 +198,7 @@ nodes to be present and contain the properties described below.
"qcom,gcc-msm8660"
"qcom,kpss-acc-v1"
"qcom,kpss-acc-v2"
+ "rockchip,rk3036-smp"
"rockchip,rk3066-smp"
"ste,dbx500-smp"

diff --git a/arch/arm/mach-rockchip/platsmp.c b/arch/arm/mach-rockchip/platsmp.c
index 3e7a4b7..5c138f9 100644
--- a/arch/arm/mach-rockchip/platsmp.c
+++ b/arch/arm/mach-rockchip/platsmp.c
@@ -42,6 +42,7 @@ static int ncores;
#define PMU_PWRDN_SCU 4

static struct regmap *pmu;
+static int has_pmu = true;

static int pmu_power_domain_is_on(int pd)
{
@@ -89,20 +90,23 @@ static int pmu_set_power_domain(int pd, bool on)
if (!IS_ERR(rstc) && !on)
reset_control_assert(rstc);

- ret = regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), val);
- if (ret < 0) {
- pr_err("%s: could not update power domain\n", __func__);
- return ret;
- }
-
- ret = -1;
- while (ret != on) {
- ret = pmu_power_domain_is_on(pd);
+ if (has_pmu) {
+ ret = regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), val);
if (ret < 0) {
- pr_err("%s: could not read power domain state\n",
+ pr_err("%s: could not update power domain\n",
__func__);
return ret;
}
+
+ ret = -1;
+ while (ret != on) {
+ ret = pmu_power_domain_is_on(pd);
+ if (ret < 0) {
+ pr_err("%s: could not read power domain state\n",
+ __func__);
+ return ret;
+ }
+ }
}

if (!IS_ERR(rstc)) {
@@ -122,7 +126,7 @@ static int rockchip_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
int ret;

- if (!sram_base_addr || !pmu) {
+ if (!sram_base_addr || (has_pmu && !pmu)) {
pr_err("%s: sram or pmu missing for cpu boot\n", __func__);
return -ENXIO;
}
@@ -275,7 +279,7 @@ static void __init rockchip_smp_prepare_cpus(unsigned int max_cpus)
return;
}

- if (rockchip_smp_prepare_pmu())
+ if (has_pmu && rockchip_smp_prepare_pmu())
return;

if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) {
@@ -318,6 +322,13 @@ static void __init rockchip_smp_prepare_cpus(unsigned int max_cpus)
pmu_set_power_domain(0 + i, false);
}

+static void __init rk3036_smp_prepare_cpus(unsigned int max_cpus)
+{
+ has_pmu = false;
+
+ rockchip_smp_prepare_cpus(max_cpus);
+}
+
#ifdef CONFIG_HOTPLUG_CPU
static int rockchip_cpu_kill(unsigned int cpu)
{
@@ -340,6 +351,15 @@ static void rockchip_cpu_die(unsigned int cpu)
}
#endif

+static struct smp_operations rk3036_smp_ops __initdata = {
+ .smp_prepare_cpus = rk3036_smp_prepare_cpus,
+ .smp_boot_secondary = rockchip_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+ .cpu_kill = rockchip_cpu_kill,
+ .cpu_die = rockchip_cpu_die,
+#endif
+};
+
static struct smp_operations rockchip_smp_ops __initdata = {
.smp_prepare_cpus = rockchip_smp_prepare_cpus,
.smp_boot_secondary = rockchip_boot_secondary,
@@ -349,4 +369,5 @@ static struct smp_operations rockchip_smp_ops __initdata = {
#endif
};

+CPU_METHOD_OF_DECLARE(rk3036_smp, "rockchip,rk3036-smp", &rk3036_smp_ops);
CPU_METHOD_OF_DECLARE(rk3066_smp, "rockchip,rk3066-smp", &rockchip_smp_ops);
--
2.5.3
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