Re: [PATCH 3/4] ARM: msm: Add SMP support for 8960

[Rohit Vaswani <rvaswani@codeaurora.org>]

On 8/2/2013 8:43 AM, Kumar Gala wrote:
> On Aug 1, 2013, at 9:15 PM, Rohit Vaswani wrote:
>
>> Add the cpus bindings and the Krait release sequence
>> to make SMP work for MSM8960
>>
>> Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
>> ---
>> Documentation/devicetree/bindings/arm/cpus.txt     |  2 +
>> Documentation/devicetree/bindings/arm/msm/kpss.txt | 16 ++++++
>> arch/arm/boot/dts/msm8960-cdp.dts                  | 22 +++++++++
>> arch/arm/mach-msm/platsmp.c                        | 57 ++++++++++++++++++++++
>> arch/arm/mach-msm/scm-boot.h                       |  8 +--
>> 5 files changed, 102 insertions(+), 3 deletions(-)
>> create mode 100644 Documentation/devicetree/bindings/arm/msm/kpss.txt
>>
>> diff --git a/Documentation/devicetree/bindings/arm/cpus.txt b/Documentation/devicetree/bindings/arm/cpus.txt
>> index 327aad2..1132eac 100644
>> --- a/Documentation/devicetree/bindings/arm/cpus.txt
>> +++ b/Documentation/devicetree/bindings/arm/cpus.txt
>> @@ -45,11 +45,13 @@ For the ARM architecture every CPU node must contain the following properties:
>> 		"marvell,xsc3"
>> 		"marvell,xscale"
>> 		"qcom,scorpion"
>> +		"qcom,krait"
>> - enable-method: Specifies the method used to enable or take the secondary cores
>> 		 out of reset. This allows different reset sequence for
>> 		 different types of cpus.
>> 		 This should be one of:
>> 		 "qcom,scss"
>> +		 "qcom,kpssv1"
>>
>> Example:
>>
>> diff --git a/Documentation/devicetree/bindings/arm/msm/kpss.txt b/Documentation/devicetree/bindings/arm/msm/kpss.txt
>> new file mode 100644
>> index 0000000..7272340
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/arm/msm/kpss.txt
>> @@ -0,0 +1,16 @@
>> +* KPSS - Krait Processor Sub-system
>> +
>> +Properties
>> +
>> +- compatible : Should contain "qcom,kpss".
>> +
>> +- reg: Specifies the base address for the KPSS registers used for
>> +       booting up secondary cores.
>> +
>> +Example:
>> +
>> +	kpss@2088000 {
>> +		compatible = "qcom,kpss";
>> +		reg = <0x02088000 0x1000
>> +			0x02098000 0x2000>;
>> +	};
>> diff --git a/arch/arm/boot/dts/msm8960-cdp.dts b/arch/arm/boot/dts/msm8960-cdp.dts
>> index db2060c..8c82d5e 100644
>> --- a/arch/arm/boot/dts/msm8960-cdp.dts
>> +++ b/arch/arm/boot/dts/msm8960-cdp.dts
>> @@ -7,6 +7,22 @@
>> 	compatible = "qcom,msm8960-cdp", "qcom,msm8960";
>> 	interrupt-parent = <&intc>;
>>
>> +	cpus {
>> +		#address-cells = <1>;
>> +		#size-cells = <0>;
>> +		compatible = "qcom,krait";
>> +		device_type = "cpu";
>> +		enable-method = "qcom,kpssv1";
>> +
>> +		cpu@0 {
>> +			reg = <0>;
>> +		};
>> +
>> +		cpu@1 {
>> +			reg = <1>;
>> +		};
>> +	};
>> +
>> 	intc: interrupt-controller@2000000 {
>> 		compatible = "qcom,msm-qgic2";
>> 		interrupt-controller;
>> @@ -37,6 +53,12 @@
>> 		reg = <0xfd510000 0x4000>;
>> 	};
>>
>> +	kpss@2088000 {
>> +		compatible = "qcom,kpss";
>> +		reg = <0x02088000 0x1000
>> +			0x02098000 0x2000>;
>> +	};
>> +
>> 	serial@16440000 {
>> 		compatible = "qcom,msm-hsuart", "qcom,msm-uart";
>> 		reg = <0x16440000 0x1000>,
>> diff --git a/arch/arm/mach-msm/platsmp.c b/arch/arm/mach-msm/platsmp.c
>> index 17022e0..82eb079 100644
>> --- a/arch/arm/mach-msm/platsmp.c
>> +++ b/arch/arm/mach-msm/platsmp.c
>> @@ -74,6 +74,56 @@ static int scorpion_release_secondary(void)
>> 	return 0;
>> }
>>
>> +static int msm8960_release_secondary(unsigned int cpu)
>> +{
>> +	void __iomem *reg;
>> +	struct device_node *dn = NULL;
>> +
>> +	if (cpu == 0 || cpu >= num_possible_cpus())
>> +		return -EINVAL;
>> +
>> +	dn = of_find_compatible_node(dn, NULL, "qcom,kpss");
>> +	if (!dn) {
>> +		pr_err("%s : Missing kpss node from device tree\n", __func__);
>> +		return -ENXIO;
>> +	}
>> +
>> +	reg = of_iomap(dn, cpu);
>> +	if (!reg)
>> +		return -ENOMEM;
>> +
>> +	pr_debug("Starting secondary CPU %d\n", cpu);
>> +
>> +	/* Turn on CPU Rail */
>> +	writel_relaxed(0xA4, reg+0x1014);
> Is there some reason we are using magic numbers for both values and offsets?
Yes. The names are not defined by hardware spec. Would you prefer having 
multiple #defines for each value, register ?
>
>> +	mb();
>> +	udelay(512);
>> +
>> +	/* Krait bring-up sequence */
>> +	writel_relaxed(0x109, reg+0x04);
>> +	writel_relaxed(0x101, reg+0x04);
>> +	mb();
>> +	ndelay(300);
>> +
>> +	writel_relaxed(0x121, reg+0x04);
>> +	mb();
>> +	udelay(2);
>> +
>> +	writel_relaxed(0x120, reg+0x04);
>> +	mb();
>> +	udelay(2);
>> +
>> +	writel_relaxed(0x100, reg+0x04);
>> +	mb();
>> +	udelay(100);
>> +
>> +	writel_relaxed(0x180, reg+0x04);
>> +	mb();
>> +
>> +	iounmap(reg);
>> +	return 0;
>> +}
>> +
>> static DEFINE_PER_CPU(int, cold_boot_done);
>>
>> static void boot_cold_cpu(unsigned int cpu)
>> @@ -96,6 +146,11 @@ static void boot_cold_cpu(unsigned int cpu)
>> 			scorpion_release_secondary();
>> 			per_cpu(cold_boot_done, cpu) = true;
>> 		}
>> +	} else if (!strcmp(enable_method, "qcom,kpssv1")) {
>> +		if (per_cpu(cold_boot_done, cpu) == false) {
>> +			msm8960_release_secondary(cpu);
> Is this really msm8960 specific, if so than we should be doing something other than comparing against "qcom,kpssv1" or we should change the function to kpssv1_release_secondary()
Will do.
>
>> +			per_cpu(cold_boot_done, cpu) = true;
>> +		}
>> 	} else {
>> 		pr_err("%s: Invalid enable-method property: %s\n",
>> 				__func__, enable_method);
>> @@ -151,6 +206,8 @@ static void __init msm_smp_init_cpus(void)
>> static const int cold_boot_flags[] __initconst = {
>> 	0,
>> 	SCM_FLAG_COLDBOOT_CPU1,
>> +	SCM_FLAG_COLDBOOT_CPU2,
>> +	SCM_FLAG_COLDBOOT_CPU3,
>> };
>>
>> static void __init msm_smp_prepare_cpus(unsigned int max_cpus)
>> diff --git a/arch/arm/mach-msm/scm-boot.h b/arch/arm/mach-msm/scm-boot.h
>> index 7be32ff..6aabb24 100644
>> --- a/arch/arm/mach-msm/scm-boot.h
>> +++ b/arch/arm/mach-msm/scm-boot.h
>> @@ -13,9 +13,11 @@
>> #define __MACH_SCM_BOOT_H
>>
>> #define SCM_BOOT_ADDR			0x1
>> -#define SCM_FLAG_COLDBOOT_CPU1		0x1
>> -#define SCM_FLAG_WARMBOOT_CPU1		0x2
>> -#define SCM_FLAG_WARMBOOT_CPU0		0x4
>> +#define SCM_FLAG_COLDBOOT_CPU1		0x01
>> +#define SCM_FLAG_COLDBOOT_CPU2		0x08
>> +#define SCM_FLAG_COLDBOOT_CPU3		0x20
>> +#define SCM_FLAG_WARMBOOT_CPU0		0x04
>> +#define SCM_FLAG_WARMBOOT_CPU1		0x02
>>
>> int scm_set_boot_addr(phys_addr_t addr, int flags);
>>
>> -- 
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>> hosted by The Linux Foundation
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> --
> Employee of Qualcomm Innovation Center, Inc.
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>
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Thanks,
Rohit Vaswani

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation