Re: [PATCH 3/4] ARM: msm: Add SMP support for 8960
From: Kumar Gala
Date: Fri Aug 02 2013 - 11:43:58 EST
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@xxxxxxxxxxxxxx>
> ---
> 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?
> + 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()
> + 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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