This makes it easy to add SMP support for new targets
by adding cpus property and the release sequence.
We add the enable-method property for the cpus property to
specify which release sequence to use.
While at it, add the 8660 cpus bindings to make SMP work.

Signed-off-by: Rohit Vaswani <rvasw...@codeaurora.org>
---
 Documentation/devicetree/bindings/arm/cpus.txt     |  6 ++
 Documentation/devicetree/bindings/arm/msm/scss.txt | 15 ++++
 arch/arm/boot/dts/msm8660-surf.dts                 | 23 +++++-
 arch/arm/mach-msm/platsmp.c                        | 96 ++++++++++++++++------
 4 files changed, 116 insertions(+), 24 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/arm/msm/scss.txt

diff --git a/Documentation/devicetree/bindings/arm/cpus.txt 
b/Documentation/devicetree/bindings/arm/cpus.txt
index f32494d..327aad2 100644
--- a/Documentation/devicetree/bindings/arm/cpus.txt
+++ b/Documentation/devicetree/bindings/arm/cpus.txt
@@ -44,6 +44,12 @@ For the ARM architecture every CPU node must contain the 
following properties:
                "marvell,mohawk"
                "marvell,xsc3"
                "marvell,xscale"
+               "qcom,scorpion"
+- 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"
 
 Example:
 
diff --git a/Documentation/devicetree/bindings/arm/msm/scss.txt 
b/Documentation/devicetree/bindings/arm/msm/scss.txt
new file mode 100644
index 0000000..21c3e26
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/msm/scss.txt
@@ -0,0 +1,15 @@
+* SCSS - Scorpion Sub-system
+
+Properties
+
+- compatible : Should contain "qcom,scss".
+
+- reg: Specifies the base address for the SCSS registers used for
+       booting up secondary cores.
+
+Example:
+
+       scss@902000 {
+               compatible = "qcom,scss";
+               reg = <0x00902000 0x2000>;
+       };
diff --git a/arch/arm/boot/dts/msm8660-surf.dts 
b/arch/arm/boot/dts/msm8660-surf.dts
index cdc010e..203e51a 100644
--- a/arch/arm/boot/dts/msm8660-surf.dts
+++ b/arch/arm/boot/dts/msm8660-surf.dts
@@ -7,6 +7,22 @@
        compatible = "qcom,msm8660-surf", "qcom,msm8660";
        interrupt-parent = <&intc>;
 
+       cpus {
+               #address-cells = <1>;
+               #size-cells = <0>;
+               compatible = "qcom,scorpion";
+               device_type = "cpu";
+               enable-method = "qcom,scss";
+
+               cpu@0 {
+                       reg = <0>;
+               };
+
+               cpu@1 {
+                       reg = <1>;
+               };
+       };
+
        intc: interrupt-controller@2080000 {
                compatible = "qcom,msm-8660-qgic";
                interrupt-controller;
@@ -37,7 +53,12 @@
                #interrupt-cells = <2>;
        };
 
-       serial@19c40000 {
+       scss@902000 {
+               compatible = "qcom,scss";
+               reg = <0x00902000 0x2000>;
+       };
+
+       serial@19c400000 {
                compatible = "qcom,msm-hsuart", "qcom,msm-uart";
                reg = <0x19c40000 0x1000>,
                      <0x19c00000 0x1000>;
diff --git a/arch/arm/mach-msm/platsmp.c b/arch/arm/mach-msm/platsmp.c
index 7d48759..17022e0 100644
--- a/arch/arm/mach-msm/platsmp.c
+++ b/arch/arm/mach-msm/platsmp.c
@@ -13,6 +13,8 @@
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/jiffies.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/smp.h>
 #include <linux/io.h>
 
@@ -38,7 +40,7 @@ static inline int get_core_count(void)
        return ((read_cpuid_id() >> 4) & 3) + 1;
 }
 
-static void __cpuinit msm_secondary_init(unsigned int cpu)
+static void msm_secondary_init(unsigned int cpu)
 {
        /*
         * Synchronise with the boot thread.
@@ -47,35 +49,63 @@ static void __cpuinit msm_secondary_init(unsigned int cpu)
        spin_unlock(&boot_lock);
 }
 
-static __cpuinit void prepare_cold_cpu(unsigned int cpu)
+static int scorpion_release_secondary(void)
 {
-       int ret;
-       ret = scm_set_boot_addr(virt_to_phys(secondary_startup),
-                               SCM_FLAG_COLDBOOT_CPU1);
-       if (ret == 0) {
-               void __iomem *sc1_base_ptr;
-               sc1_base_ptr = ioremap_nocache(0x00902000, SZ_4K*2);
-               if (sc1_base_ptr) {
-                       writel(0, sc1_base_ptr + VDD_SC1_ARRAY_CLAMP_GFS_CTL);
-                       writel(0, sc1_base_ptr + SCSS_CPU1CORE_RESET);
-                       writel(3, sc1_base_ptr + SCSS_DBG_STATUS_CORE_PWRDUP);
-                       iounmap(sc1_base_ptr);
-               }
-       } else
-               printk(KERN_DEBUG "Failed to set secondary core boot "
-                                 "address\n");
+       void __iomem *sc1_base_ptr;
+       struct device_node *dn = NULL;
+
+       dn = of_find_compatible_node(dn, NULL, "qcom,scss");
+       if (!dn) {
+               pr_err("%s: Missing scss node in device tree\n", __func__);
+               return -ENXIO;
+       }
+
+       sc1_base_ptr = of_iomap(dn, 0);
+       if (sc1_base_ptr) {
+               writel_relaxed(0, sc1_base_ptr + VDD_SC1_ARRAY_CLAMP_GFS_CTL);
+               writel_relaxed(0, sc1_base_ptr + SCSS_CPU1CORE_RESET);
+               writel_relaxed(3, sc1_base_ptr + SCSS_DBG_STATUS_CORE_PWRDUP);
+               mb();
+               iounmap(sc1_base_ptr);
+       } else {
+               return -ENOMEM;
+       }
+
+       return 0;
 }
 
-static int __cpuinit msm_boot_secondary(unsigned int cpu, struct task_struct 
*idle)
+static DEFINE_PER_CPU(int, cold_boot_done);
+
+static void boot_cold_cpu(unsigned int cpu)
 {
-       static int cold_boot_done;
+       const char *enable_method;
+       struct device_node *dn = NULL;
 
-       /* Only need to bring cpu out of reset this way once */
-       if (cold_boot_done == false) {
-               prepare_cold_cpu(cpu);
-               cold_boot_done = true;
+       dn = of_find_node_by_name(dn, "cpus");
+       if (!dn) {
+               pr_err("%s: Missing node cpus in device tree\n", __func__);
+               return;
        }
 
+       enable_method = of_get_property(dn, "enable-method", NULL);
+       if (!enable_method) {
+                       pr_err("%s: cpus node is missing enable-method 
property\n",
+                                       __func__);
+       } else if (!strcmp(enable_method, "qcom,scss")) {
+               if (per_cpu(cold_boot_done, cpu) == false) {
+                       scorpion_release_secondary();
+                       per_cpu(cold_boot_done, cpu) = true;
+               }
+       } else {
+               pr_err("%s: Invalid enable-method property: %s\n",
+                               __func__, enable_method);
+       }
+}
+
+static int msm_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+       boot_cold_cpu(cpu);
+
        /*
         * set synchronisation state between this boot processor
         * and the secondary one
@@ -118,8 +148,28 @@ static void __init msm_smp_init_cpus(void)
                set_cpu_possible(i, true);
 }
 
+static const int cold_boot_flags[] __initconst = {
+       0,
+       SCM_FLAG_COLDBOOT_CPU1,
+};
+
 static void __init msm_smp_prepare_cpus(unsigned int max_cpus)
 {
+       int cpu, map;
+       unsigned int flags = 0;
+
+       for_each_present_cpu(cpu) {
+               map = cpu_logical_map(cpu);
+               if (map > ARRAY_SIZE(cold_boot_flags)) {
+                       set_cpu_present(cpu, false);
+                       __WARN();
+                       continue;
+               }
+               flags |= cold_boot_flags[map];
+       }
+
+       if (scm_set_boot_addr(virt_to_phys(secondary_startup), flags))
+               pr_warn("Failed to set CPU boot address\n");
 }
 
 struct smp_operations msm_smp_ops __initdata = {
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation

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