On 10/14/2013 05:08 PM, Vyacheslav Tyrtov wrote:
From: Tarek Dakhran <t.dakh...@samsung.com>

Add EDCS(Exynos Dual Cluster Support) for Samsung Exynos5410 SoC.
This enables all 8 cores, 4 x A7 and 4 x A15 run at the same time.

IIUC, the 5410 has a CCI-400 bug preventing to use the two clusters at the same time. Right ? Could you explain how you fixed it ?

Signed-off-by: Tarek Dakhran <t.dakh...@samsung.com>
Signed-off-by: Vyacheslav Tyrtov <v.tyr...@samsung.com>
---
  arch/arm/mach-exynos/Makefile |   2 +
  arch/arm/mach-exynos/edcs.c   | 270 ++++++++++++++++++++++++++++++++++++++++++
  2 files changed, 272 insertions(+)
  create mode 100644 arch/arm/mach-exynos/edcs.c

diff --git a/arch/arm/mach-exynos/Makefile b/arch/arm/mach-exynos/Makefile
index 5369615..ba6efdb 100644
--- a/arch/arm/mach-exynos/Makefile
+++ b/arch/arm/mach-exynos/Makefile
@@ -34,3 +34,5 @@ AFLAGS_exynos-smc.o           :=-Wa,-march=armv7-a$(plus_sec)

  obj-$(CONFIG_MACH_EXYNOS4_DT)         += mach-exynos4-dt.o
  obj-$(CONFIG_MACH_EXYNOS5_DT)         += mach-exynos5-dt.o
+
+obj-$(CONFIG_SOC_EXYNOS5410)           += edcs.o
diff --git a/arch/arm/mach-exynos/edcs.c b/arch/arm/mach-exynos/edcs.c
new file mode 100644
index 0000000..e304bd9
--- /dev/null
+++ b/arch/arm/mach-exynos/edcs.c
@@ -0,0 +1,270 @@
+/*
+ * arch/arm/mach-exynos/edcs.c - exynos dual cluster power management support
+ *
+ * Copyright (c) 2013 Samsung Electronics Co., Ltd.
+ * Author: Tarek Dakhran <t.dakh...@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * EDCS(exynos dual cluster support) for Exynos5410 SoC.
+ */
+
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/spinlock.h>
+#include <linux/errno.h>
+
+#include <asm/mcpm.h>
+#include <asm/proc-fns.h>
+#include <asm/cacheflush.h>
+#include <asm/cputype.h>
+#include <asm/cp15.h>
+
+#include <linux/arm-cci.h>
+#include <mach/regs-pmu.h>
+
+#define EDCS_CPUS_PER_CLUSTER  4
+#define EDCS_CLUSTERS          2
+
+/* Exynos5410 power management registers */
+#define EDCS_CORE_CONFIGURATION(_nr)   (S5P_ARM_CORE0_CONFIGURATION    \
+                                               + ((_nr) * 0x80))
+#define EDCS_CORE_STATUS(_nr)          (EDCS_CORE_CONFIGURATION(_nr) + 0x4)
+#define EDCS_CORE_OPTION(_nr)          (EDCS_CORE_CONFIGURATION(_nr) + 0x8)
+
+#define REG_CPU_STATE_ADDR0            (S5P_VA_SYSRAM_NS + 0x28)
+#define REG_CPU_STATE_ADDR(_nr)                (REG_CPU_STATE_ADDR0 +  \
+                                                _nr * EDCS_CPUS_PER_CLUSTER)
+
+static arch_spinlock_t edcs_lock = __ARCH_SPIN_LOCK_UNLOCKED;
+
+static int edcs_use_count[EDCS_CPUS_PER_CLUSTER][EDCS_CLUSTERS];
+static int core_count[EDCS_CLUSTERS];
+
+static void exynos_core_power_control(unsigned int cpu, unsigned int cluster,
+                               bool enable)
+{
+       unsigned int offset = cluster * EDCS_CPUS_PER_CLUSTER + cpu;
+       int value = enable ? S5P_CORE_LOCAL_PWR_EN : 0;
+
+       if ((__raw_readl(EDCS_CORE_STATUS(offset)) & 0x3) != value)
+               __raw_writel(value, EDCS_CORE_CONFIGURATION(offset));
+}
+
+static void exynos_core_power_up(unsigned int cpu, unsigned int cluster)
+{
+       exynos_core_power_control(cpu, cluster, true);
+}
+
+static void exynos_core_power_down(unsigned int cpu, unsigned int cluster)
+{
+       exynos_core_power_control(cpu, cluster, false);
+}
+
+void set_boot_flag(unsigned int cpu, unsigned int mode)
+{
+       __raw_writel(mode, REG_CPU_STATE_ADDR(cpu));
+}
+
+static int exynos_power_up(unsigned int cpu, unsigned int cluster)
+{
+       pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
+       BUG_ON(cpu >= EDCS_CPUS_PER_CLUSTER || cluster >= EDCS_CLUSTERS);
+
+       local_irq_disable();
+       arch_spin_lock(&edcs_lock);
+
+       edcs_use_count[cpu][cluster]++;
+       if (edcs_use_count[cpu][cluster] == 1) {
+               ++core_count[cluster];
+               set_boot_flag(cpu, 0x2);
+               exynos_core_power_up(cpu, cluster);
+       } else if (edcs_use_count[cpu][cluster] != 2) {
+               /*
+                * The only possible values are:
+                * 0 = CPU down
+                * 1 = CPU (still) up
+                * 2 = CPU requested to be up before it had a chance
+                *     to actually make itself down.
+                * Any other value is a bug.
+                */
+               BUG();
+       }
+
+       arch_spin_unlock(&edcs_lock);
+       local_irq_enable();
+
+       return 0;
+}
+static void exynos_power_down(void)
+{
+       unsigned int mpidr, cpu, cluster;
+       bool last_man = false, skip_wfi = false;
+
+       mpidr = read_cpuid_mpidr();
+       cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+       cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+
+       pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
+       BUG_ON(cpu >= EDCS_CPUS_PER_CLUSTER  || cluster >= EDCS_CLUSTERS);
+
+       __mcpm_cpu_going_down(cpu, cluster);
+
+       arch_spin_lock(&edcs_lock);
+       BUG_ON(__mcpm_cluster_state(cluster) != CLUSTER_UP);
+       edcs_use_count[cpu][cluster]--;
+       if (edcs_use_count[cpu][cluster] == 0) {
+               --core_count[cluster];
+               if (core_count[cluster] == 0)
+                       last_man = true;
+       } else if (edcs_use_count[cpu][cluster] == 1) {
+               /*
+                * A power_up request went ahead of us.
+                * Even if we do not want to shut this CPU down,
+                * the caller expects a certain state as if the WFI
+                * was aborted.  So let's continue with cache cleaning.
+                */
+               skip_wfi = true;
+       } else
+               BUG();
+
+       if (last_man && __mcpm_outbound_enter_critical(cpu, cluster)) {
+               arch_spin_unlock(&edcs_lock);
+
+               if (read_cpuid_part_number() == ARM_CPU_PART_CORTEX_A15) {
+                       /*
+                        * On the Cortex-A15 we need to disable
+                        * L2 prefetching before flushing the cache.
+                        */
+                       asm volatile(
+                       "mcr       p15, 1, %0, c15, c0, 3\n\t"
+                       "isb\n\t"
+                       "dsb"
+                       : : "r" (0x400));
+               }
+
+               /*
+                * We need to disable and flush the whole (L1 and L2) cache.
+                * Let's do it in the safest possible way i.e. with
+                * no memory access within the following sequence
+                * including the stack.
+                *
+                * Note: fp is preserved to the stack explicitly prior doing
+                * this since adding it to the clobber list is incompatible
+                * with having CONFIG_FRAME_POINTER=y.
+                */
+               asm volatile(
+               "str       fp, [sp, #-4]!\n\t"
+               "mrc       p15, 0, r0, c1, c0, 0   @ get CR\n\t"
+               "bic       r0, r0, #"__stringify(CR_C)"\n\t"
+               "mcr       p15, 0, r0, c1, c0, 0   @ set CR\n\t"
+               "isb\n\t"
+               "bl        v7_flush_dcache_all\n\t"
+               "clrex\n\t"
+               "mrc       p15, 0, r0, c1, c0, 1   @ get AUXCR\n\t"
+               "bic       r0, r0, #(1 << 6) @ disable local coherency\n\t"
+               "mcr       p15, 0, r0, c1, c0, 1   @ set AUXCR\n\t"
+               "isb\n\t"
+               "dsb\n\t"
+               "ldr       fp, [sp], #4"
+               : : : "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
+                       "r9", "r10", "lr", "memory");
+
+               cci_disable_port_by_cpu(mpidr);
+
+               __mcpm_outbound_leave_critical(cluster, CLUSTER_DOWN);
+
+       } else {
+               arch_spin_unlock(&edcs_lock);
+               /*
+                       * We need to disable and flush only the L1 cache.
+                       * Let's do it in the safest possible way as above.
+               */
+               asm volatile(
+               "str       fp, [sp, #-4]!\n\t"
+               "mrc       p15, 0, r0, c1, c0, 0   @ get CR\n\t"
+               "bic       r0, r0, #"__stringify(CR_C)"\n\t"
+               "mcr       p15, 0, r0, c1, c0, 0   @ set CR\n\t"
+               "isb\n\t"
+               "bl        v7_flush_dcache_louis\n\t"
+               "clrex\n\t"
+               "mrc       p15, 0, r0, c1, c0, 1   @ get AUXCR\n\t"
+               "bic       r0, r0, #(1 << 6) @ disable local coherency\n\t"
+               "mcr       p15, 0, r0, c1, c0, 1   @ set AUXCR\n\t"
+               "isb\n\t"
+               "dsb\n\t"
+               "ldr       fp, [sp], #4"
+               : : : "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
+                     "r9", "r10", "lr", "memory");
+
+       }
+       __mcpm_cpu_down(cpu, cluster);
+
+       if (!skip_wfi) {
+               exynos_core_power_down(cpu, cluster);
+               wfi();
+       }
+}

I did not looked line by line but these functions looks very similar than the tc2_pm.c's function. no ?

May be some code consolidation could be considered here.

Added Nico and Lorenzo in Cc.

Thanks
  -- Daniel

+static const struct mcpm_platform_ops exynos_power_ops = {
+       .power_up       = exynos_power_up,
+       .power_down     = exynos_power_down,
+};
+
+static void __init edcs_data_init(void)
+{
+       unsigned int mpidr, cpu, cluster;
+
+       mpidr = read_cpuid_mpidr();
+       cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+       cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+
+       pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
+       BUG_ON(cpu >= EDCS_CPUS_PER_CLUSTER  || cluster >= EDCS_CLUSTERS);
+       edcs_use_count[cpu][cluster] = 1;
+       ++core_count[cluster];
+}
+
+/*
+ * Enable cluster-level coherency, in preparation for turning on the MMU.
+ */
+static void __naked edcs_power_up_setup(unsigned int affinity_level)
+{
+       asm volatile ("\n"
+       "b cci_enable_port_for_self");
+}
+
+static int __init edcs_init(void)
+{
+       int ret;
+       struct device_node *node;
+
+       node = of_find_compatible_node(NULL, NULL, "samsung,exynos5410");
+       if (!node)
+               return -ENODEV;
+
+       if (!cci_probed())
+               return -ENODEV;
+
+       /*
+        * Future entries into the kernel can now go
+        * through the cluster entry vectors.
+        */
+       __raw_writel(virt_to_phys(mcpm_entry_point),
+                               S5P_VA_SYSRAM_NS + 0x1c);
+
+       edcs_data_init();
+       mcpm_smp_set_ops();
+
+       ret = mcpm_platform_register(&exynos_power_ops);
+       if (!ret) {
+               mcpm_sync_init(edcs_power_up_setup);
+               pr_info("EDCS power management initialized\n");
+       }
+       return ret;
+}
+
+early_initcall(edcs_init);



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