On 13 July 2014 05:31, Nicolas Pitre [off-list ref] wrote:

On Thu, 10 Jul 2014, Haojian Zhuang wrote:

quoted

Multiple CPU clusters are used in Hisilicon HiP04 SoC. Now use MCPM
framework to manage power on HiP04 SoC.

Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
---
 arch/arm/mach-hisi/Makefile   |   1 +
 arch/arm/mach-hisi/platmcpm.c | 331 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 332 insertions(+)
 create mode 100644 arch/arm/mach-hisi/platmcpm.c

diff --git a/arch/arm/mach-hisi/Makefile b/arch/arm/mach-hisi/Makefile
index ee2506b..d64831e 100644
+
+static void hip04_mcpm_power_down(void)
+{
+     unsigned int mpidr, cpu, cluster, data = 0;
+     bool skip_reset = false;
+
+     mpidr = read_cpuid_mpidr();
+     cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+     cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+
+     __mcpm_cpu_going_down(cpu, cluster);
+
+     spin_lock(&boot_lock);
+     BUG_ON(__mcpm_cluster_state(cluster) != CLUSTER_UP);
+     hip04_cpu_table[cluster][cpu]--;
+     if (hip04_cpu_table[cluster][cpu] == 1) {
+             /* A power_up request went ahead of us. */
+             skip_reset = true;
+     } else if (hip04_cpu_table[cluster][cpu] > 1) {
+             pr_err("Cluster %d CPU%d boots multiple times\n", cluster, cpu);
+             BUG();
+     }
+     spin_unlock(&boot_lock);
+
+     v7_exit_coherency_flush(louis);
+
+     __mcpm_cpu_down(cpu, cluster);

What if there is a hip04_mcpm_power_up() being called on another CPU
right here?  There is a race that I illustrated in a previous email
which is still unresolved.

Thanks for your reminder again. I'll move it into the protection.

quoted

+
+     if (!skip_reset) {
+             data = CORE_RESET_BIT(cpu) | NEON_RESET_BIT(cpu) | \
+                    CORE_DEBUG_RESET_BIT(cpu);
+             writel_relaxed(data, sysctrl + SC_CPU_RESET_REQ(cluster));
+     }
+}
+
+static int hip04_mcpm_wait_for_powerdown(unsigned int cpu, unsigned int cluster)
+{
+     unsigned int data, tries;
+
+     BUG_ON(cluster >= HIP04_MAX_CLUSTERS ||
+            cpu >= HIP04_MAX_CPUS_PER_CLUSTER);
+
+     for (tries = 0; tries < TIMEOUT_MSEC / POLL_MSEC; tries++) {
+             data = readl_relaxed(sysctrl + SC_CPU_RESET_STATUS(cluster));
+             if (!(data & CORE_RESET_STATUS(cpu))) {
+                     msleep(POLL_MSEC);
+                     continue;
+             }
+             return 0;
+     }
+     return -ETIMEDOUT;
+}
+
+static void hip04_mcpm_powered_up(void)
+{
+     if (!relocation)
+             return;
+     spin_lock(&boot_lock);
+     writel_relaxed(0, relocation);
+     writel_relaxed(0, relocation + 4);
+     writel_relaxed(0, relocation + 8);
+     writel_relaxed(0, relocation + 12);
+     spin_unlock(&boot_lock);
+}
+
+static void __naked hip04_mcpm_power_up_setup(unsigned int affinity_level)
+{
+     asm volatile ("                 \n"
+     /* calculate fabric phys address */
+"    adr     r2, 2f                  \n"
+"    ldmia   r2, {r1, r3}            \n"
+"    sub     r0, r2, r1              \n"
+"    add     r2, r0, r3              \n"
+"    ldr     r2, [r2]                \n"

You may replace the above 2 instructions with "ldr r2, [r0, r3]".

OK.

quoted

+     /* get cluster id from MPIDR */
+"    mrc     p15, 0, r0, c0, c0, 5   \n"
+"    ubfx    r1, r0, #8, #8          \n"
+"    and     r1, r1, #0xf            \n"

You don't need the "and" here.  It is implicit in ubfx.

OK.

quoted

+     /* 1 << cluster id */
+"    mov     r0, #1                  \n"
+"    mov     r3, r0, lsl r1          \n"
+"    ldr     r0, [r2, #"__stringify(FAB_SF_MODE)"]   \n"
+"    tst     r0, r3                  \n"
+"    bxne    lr                      \n"

Instead of running all this code all the time, you could simply test r0
at the very beginning and if it is not equal to 1 then return
immediately. If it is 1 that means the CPU executing this code is the
first one to run in the cluster, in which case you also don't have to
test if the cluster snoop is already enabled here.

Since I need to enable the cluster snoop for cluster 0. At this time,
it's not enabled although core0 is running.

quoted

+"    orr     r1, r0, r3              \n"
+"    str     r1, [r2, #"__stringify(FAB_SF_MODE)"]   \n"
+"1:  ldr     r0, [r2, #"__stringify(FAB_SF_MODE)"]   \n"
+"    tst     r0, r3                  \n"
+"    beq     1b                      \n"
+"    bx      lr                      \n"
+
+"    .align  2                       \n"
+"2:  .word   .                       \n"
+"    .word   fabric_phys_addr        \n"
+     );
+}

Of course you will also have to enable the snoops for the current
cluster in hip04_cpu_table_init() as well.

It means that I need to reserve the copy to enable the snoop in c code
for cluster 0. Is it right?

quoted

+
+static const struct mcpm_platform_ops hip04_mcpm_ops = {
+     .power_up               = hip04_mcpm_power_up,
+     .power_down             = hip04_mcpm_power_down,
+     .wait_for_powerdown     = hip04_mcpm_wait_for_powerdown,
+     .powered_up             = hip04_mcpm_powered_up,
+};
+
+static bool __init hip04_cpu_table_init(void)
+{
+     unsigned int mpidr, cpu, cluster;
+
+     mpidr = read_cpuid_mpidr();
+     cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+     cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+
+     if (cluster >= HIP04_MAX_CLUSTERS ||
+         cpu >= HIP04_MAX_CPUS_PER_CLUSTER) {
+             pr_err("%s: boot CPU is out of bound!\n", __func__);
+             return false;
+     }
+     hip04_cpu_table[cluster][cpu] = 1;
+     return true;
+}
+
+static int __init hip04_mcpm_init(void)
+{
+     struct device_node *np, *np_fab;
+     struct resource fab_res;
+     int ret = -ENODEV;
+
+     np = of_find_compatible_node(NULL, NULL, "hisilicon,sysctrl");
+     if (!np)
+             goto err;
+     np_fab = of_find_compatible_node(NULL, NULL, "hisilicon,hip04-fabric");
+     if (!np_fab)
+             goto err;
+
+     if (of_property_read_u32(np, "bootwrapper-phys",
+                              &hip04_boot.bootwrapper_phys)) {
+             pr_err("failed to get bootwrapper-phys\n");
+             ret = -EINVAL;
+             goto err;
+     }
+     if (of_property_read_u32(np, "bootwrapper-size",
+                              &hip04_boot.bootwrapper_size)) {
+             pr_err("failed to get bootwrapper-size\n");
+             ret = -EINVAL;
+             goto err;
+     }
+     if (of_property_read_u32(np, "bootwrapper-magic",
+                              &hip04_boot.bootwrapper_magic)) {
+             pr_err("failed to get bootwrapper-magic\n");
+             ret = -EINVAL;
+             goto err;
+     }
+     if (of_property_read_u32(np, "relocation-entry",
+                              &hip04_boot.relocation_entry)) {
+             pr_err("failed to get relocation-entry\n");
+             ret = -EINVAL;
+             goto err;
+     }
+     if (of_property_read_u32(np, "relocation-size",
+                              &hip04_boot.relocation_size)) {
+             pr_err("failed to get relocation-size\n");
+             ret = -EINVAL;
+             goto err;
+     }
+
+     relocation = ioremap(hip04_boot.relocation_entry,
+                          hip04_boot.relocation_size);
+     if (!relocation) {
+             pr_err("failed to map relocation space\n");
+             ret = -ENOMEM;
+             goto err;
+     }
+     sysctrl = of_iomap(np, 0);
+     if (!sysctrl) {
+             pr_err("failed to get sysctrl base\n");
+             ret = -ENOMEM;
+             goto err_sysctrl;
+     }
+     ret = of_address_to_resource(np_fab, 0, &fab_res);
+     if (ret) {
+             pr_err("failed to get fabric base phys\n");
+             goto err_fabric;
+     }
+     fabric_phys_addr = fab_res.start;
+     sync_cache_w(&fabric_phys_addr);
+     fabric = of_iomap(np_fab, 0);
+     if (!fabric) {
+             pr_err("failed to get fabric base\n");
+             ret = -ENOMEM;
+             goto err_fabric;
+     }
+
+     if (!hip04_cpu_table_init())
+             return -EINVAL;
+     ret = mcpm_platform_register(&hip04_mcpm_ops);
+     if (!ret) {
+             mcpm_sync_init(hip04_mcpm_power_up_setup);
+             pr_info("HiP04 MCPM initialized\n");
+     }
+     mcpm_smp_set_ops();
+     return ret;
+err_fabric:
+     iounmap(sysctrl);
+err_sysctrl:
+     iounmap(relocation);
+err:
+     return ret;
+}
+early_initcall(hip04_mcpm_init);
--
1.9.1