[PATCH v4 20/28] ARM: owl: Implement CPU enable-method for S500
Andreas Färber
afaerber at suse.de
Mon Jun 5 17:54:18 PDT 2017
Allow to bring up CPU1.
Based on LeMaker linux-actions tree.
Signed-off-by: Andreas Färber <afaerber at suse.de>
---
v3 -> v4: Unchanged
v3: new
arch/arm/mach-actions/Makefile | 3 +
arch/arm/mach-actions/headsmp.S | 68 ++++++++++++++++
arch/arm/mach-actions/platsmp.c | 166 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 237 insertions(+)
create mode 100644 arch/arm/mach-actions/headsmp.S
create mode 100644 arch/arm/mach-actions/platsmp.c
diff --git a/arch/arm/mach-actions/Makefile b/arch/arm/mach-actions/Makefile
index 524c3817bcb3..217e95d04b43 100644
--- a/arch/arm/mach-actions/Makefile
+++ b/arch/arm/mach-actions/Makefile
@@ -1 +1,4 @@
obj-$(CONFIG_ARCH_ACTIONS) += owl.o
+obj-${CONFIG_ARCH_ACTIONS} += platsmp.o headsmp.o
+
+AFLAGS_headsmp.o := -Wa,-march=armv7-a
diff --git a/arch/arm/mach-actions/headsmp.S b/arch/arm/mach-actions/headsmp.S
new file mode 100644
index 000000000000..dc4832fc101a
--- /dev/null
+++ b/arch/arm/mach-actions/headsmp.S
@@ -0,0 +1,68 @@
+/*
+ * Copyright 2012 Actions Semi Inc.
+ * Author: Actions Semi, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/linkage.h>
+#include <linux/init.h>
+
+ENTRY(owl_v7_invalidate_l1)
+ mov r0, #0
+ mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
+ mcr p15, 2, r0, c0, c0, 0
+ mrc p15, 1, r0, c0, c0, 0
+
+ ldr r1, =0x7fff
+ and r2, r1, r0, lsr #13
+
+ ldr r1, =0x3ff
+
+ and r3, r1, r0, lsr #3 @ NumWays - 1
+ add r2, r2, #1 @ NumSets
+
+ and r0, r0, #0x7
+ add r0, r0, #4 @ SetShift
+
+ clz r1, r3 @ WayShift
+ add r4, r3, #1 @ NumWays
+1: sub r2, r2, #1 @ NumSets--
+ mov r3, r4 @ Temp = NumWays
+2: subs r3, r3, #1 @ Temp--
+ mov r5, r3, lsl r1
+ mov r6, r2, lsl r0
+ orr r5, r5, r6 @ Reg = (Temp<<WayShift)|(NumSets<<SetShift)
+ mcr p15, 0, r5, c7, c6, 2
+ bgt 2b
+ cmp r2, #0
+ bgt 1b
+ dsb
+ isb
+ mov pc, lr
+ENDPROC(owl_v7_invalidate_l1)
+
+ENTRY(owl_secondary_startup)
+ mrc p15, 0, r0, c0, c0, 5
+ and r0, r0, #0xf
+ adr r4, 1f
+ ldmia r4, {r5, r6}
+ sub r4, r4, r5
+ add r6, r6, r4
+pen:
+ ldr r7, [r6]
+ cmp r7, r0
+ bne pen
+
+ /*
+ * we've been released from the holding pen: secondary_stack
+ * should now contain the SVC stack for this core
+ */
+ bl owl_v7_invalidate_l1
+ b secondary_startup
+
+1: .long .
+ .long pen_release
diff --git a/arch/arm/mach-actions/platsmp.c b/arch/arm/mach-actions/platsmp.c
new file mode 100644
index 000000000000..9d3601ebe535
--- /dev/null
+++ b/arch/arm/mach-actions/platsmp.c
@@ -0,0 +1,166 @@
+/*
+ * Actions Semi Leopard
+ *
+ * This file is based on arm realview smp platform.
+ *
+ * Copyright 2012 Actions Semi Inc.
+ * Author: Actions Semi, Inc.
+ *
+ * Copyright (c) 2017 Andreas Färber
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/smp.h>
+#include <asm/cacheflush.h>
+#include <asm/smp_plat.h>
+#include <asm/smp_scu.h>
+
+#define OWL_CPU1_ADDR 0x50
+#define OWL_CPU1_FLAG 0x5c
+
+#define OWL_CPUx_FLAG_BOOT 0x55aa
+
+static void __iomem *scu_base_addr;
+static void __iomem *timer_base_addr;
+static int ncores;
+
+static DEFINE_SPINLOCK(boot_lock);
+
+static void write_pen_release(int val)
+{
+ pen_release = val;
+ smp_wmb();
+ __cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release));
+ outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1));
+}
+
+static void s500_smp_secondary_init(unsigned int cpu)
+{
+ /*
+ * let the primary processor know we're out of the
+ * pen, then head off into the C entry point
+ */
+ write_pen_release(-1);
+
+ spin_lock(&boot_lock);
+ spin_unlock(&boot_lock);
+}
+
+void owl_secondary_startup(void);
+
+static int s500_wakeup_secondary(unsigned int cpu)
+{
+ if (cpu > 3)
+ return -EINVAL;
+
+ switch (cpu) {
+ case 2:
+ case 3:
+ /* CPU2/3 are power-gated */
+ return -EINVAL;
+ }
+
+ /* wait for CPUx to run to WFE instruction */
+ udelay(200);
+
+ writel(virt_to_phys(owl_secondary_startup),
+ timer_base_addr + OWL_CPU1_ADDR + (cpu - 1) * 4);
+ writel(OWL_CPUx_FLAG_BOOT,
+ timer_base_addr + OWL_CPU1_FLAG + (cpu - 1) * 4);
+
+ dsb_sev();
+ mb();
+
+ return 0;
+}
+
+static int s500_smp_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+ unsigned long timeout;
+ int ret;
+
+ ret = s500_wakeup_secondary(cpu);
+ if (ret)
+ return ret;
+
+ udelay(10);
+
+ spin_lock(&boot_lock);
+
+ /*
+ * The secondary processor is waiting to be released from
+ * the holding pen - release it, then wait for it to flag
+ * that it has been released by resetting pen_release.
+ */
+ write_pen_release(cpu_logical_map(cpu));
+ smp_send_reschedule(cpu);
+
+ timeout = jiffies + (1 * HZ);
+ while (time_before(jiffies, timeout)) {
+ if (pen_release == -1)
+ break;
+ }
+
+ writel(0, timer_base_addr + OWL_CPU1_ADDR + (cpu - 1) * 4);
+ writel(0, timer_base_addr + OWL_CPU1_FLAG + (cpu - 1) * 4);
+
+ spin_unlock(&boot_lock);
+
+ return pen_release != -1 ? -ENOSYS : 0;
+}
+
+static void __init s500_smp_prepare_cpus(unsigned int max_cpus)
+{
+ struct device_node *node;
+
+ node = of_find_compatible_node(NULL, NULL, "actions,s500-timer");
+ if (!node) {
+ pr_err("%s: missing timer\n", __func__);
+ return;
+ }
+
+ timer_base_addr = of_iomap(node, 0);
+ if (!timer_base_addr) {
+ pr_err("%s: could not map timer registers\n", __func__);
+ return;
+ }
+
+ if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) {
+ node = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
+ if (!node) {
+ pr_err("%s: missing scu\n", __func__);
+ return;
+ }
+
+ scu_base_addr = of_iomap(node, 0);
+ if (!scu_base_addr) {
+ pr_err("%s: could not map scu registers\n", __func__);
+ return;
+ }
+
+ /*
+ * While the number of cpus is gathered from dt, also get the
+ * number of cores from the scu to verify this value when
+ * booting the cores.
+ */
+ ncores = scu_get_core_count(scu_base_addr);
+ pr_debug("%s: ncores %d\n", __func__, ncores);
+
+ scu_enable(scu_base_addr);
+ }
+}
+
+static const struct smp_operations s500_smp_ops __initconst = {
+ .smp_prepare_cpus = s500_smp_prepare_cpus,
+ .smp_secondary_init = s500_smp_secondary_init,
+ .smp_boot_secondary = s500_smp_boot_secondary,
+};
+CPU_METHOD_OF_DECLARE(s500_smp, "actions,s500-smp", &s500_smp_ops);
--
2.12.3
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