From 10ebd8556b7990499c896a550e3d416b444211e6 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 10 May 2024 02:23:07 +0000
Subject: [PATCH] add led
---
kernel/arch/arm/mach-sti/platsmp.c | 93 +++++++---------------------------------------
1 files changed, 15 insertions(+), 78 deletions(-)
diff --git a/kernel/arch/arm/mach-sti/platsmp.c b/kernel/arch/arm/mach-sti/platsmp.c
index a3419b7..e2ba04b 100644
--- a/kernel/arch/arm/mach-sti/platsmp.c
+++ b/kernel/arch/arm/mach-sti/platsmp.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* arch/arm/mach-sti/platsmp.c
*
@@ -8,10 +9,6 @@
*
* Copyright (C) 2002 ARM Ltd.
* All Rights Reserved
- *
- * 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.
*/
#include <linux/init.h>
#include <linux/errno.h>
@@ -28,82 +25,33 @@
#include "smp.h"
-static void write_pen_release(int val)
-{
- pen_release = val;
- smp_wmb();
- sync_cache_w(&pen_release);
-}
-
-static DEFINE_RAW_SPINLOCK(boot_lock);
-
-static void sti_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);
-
- /*
- * Synchronise with the boot thread.
- */
- raw_spin_lock(&boot_lock);
- raw_spin_unlock(&boot_lock);
-}
+static u32 __iomem *cpu_strt_ptr;
static int sti_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
- unsigned long timeout;
+ unsigned long entry_pa = __pa_symbol(secondary_startup);
/*
- * set synchronisation state between this boot processor
- * and the secondary one
+ * Secondary CPU is initialised and started by a U-BOOTROM firmware.
+ * Secondary CPU is spinning and waiting for a write at cpu_strt_ptr.
+ * Writing secondary_startup address at cpu_strt_ptr makes it to
+ * jump directly to secondary_startup().
*/
- raw_spin_lock(&boot_lock);
+ __raw_writel(entry_pa, cpu_strt_ptr);
- /*
- * 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.
- *
- * Note that "pen_release" is the hardware CPU ID, whereas
- * "cpu" is Linux's internal ID.
- */
- write_pen_release(cpu_logical_map(cpu));
+ /* wmb so that data is actually written before cache flush is done */
+ smp_wmb();
+ sync_cache_w(cpu_strt_ptr);
- /*
- * Send the secondary CPU a soft interrupt, thereby causing
- * it to jump to the secondary entrypoint.
- */
- arch_send_wakeup_ipi_mask(cpumask_of(cpu));
-
- timeout = jiffies + (1 * HZ);
- while (time_before(jiffies, timeout)) {
- smp_rmb();
- if (pen_release == -1)
- break;
-
- udelay(10);
- }
-
- /*
- * now the secondary core is starting up let it run its
- * calibrations, then wait for it to finish
- */
- raw_spin_unlock(&boot_lock);
-
- return pen_release != -1 ? -ENOSYS : 0;
+ return 0;
}
static void __init sti_smp_prepare_cpus(unsigned int max_cpus)
{
struct device_node *np;
void __iomem *scu_base;
- u32 __iomem *cpu_strt_ptr;
u32 release_phys;
int cpu;
- unsigned long entry_pa = __pa_symbol(sti_secondary_startup);
np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
@@ -131,8 +79,8 @@
}
/*
- * holding pen is usually configured in SBC DMEM but can also be
- * in RAM.
+ * cpu-release-addr is usually configured in SBC DMEM but can
+ * also be in RAM.
*/
if (!memblock_is_memory(release_phys))
@@ -142,22 +90,11 @@
cpu_strt_ptr =
(u32 __iomem *)phys_to_virt(release_phys);
- __raw_writel(entry_pa, cpu_strt_ptr);
-
- /*
- * wmb so that data is actually written
- * before cache flush is done
- */
- smp_wmb();
- sync_cache_w(cpu_strt_ptr);
-
- if (!memblock_is_memory(release_phys))
- iounmap(cpu_strt_ptr);
+ set_cpu_possible(cpu, true);
}
}
const struct smp_operations sti_smp_ops __initconst = {
.smp_prepare_cpus = sti_smp_prepare_cpus,
- .smp_secondary_init = sti_secondary_init,
.smp_boot_secondary = sti_boot_secondary,
};
--
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