From 6778948f9de86c3cfaf36725a7c87dcff9ba247f Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 08:20:59 +0000
Subject: [PATCH] kernel_5.10 no rt
---
kernel/arch/riscv/kernel/smp.c | 268 +++++++++++++++++++++++++++++++++++------------------
1 files changed, 177 insertions(+), 91 deletions(-)
diff --git a/kernel/arch/riscv/kernel/smp.c b/kernel/arch/riscv/kernel/smp.c
index 906fe21..d445674 100644
--- a/kernel/arch/riscv/kernel/smp.c
+++ b/kernel/arch/riscv/kernel/smp.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* SMP initialisation and IPI support
* Based on arch/arm64/kernel/smp.c
@@ -5,39 +6,71 @@
* Copyright (C) 2012 ARM Ltd.
* Copyright (C) 2015 Regents of the University of California
* Copyright (C) 2017 SiFive
- *
- * 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.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <linux/cpu.h>
#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/profile.h>
#include <linux/smp.h>
#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/delay.h>
+#include <linux/irq_work.h>
#include <asm/sbi.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
-/* A collection of single bit ipi messages. */
-static struct {
- unsigned long bits ____cacheline_aligned;
-} ipi_data[NR_CPUS] __cacheline_aligned;
-
enum ipi_message_type {
IPI_RESCHEDULE,
IPI_CALL_FUNC,
+ IPI_CPU_STOP,
+ IPI_IRQ_WORK,
IPI_MAX
};
+unsigned long __cpuid_to_hartid_map[NR_CPUS] = {
+ [0 ... NR_CPUS-1] = INVALID_HARTID
+};
+
+void __init smp_setup_processor_id(void)
+{
+ cpuid_to_hartid_map(0) = boot_cpu_hartid;
+}
+
+/* A collection of single bit ipi messages. */
+static struct {
+ unsigned long stats[IPI_MAX] ____cacheline_aligned;
+ unsigned long bits ____cacheline_aligned;
+} ipi_data[NR_CPUS] __cacheline_aligned;
+
+int riscv_hartid_to_cpuid(int hartid)
+{
+ int i;
+
+ for (i = 0; i < NR_CPUS; i++)
+ if (cpuid_to_hartid_map(i) == hartid)
+ return i;
+
+ pr_err("Couldn't find cpu id for hartid [%d]\n", hartid);
+ return -ENOENT;
+}
+
+void riscv_cpuid_to_hartid_mask(const struct cpumask *in, struct cpumask *out)
+{
+ int cpu;
+
+ cpumask_clear(out);
+ for_each_cpu(cpu, in)
+ cpumask_set_cpu(cpuid_to_hartid_map(cpu), out);
+}
+EXPORT_SYMBOL_GPL(riscv_cpuid_to_hartid_mask);
+
+bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
+{
+ return phys_id == cpuid_to_hartid_map(cpu);
+}
/* Unsupported */
int setup_profiling_timer(unsigned int multiplier)
@@ -45,12 +78,73 @@
return -EINVAL;
}
-void riscv_software_interrupt(void)
+static void ipi_stop(void)
{
- unsigned long *pending_ipis = &ipi_data[smp_processor_id()].bits;
+ set_cpu_online(smp_processor_id(), false);
+ while (1)
+ wait_for_interrupt();
+}
- /* Clear pending IPI */
- csr_clear(sip, SIE_SSIE);
+static struct riscv_ipi_ops *ipi_ops;
+
+void riscv_set_ipi_ops(struct riscv_ipi_ops *ops)
+{
+ ipi_ops = ops;
+}
+EXPORT_SYMBOL_GPL(riscv_set_ipi_ops);
+
+void riscv_clear_ipi(void)
+{
+ if (ipi_ops && ipi_ops->ipi_clear)
+ ipi_ops->ipi_clear();
+
+ csr_clear(CSR_IP, IE_SIE);
+}
+EXPORT_SYMBOL_GPL(riscv_clear_ipi);
+
+static void send_ipi_mask(const struct cpumask *mask, enum ipi_message_type op)
+{
+ int cpu;
+
+ smp_mb__before_atomic();
+ for_each_cpu(cpu, mask)
+ set_bit(op, &ipi_data[cpu].bits);
+ smp_mb__after_atomic();
+
+ if (ipi_ops && ipi_ops->ipi_inject)
+ ipi_ops->ipi_inject(mask);
+ else
+ pr_warn("SMP: IPI inject method not available\n");
+}
+
+static void send_ipi_single(int cpu, enum ipi_message_type op)
+{
+ smp_mb__before_atomic();
+ set_bit(op, &ipi_data[cpu].bits);
+ smp_mb__after_atomic();
+
+ if (ipi_ops && ipi_ops->ipi_inject)
+ ipi_ops->ipi_inject(cpumask_of(cpu));
+ else
+ pr_warn("SMP: IPI inject method not available\n");
+}
+
+#ifdef CONFIG_IRQ_WORK
+void arch_irq_work_raise(void)
+{
+ send_ipi_single(smp_processor_id(), IPI_IRQ_WORK);
+}
+#endif
+
+void handle_IPI(struct pt_regs *regs)
+{
+ struct pt_regs *old_regs = set_irq_regs(regs);
+ unsigned long *pending_ipis = &ipi_data[smp_processor_id()].bits;
+ unsigned long *stats = ipi_data[smp_processor_id()].stats;
+
+ irq_enter();
+
+ riscv_clear_ipi();
while (true) {
unsigned long ops;
@@ -60,104 +154,96 @@
ops = xchg(pending_ipis, 0);
if (ops == 0)
- return;
+ goto done;
- if (ops & (1 << IPI_RESCHEDULE))
+ if (ops & (1 << IPI_RESCHEDULE)) {
+ stats[IPI_RESCHEDULE]++;
scheduler_ipi();
+ }
- if (ops & (1 << IPI_CALL_FUNC))
+ if (ops & (1 << IPI_CALL_FUNC)) {
+ stats[IPI_CALL_FUNC]++;
generic_smp_call_function_interrupt();
+ }
+
+ if (ops & (1 << IPI_CPU_STOP)) {
+ stats[IPI_CPU_STOP]++;
+ ipi_stop();
+ }
+
+ if (ops & (1 << IPI_IRQ_WORK)) {
+ stats[IPI_IRQ_WORK]++;
+ irq_work_run();
+ }
BUG_ON((ops >> IPI_MAX) != 0);
/* Order data access and bit testing. */
mb();
}
+
+done:
+ irq_exit();
+ set_irq_regs(old_regs);
}
-static void
-send_ipi_message(const struct cpumask *to_whom, enum ipi_message_type operation)
+static const char * const ipi_names[] = {
+ [IPI_RESCHEDULE] = "Rescheduling interrupts",
+ [IPI_CALL_FUNC] = "Function call interrupts",
+ [IPI_CPU_STOP] = "CPU stop interrupts",
+ [IPI_IRQ_WORK] = "IRQ work interrupts",
+};
+
+void show_ipi_stats(struct seq_file *p, int prec)
{
- int i;
+ unsigned int cpu, i;
- mb();
- for_each_cpu(i, to_whom)
- set_bit(operation, &ipi_data[i].bits);
-
- mb();
- sbi_send_ipi(cpumask_bits(to_whom));
+ for (i = 0; i < IPI_MAX; i++) {
+ seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i,
+ prec >= 4 ? " " : "");
+ for_each_online_cpu(cpu)
+ seq_printf(p, "%10lu ", ipi_data[cpu].stats[i]);
+ seq_printf(p, " %s\n", ipi_names[i]);
+ }
}
void arch_send_call_function_ipi_mask(struct cpumask *mask)
{
- send_ipi_message(mask, IPI_CALL_FUNC);
+ send_ipi_mask(mask, IPI_CALL_FUNC);
}
void arch_send_call_function_single_ipi(int cpu)
{
- send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC);
-}
-
-static void ipi_stop(void *unused)
-{
- while (1)
- wait_for_interrupt();
+ send_ipi_single(cpu, IPI_CALL_FUNC);
}
void smp_send_stop(void)
{
- on_each_cpu(ipi_stop, NULL, 1);
+ unsigned long timeout;
+
+ if (num_online_cpus() > 1) {
+ cpumask_t mask;
+
+ cpumask_copy(&mask, cpu_online_mask);
+ cpumask_clear_cpu(smp_processor_id(), &mask);
+
+ if (system_state <= SYSTEM_RUNNING)
+ pr_crit("SMP: stopping secondary CPUs\n");
+ send_ipi_mask(&mask, IPI_CPU_STOP);
+ }
+
+ /* Wait up to one second for other CPUs to stop */
+ timeout = USEC_PER_SEC;
+ while (num_online_cpus() > 1 && timeout--)
+ udelay(1);
+
+ if (num_online_cpus() > 1)
+ pr_warn("SMP: failed to stop secondary CPUs %*pbl\n",
+ cpumask_pr_args(cpu_online_mask));
}
void smp_send_reschedule(int cpu)
{
- send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
+ send_ipi_single(cpu, IPI_RESCHEDULE);
}
-
-/*
- * Performs an icache flush for the given MM context. RISC-V has no direct
- * mechanism for instruction cache shoot downs, so instead we send an IPI that
- * informs the remote harts they need to flush their local instruction caches.
- * To avoid pathologically slow behavior in a common case (a bunch of
- * single-hart processes on a many-hart machine, ie 'make -j') we avoid the
- * IPIs for harts that are not currently executing a MM context and instead
- * schedule a deferred local instruction cache flush to be performed before
- * execution resumes on each hart.
- */
-void flush_icache_mm(struct mm_struct *mm, bool local)
-{
- unsigned int cpu;
- cpumask_t others, *mask;
-
- preempt_disable();
-
- /* Mark every hart's icache as needing a flush for this MM. */
- mask = &mm->context.icache_stale_mask;
- cpumask_setall(mask);
- /* Flush this hart's I$ now, and mark it as flushed. */
- cpu = smp_processor_id();
- cpumask_clear_cpu(cpu, mask);
- local_flush_icache_all();
-
- /*
- * Flush the I$ of other harts concurrently executing, and mark them as
- * flushed.
- */
- cpumask_andnot(&others, mm_cpumask(mm), cpumask_of(cpu));
- local |= cpumask_empty(&others);
- if (mm != current->active_mm || !local)
- sbi_remote_fence_i(others.bits);
- else {
- /*
- * It's assumed that at least one strongly ordered operation is
- * performed on this hart between setting a hart's cpumask bit
- * and scheduling this MM context on that hart. Sending an SBI
- * remote message will do this, but in the case where no
- * messages are sent we still need to order this hart's writes
- * with flush_icache_deferred().
- */
- smp_mb();
- }
-
- preempt_enable();
-}
+EXPORT_SYMBOL_GPL(smp_send_reschedule);
--
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