[PATCH 00/10] MIPS: IPI Improvements

[PATCH 00/10] MIPS: IPI Improvements

[Jiaxun Yang]

Hi all,

This series improved general handling to MIPS IPI interrupts, made
IPI numbers scalable, and switch to IPI-MUX for all GERNERIC_IPI
users on mux.

It is a prerequisite for enabling IRQ_WORK for MIPS.

It has been tested on MIPS Boston I6500, malta SOC-It, Loongson-2K,
Cavium CN7130 (EdgeRouter 4), and an unannounced interaptiv UP MT
platform with EIC.

I don't really know broadcom platforms and SGI platforms well so
changes to those platforms are kept minimal (no functional change).

Please review.
Thanks

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
Jiaxun Yang (10):
      MIPS: smp: Make IPI interrupts scalable
      MIPS: smp: Manage IPI interrupts as percpu_devid interrupts
      MIPS: smp: Provide platform IPI virq & domain hooks
      MIPS: Move mips_smp_ipi_init call after prepare_cpus
      MIPS: smp: Implement IPI stats
      irqchip: irq-mips-gic: Switch to ipi_mux
      MIPS: Implement get_mips_sw_int hook
      MIPS: GIC: Implement get_sw_int hook
      irqchip: irq-mips-cpu: Rework software IRQ handling flow
      MIPS: smp-mt: Rework IPI functions

 arch/mips/Kconfig                |   2 +
 arch/mips/cavium-octeon/smp.c    | 109 +++++++-------------
 arch/mips/generic/irq.c          |  15 +++
 arch/mips/include/asm/ipi.h      |  71 +++++++++++++
 arch/mips/include/asm/irq.h      |   1 +
 arch/mips/include/asm/irq_cpu.h  |   3 +
 arch/mips/include/asm/mips-gic.h |  10 ++
 arch/mips/include/asm/smp-ops.h  |   8 +-
 arch/mips/include/asm/smp.h      |  42 +++-----
 arch/mips/kernel/irq.c           |  21 ++++
 arch/mips/kernel/smp-bmips.c     |  43 ++++----
 arch/mips/kernel/smp-cps.c       |   1 +
 arch/mips/kernel/smp-mt.c        |  70 +++++++++++++
 arch/mips/kernel/smp.c           | 216 ++++++++++++++++++++++++---------------
 arch/mips/loongson64/smp.c       |  51 ++++-----
 arch/mips/mm/c-octeon.c          |   2 +-
 arch/mips/sgi-ip27/ip27-smp.c    |  15 +--
 arch/mips/sgi-ip30/ip30-smp.c    |  15 +--
 arch/mips/sibyte/bcm1480/smp.c   |  19 ++--
 arch/mips/sibyte/sb1250/smp.c    |  13 +--
 drivers/irqchip/Kconfig          |   2 +-
 drivers/irqchip/irq-mips-cpu.c   | 180 +++++++++-----------------------
 drivers/irqchip/irq-mips-gic.c   | 213 ++++++++++++++------------------------
 23 files changed, 594 insertions(+), 528 deletions(-)
---
base-commit: a2a47d53ca1f74f60931487c27eeba3c17fb69c9
change-id: 20240616-b4-mips-ipi-improvements-f8c86b1dc677

Best regards,
-- 
Jiaxun Yang <jiaxun.yang@flygoat.com>

[PATCH 01/10] MIPS: smp: Make IPI interrupts scalable

[Jiaxun Yang]

Define enum ipi_message_type as other architectures did to
allow easy extension to number of IPI interrupts, fiddle
around platform IPI code to adopt to the new infra, add
extensive BUILD_BUG_ON on IPI numbers to ensure future
extensions won't break existing platforms.

IPI related stuff are pulled to asm/ipi.h to avoid include
linux/interrupt.h in asm/smp.h.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 arch/mips/cavium-octeon/smp.c   | 109 ++++++++++++-----------------------
 arch/mips/include/asm/ipi.h     |  34 +++++++++++
 arch/mips/include/asm/smp-ops.h |   8 +--
 arch/mips/include/asm/smp.h     |  42 ++++++--------
 arch/mips/kernel/smp-bmips.c    |  43 +++++++-------
 arch/mips/kernel/smp-cps.c      |   1 +
 arch/mips/kernel/smp.c          | 124 ++++++++++++++++++++--------------------
 arch/mips/loongson64/smp.c      |  51 +++++++++--------
 arch/mips/mm/c-octeon.c         |   2 +-
 arch/mips/sgi-ip27/ip27-smp.c   |  15 +++--
 arch/mips/sgi-ip30/ip30-smp.c   |  15 +++--
 arch/mips/sibyte/bcm1480/smp.c  |  19 +++---
 arch/mips/sibyte/sb1250/smp.c   |  13 +++--
 13 files changed, 236 insertions(+), 240 deletions(-)

diff --git a/arch/mips/cavium-octeon/smp.c b/arch/mips/cavium-octeon/smp.c
index 08ea2cde1eb5..7cf8dd2eddce 100644
--- a/arch/mips/cavium-octeon/smp.c
+++ b/arch/mips/cavium-octeon/smp.c
@@ -17,6 +17,7 @@
 #include <linux/export.h>
 #include <linux/kexec.h>
 
+#include <asm/ipi.h>
 #include <asm/mmu_context.h>
 #include <asm/time.h>
 #include <asm/setup.h>
@@ -40,30 +41,19 @@ EXPORT_SYMBOL(octeon_bootloader_entry_addr);
 
 extern void kernel_entry(unsigned long arg1, ...);
 
-static void octeon_icache_flush(void)
+static irqreturn_t octeon_icache_flush(int irq, void *dev_id)
 {
 	asm volatile ("synci 0($0)\n");
+	return IRQ_HANDLED;
 }
 
-static void (*octeon_message_functions[8])(void) = {
-	scheduler_ipi,
-	generic_smp_call_function_interrupt,
-	octeon_icache_flush,
-};
-
 static irqreturn_t mailbox_interrupt(int irq, void *dev_id)
 {
 	u64 mbox_clrx = CVMX_CIU_MBOX_CLRX(cvmx_get_core_num());
-	u64 action;
-	int i;
+	unsigned long action;
+	int op;
 
-	/*
-	 * Make sure the function array initialization remains
-	 * correct.
-	 */
-	BUILD_BUG_ON(SMP_RESCHEDULE_YOURSELF != (1 << 0));
-	BUILD_BUG_ON(SMP_CALL_FUNCTION       != (1 << 1));
-	BUILD_BUG_ON(SMP_ICACHE_FLUSH        != (1 << 2));
+	BUILD_BUG_ON(IPI_MAX > 8);
 
 	/*
 	 * Load the mailbox register to figure out what we're supposed
@@ -79,16 +69,10 @@ static irqreturn_t mailbox_interrupt(int irq, void *dev_id)
 	/* Clear the mailbox to clear the interrupt */
 	cvmx_write_csr(mbox_clrx, action);
 
-	for (i = 0; i < ARRAY_SIZE(octeon_message_functions) && action;) {
-		if (action & 1) {
-			void (*fn)(void) = octeon_message_functions[i];
-
-			if (fn)
-				fn();
-		}
-		action >>= 1;
-		i++;
+	for_each_set_bit(op, &action, IPI_MAX) {
+		ipi_handlers[op](0, NULL);
 	}
+
 	return IRQ_HANDLED;
 }
 
@@ -97,23 +81,23 @@ static irqreturn_t mailbox_interrupt(int irq, void *dev_id)
  * cpu.	 When the function has finished, increment the finished field of
  * call_data.
  */
-void octeon_send_ipi_single(int cpu, unsigned int action)
+void octeon_send_ipi_single(int cpu, enum ipi_message_type op)
 {
 	int coreid = cpu_logical_map(cpu);
 	/*
 	pr_info("SMP: Mailbox send cpu=%d, coreid=%d, action=%u\n", cpu,
 	       coreid, action);
 	*/
-	cvmx_write_csr(CVMX_CIU_MBOX_SETX(coreid), action);
+	cvmx_write_csr(CVMX_CIU_MBOX_SETX(coreid), BIT(op));
 }
 
 static inline void octeon_send_ipi_mask(const struct cpumask *mask,
-					unsigned int action)
+					enum ipi_message_type op)
 {
 	unsigned int i;
 
 	for_each_cpu(i, mask)
-		octeon_send_ipi_single(i, action);
+		octeon_send_ipi_single(i, BIT(op));
 }
 
 /*
@@ -149,6 +133,9 @@ static void __init octeon_smp_setup(void)
 	unsigned int num_cores = cvmx_octeon_num_cores();
 #endif
 
+	ipi_handlers[IPI_ICACHE_FLUSH] = octeon_icache_flush;
+	ipi_names[IPI_ICACHE_FLUSH] = "Octeon ICache Flush";
+
 	/* The present CPUs are initially just the boot cpu (CPU 0). */
 	for (id = 0; id < NR_CPUS; id++) {
 		set_cpu_possible(id, id == 0);
@@ -427,67 +414,41 @@ static const struct plat_smp_ops octeon_smp_ops = {
 #endif
 };
 
-static irqreturn_t octeon_78xx_reched_interrupt(int irq, void *dev_id)
-{
-	scheduler_ipi();
-	return IRQ_HANDLED;
-}
-
-static irqreturn_t octeon_78xx_call_function_interrupt(int irq, void *dev_id)
-{
-	generic_smp_call_function_interrupt();
-	return IRQ_HANDLED;
-}
-
-static irqreturn_t octeon_78xx_icache_flush_interrupt(int irq, void *dev_id)
-{
-	octeon_icache_flush();
-	return IRQ_HANDLED;
-}
-
 /*
  * Callout to firmware before smp_init
  */
 static void octeon_78xx_prepare_cpus(unsigned int max_cpus)
 {
-	if (request_irq(OCTEON_IRQ_MBOX0 + 0,
-			octeon_78xx_reched_interrupt,
-			IRQF_PERCPU | IRQF_NO_THREAD, "Scheduler",
-			octeon_78xx_reched_interrupt)) {
-		panic("Cannot request_irq for SchedulerIPI");
-	}
-	if (request_irq(OCTEON_IRQ_MBOX0 + 1,
-			octeon_78xx_call_function_interrupt,
-			IRQF_PERCPU | IRQF_NO_THREAD, "SMP-Call",
-			octeon_78xx_call_function_interrupt)) {
-		panic("Cannot request_irq for SMP-Call");
-	}
-	if (request_irq(OCTEON_IRQ_MBOX0 + 2,
-			octeon_78xx_icache_flush_interrupt,
-			IRQF_PERCPU | IRQF_NO_THREAD, "ICache-Flush",
-			octeon_78xx_icache_flush_interrupt)) {
-		panic("Cannot request_irq for ICache-Flush");
+	int i;
+
+	/*
+	 * FIXME: Hardware have 10 MBOX but only 4 virqs are reserved
+	 * for CIU3 MBOX.
+	 */
+	BUILD_BUG_ON(IPI_MAX > 4);
+
+	for (i = 0; i < IPI_MAX; i++) {
+		if (request_irq(OCTEON_IRQ_MBOX0 + i,
+				ipi_handlers[i],
+				IRQF_PERCPU | IRQF_NO_THREAD, "IPI",
+				ipi_handlers[i])) {
+			panic("Cannot request_irq for %s", ipi_names[i]);
+		}
 	}
 }
 
-static void octeon_78xx_send_ipi_single(int cpu, unsigned int action)
+static void octeon_78xx_send_ipi_single(int cpu, enum ipi_message_type op)
 {
-	int i;
-
-	for (i = 0; i < 8; i++) {
-		if (action & 1)
-			octeon_ciu3_mbox_send(cpu, i);
-		action >>= 1;
-	}
+	octeon_ciu3_mbox_send(cpu, op);
 }
 
 static void octeon_78xx_send_ipi_mask(const struct cpumask *mask,
-				      unsigned int action)
+				      enum ipi_message_type op)
 {
 	unsigned int cpu;
 
 	for_each_cpu(cpu, mask)
-		octeon_78xx_send_ipi_single(cpu, action);
+		octeon_78xx_send_ipi_single(cpu, op);
 }
 
 static const struct plat_smp_ops octeon_78xx_smp_ops = {
diff --git a/arch/mips/include/asm/ipi.h b/arch/mips/include/asm/ipi.h
new file mode 100644
index 000000000000..df7a0ac4227a
--- /dev/null
+++ b/arch/mips/include/asm/ipi.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <linux/cpumask.h>
+#include <linux/interrupt.h>
+
+#ifndef __ASM_IPI_H
+#define __ASM_IPI_H
+
+#ifdef CONFIG_SMP
+extern const char *ipi_names[];
+extern irq_handler_t ipi_handlers[];
+
+#ifdef CONFIG_GENERIC_IRQ_IPI
+extern void mips_smp_send_ipi_single(int cpu,
+				     enum ipi_message_type op);
+extern void mips_smp_send_ipi_mask(const struct cpumask *mask,
+				   enum ipi_message_type op);
+
+/*
+ * This function will set up the necessary IPIs for Linux to communicate
+ * with the CPUs in mask.
+ * Return 0 on success.
+ */
+int mips_smp_ipi_allocate(const struct cpumask *mask);
+
+/*
+ * This function will free up IPIs allocated with mips_smp_ipi_allocate to the
+ * CPUs in mask, which must be a subset of the IPIs that have been configured.
+ * Return 0 on success.
+ */
+int mips_smp_ipi_free(const struct cpumask *mask);
+#endif /* CONFIG_GENERIC_IRQ_IPI */
+#endif /* CONFIG_SMP */
+#endif
diff --git a/arch/mips/include/asm/smp-ops.h b/arch/mips/include/asm/smp-ops.h
index 1617b207723f..8cf4156cb301 100644
--- a/arch/mips/include/asm/smp-ops.h
+++ b/arch/mips/include/asm/smp-ops.h
@@ -20,8 +20,8 @@
 struct task_struct;
 
 struct plat_smp_ops {
-	void (*send_ipi_single)(int cpu, unsigned int action);
-	void (*send_ipi_mask)(const struct cpumask *mask, unsigned int action);
+	void (*send_ipi_single)(int cpu, enum ipi_message_type op);
+	void (*send_ipi_mask)(const struct cpumask *mask, enum ipi_message_type op);
 	void (*init_secondary)(void);
 	void (*smp_finish)(void);
 	int (*boot_secondary)(int cpu, struct task_struct *idle);
@@ -47,10 +47,6 @@ static inline void plat_smp_setup(void)
 	mp_ops->smp_setup();
 }
 
-extern void mips_smp_send_ipi_single(int cpu, unsigned int action);
-extern void mips_smp_send_ipi_mask(const struct cpumask *mask,
-				      unsigned int action);
-
 #else /* !CONFIG_SMP */
 
 struct plat_smp_ops;
diff --git a/arch/mips/include/asm/smp.h b/arch/mips/include/asm/smp.h
index bc2c240f414b..0c7467f15014 100644
--- a/arch/mips/include/asm/smp.h
+++ b/arch/mips/include/asm/smp.h
@@ -16,8 +16,6 @@
 #include <linux/threads.h>
 #include <linux/cpumask.h>
 
-#include <asm/smp-ops.h>
-
 extern int smp_num_siblings;
 extern cpumask_t cpu_sibling_map[];
 extern cpumask_t cpu_core_map[];
@@ -46,12 +44,6 @@ extern int __cpu_logical_map[NR_CPUS];
 
 #define NO_PROC_ID	(-1)
 
-#define SMP_RESCHEDULE_YOURSELF 0x1	/* XXX braindead */
-#define SMP_CALL_FUNCTION	0x2
-/* Octeon - Tell another core to flush its icache */
-#define SMP_ICACHE_FLUSH	0x4
-#define SMP_ASK_C0COUNT		0x8
-
 /* Mask of CPUs which are currently definitely operating coherently */
 extern cpumask_t cpu_coherent_mask;
 
@@ -63,6 +55,20 @@ extern void calculate_cpu_foreign_map(void);
 
 asmlinkage void start_secondary(void);
 
+enum ipi_message_type {
+	IPI_RESCHEDULE,
+	IPI_CALL_FUNC,
+#ifdef CONFIG_CAVIUM_OCTEON_SOC
+	IPI_ICACHE_FLUSH,
+#endif
+#ifdef CONFIG_MACH_LOONGSON64
+	IPI_ASK_C0COUNT,
+#endif
+	IPI_MAX
+};
+
+#include <asm/smp-ops.h>
+
 /*
  * this function sends a 'reschedule' IPI to another CPU.
  * it goes straight through and wastes no time serializing
@@ -72,7 +78,7 @@ static inline void arch_smp_send_reschedule(int cpu)
 {
 	extern const struct plat_smp_ops *mp_ops;	/* private */
 
-	mp_ops->send_ipi_single(cpu, SMP_RESCHEDULE_YOURSELF);
+	mp_ops->send_ipi_single(cpu, IPI_RESCHEDULE);
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -109,32 +115,18 @@ static inline void *kexec_nonboot_cpu_func(void)
 }
 #endif
 
-/*
- * This function will set up the necessary IPIs for Linux to communicate
- * with the CPUs in mask.
- * Return 0 on success.
- */
-int mips_smp_ipi_allocate(const struct cpumask *mask);
-
-/*
- * This function will free up IPIs allocated with mips_smp_ipi_allocate to the
- * CPUs in mask, which must be a subset of the IPIs that have been configured.
- * Return 0 on success.
- */
-int mips_smp_ipi_free(const struct cpumask *mask);
-
 static inline void arch_send_call_function_single_ipi(int cpu)
 {
 	extern const struct plat_smp_ops *mp_ops;	/* private */
 
-	mp_ops->send_ipi_single(cpu, SMP_CALL_FUNCTION);
+	mp_ops->send_ipi_single(cpu, IPI_CALL_FUNC);
 }
 
 static inline void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 {
 	extern const struct plat_smp_ops *mp_ops;	/* private */
 
-	mp_ops->send_ipi_mask(mask, SMP_CALL_FUNCTION);
+	mp_ops->send_ipi_mask(mask, IPI_CALL_FUNC);
 }
 
 #endif /* __ASM_SMP_H */
diff --git a/arch/mips/kernel/smp-bmips.c b/arch/mips/kernel/smp-bmips.c
index b3dbf9ecb0d6..428b39aee344 100644
--- a/arch/mips/kernel/smp-bmips.c
+++ b/arch/mips/kernel/smp-bmips.c
@@ -32,6 +32,7 @@
 #include <asm/processor.h>
 #include <asm/bootinfo.h>
 #include <asm/cacheflush.h>
+#include <asm/ipi.h>
 #include <asm/tlbflush.h>
 #include <asm/mipsregs.h>
 #include <asm/bmips.h>
@@ -282,36 +283,31 @@ static void bmips_smp_finish(void)
  * BMIPS5000 raceless IPIs
  *
  * Each CPU has two inbound SW IRQs which are independent of all other CPUs.
- * IPI0 is used for SMP_RESCHEDULE_YOURSELF
- * IPI1 is used for SMP_CALL_FUNCTION
  */
 
-static void bmips5000_send_ipi_single(int cpu, unsigned int action)
+static void bmips5000_send_ipi_single(int cpu, enum ipi_message_type op)
 {
-	write_c0_brcm_action(ACTION_SET_IPI(cpu, action == SMP_CALL_FUNCTION));
+	write_c0_brcm_action(ACTION_SET_IPI(cpu, op));
 }
 
 static irqreturn_t bmips5000_ipi_interrupt(int irq, void *dev_id)
 {
 	int action = irq - IPI0_IRQ;
 
-	write_c0_brcm_action(ACTION_CLR_IPI(smp_processor_id(), action));
+	BUILD_BUG_ON(IPI_MAX > 2);
 
-	if (action == 0)
-		scheduler_ipi();
-	else
-		generic_smp_call_function_interrupt();
+	write_c0_brcm_action(ACTION_CLR_IPI(smp_processor_id(), action));
 
-	return IRQ_HANDLED;
+	return ipi_handlers[action](0, NULL);
 }
 
 static void bmips5000_send_ipi_mask(const struct cpumask *mask,
-	unsigned int action)
+	enum ipi_message_type op)
 {
 	unsigned int i;
 
 	for_each_cpu(i, mask)
-		bmips5000_send_ipi_single(i, action);
+		bmips5000_send_ipi_single(i, op);
 }
 
 /*
@@ -325,23 +321,26 @@ static void bmips5000_send_ipi_mask(const struct cpumask *mask,
  */
 
 static DEFINE_SPINLOCK(ipi_lock);
-static DEFINE_PER_CPU(int, ipi_action_mask);
+static DEFINE_PER_CPU(unsigned long, ipi_action_mask);
 
-static void bmips43xx_send_ipi_single(int cpu, unsigned int action)
+static void bmips43xx_send_ipi_single(int cpu, enum ipi_message_type op)
 {
 	unsigned long flags;
 
 	spin_lock_irqsave(&ipi_lock, flags);
 	set_c0_cause(cpu ? C_SW1 : C_SW0);
-	per_cpu(ipi_action_mask, cpu) |= action;
+	per_cpu(ipi_action_mask, cpu) |= BIT(op);
 	irq_enable_hazard();
 	spin_unlock_irqrestore(&ipi_lock, flags);
 }
 
 static irqreturn_t bmips43xx_ipi_interrupt(int irq, void *dev_id)
 {
-	unsigned long flags;
-	int action, cpu = irq - IPI0_IRQ;
+	unsigned long flags, action;
+	int cpu = irq - IPI0_IRQ;
+	int op;
+
+	BUILD_BUG_ON(IPI_MAX > BITS_PER_LONG);
 
 	spin_lock_irqsave(&ipi_lock, flags);
 	action = __this_cpu_read(ipi_action_mask);
@@ -349,21 +348,19 @@ static irqreturn_t bmips43xx_ipi_interrupt(int irq, void *dev_id)
 	clear_c0_cause(cpu ? C_SW1 : C_SW0);
 	spin_unlock_irqrestore(&ipi_lock, flags);
 
-	if (action & SMP_RESCHEDULE_YOURSELF)
-		scheduler_ipi();
-	if (action & SMP_CALL_FUNCTION)
-		generic_smp_call_function_interrupt();
+	for_each_set_bit(op, &action, IPI_MAX)
+		ipi_handlers[op](0, NULL);
 
 	return IRQ_HANDLED;
 }
 
 static void bmips43xx_send_ipi_mask(const struct cpumask *mask,
-	unsigned int action)
+	enum ipi_message_type op)
 {
 	unsigned int i;
 
 	for_each_cpu(i, mask)
-		bmips43xx_send_ipi_single(i, action);
+		bmips43xx_send_ipi_single(i, op);
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c
index 9cc087dd1c19..8c322f441164 100644
--- a/arch/mips/kernel/smp-cps.c
+++ b/arch/mips/kernel/smp-cps.c
@@ -16,6 +16,7 @@
 #include <linux/irq.h>
 
 #include <asm/bcache.h>
+#include <asm/ipi.h>
 #include <asm/mips-cps.h>
 #include <asm/mips_mt.h>
 #include <asm/mipsregs.h>
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index 0b53d35a116e..a6cf6444533e 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -31,6 +31,7 @@
 #include <asm/ginvt.h>
 #include <asm/processor.h>
 #include <asm/idle.h>
+#include <asm/ipi.h>
 #include <asm/r4k-timer.h>
 #include <asm/mips-cps.h>
 #include <asm/mmu_context.h>
@@ -92,11 +93,6 @@ static int __init early_smt(char *s)
 }
 early_param("smt", early_smt);
 
-#ifdef CONFIG_GENERIC_IRQ_IPI
-static struct irq_desc *call_desc;
-static struct irq_desc *sched_desc;
-#endif
-
 static inline void set_cpu_sibling_map(int cpu)
 {
 	int i;
@@ -164,13 +160,42 @@ void register_smp_ops(const struct plat_smp_ops *ops)
 	mp_ops = ops;
 }
 
+static irqreturn_t ipi_resched_interrupt(int irq, void *dev_id)
+{
+	scheduler_ipi();
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
+{
+	generic_smp_call_function_interrupt();
+
+	return IRQ_HANDLED;
+}
+
+
+const char *ipi_names[IPI_MAX] __read_mostly = {
+	[IPI_RESCHEDULE]	= "Rescheduling interrupts",
+	[IPI_CALL_FUNC]		= "Function call interrupts",
+};
+
+irq_handler_t ipi_handlers[IPI_MAX] __read_mostly = {
+	[IPI_RESCHEDULE]	= ipi_resched_interrupt,
+	[IPI_CALL_FUNC]		= ipi_call_interrupt,
+};
+
 #ifdef CONFIG_GENERIC_IRQ_IPI
-void mips_smp_send_ipi_single(int cpu, unsigned int action)
+static int ipi_virqs[IPI_MAX] __ro_after_init;
+static struct irq_desc *ipi_desc[IPI_MAX] __read_mostly;
+
+void mips_smp_send_ipi_single(int cpu, enum ipi_message_type op)
 {
-	mips_smp_send_ipi_mask(cpumask_of(cpu), action);
+	mips_smp_send_ipi_mask(cpumask_of(cpu), op);
 }
 
-void mips_smp_send_ipi_mask(const struct cpumask *mask, unsigned int action)
+void mips_smp_send_ipi_mask(const struct cpumask *mask,
+			    enum ipi_message_type op)
 {
 	unsigned long flags;
 	unsigned int core;
@@ -178,18 +203,7 @@ void mips_smp_send_ipi_mask(const struct cpumask *mask, unsigned int action)
 
 	local_irq_save(flags);
 
-	switch (action) {
-	case SMP_CALL_FUNCTION:
-		__ipi_send_mask(call_desc, mask);
-		break;
-
-	case SMP_RESCHEDULE_YOURSELF:
-		__ipi_send_mask(sched_desc, mask);
-		break;
-
-	default:
-		BUG();
-	}
+	__ipi_send_mask(ipi_desc[op], mask);
 
 	if (mips_cpc_present()) {
 		for_each_cpu(cpu, mask) {
@@ -211,21 +225,6 @@ void mips_smp_send_ipi_mask(const struct cpumask *mask, unsigned int action)
 	local_irq_restore(flags);
 }
 
-
-static irqreturn_t ipi_resched_interrupt(int irq, void *dev_id)
-{
-	scheduler_ipi();
-
-	return IRQ_HANDLED;
-}
-
-static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
-{
-	generic_smp_call_function_interrupt();
-
-	return IRQ_HANDLED;
-}
-
 static void smp_ipi_init_one(unsigned int virq, const char *name,
 			     irq_handler_t handler)
 {
@@ -236,11 +235,9 @@ static void smp_ipi_init_one(unsigned int virq, const char *name,
 	BUG_ON(ret);
 }
 
-static unsigned int call_virq, sched_virq;
-
 int mips_smp_ipi_allocate(const struct cpumask *mask)
 {
-	int virq;
+	int virq, i;
 	struct irq_domain *ipidomain;
 	struct device_node *node;
 
@@ -267,33 +264,30 @@ int mips_smp_ipi_allocate(const struct cpumask *mask)
 	 * setup, if we're running with only a single CPU.
 	 */
 	if (!ipidomain) {
-		BUG_ON(num_present_cpus() > 1);
+		WARN_ON(num_present_cpus() > 1);
 		return 0;
 	}
 
-	virq = irq_reserve_ipi(ipidomain, mask);
-	BUG_ON(!virq);
-	if (!call_virq)
-		call_virq = virq;
-
-	virq = irq_reserve_ipi(ipidomain, mask);
-	BUG_ON(!virq);
-	if (!sched_virq)
-		sched_virq = virq;
+	for (i = 0; i < IPI_MAX; i++) {
+		virq = irq_reserve_ipi(ipidomain, mask);
+		WARN_ON(!virq);
+		ipi_virqs[i] = virq;
+	}
 
 	if (irq_domain_is_ipi_per_cpu(ipidomain)) {
 		int cpu;
 
 		for_each_cpu(cpu, mask) {
-			smp_ipi_init_one(call_virq + cpu, "IPI call",
-					 ipi_call_interrupt);
-			smp_ipi_init_one(sched_virq + cpu, "IPI resched",
-					 ipi_resched_interrupt);
+			for (i = 0; i < IPI_MAX; i++) {
+				smp_ipi_init_one(ipi_virqs[i] + cpu, ipi_names[i],
+						 ipi_handlers[i]);
+			}
 		}
 	} else {
-		smp_ipi_init_one(call_virq, "IPI call", ipi_call_interrupt);
-		smp_ipi_init_one(sched_virq, "IPI resched",
-				 ipi_resched_interrupt);
+		for (i = 0; i < IPI_MAX; i++) {
+			smp_ipi_init_one(ipi_virqs[i], ipi_names[i],
+					 ipi_handlers[i]);
+		}
 	}
 
 	return 0;
@@ -301,6 +295,7 @@ int mips_smp_ipi_allocate(const struct cpumask *mask)
 
 int mips_smp_ipi_free(const struct cpumask *mask)
 {
+	int i;
 	struct irq_domain *ipidomain;
 	struct device_node *node;
 
@@ -321,25 +316,32 @@ int mips_smp_ipi_free(const struct cpumask *mask)
 		int cpu;
 
 		for_each_cpu(cpu, mask) {
-			free_irq(call_virq + cpu, NULL);
-			free_irq(sched_virq + cpu, NULL);
+			for (i = 0; i < IPI_MAX; i++)
+				free_irq(ipi_virqs[i] + cpu, NULL);
 		}
 	}
-	irq_destroy_ipi(call_virq, mask);
-	irq_destroy_ipi(sched_virq, mask);
+
+	for (i = 0; i < IPI_MAX; i++)
+		irq_destroy_ipi(ipi_virqs[i], mask);
+
 	return 0;
 }
 
 
 static int __init mips_smp_ipi_init(void)
 {
+	int i;
+
 	if (num_possible_cpus() == 1)
 		return 0;
 
 	mips_smp_ipi_allocate(cpu_possible_mask);
 
-	call_desc = irq_to_desc(call_virq);
-	sched_desc = irq_to_desc(sched_virq);
+	for (i = 0; i < IPI_MAX; i++) {
+		ipi_desc[i] = irq_to_desc(ipi_virqs[i]);
+		if (!ipi_desc[i])
+			return -ENODEV;
+	}
 
 	return 0;
 }
diff --git a/arch/mips/loongson64/smp.c b/arch/mips/loongson64/smp.c
index 5a990cdef91a..3c64d7cd835b 100644
--- a/arch/mips/loongson64/smp.c
+++ b/arch/mips/loongson64/smp.c
@@ -13,8 +13,8 @@
 #include <linux/smp.h>
 #include <linux/cpufreq.h>
 #include <linux/kexec.h>
+#include <asm/ipi.h>
 #include <asm/processor.h>
-#include <asm/smp.h>
 #include <asm/time.h>
 #include <asm/tlbflush.h>
 #include <asm/cacheflush.h>
@@ -368,44 +368,44 @@ static void ipi_mailbox_buf_init(void)
 /*
  * Simple enough, just poke the appropriate ipi register
  */
-static void loongson3_send_ipi_single(int cpu, unsigned int action)
+static void loongson3_send_ipi_single(int cpu, enum ipi_message_type op)
 {
-	ipi_write_action(cpu_logical_map(cpu), (u32)action);
+	ipi_write_action(cpu_logical_map(cpu), BIT(op));
 }
 
 static void
-loongson3_send_ipi_mask(const struct cpumask *mask, unsigned int action)
+loongson3_send_ipi_mask(const struct cpumask *mask, enum ipi_message_type op)
 {
 	unsigned int i;
 
 	for_each_cpu(i, mask)
-		ipi_write_action(cpu_logical_map(i), (u32)action);
+		ipi_write_action(cpu_logical_map(i), BIT(op));
 }
 
-
-static irqreturn_t loongson3_ipi_interrupt(int irq, void *dev_id)
+static irqreturn_t loongson3_ask_c0count(int irq, void *dev_id)
 {
 	int i, cpu = smp_processor_id();
-	unsigned int action, c0count;
+	unsigned long c0count;
 
-	action = ipi_read_clear(cpu);
+	BUG_ON(cpu != 0);
+	c0count = read_c0_count();
+	c0count = c0count ? c0count : 1;
+	for (i = 1; i < nr_cpu_ids; i++)
+		core0_c0count[i] = c0count;
+	nudge_writes(); /* Let others see the result ASAP */
 
-	if (action & SMP_RESCHEDULE_YOURSELF)
-		scheduler_ipi();
+	return IRQ_HANDLED;
+}
 
-	if (action & SMP_CALL_FUNCTION) {
-		irq_enter();
-		generic_smp_call_function_interrupt();
-		irq_exit();
-	}
+static irqreturn_t loongson3_ipi_interrupt(int irq, void *dev_id)
+{
+	int op, cpu = smp_processor_id();
+	unsigned long action;
 
-	if (action & SMP_ASK_C0COUNT) {
-		BUG_ON(cpu != 0);
-		c0count = read_c0_count();
-		c0count = c0count ? c0count : 1;
-		for (i = 1; i < nr_cpu_ids; i++)
-			core0_c0count[i] = c0count;
-		nudge_writes(); /* Let others see the result ASAP */
+	action = ipi_read_clear(cpu);
+
+	for_each_set_bit(op, &action, IPI_MAX) {
+		ipi_handlers[op](0, NULL);
 	}
 
 	return IRQ_HANDLED;
@@ -435,7 +435,7 @@ static void loongson3_init_secondary(void)
 
 	i = 0;
 	core0_c0count[cpu] = 0;
-	loongson3_send_ipi_single(0, SMP_ASK_C0COUNT);
+	loongson3_send_ipi_single(0, IPI_ASK_C0COUNT);
 	while (!core0_c0count[cpu]) {
 		i++;
 		cpu_relax();
@@ -493,6 +493,9 @@ static void __init loongson3_smp_setup(void)
 		num++;
 	}
 
+	ipi_handlers[IPI_ASK_C0COUNT] = loongson3_ask_c0count;
+	ipi_names[IPI_ASK_C0COUNT] = "Loongson Ask C0 Count";
+
 	csr_ipi_probe();
 	ipi_set0_regs_init();
 	ipi_clear0_regs_init();
diff --git a/arch/mips/mm/c-octeon.c b/arch/mips/mm/c-octeon.c
index b7393b61cfa7..10b201a09859 100644
--- a/arch/mips/mm/c-octeon.c
+++ b/arch/mips/mm/c-octeon.c
@@ -85,7 +85,7 @@ static void octeon_flush_icache_all_cores(struct vm_area_struct *vma)
 	cpumask_clear_cpu(cpu, &mask);
 #ifdef CONFIG_CAVIUM_OCTEON_SOC
 	for_each_cpu(cpu, &mask)
-		octeon_send_ipi_single(cpu, SMP_ICACHE_FLUSH);
+		octeon_send_ipi_single(cpu, IPI_ICACHE_FLUSH);
 #else
 	smp_call_function_many(&mask, (smp_call_func_t)octeon_local_flush_icache,
 			       NULL, 1);
diff --git a/arch/mips/sgi-ip27/ip27-smp.c b/arch/mips/sgi-ip27/ip27-smp.c
index 5d2652a1d35a..87da545d0c3f 100644
--- a/arch/mips/sgi-ip27/ip27-smp.c
+++ b/arch/mips/sgi-ip27/ip27-smp.c
@@ -94,15 +94,17 @@ static __init void intr_clear_all(nasid_t nasid)
 		REMOTE_HUB_CLR_INTR(nasid, i);
 }
 
-static void ip27_send_ipi_single(int destid, unsigned int action)
+static void ip27_send_ipi_single(int destid, enum ipi_message_type op)
 {
 	int irq;
 
-	switch (action) {
-	case SMP_RESCHEDULE_YOURSELF:
+	BUILD_BUG_ON(IPI_MAX > 2);
+
+	switch (op) {
+	case IPI_RESCHEDULE:
 		irq = CPU_RESCHED_A_IRQ;
 		break;
-	case SMP_CALL_FUNCTION:
+	case IPI_CALL_FUNC:
 		irq = CPU_CALL_A_IRQ;
 		break;
 	default:
@@ -118,12 +120,13 @@ static void ip27_send_ipi_single(int destid, unsigned int action)
 	REMOTE_HUB_SEND_INTR(cpu_to_node(destid), irq);
 }
 
-static void ip27_send_ipi_mask(const struct cpumask *mask, unsigned int action)
+static void ip27_send_ipi_mask(const struct cpumask *mask,
+			       enum ipi_message_type op)
 {
 	unsigned int i;
 
 	for_each_cpu(i, mask)
-		ip27_send_ipi_single(i, action);
+		ip27_send_ipi_single(i, op);
 }
 
 static void ip27_init_cpu(void)
diff --git a/arch/mips/sgi-ip30/ip30-smp.c b/arch/mips/sgi-ip30/ip30-smp.c
index 4bfe654602b1..1c674c0cf419 100644
--- a/arch/mips/sgi-ip30/ip30-smp.c
+++ b/arch/mips/sgi-ip30/ip30-smp.c
@@ -43,15 +43,17 @@ struct mpconf {
 	u32 idleflag;
 };
 
-static void ip30_smp_send_ipi_single(int cpu, u32 action)
+static void ip30_smp_send_ipi_single(int cpu, enum ipi_message_type op)
 {
 	int irq;
 
-	switch (action) {
-	case SMP_RESCHEDULE_YOURSELF:
+	BUILD_BUG_ON(IPI_MAX > 2);
+
+	switch (op) {
+	case IPI_RESCHEDULE:
 		irq = HEART_L2_INT_RESCHED_CPU_0;
 		break;
-	case SMP_CALL_FUNCTION:
+	case IPI_CALL_FUNC:
 		irq = HEART_L2_INT_CALL_CPU_0;
 		break;
 	default:
@@ -64,12 +66,13 @@ static void ip30_smp_send_ipi_single(int cpu, u32 action)
 	heart_write(BIT_ULL(irq), &heart_regs->set_isr);
 }
 
-static void ip30_smp_send_ipi_mask(const struct cpumask *mask, u32 action)
+static void ip30_smp_send_ipi_mask(const struct cpumask *mask,
+				   enum ipi_message_type op)
 {
 	u32 i;
 
 	for_each_cpu(i, mask)
-		ip30_smp_send_ipi_single(i, action);
+		ip30_smp_send_ipi_single(i, op);
 }
 
 static void __init ip30_smp_setup(void)
diff --git a/arch/mips/sibyte/bcm1480/smp.c b/arch/mips/sibyte/bcm1480/smp.c
index 5861e50255bf..040230e3f4a0 100644
--- a/arch/mips/sibyte/bcm1480/smp.c
+++ b/arch/mips/sibyte/bcm1480/smp.c
@@ -12,6 +12,7 @@
 
 #include <asm/mmu_context.h>
 #include <asm/io.h>
+#include <asm/ipi.h>
 #include <asm/fw/cfe/cfe_api.h>
 #include <asm/sibyte/sb1250.h>
 #include <asm/sibyte/bcm1480_regs.h>
@@ -64,18 +65,18 @@ void bcm1480_smp_init(void)
  * Simple enough; everything is set up, so just poke the appropriate mailbox
  * register, and we should be set
  */
-static void bcm1480_send_ipi_single(int cpu, unsigned int action)
+static void bcm1480_send_ipi_single(int cpu, enum ipi_message_type op)
 {
-	__raw_writeq((((u64)action)<< 48), mailbox_0_set_regs[cpu]);
+	__raw_writeq((((u64)BIT_ULL(op)) << 48), mailbox_0_set_regs[cpu]);
 }
 
 static void bcm1480_send_ipi_mask(const struct cpumask *mask,
-				  unsigned int action)
+				  enum ipi_message_type op)
 {
 	unsigned int i;
 
 	for_each_cpu(i, mask)
-		bcm1480_send_ipi_single(i, action);
+		bcm1480_send_ipi_single(i, op);
 }
 
 /*
@@ -159,19 +160,21 @@ void bcm1480_mailbox_interrupt(void)
 {
 	int cpu = smp_processor_id();
 	int irq = K_BCM1480_INT_MBOX_0_0;
-	unsigned int action;
+	u64 action;
+
+	BUILD_BUG_ON(IPI_MAX > 2);
 
 	kstat_incr_irq_this_cpu(irq);
 	/* Load the mailbox register to figure out what we're supposed to do */
 	action = (__raw_readq(mailbox_0_regs[cpu]) >> 48) & 0xffff;
 
 	/* Clear the mailbox to clear the interrupt */
-	__raw_writeq(((u64)action)<<48, mailbox_0_clear_regs[cpu]);
+	__raw_writeq(((u64)action) << 48, mailbox_0_clear_regs[cpu]);
 
-	if (action & SMP_RESCHEDULE_YOURSELF)
+	if (action & BIT_ULL(IPI_RESCHEDULE))
 		scheduler_ipi();
 
-	if (action & SMP_CALL_FUNCTION) {
+	if (action & BIT_ULL(IPI_CALL_FUNC)) {
 		irq_enter();
 		generic_smp_call_function_interrupt();
 		irq_exit();
diff --git a/arch/mips/sibyte/sb1250/smp.c b/arch/mips/sibyte/sb1250/smp.c
index 7a794234e3d7..dc2c889fa0b6 100644
--- a/arch/mips/sibyte/sb1250/smp.c
+++ b/arch/mips/sibyte/sb1250/smp.c
@@ -12,6 +12,7 @@
 
 #include <asm/mmu_context.h>
 #include <asm/io.h>
+#include <asm/ipi.h>
 #include <asm/fw/cfe/cfe_api.h>
 #include <asm/sibyte/sb1250.h>
 #include <asm/sibyte/sb1250_regs.h>
@@ -53,18 +54,18 @@ void sb1250_smp_init(void)
  * Simple enough; everything is set up, so just poke the appropriate mailbox
  * register, and we should be set
  */
-static void sb1250_send_ipi_single(int cpu, unsigned int action)
+static void sb1250_send_ipi_single(int cpu, enum ipi_message_type op)
 {
-	__raw_writeq((((u64)action) << 48), mailbox_set_regs[cpu]);
+	__raw_writeq((((u64)BIT_ULL(op)) << 48), mailbox_set_regs[cpu]);
 }
 
 static inline void sb1250_send_ipi_mask(const struct cpumask *mask,
-					unsigned int action)
+					enum ipi_message_type op)
 {
 	unsigned int i;
 
 	for_each_cpu(i, mask)
-		sb1250_send_ipi_single(i, action);
+		sb1250_send_ipi_single(i, op);
 }
 
 /*
@@ -157,10 +158,10 @@ void sb1250_mailbox_interrupt(void)
 	/* Clear the mailbox to clear the interrupt */
 	____raw_writeq(((u64)action) << 48, mailbox_clear_regs[cpu]);
 
-	if (action & SMP_RESCHEDULE_YOURSELF)
+	if (action & BIT(IPI_RESCHEDULE))
 		scheduler_ipi();
 
-	if (action & SMP_CALL_FUNCTION) {
+	if (action & BIT(IPI_CALL_FUNC)) {
 		irq_enter();
 		generic_smp_call_function_interrupt();
 		irq_exit();

-- 
2.43.0

Re: [PATCH 01/10] MIPS: smp: Make IPI interrupts scalable

[Thomas Bogendoerfer]

On Sun, Jun 16, 2024 at 10:03:05PM +0100, Jiaxun Yang wrote:
> Define enum ipi_message_type as other architectures did to
> allow easy extension to number of IPI interrupts, fiddle
> around platform IPI code to adopt to the new infra, add
> extensive BUILD_BUG_ON on IPI numbers to ensure future
> extensions won't break existing platforms.
> 
> IPI related stuff are pulled to asm/ipi.h to avoid include
> linux/interrupt.h in asm/smp.h.
> 
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
>  arch/mips/cavium-octeon/smp.c   | 109 ++++++++++++-----------------------
>  arch/mips/include/asm/ipi.h     |  34 +++++++++++
>  arch/mips/include/asm/smp-ops.h |   8 +--
>  arch/mips/include/asm/smp.h     |  42 ++++++--------
>  arch/mips/kernel/smp-bmips.c    |  43 +++++++-------
>  arch/mips/kernel/smp-cps.c      |   1 +
>  arch/mips/kernel/smp.c          | 124 ++++++++++++++++++++--------------------
>  arch/mips/loongson64/smp.c      |  51 +++++++++--------
>  arch/mips/mm/c-octeon.c         |   2 +-
>  arch/mips/sgi-ip27/ip27-smp.c   |  15 +++--
>  arch/mips/sgi-ip30/ip30-smp.c   |  15 +++--
>  arch/mips/sibyte/bcm1480/smp.c  |  19 +++---
>  arch/mips/sibyte/sb1250/smp.c   |  13 +++--
>  13 files changed, 236 insertions(+), 240 deletions(-)

you are touching a lot of platforms, how many did you test ?

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH 01/10] MIPS: smp: Make IPI interrupts scalable

[Jiaxun Yang]

在2024年7月3日七月 下午11:04，Thomas Bogendoerfer写道：
> On Sun, Jun 16, 2024 at 10:03:05PM +0100, Jiaxun Yang wrote:
>> Define enum ipi_message_type as other architectures did to
>> allow easy extension to number of IPI interrupts, fiddle
>> around platform IPI code to adopt to the new infra, add
>> extensive BUILD_BUG_ON on IPI numbers to ensure future
>> extensions won't break existing platforms.
>> 
>> IPI related stuff are pulled to asm/ipi.h to avoid include
>> linux/interrupt.h in asm/smp.h.
>> 
>> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
>> ---
>>  arch/mips/cavium-octeon/smp.c   | 109 ++++++++++++-----------------------
>>  arch/mips/include/asm/ipi.h     |  34 +++++++++++
>>  arch/mips/include/asm/smp-ops.h |   8 +--
>>  arch/mips/include/asm/smp.h     |  42 ++++++--------
>>  arch/mips/kernel/smp-bmips.c    |  43 +++++++-------
>>  arch/mips/kernel/smp-cps.c      |   1 +
>>  arch/mips/kernel/smp.c          | 124 ++++++++++++++++++++--------------------
>>  arch/mips/loongson64/smp.c      |  51 +++++++++--------
>>  arch/mips/mm/c-octeon.c         |   2 +-
>>  arch/mips/sgi-ip27/ip27-smp.c   |  15 +++--
>>  arch/mips/sgi-ip30/ip30-smp.c   |  15 +++--
>>  arch/mips/sibyte/bcm1480/smp.c  |  19 +++---
>>  arch/mips/sibyte/sb1250/smp.c   |  13 +++--
>>  13 files changed, 236 insertions(+), 240 deletions(-)
>
> you are touching a lot of platforms, how many did you test ?

As mentioned in cover letter:

```
It has been tested on MIPS Boston I6500, malta SOC-It, Loongson-2K,
Cavium CN7130 (EdgeRouter 4), and an unannounced interaptiv UP MT
platform with EIC.

I don't really know broadcom platforms and SGI platforms well so
changes to those platforms are kept minimal (no functional change).
```

Thanks
- Jiaxun

>
> Thomas.
>
> -- 
> Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
> good idea.                                                [ RFC1925, 2.3 ]

-- 
- Jiaxun

Re: [PATCH 01/10] MIPS: smp: Make IPI interrupts scalable

[Maciej W. Rozycki]

On Thu, 4 Jul 2024, Jiaxun Yang wrote:

> It has been tested on MIPS Boston I6500, malta SOC-It, Loongson-2K,

 SOC-it (or SOC-it 101 to be precise) is the name of a bus controller:

System controller/revision =    MIPS SOC-it 101 OCP / 1.3   SDR-FW-4:1

used across numerous platforms from the M4K core onwards, UP, MT, or MP.  
I think it would make sense if you revealed the processor type instead.

> I don't really know broadcom platforms and SGI platforms well so
> changes to those platforms are kept minimal (no functional change).

 Technically I could run it on my SB1250, but I'm too overloaded now to 
commit to any timescale.  Sorry.

  Maciej

Re: [PATCH 01/10] MIPS: smp: Make IPI interrupts scalable

[Jiaxun Yang]

在2024年7月4日七月 上午5:26，Maciej W. Rozycki写道：
> On Thu, 4 Jul 2024, Jiaxun Yang wrote:
>
>> It has been tested on MIPS Boston I6500, malta SOC-It, Loongson-2K,
>
>  SOC-it (or SOC-it 101 to be precise) is the name of a bus controller:
>
> System controller/revision =    MIPS SOC-it 101 OCP / 1.3   SDR-FW-4:1
>
> used across numerous platforms from the M4K core onwards, UP, MT, or MP.  
> I think it would make sense if you revealed the processor type instead.

Sure, sorry to be vague on the platform detail.

I actually tried on two Malta configurations, CoreFPGA6 interAptiv 2MPF (2 cores, 2 VPE, 4TC),
and CoreFPGA3 34Kc MT (2VPE 9TC).

>
>> I don't really know broadcom platforms and SGI platforms well so
>> changes to those platforms are kept minimal (no functional change).
>
>  Technically I could run it on my SB1250, but I'm too overloaded now to 
> commit to any timescale.  Sorry.

No worries, I'll try to fetch a BMIPS3000 SMP router to get Broadcom platform
undercover.

Thanks
>
>   Maciej

-- 
- Jiaxun

Re: [PATCH 01/10] MIPS: smp: Make IPI interrupts scalable

[Florian Fainelli]

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On 7/3/2024 11:07 PM, Jiaxun Yang wrote:
> 
> 
> 在2024年7月4日七月 上午5:26，Maciej W. Rozycki写道：
>> On Thu, 4 Jul 2024, Jiaxun Yang wrote:
>>
>>> It has been tested on MIPS Boston I6500, malta SOC-It, Loongson-2K,
>>
>>   SOC-it (or SOC-it 101 to be precise) is the name of a bus controller:
>>
>> System controller/revision =    MIPS SOC-it 101 OCP / 1.3   SDR-FW-4:1
>>
>> used across numerous platforms from the M4K core onwards, UP, MT, or MP.
>> I think it would make sense if you revealed the processor type instead.
> 
> Sure, sorry to be vague on the platform detail.
> 
> I actually tried on two Malta configurations, CoreFPGA6 interAptiv 2MPF (2 cores, 2 VPE, 4TC),
> and CoreFPGA3 34Kc MT (2VPE 9TC).
> 
>>
>>> I don't really know broadcom platforms and SGI platforms well so
>>> changes to those platforms are kept minimal (no functional change).
>>
>>   Technically I could run it on my SB1250, but I'm too overloaded now to
>> commit to any timescale.  Sorry.
> 
> No worries, I'll try to fetch a BMIPS3000 SMP router to get Broadcom platform
> undercover.

BMIPS3300 is not a SMP-capable CPU, prefer a BCM6328 or newer which use 
BMIPS43xx cores and are SMP capable. I should be able to test this patch 
series in about a week.
-- 
Florian

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Re: [PATCH 01/10] MIPS: smp: Make IPI interrupts scalable

[Maciej W. Rozycki]

On Thu, 4 Jul 2024, Jiaxun Yang wrote:

> >  SOC-it (or SOC-it 101 to be precise) is the name of a bus controller:
> >
> > System controller/revision =    MIPS SOC-it 101 OCP / 1.3   SDR-FW-4:1
> >
> > used across numerous platforms from the M4K core onwards, UP, MT, or MP.  
> > I think it would make sense if you revealed the processor type instead.
> 
> Sure, sorry to be vague on the platform detail.
> 
> I actually tried on two Malta configurations, CoreFPGA6 interAptiv 2MPF (2 cores, 2 VPE, 4TC),
> and CoreFPGA3 34Kc MT (2VPE 9TC).

 This is much better, thanks, and the choice of CPUs feels adequate.  The 
mention of the 34K CPU brings fond memories too, as I was a member of the 
development team for this design, very innovative at its time, and still 
nowadays I believe.

> >  Technically I could run it on my SB1250, but I'm too overloaded now to 
> > commit to any timescale.  Sorry.
> 
> No worries, I'll try to fetch a BMIPS3000 SMP router to get Broadcom platform
> undercover.

 But that's a completely different design from the SB-1 line, isn't it?

  Maciej

Re: [PATCH 01/10] MIPS: smp: Make IPI interrupts scalable

[Thomas Bogendoerfer]

On Thu, Jul 04, 2024 at 11:36:02PM +0100, Maciej W. Rozycki wrote:
> On Thu, 4 Jul 2024, Jiaxun Yang wrote:
> > No worries, I'll try to fetch a BMIPS3000 SMP router to get Broadcom platform
> > undercover.
> 
>  But that's a completely different design from the SB-1 line, isn't it?

I have a BCM1480 system to test, so that's covered. I'm going to
test on IP27 and IP30, too.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH 01/10] MIPS: smp: Make IPI interrupts scalable

[Thomas Bogendoerfer]

On Thu, Jul 04, 2024 at 04:15:21AM +0800, Jiaxun Yang wrote:
> 
> 
> 在2024年7月3日七月 下午11:04，Thomas Bogendoerfer写道：
> > On Sun, Jun 16, 2024 at 10:03:05PM +0100, Jiaxun Yang wrote:
> >> Define enum ipi_message_type as other architectures did to
> >> allow easy extension to number of IPI interrupts, fiddle
> >> around platform IPI code to adopt to the new infra, add
> >> extensive BUILD_BUG_ON on IPI numbers to ensure future
> >> extensions won't break existing platforms.
> >> 
> >> IPI related stuff are pulled to asm/ipi.h to avoid include
> >> linux/interrupt.h in asm/smp.h.
> >> 
> >> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> >> ---
> >>  arch/mips/cavium-octeon/smp.c   | 109 ++++++++++++-----------------------
> >>  arch/mips/include/asm/ipi.h     |  34 +++++++++++
> >>  arch/mips/include/asm/smp-ops.h |   8 +--
> >>  arch/mips/include/asm/smp.h     |  42 ++++++--------
> >>  arch/mips/kernel/smp-bmips.c    |  43 +++++++-------
> >>  arch/mips/kernel/smp-cps.c      |   1 +
> >>  arch/mips/kernel/smp.c          | 124 ++++++++++++++++++++--------------------
> >>  arch/mips/loongson64/smp.c      |  51 +++++++++--------
> >>  arch/mips/mm/c-octeon.c         |   2 +-
> >>  arch/mips/sgi-ip27/ip27-smp.c   |  15 +++--
> >>  arch/mips/sgi-ip30/ip30-smp.c   |  15 +++--
> >>  arch/mips/sibyte/bcm1480/smp.c  |  19 +++---
> >>  arch/mips/sibyte/sb1250/smp.c   |  13 +++--
> >>  13 files changed, 236 insertions(+), 240 deletions(-)
> >
> > you are touching a lot of platforms, how many did you test ?
> 
> As mentioned in cover letter:
> 
> ```
> It has been tested on MIPS Boston I6500, malta SOC-It, Loongson-2K,
> Cavium CN7130 (EdgeRouter 4), and an unannounced interaptiv UP MT
> platform with EIC.
> 
> I don't really know broadcom platforms and SGI platforms well so
> changes to those platforms are kept minimal (no functional change).

I get a merge conflict in arch/mips/loongson64/smp.c and see following
warnings:

IP30 build:

  CC      arch/mips/fw/arc/init.o
In file included from /local/tbogendoerfer/korg/linux/arch/mips/fw/arc/init.c:15:
/local/tbogendoerfer/korg/linux/arch/mips/include/asm/smp-ops.h:23:40: error: ‘enum ipi_message_type’ declared inside parameter list will not be visible outside of this definition or declaration [-Werror]
   23 |  void (*send_ipi_single)(int cpu, enum ipi_message_type op);
      |                                        ^~~~~~~~~~~~~~~~
/local/tbogendoerfer/korg/linux/arch/mips/include/asm/smp-ops.h:24:57: error: ‘enum ipi_message_type’ declared inside parameter list will not be visible outside of this definition or declaration [-Werror]
   24 |  void (*send_ipi_mask)(const struct cpumask *mask, enum ipi_message_type op);
      |   

/local/tbogendoerfer/korg/linux/arch/mips/kernel/smp.c: In function ‘smp_prepare_cpus’:
/local/tbogendoerfer/korg/linux/arch/mips/kernel/smp.c:475:6: warning: unused variable ‘rc’ [-Wunused-variable]
  475 |  int rc;

/local/tbogendoerfer/korg/linux/arch/mips/include/asm/ipi.h:49:13: warning: ‘mips_smp_show_ipi_stats’ defined but not used [-Wunused-function]
   49 | static void mips_smp_show_ipi_stats(struct seq_file *p, int prec)


bcm1480 build:

/local/tbogendoerfer/korg/linux/arch/mips/kernel/smp.c: In function ‘smp_prepare_cpus’:
/local/tbogendoerfer/korg/linux/arch/mips/kernel/smp.c:475:6: warning: unused variable ‘rc’ [-Wunused-variable]
  475 |  int rc;
      |      ^~

In file included from /local/tbogendoerfer/korg/linux/arch/mips/kernel/smp.c:34:
At top level:
/local/tbogendoerfer/korg/linux/arch/mips/include/asm/ipi.h:49:13: warning: ‘mips_smp_show_ipi_stats’ defined but not used [-Wunused-function]
   49 | static void mips_smp_show_ipi_stats(struct seq_file *p, int prec)

octeon build:

/local/tbogendoerfer/korg/linux/arch/mips/cavium-octeon/smp.c:84:6: warning: no previous prototype for ‘octeon_send_ipi_single’ [-Wmissing-prototypes]
   84 | void octeon_send_ipi_single(int cpu, enum ipi_message_type op)
      |      ^~~~~~~~~~~~~~~~~~~~~~
In file included from /local/tbogendoerfer/korg/linux/arch/mips/cavium-octeon/smp.c:20:
/local/tbogendoerfer/korg/linux/arch/mips/include/asm/ipi.h:49:13: warning: ‘mips_smp_show_ipi_stats’ defined but not used [-Wunused-function]
   49 | static void mips_smp_show_ipi_stats(struct seq_file *p, int prec)
      |             ^~~~~~~~~~~~~~~~~~~~~~~
 
/local/tbogendoerfer/korg/linux/arch/mips/kernel/smp.c: In function ‘smp_prepare_cpus’:
/local/tbogendoerfer/korg/linux/arch/mips/kernel/smp.c:475:6: warning: unused variable ‘rc’ [-Wunused-variable]
  475 |  int rc;

/local/tbogendoerfer/korg/linux/arch/mips/include/asm/ipi.h:49:13: warning: ‘mips_smp_show_ipi_stats’ defined but not used [-Wunused-function]
   49 | static void mips_smp_show_ipi_stats(struct seq_file *p, int prec)

Please fix.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH 01/10] MIPS: smp: Make IPI interrupts scalable

[Serge Semin]

Hi folks,

On Wed, Jul 03, 2024 at 05:04:49PM +0200, Thomas Bogendoerfer wrote:
> On Sun, Jun 16, 2024 at 10:03:05PM +0100, Jiaxun Yang wrote:
> > Define enum ipi_message_type as other architectures did to
> > allow easy extension to number of IPI interrupts, fiddle
> > around platform IPI code to adopt to the new infra, add
> > extensive BUILD_BUG_ON on IPI numbers to ensure future
> > extensions won't break existing platforms.
> > 
> > IPI related stuff are pulled to asm/ipi.h to avoid include
> > linux/interrupt.h in asm/smp.h.
> > 
> > Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> > ---
> >  arch/mips/cavium-octeon/smp.c   | 109 ++++++++++++-----------------------
> >  arch/mips/include/asm/ipi.h     |  34 +++++++++++
> >  arch/mips/include/asm/smp-ops.h |   8 +--
> >  arch/mips/include/asm/smp.h     |  42 ++++++--------
> >  arch/mips/kernel/smp-bmips.c    |  43 +++++++-------
> >  arch/mips/kernel/smp-cps.c      |   1 +
> >  arch/mips/kernel/smp.c          | 124 ++++++++++++++++++++--------------------
> >  arch/mips/loongson64/smp.c      |  51 +++++++++--------
> >  arch/mips/mm/c-octeon.c         |   2 +-
> >  arch/mips/sgi-ip27/ip27-smp.c   |  15 +++--
> >  arch/mips/sgi-ip30/ip30-smp.c   |  15 +++--
> >  arch/mips/sibyte/bcm1480/smp.c  |  19 +++---
> >  arch/mips/sibyte/sb1250/smp.c   |  13 +++--
> >  13 files changed, 236 insertions(+), 240 deletions(-)
> 
> you are touching a lot of platforms, how many did you test ?

In a one or two days I'll be able to test the series on the SoC with
2x MIPS P5600 Warrior.

-Serge(y)

> 
> Thomas.
> 
> -- 
> Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
> good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH 01/10] MIPS: smp: Make IPI interrupts scalable

[Jiaxun Yang]

在2024年7月5日七月 下午4:40，Serge Semin写道：
> Hi folks,
>
> On Wed, Jul 03, 2024 at 05:04:49PM +0200, Thomas Bogendoerfer wrote:
>> On Sun, Jun 16, 2024 at 10:03:05PM +0100, Jiaxun Yang wrote:
>> > Define enum ipi_message_type as other architectures did to
>> > allow easy extension to number of IPI interrupts, fiddle
>> > around platform IPI code to adopt to the new infra, add
>> > extensive BUILD_BUG_ON on IPI numbers to ensure future
>> > extensions won't break existing platforms.
>> > 
>> > IPI related stuff are pulled to asm/ipi.h to avoid include
>> > linux/interrupt.h in asm/smp.h.
>> > 
>> > Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
>> > ---
>> >  arch/mips/cavium-octeon/smp.c   | 109 ++++++++++++-----------------------
>> >  arch/mips/include/asm/ipi.h     |  34 +++++++++++
>> >  arch/mips/include/asm/smp-ops.h |   8 +--
>> >  arch/mips/include/asm/smp.h     |  42 ++++++--------
>> >  arch/mips/kernel/smp-bmips.c    |  43 +++++++-------
>> >  arch/mips/kernel/smp-cps.c      |   1 +
>> >  arch/mips/kernel/smp.c          | 124 ++++++++++++++++++++--------------------
>> >  arch/mips/loongson64/smp.c      |  51 +++++++++--------
>> >  arch/mips/mm/c-octeon.c         |   2 +-
>> >  arch/mips/sgi-ip27/ip27-smp.c   |  15 +++--
>> >  arch/mips/sgi-ip30/ip30-smp.c   |  15 +++--
>> >  arch/mips/sibyte/bcm1480/smp.c  |  19 +++---
>> >  arch/mips/sibyte/sb1250/smp.c   |  13 +++--
>> >  13 files changed, 236 insertions(+), 240 deletions(-)
>> 
>> you are touching a lot of platforms, how many did you test ?
>
> In a one or two days I'll be able to test the series on the SoC with
> 2x MIPS P5600 Warrior.

Thanks everyone for the collaborative effort, I’m  impressed!

Will respin this series later today.

Thanks
>
> -Serge(y)
>
>> 
>> Thomas.
>> 
>> -- 
>> Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
>> good idea.                                                [ RFC1925, 2.3 ]

-- 
- Jiaxun

[PATCH 02/10] MIPS: smp: Manage IPI interrupts as percpu_devid interrupts

[Jiaxun Yang]

IPI interrupts need to be enabled when a new CPU coming up.

Manage them as percpu_devid interrupts and invoke enable/disable
functions at appropriate time to perform enabling as required,
similar to what RISC-V and Arm doing.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 arch/mips/include/asm/ipi.h | 11 +++++++++++
 arch/mips/kernel/smp.c      | 26 ++++++++++++++++++++++++--
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/arch/mips/include/asm/ipi.h b/arch/mips/include/asm/ipi.h
index df7a0ac4227a..88b507339f51 100644
--- a/arch/mips/include/asm/ipi.h
+++ b/arch/mips/include/asm/ipi.h
@@ -29,6 +29,17 @@ int mips_smp_ipi_allocate(const struct cpumask *mask);
  * Return 0 on success.
  */
 int mips_smp_ipi_free(const struct cpumask *mask);
+
+void mips_smp_ipi_enable(void);
+void mips_smp_ipi_disable(void);
+#else
+static inline void mips_smp_ipi_enable(void)
+{
+}
+
+static inline void mips_smp_ipi_disable(void)
+{
+}
 #endif /* CONFIG_GENERIC_IRQ_IPI */
 #endif /* CONFIG_SMP */
 #endif
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index a6cf6444533e..710644d47106 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -186,6 +186,7 @@ irq_handler_t ipi_handlers[IPI_MAX] __read_mostly = {
 };
 
 #ifdef CONFIG_GENERIC_IRQ_IPI
+static DEFINE_PER_CPU_READ_MOSTLY(int, ipi_dummy_dev);
 static int ipi_virqs[IPI_MAX] __ro_after_init;
 static struct irq_desc *ipi_desc[IPI_MAX] __read_mostly;
 
@@ -225,13 +226,29 @@ void mips_smp_send_ipi_mask(const struct cpumask *mask,
 	local_irq_restore(flags);
 }
 
+void mips_smp_ipi_enable(void)
+{
+	int i;
+
+	for (i = 0; i < IPI_MAX; i++)
+		enable_percpu_irq(ipi_virqs[i], IRQ_TYPE_NONE);
+}
+
+void mips_smp_ipi_disable(void)
+{
+	int i;
+
+	for (i = 0; i < IPI_MAX; i++)
+		disable_percpu_irq(ipi_virqs[i]);
+}
+
 static void smp_ipi_init_one(unsigned int virq, const char *name,
 			     irq_handler_t handler)
 {
 	int ret;
 
-	irq_set_handler(virq, handle_percpu_irq);
-	ret = request_irq(virq, handler, IRQF_PERCPU, name, NULL);
+	irq_set_percpu_devid(virq);
+	ret = request_percpu_irq(virq, handler, "IPI", &ipi_dummy_dev);
 	BUG_ON(ret);
 }
 
@@ -343,6 +360,9 @@ static int __init mips_smp_ipi_init(void)
 			return -ENODEV;
 	}
 
+	/* Enable IPI for Boot CPU */
+	mips_smp_ipi_enable();
+
 	return 0;
 }
 early_initcall(mips_smp_ipi_init);
@@ -383,6 +403,8 @@ asmlinkage void start_secondary(void)
 
 	synchronise_count_slave(cpu);
 
+	mips_smp_ipi_enable();
+
 	/* The CPU is running and counters synchronised, now mark it online */
 	set_cpu_online(cpu, true);
 

-- 
2.43.0

Re: [PATCH 02/10] MIPS: smp: Manage IPI interrupts as percpu_devid interrupts

[Thomas Bogendoerfer]

On Sun, Jun 16, 2024 at 10:03:06PM +0100, Jiaxun Yang wrote:
> IPI interrupts need to be enabled when a new CPU coming up.
> 
> Manage them as percpu_devid interrupts and invoke enable/disable
> functions at appropriate time to perform enabling as required,
> similar to what RISC-V and Arm doing.
> 
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
>  arch/mips/include/asm/ipi.h | 11 +++++++++++
>  arch/mips/kernel/smp.c      | 26 ++++++++++++++++++++++++--
>  2 files changed, 35 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/mips/include/asm/ipi.h b/arch/mips/include/asm/ipi.h
> index df7a0ac4227a..88b507339f51 100644
> --- a/arch/mips/include/asm/ipi.h
> +++ b/arch/mips/include/asm/ipi.h
> @@ -29,6 +29,17 @@ int mips_smp_ipi_allocate(const struct cpumask *mask);
>   * Return 0 on success.
>   */
>  int mips_smp_ipi_free(const struct cpumask *mask);
> +
> +void mips_smp_ipi_enable(void);
> +void mips_smp_ipi_disable(void);
> +#else
> +static inline void mips_smp_ipi_enable(void)
> +{
> +}
> +
> +static inline void mips_smp_ipi_disable(void)
> +{
> +}
>  #endif /* CONFIG_GENERIC_IRQ_IPI */
>  #endif /* CONFIG_SMP */
>  #endif
> diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
> index a6cf6444533e..710644d47106 100644
> --- a/arch/mips/kernel/smp.c
> +++ b/arch/mips/kernel/smp.c
> @@ -186,6 +186,7 @@ irq_handler_t ipi_handlers[IPI_MAX] __read_mostly = {
>  };
>  
>  #ifdef CONFIG_GENERIC_IRQ_IPI
> +static DEFINE_PER_CPU_READ_MOSTLY(int, ipi_dummy_dev);
>  static int ipi_virqs[IPI_MAX] __ro_after_init;
>  static struct irq_desc *ipi_desc[IPI_MAX] __read_mostly;
>  
> @@ -225,13 +226,29 @@ void mips_smp_send_ipi_mask(const struct cpumask *mask,
>  	local_irq_restore(flags);
>  }
>  
> +void mips_smp_ipi_enable(void)
> +{
> +	int i;
> +
> +	for (i = 0; i < IPI_MAX; i++)
> +		enable_percpu_irq(ipi_virqs[i], IRQ_TYPE_NONE);
> +}
> +
> +void mips_smp_ipi_disable(void)
> +{
> +	int i;
> +
> +	for (i = 0; i < IPI_MAX; i++)
> +		disable_percpu_irq(ipi_virqs[i]);
> +}
> +

there is no user of mips_smp_ipi_disable() (at least I didn't see one),
so do we need this patch at all ? Just looking like ARM or RiscV isn't
a justification for code churn.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH 02/10] MIPS: smp: Manage IPI interrupts as percpu_devid interrupts

[Jiaxun Yang]

在2024年7月3日七月 下午11:03，Thomas Bogendoerfer写道：
[...]
>
> there is no user of mips_smp_ipi_disable() (at least I didn't see one),
> so do we need this patch at all ? Just looking like ARM or RiscV isn't
> a justification for code churn.

Hi Thomas,

The per-cpu enablement process is necessary for IPI_MUX and
my upcoming IPI driver.

The disablement, I'm not really sure, maybe it's a good idea to call it at
platform's __cpu_disable to prevent spurious IPI after IRQ migration.

Thanks
- Jiaxun

>
> Thomas.
>
> -- 
> Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
> good idea.                                                [ RFC1925, 2.3 ]

-- 
- Jiaxun

Re: [PATCH 02/10] MIPS: smp: Manage IPI interrupts as percpu_devid interrupts

[Thomas Bogendoerfer]

On Thu, Jul 04, 2024 at 04:08:09AM +0800, Jiaxun Yang wrote:
> 
> 
> 在2024年7月3日七月 下午11:03，Thomas Bogendoerfer写道：
> [...]
> >
> > there is no user of mips_smp_ipi_disable() (at least I didn't see one),
> > so do we need this patch at all ? Just looking like ARM or RiscV isn't
> > a justification for code churn.
> 
> Hi Thomas,
> 
> The per-cpu enablement process is necessary for IPI_MUX and
> my upcoming IPI driver.
> 
> The disablement, I'm not really sure, maybe it's a good idea to call it at
> platform's __cpu_disable to prevent spurious IPI after IRQ migration.

don't add dead code, so drop mips_smp_ipi_disable() for now.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

[PATCH 03/10] MIPS: smp: Provide platform IPI virq & domain hooks

[Jiaxun Yang]

Provide platform virq & domain hooks to allow platform
interrupt controllers or SMP code to override IPI interrupt
allocation.

This is required by ipi-mux, the API is aligned with RISC-V
and Arm.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 arch/mips/include/asm/ipi.h | 17 ++++++++++
 arch/mips/kernel/smp.c      | 78 +++++++++++++++++++++++++--------------------
 2 files changed, 61 insertions(+), 34 deletions(-)

diff --git a/arch/mips/include/asm/ipi.h b/arch/mips/include/asm/ipi.h
index 88b507339f51..0fc8c31c6a52 100644
--- a/arch/mips/include/asm/ipi.h
+++ b/arch/mips/include/asm/ipi.h
@@ -2,6 +2,7 @@
 
 #include <linux/cpumask.h>
 #include <linux/interrupt.h>
+#include <linux/irqdomain.h>
 
 #ifndef __ASM_IPI_H
 #define __ASM_IPI_H
@@ -32,6 +33,9 @@ int mips_smp_ipi_free(const struct cpumask *mask);
 
 void mips_smp_ipi_enable(void);
 void mips_smp_ipi_disable(void);
+extern bool mips_smp_ipi_have_virq_range(void);
+void mips_smp_ipi_set_irqdomain(struct irq_domain *d);
+extern void mips_smp_ipi_set_virq_range(int virq, int nr);
 #else
 static inline void mips_smp_ipi_enable(void)
 {
@@ -41,5 +45,18 @@ static inline void mips_smp_ipi_disable(void)
 {
 }
 #endif /* CONFIG_GENERIC_IRQ_IPI */
+#else
+void mips_smp_ipi_set_virq_range(int virq, int nr)
+{
+}
+
+void mips_smp_ipi_set_irqdomain(struct irq_domain *d)
+{
+}
+
+static inline bool mips_smp_ipi_have_virq_range(void)
+{
+	return false;
+}
 #endif /* CONFIG_SMP */
 #endif
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index 710644d47106..fe053fe52147 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -189,6 +189,7 @@ irq_handler_t ipi_handlers[IPI_MAX] __read_mostly = {
 static DEFINE_PER_CPU_READ_MOSTLY(int, ipi_dummy_dev);
 static int ipi_virqs[IPI_MAX] __ro_after_init;
 static struct irq_desc *ipi_desc[IPI_MAX] __read_mostly;
+static struct irq_domain *ipidomain;
 
 void mips_smp_send_ipi_single(int cpu, enum ipi_message_type op)
 {
@@ -255,11 +256,12 @@ static void smp_ipi_init_one(unsigned int virq, const char *name,
 int mips_smp_ipi_allocate(const struct cpumask *mask)
 {
 	int virq, i;
-	struct irq_domain *ipidomain;
 	struct device_node *node;
 
-	node = of_irq_find_parent(of_root);
-	ipidomain = irq_find_matching_host(node, DOMAIN_BUS_IPI);
+	if (!ipidomain) {
+		node = of_irq_find_parent(of_root);
+		ipidomain = irq_find_matching_host(node, DOMAIN_BUS_IPI);
+	}
 
 	/*
 	 * Some platforms have half DT setup. So if we found irq node but
@@ -291,43 +293,15 @@ int mips_smp_ipi_allocate(const struct cpumask *mask)
 		ipi_virqs[i] = virq;
 	}
 
-	if (irq_domain_is_ipi_per_cpu(ipidomain)) {
-		int cpu;
-
-		for_each_cpu(cpu, mask) {
-			for (i = 0; i < IPI_MAX; i++) {
-				smp_ipi_init_one(ipi_virqs[i] + cpu, ipi_names[i],
-						 ipi_handlers[i]);
-			}
-		}
-	} else {
-		for (i = 0; i < IPI_MAX; i++) {
-			smp_ipi_init_one(ipi_virqs[i], ipi_names[i],
-					 ipi_handlers[i]);
-		}
-	}
-
 	return 0;
 }
 
 int mips_smp_ipi_free(const struct cpumask *mask)
 {
 	int i;
-	struct irq_domain *ipidomain;
-	struct device_node *node;
-
-	node = of_irq_find_parent(of_root);
-	ipidomain = irq_find_matching_host(node, DOMAIN_BUS_IPI);
-
-	/*
-	 * Some platforms have half DT setup. So if we found irq node but
-	 * didn't find an ipidomain, try to search for one that is not in the
-	 * DT.
-	 */
-	if (node && !ipidomain)
-		ipidomain = irq_find_matching_host(NULL, DOMAIN_BUS_IPI);
 
-	BUG_ON(!ipidomain);
+	if (!ipidomain)
+		return -ENODEV;
 
 	if (irq_domain_is_ipi_per_cpu(ipidomain)) {
 		int cpu;
@@ -344,6 +318,25 @@ int mips_smp_ipi_free(const struct cpumask *mask)
 	return 0;
 }
 
+void mips_smp_ipi_set_virq_range(int virq, int nr)
+{
+	int i;
+
+	WARN_ON(nr < IPI_MAX);
+
+	for (i = 0; i < IPI_MAX; i++)
+		ipi_virqs[i] = virq + i;
+}
+
+void mips_smp_ipi_set_irqdomain(struct irq_domain *d)
+{
+	ipidomain = d;
+}
+
+bool mips_smp_ipi_have_virq_range(void)
+{
+	return ipi_virqs[0];
+}
 
 static int __init mips_smp_ipi_init(void)
 {
@@ -352,7 +345,24 @@ static int __init mips_smp_ipi_init(void)
 	if (num_possible_cpus() == 1)
 		return 0;
 
-	mips_smp_ipi_allocate(cpu_possible_mask);
+	if (!mips_smp_ipi_have_virq_range())
+		mips_smp_ipi_allocate(cpu_possible_mask);
+
+	if (ipidomain && irq_domain_is_ipi_per_cpu(ipidomain)) {
+		int cpu;
+
+		for_each_possible_cpu(cpu) {
+			for (i = 0; i < IPI_MAX; i++) {
+				smp_ipi_init_one(ipi_virqs[i] + cpu, ipi_names[i],
+						 ipi_handlers[i]);
+			}
+		}
+	} else {
+		for (i = 0; i < IPI_MAX; i++) {
+			smp_ipi_init_one(ipi_virqs[i], ipi_names[i],
+					 ipi_handlers[i]);
+		}
+	}
 
 	for (i = 0; i < IPI_MAX; i++) {
 		ipi_desc[i] = irq_to_desc(ipi_virqs[i]);

-- 
2.43.0

[PATCH 04/10] MIPS: Move mips_smp_ipi_init call after prepare_cpus

[Jiaxun Yang]

This will give platform code a genuine chance to setup
IPI IRQ in prepare_cpus.

This is the best place for platforms to setup IPI as smp_setup
is too early for IRQ subsystem.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 arch/mips/kernel/smp.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index fe053fe52147..ddf96c28e2f0 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -375,7 +375,6 @@ static int __init mips_smp_ipi_init(void)
 
 	return 0;
 }
-early_initcall(mips_smp_ipi_init);
 #endif
 
 /*
@@ -460,12 +459,22 @@ void __init smp_cpus_done(unsigned int max_cpus)
 /* called from main before smp_init() */
 void __init smp_prepare_cpus(unsigned int max_cpus)
 {
+	int rc;
+
 	init_new_context(current, &init_mm);
 	current_thread_info()->cpu = 0;
 	mp_ops->prepare_cpus(max_cpus);
 	set_cpu_sibling_map(0);
 	set_cpu_core_map(0);
 	calculate_cpu_foreign_map();
+#ifdef CONFIG_GENERIC_IRQ_IPI
+	rc = mips_smp_ipi_init();
+	if (rc) {
+		pr_err("Failed to initialize IPI - disabling SMP");
+		init_cpu_present(cpumask_of(0));
+		return;
+	}
+#endif
 #ifndef CONFIG_HOTPLUG_CPU
 	init_cpu_present(cpu_possible_mask);
 #endif

-- 
2.43.0

Re: [PATCH 04/10] MIPS: Move mips_smp_ipi_init call after prepare_cpus

[Huacai Chen]

Hi, Jiaxun

On Mon, Jun 17, 2024 at 5:03 AM Jiaxun Yang <jiaxun.yang@flygoat.com> wrote:
>
> This will give platform code a genuine chance to setup
> IPI IRQ in prepare_cpus.
>
> This is the best place for platforms to setup IPI as smp_setup
> is too early for IRQ subsystem.
mips_smp_ipi_init() is an early_initcall() function, why do you say it
is in smp_setup()?


Huacai
>
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
>  arch/mips/kernel/smp.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
> index fe053fe52147..ddf96c28e2f0 100644
> --- a/arch/mips/kernel/smp.c
> +++ b/arch/mips/kernel/smp.c
> @@ -375,7 +375,6 @@ static int __init mips_smp_ipi_init(void)
>
>         return 0;
>  }
> -early_initcall(mips_smp_ipi_init);
>  #endif
>
>  /*
> @@ -460,12 +459,22 @@ void __init smp_cpus_done(unsigned int max_cpus)
>  /* called from main before smp_init() */
>  void __init smp_prepare_cpus(unsigned int max_cpus)
>  {
> +       int rc;
> +
>         init_new_context(current, &init_mm);
>         current_thread_info()->cpu = 0;
>         mp_ops->prepare_cpus(max_cpus);
>         set_cpu_sibling_map(0);
>         set_cpu_core_map(0);
>         calculate_cpu_foreign_map();
> +#ifdef CONFIG_GENERIC_IRQ_IPI
> +       rc = mips_smp_ipi_init();
> +       if (rc) {
> +               pr_err("Failed to initialize IPI - disabling SMP");
> +               init_cpu_present(cpumask_of(0));
> +               return;
> +       }
> +#endif
>  #ifndef CONFIG_HOTPLUG_CPU
>         init_cpu_present(cpu_possible_mask);
>  #endif
>
> --
> 2.43.0
>

Re: [PATCH 04/10] MIPS: Move mips_smp_ipi_init call after prepare_cpus

[Jiaxun Yang]

在2024年6月17日六月 下午2:53，Huacai Chen写道：
> Hi, Jiaxun
>
> On Mon, Jun 17, 2024 at 5:03 AM Jiaxun Yang <jiaxun.yang@flygoat.com> wrote:
>>
>> This will give platform code a genuine chance to setup
>> IPI IRQ in prepare_cpus.
>>
>> This is the best place for platforms to setup IPI as smp_setup
>> is too early for IRQ subsystem.
> mips_smp_ipi_init() is an early_initcall() function, why do you say it
> is in smp_setup()?

Sorry, I was trying to say that smp_setup is not a good point so we should
go prepare_cpus.

The intention of this patch is to move mips_smp_ipi_init to a certain point
so platform would gain control over it.

Thanks
- Jiaxun

>
>
> Huacai
>>
>> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
>> ---
>>  arch/mips/kernel/smp.c | 11 ++++++++++-
>>  1 file changed, 10 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
>> index fe053fe52147..ddf96c28e2f0 100644
>> --- a/arch/mips/kernel/smp.c
>> +++ b/arch/mips/kernel/smp.c
>> @@ -375,7 +375,6 @@ static int __init mips_smp_ipi_init(void)
>>
>>         return 0;
>>  }
>> -early_initcall(mips_smp_ipi_init);
>>  #endif
>>
>>  /*
>> @@ -460,12 +459,22 @@ void __init smp_cpus_done(unsigned int max_cpus)
>>  /* called from main before smp_init() */
>>  void __init smp_prepare_cpus(unsigned int max_cpus)
>>  {
>> +       int rc;
>> +
>>         init_new_context(current, &init_mm);
>>         current_thread_info()->cpu = 0;
>>         mp_ops->prepare_cpus(max_cpus);
>>         set_cpu_sibling_map(0);
>>         set_cpu_core_map(0);
>>         calculate_cpu_foreign_map();
>> +#ifdef CONFIG_GENERIC_IRQ_IPI
>> +       rc = mips_smp_ipi_init();
>> +       if (rc) {
>> +               pr_err("Failed to initialize IPI - disabling SMP");
>> +               init_cpu_present(cpumask_of(0));
>> +               return;
>> +       }
>> +#endif
>>  #ifndef CONFIG_HOTPLUG_CPU
>>         init_cpu_present(cpu_possible_mask);
>>  #endif
>>
>> --
>> 2.43.0
>>

-- 
- Jiaxun

Re: [PATCH 04/10] MIPS: Move mips_smp_ipi_init call after prepare_cpus

[Huacai Chen]

On Tue, Jun 18, 2024 at 6:10 AM Jiaxun Yang <jiaxun.yang@flygoat.com> wrote:
>
>
>
> 在2024年6月17日六月 下午2:53，Huacai Chen写道：
> > Hi, Jiaxun
> >
> > On Mon, Jun 17, 2024 at 5:03 AM Jiaxun Yang <jiaxun.yang@flygoat.com> wrote:
> >>
> >> This will give platform code a genuine chance to setup
> >> IPI IRQ in prepare_cpus.
> >>
> >> This is the best place for platforms to setup IPI as smp_setup
> >> is too early for IRQ subsystem.
> > mips_smp_ipi_init() is an early_initcall() function, why do you say it
> > is in smp_setup()?
>
> Sorry, I was trying to say that smp_setup is not a good point so we should
> go prepare_cpus.
It is not in smp_setup() now, then how do you move it from smp_setup()?

Huacai

>
> The intention of this patch is to move mips_smp_ipi_init to a certain point
> so platform would gain control over it.
>
> Thanks
> - Jiaxun
>
> >
> >
> > Huacai
> >>
> >> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> >> ---
> >>  arch/mips/kernel/smp.c | 11 ++++++++++-
> >>  1 file changed, 10 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
> >> index fe053fe52147..ddf96c28e2f0 100644
> >> --- a/arch/mips/kernel/smp.c
> >> +++ b/arch/mips/kernel/smp.c
> >> @@ -375,7 +375,6 @@ static int __init mips_smp_ipi_init(void)
> >>
> >>         return 0;
> >>  }
> >> -early_initcall(mips_smp_ipi_init);
> >>  #endif
> >>
> >>  /*
> >> @@ -460,12 +459,22 @@ void __init smp_cpus_done(unsigned int max_cpus)
> >>  /* called from main before smp_init() */
> >>  void __init smp_prepare_cpus(unsigned int max_cpus)
> >>  {
> >> +       int rc;
> >> +
> >>         init_new_context(current, &init_mm);
> >>         current_thread_info()->cpu = 0;
> >>         mp_ops->prepare_cpus(max_cpus);
> >>         set_cpu_sibling_map(0);
> >>         set_cpu_core_map(0);
> >>         calculate_cpu_foreign_map();
> >> +#ifdef CONFIG_GENERIC_IRQ_IPI
> >> +       rc = mips_smp_ipi_init();
> >> +       if (rc) {
> >> +               pr_err("Failed to initialize IPI - disabling SMP");
> >> +               init_cpu_present(cpumask_of(0));
> >> +               return;
> >> +       }
> >> +#endif
> >>  #ifndef CONFIG_HOTPLUG_CPU
> >>         init_cpu_present(cpu_possible_mask);
> >>  #endif
> >>
> >> --
> >> 2.43.0
> >>
>
> --
> - Jiaxun

Re: [PATCH 04/10] MIPS: Move mips_smp_ipi_init call after prepare_cpus

[Jiaxun Yang]

在2024年6月18日六月 上午4:51，Huacai Chen写道：
> On Tue, Jun 18, 2024 at 6:10 AM Jiaxun Yang <jiaxun.yang@flygoat.com> wrote:
>>
>>
>>
>> 在2024年6月17日六月 下午2:53，Huacai Chen写道：
>> > Hi, Jiaxun
>> >
>> > On Mon, Jun 17, 2024 at 5:03 AM Jiaxun Yang <jiaxun.yang@flygoat.com> wrote:
>> >>
>> >> This will give platform code a genuine chance to setup
>> >> IPI IRQ in prepare_cpus.
>> >>
>> >> This is the best place for platforms to setup IPI as smp_setup
>> >> is too early for IRQ subsystem.
>> > mips_smp_ipi_init() is an early_initcall() function, why do you say it
>> > is in smp_setup()?
>>
>> Sorry, I was trying to say that smp_setup is not a good point so we should
>> go prepare_cpus.
> It is not in smp_setup() now, then how do you move it from smp_setup()?
[...]

Well I was trying to justify where should I move it to, not where
does it from.

I should improve the commit message to justify the reason first.

Thanks
- Jiaxun
>
> Huacai
>
>>
>> The intention of this patch is to move mips_smp_ipi_init to a certain point
>> so platform would gain control over it.
>>
>> Thanks
>> - Jiaxun
>>
>> >
>> >
>> > Huacai
>> >>
>> >> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
>> >> ---
>> >>  arch/mips/kernel/smp.c | 11 ++++++++++-
>> >>  1 file changed, 10 insertions(+), 1 deletion(-)
>> >>
>> >> diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
>> >> index fe053fe52147..ddf96c28e2f0 100644
>> >> --- a/arch/mips/kernel/smp.c
>> >> +++ b/arch/mips/kernel/smp.c
>> >> @@ -375,7 +375,6 @@ static int __init mips_smp_ipi_init(void)
>> >>
>> >>         return 0;
>> >>  }
>> >> -early_initcall(mips_smp_ipi_init);
>> >>  #endif
>> >>
>> >>  /*
>> >> @@ -460,12 +459,22 @@ void __init smp_cpus_done(unsigned int max_cpus)
>> >>  /* called from main before smp_init() */
>> >>  void __init smp_prepare_cpus(unsigned int max_cpus)
>> >>  {
>> >> +       int rc;
>> >> +
>> >>         init_new_context(current, &init_mm);
>> >>         current_thread_info()->cpu = 0;
>> >>         mp_ops->prepare_cpus(max_cpus);
>> >>         set_cpu_sibling_map(0);
>> >>         set_cpu_core_map(0);
>> >>         calculate_cpu_foreign_map();
>> >> +#ifdef CONFIG_GENERIC_IRQ_IPI
>> >> +       rc = mips_smp_ipi_init();
>> >> +       if (rc) {
>> >> +               pr_err("Failed to initialize IPI - disabling SMP");
>> >> +               init_cpu_present(cpumask_of(0));
>> >> +               return;
>> >> +       }
>> >> +#endif
>> >>  #ifndef CONFIG_HOTPLUG_CPU
>> >>         init_cpu_present(cpu_possible_mask);
>> >>  #endif
>> >>
>> >> --
>> >> 2.43.0
>> >>
>>
>> --
>> - Jiaxun

-- 
- Jiaxun

Re: [PATCH 04/10] MIPS: Move mips_smp_ipi_init call after prepare_cpus

[Thomas Bogendoerfer]

On Tue, Jun 18, 2024 at 03:50:33PM +0100, Jiaxun Yang wrote:
> 
> 
> 在2024年6月18日六月 上午4:51，Huacai Chen写道：
> > On Tue, Jun 18, 2024 at 6:10 AM Jiaxun Yang <jiaxun.yang@flygoat.com> wrote:
> >>
> >>
> >>
> >> 在2024年6月17日六月 下午2:53，Huacai Chen写道：
> >> > Hi, Jiaxun
> >> >
> >> > On Mon, Jun 17, 2024 at 5:03 AM Jiaxun Yang <jiaxun.yang@flygoat.com> wrote:
> >> >>
> >> >> This will give platform code a genuine chance to setup
> >> >> IPI IRQ in prepare_cpus.
> >> >>
> >> >> This is the best place for platforms to setup IPI as smp_setup
> >> >> is too early for IRQ subsystem.
> >> > mips_smp_ipi_init() is an early_initcall() function, why do you say it
> >> > is in smp_setup()?
> >>
> >> Sorry, I was trying to say that smp_setup is not a good point so we should
> >> go prepare_cpus.
> > It is not in smp_setup() now, then how do you move it from smp_setup()?
> [...]
> 
> Well I was trying to justify where should I move it to, not where
> does it from.
> 
> I should improve the commit message to justify the reason first.

please do

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

[PATCH 05/10] MIPS: smp: Implement IPI stats

[Jiaxun Yang]

Show IPI statistics in arch_show_interrupts as what RISC-V
did.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 arch/mips/include/asm/ipi.h |  9 +++++++++
 arch/mips/kernel/irq.c      |  4 ++++
 arch/mips/kernel/smp.c      | 13 +++++++++++++
 3 files changed, 26 insertions(+)

diff --git a/arch/mips/include/asm/ipi.h b/arch/mips/include/asm/ipi.h
index 0fc8c31c6a52..1a486f0c934f 100644
--- a/arch/mips/include/asm/ipi.h
+++ b/arch/mips/include/asm/ipi.h
@@ -36,6 +36,7 @@ void mips_smp_ipi_disable(void);
 extern bool mips_smp_ipi_have_virq_range(void);
 void mips_smp_ipi_set_irqdomain(struct irq_domain *d);
 extern void mips_smp_ipi_set_virq_range(int virq, int nr);
+extern void mips_smp_show_ipi_stats(struct seq_file *p, int prec);
 #else
 static inline void mips_smp_ipi_enable(void)
 {
@@ -44,6 +45,10 @@ static inline void mips_smp_ipi_enable(void)
 static inline void mips_smp_ipi_disable(void)
 {
 }
+
+static void mips_smp_show_ipi_stats(struct seq_file *p, int prec)
+{
+}
 #endif /* CONFIG_GENERIC_IRQ_IPI */
 #else
 void mips_smp_ipi_set_virq_range(int virq, int nr)
@@ -58,5 +63,9 @@ static inline bool mips_smp_ipi_have_virq_range(void)
 {
 	return false;
 }
+
+static void mips_smp_show_ipi_stats(struct seq_file *p, int prec)
+{
+}
 #endif /* CONFIG_SMP */
 #endif
diff --git a/arch/mips/kernel/irq.c b/arch/mips/kernel/irq.c
index 5e11582fe308..c3ea8d80e0cb 100644
--- a/arch/mips/kernel/irq.c
+++ b/arch/mips/kernel/irq.c
@@ -26,6 +26,8 @@
 #include <linux/atomic.h>
 #include <linux/uaccess.h>
 
+#include <asm/ipi.h>
+
 void *irq_stack[NR_CPUS];
 
 /*
@@ -42,6 +44,8 @@ atomic_t irq_err_count;
 int arch_show_interrupts(struct seq_file *p, int prec)
 {
 	seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
+	mips_smp_show_ipi_stats(p, prec);
+
 	return 0;
 }
 
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index ddf96c28e2f0..826659214566 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -243,6 +243,19 @@ void mips_smp_ipi_disable(void)
 		disable_percpu_irq(ipi_virqs[i]);
 }
 
+void mips_smp_show_ipi_stats(struct seq_file *p, int prec)
+{
+	unsigned int cpu, i;
+
+	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, "%10u ", irq_desc_kstat_cpu(ipi_desc[i], cpu));
+		seq_printf(p, " %s\n", ipi_names[i]);
+	}
+}
+
 static void smp_ipi_init_one(unsigned int virq, const char *name,
 			     irq_handler_t handler)
 {

-- 
2.43.0

Re: [PATCH 05/10] MIPS: smp: Implement IPI stats

[Thomas Bogendoerfer]

On Sun, Jun 16, 2024 at 10:03:09PM +0100, Jiaxun Yang wrote:
> Show IPI statistics in arch_show_interrupts as what RISC-V
> did.

it probably still does, but either this is usefull on it's own or
we don't need it. IMHO it's useful, so drop the reference to RISC-V.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

[PATCH 06/10] irqchip: irq-mips-gic: Switch to ipi_mux

[Jiaxun Yang]

Use ipi_mux to implement IPI interrupts instead of
allocating vector for each individual IPI messages.

This can reduce number of reserved GIC shared vectors,
which is a huge problem on MSI enabled GIC systems.

It also allowed us to easily expand number of IPIs.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 drivers/irqchip/Kconfig        |   1 +
 drivers/irqchip/irq-mips-gic.c | 200 ++++++++++++++---------------------------
 2 files changed, 66 insertions(+), 135 deletions(-)

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 14464716bacb..8665bbf31bb5 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -329,6 +329,7 @@ config KEYSTONE_IRQ
 config MIPS_GIC
 	bool
 	select GENERIC_IRQ_IPI if SMP
+	select GENERIC_IRQ_IPI_MUX if SMP
 	select IRQ_DOMAIN_HIERARCHY
 	select MIPS_CM
 
diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
index 76253e864f23..eb58392f0e66 100644
--- a/drivers/irqchip/irq-mips-gic.c
+++ b/drivers/irqchip/irq-mips-gic.c
@@ -17,12 +17,14 @@
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
 #include <linux/irqdomain.h>
 #include <linux/of_address.h>
 #include <linux/percpu.h>
 #include <linux/sched.h>
 #include <linux/smp.h>
 
+#include <asm/ipi.h>
 #include <asm/mips-cps.h>
 #include <asm/setup.h>
 #include <asm/traps.h>
@@ -58,7 +60,7 @@ static struct irq_chip gic_level_irq_controller, gic_edge_irq_controller;
 
 #ifdef CONFIG_GENERIC_IRQ_IPI
 static DECLARE_BITMAP(ipi_resrv, GIC_MAX_INTRS);
-static DECLARE_BITMAP(ipi_available, GIC_MAX_INTRS);
+static int cpu_ipi_intr[NR_CPUS] __read_mostly;
 #endif /* CONFIG_GENERIC_IRQ_IPI */
 
 static struct gic_all_vpes_chip_data {
@@ -108,13 +110,6 @@ static void gic_bind_eic_interrupt(int irq, int set)
 	write_gic_vl_eic_shadow_set(irq, set);
 }
 
-static void gic_send_ipi(struct irq_data *d, unsigned int cpu)
-{
-	irq_hw_number_t hwirq = GIC_HWIRQ_TO_SHARED(irqd_to_hwirq(d));
-
-	write_gic_wedge(GIC_WEDGE_RW | hwirq);
-}
-
 int gic_get_c0_compare_int(void)
 {
 	if (!gic_local_irq_is_routable(GIC_LOCAL_INT_TIMER))
@@ -181,6 +176,11 @@ static void gic_mask_irq(struct irq_data *d)
 	unsigned int intr = GIC_HWIRQ_TO_SHARED(d->hwirq);
 
 	write_gic_rmask(intr);
+
+#ifdef CONFIG_GENERIC_IRQ_IPI
+	if (test_bit(intr, ipi_resrv))
+		return;
+#endif
 	gic_clear_pcpu_masks(intr);
 }
 
@@ -191,6 +191,10 @@ static void gic_unmask_irq(struct irq_data *d)
 
 	write_gic_smask(intr);
 
+#ifdef CONFIG_GENERIC_IRQ_IPI
+	if (test_bit(intr, ipi_resrv))
+		return;
+#endif
 	gic_clear_pcpu_masks(intr);
 	cpu = cpumask_first(irq_data_get_effective_affinity_mask(d));
 	set_bit(intr, per_cpu_ptr(pcpu_masks, cpu));
@@ -263,6 +267,11 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *cpumask,
 	unsigned long flags;
 	unsigned int cpu;
 
+#ifdef CONFIG_GENERIC_IRQ_IPI
+	if (test_bit(irq, ipi_resrv))
+		return -EINVAL;
+#endif
+
 	cpu = cpumask_first_and(cpumask, cpu_online_mask);
 	if (cpu >= NR_CPUS)
 		return -EINVAL;
@@ -304,7 +313,6 @@ static struct irq_chip gic_edge_irq_controller = {
 #ifdef CONFIG_SMP
 	.irq_set_affinity	=	gic_set_affinity,
 #endif
-	.ipi_send_single	=	gic_send_ipi,
 };
 
 static void gic_handle_local_int(bool chained)
@@ -475,12 +483,6 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int virq,
 	u32 map;
 
 	if (hwirq >= GIC_SHARED_HWIRQ_BASE) {
-#ifdef CONFIG_GENERIC_IRQ_IPI
-		/* verify that shared irqs don't conflict with an IPI irq */
-		if (test_bit(GIC_HWIRQ_TO_SHARED(hwirq), ipi_resrv))
-			return -EBUSY;
-#endif /* CONFIG_GENERIC_IRQ_IPI */
-
 		err = irq_domain_set_hwirq_and_chip(d, virq, hwirq,
 						    &gic_level_irq_controller,
 						    NULL);
@@ -570,146 +572,74 @@ static const struct irq_domain_ops gic_irq_domain_ops = {
 };
 
 #ifdef CONFIG_GENERIC_IRQ_IPI
-
-static int gic_ipi_domain_xlate(struct irq_domain *d, struct device_node *ctrlr,
-				const u32 *intspec, unsigned int intsize,
-				irq_hw_number_t *out_hwirq,
-				unsigned int *out_type)
-{
-	/*
-	 * There's nothing to translate here. hwirq is dynamically allocated and
-	 * the irq type is always edge triggered.
-	 * */
-	*out_hwirq = 0;
-	*out_type = IRQ_TYPE_EDGE_RISING;
-
-	return 0;
-}
-
-static int gic_ipi_domain_alloc(struct irq_domain *d, unsigned int virq,
-				unsigned int nr_irqs, void *arg)
-{
-	struct cpumask *ipimask = arg;
-	irq_hw_number_t hwirq, base_hwirq;
-	int cpu, ret, i;
-
-	base_hwirq = find_first_bit(ipi_available, gic_shared_intrs);
-	if (base_hwirq == gic_shared_intrs)
-		return -ENOMEM;
-
-	/* check that we have enough space */
-	for (i = base_hwirq; i < nr_irqs; i++) {
-		if (!test_bit(i, ipi_available))
-			return -EBUSY;
-	}
-	bitmap_clear(ipi_available, base_hwirq, nr_irqs);
-
-	/* map the hwirq for each cpu consecutively */
-	i = 0;
-	for_each_cpu(cpu, ipimask) {
-		hwirq = GIC_SHARED_TO_HWIRQ(base_hwirq + i);
-
-		ret = irq_domain_set_hwirq_and_chip(d, virq + i, hwirq,
-						    &gic_edge_irq_controller,
-						    NULL);
-		if (ret)
-			goto error;
-
-		ret = irq_domain_set_hwirq_and_chip(d->parent, virq + i, hwirq,
-						    &gic_edge_irq_controller,
-						    NULL);
-		if (ret)
-			goto error;
-
-		ret = irq_set_irq_type(virq + i, IRQ_TYPE_EDGE_RISING);
-		if (ret)
-			goto error;
-
-		ret = gic_shared_irq_domain_map(d, virq + i, hwirq, cpu);
-		if (ret)
-			goto error;
-
-		i++;
-	}
-
-	return 0;
-error:
-	bitmap_set(ipi_available, base_hwirq, nr_irqs);
-	return ret;
-}
-
-static void gic_ipi_domain_free(struct irq_domain *d, unsigned int virq,
-				unsigned int nr_irqs)
+static void gic_handle_ipi_irq(struct irq_desc *desc)
 {
-	irq_hw_number_t base_hwirq;
-	struct irq_data *data;
+	struct irq_chip *chip = irq_desc_get_chip(desc);
 
-	data = irq_get_irq_data(virq);
-	if (!data)
-		return;
-
-	base_hwirq = GIC_HWIRQ_TO_SHARED(irqd_to_hwirq(data));
-	bitmap_set(ipi_available, base_hwirq, nr_irqs);
+	chained_irq_enter(chip, desc);
+	ipi_mux_process();
+	chained_irq_exit(chip, desc);
 }
 
-static int gic_ipi_domain_match(struct irq_domain *d, struct device_node *node,
-				enum irq_domain_bus_token bus_token)
+static void gic_ipi_send(unsigned int cpu)
 {
-	bool is_ipi;
-
-	switch (bus_token) {
-	case DOMAIN_BUS_IPI:
-		is_ipi = d->bus_token == bus_token;
-		return (!node || to_of_node(d->fwnode) == node) && is_ipi;
-		break;
-	default:
-		return 0;
-	}
+	write_gic_wedge(GIC_WEDGE_RW | cpu_ipi_intr[cpu]);
 }
 
-static const struct irq_domain_ops gic_ipi_domain_ops = {
-	.xlate = gic_ipi_domain_xlate,
-	.alloc = gic_ipi_domain_alloc,
-	.free = gic_ipi_domain_free,
-	.match = gic_ipi_domain_match,
-};
-
-static int gic_register_ipi_domain(struct device_node *node)
+static int gic_ipi_mux_init(struct device_node *node, struct irq_domain *d)
 {
-	struct irq_domain *gic_ipi_domain;
-	unsigned int v[2], num_ipis;
-
-	gic_ipi_domain = irq_domain_add_hierarchy(gic_irq_domain,
-						  IRQ_DOMAIN_FLAG_IPI_PER_CPU,
-						  GIC_NUM_LOCAL_INTRS + gic_shared_intrs,
-						  node, &gic_ipi_domain_ops, NULL);
-	if (!gic_ipi_domain) {
-		pr_err("Failed to add IPI domain");
-		return -ENXIO;
-	}
-
-	irq_domain_update_bus_token(gic_ipi_domain, DOMAIN_BUS_IPI);
+	unsigned int i, v[2], num_ipis;
+	int ipi_virq, cpu = 0;
 
 	if (node &&
 	    !of_property_read_u32_array(node, "mti,reserved-ipi-vectors", v, 2)) {
 		bitmap_set(ipi_resrv, v[0], v[1]);
 	} else {
 		/*
-		 * Reserve 2 interrupts per possible CPU/VP for use as IPIs,
-		 * meeting the requirements of arch/mips SMP.
+		 * Reserve 1 interrupts per possible CPU/VP for use as IPIs
 		 */
-		num_ipis = 2 * num_possible_cpus();
+		num_ipis = num_possible_cpus();
 		bitmap_set(ipi_resrv, gic_shared_intrs - num_ipis, num_ipis);
 	}
 
-	bitmap_copy(ipi_available, ipi_resrv, GIC_MAX_INTRS);
+	ipi_virq = ipi_mux_create(IPI_MAX, gic_ipi_send);
+
+	WARN_ON(bitmap_weight(ipi_resrv, GIC_MAX_INTRS) < num_possible_cpus());
+
+	for_each_set_bit(i, ipi_resrv, GIC_MAX_INTRS) {
+		struct irq_fwspec fwspec;
+		int virq;
+
+		fwspec.fwnode = of_node_to_fwnode(node);
+		fwspec.param_count = 3;
+		fwspec.param[0] = GIC_SHARED;
+		fwspec.param[1] = i;
+		fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
+
+		virq = irq_create_fwspec_mapping(&fwspec);
+		if (!virq)
+			return -EINVAL;
+
+		gic_shared_irq_domain_map(d, virq, GIC_SHARED_TO_HWIRQ(i), cpu);
+		irq_set_chained_handler(virq, gic_handle_ipi_irq);
+		gic_clear_pcpu_masks(i);
+		set_bit(i, per_cpu_ptr(pcpu_masks, cpu));
+
+		cpu_ipi_intr[cpu] = i;
+
+		cpu++;
+		if (cpu >= num_possible_cpus())
+			break;
+	}
+
+	mips_smp_ipi_set_virq_range(ipi_virq, IPI_MAX);
 
 	return 0;
 }
 
 #else /* !CONFIG_GENERIC_IRQ_IPI */
 
-static inline int gic_register_ipi_domain(struct device_node *node)
+static inline int gic_ipi_mux_init(struct device_node *node)
 {
 	return 0;
 }
@@ -809,10 +739,6 @@ static int __init gic_of_init(struct device_node *node,
 		return -ENXIO;
 	}
 
-	ret = gic_register_ipi_domain(node);
-	if (ret)
-		return ret;
-
 	board_bind_eic_interrupt = &gic_bind_eic_interrupt;
 
 	/* Setup defaults */
@@ -822,6 +748,10 @@ static int __init gic_of_init(struct device_node *node,
 		write_gic_rmask(i);
 	}
 
+	ret = gic_ipi_mux_init(node, gic_irq_domain);
+	if (ret)
+		return ret;
+
 	return cpuhp_setup_state(CPUHP_AP_IRQ_MIPS_GIC_STARTING,
 				 "irqchip/mips/gic:starting",
 				 gic_cpu_startup, NULL);

-- 
2.43.0

[PATCH 07/10] MIPS: Implement get_mips_sw_int hook

[Jiaxun Yang]

For MIPS CPUs with VEIC, SW0 and SW1 interrupts are also
routed through external sources.

We need such hook to allow architecture code to get interrupt
source from platform EIC controllers.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 arch/mips/include/asm/irq.h     |  1 +
 arch/mips/include/asm/irq_cpu.h |  3 +++
 arch/mips/kernel/irq.c          | 17 +++++++++++++++++
 drivers/irqchip/irq-mips-cpu.c  | 11 +++++++++++
 4 files changed, 32 insertions(+)

diff --git a/arch/mips/include/asm/irq.h b/arch/mips/include/asm/irq.h
index 3a848e7e69f7..6edad40ef663 100644
--- a/arch/mips/include/asm/irq.h
+++ b/arch/mips/include/asm/irq.h
@@ -51,6 +51,7 @@ static inline int irq_canonicalize(int irq)
 #else
 #define irq_canonicalize(irq) (irq)	/* Sane hardware, sane code ... */
 #endif
+int get_mips_sw_int(int hwint);
 
 asmlinkage void plat_irq_dispatch(void);
 
diff --git a/arch/mips/include/asm/irq_cpu.h b/arch/mips/include/asm/irq_cpu.h
index 83d7331ab215..50a99ba2d503 100644
--- a/arch/mips/include/asm/irq_cpu.h
+++ b/arch/mips/include/asm/irq_cpu.h
@@ -9,7 +9,10 @@
 #ifndef _ASM_IRQ_CPU_H
 #define _ASM_IRQ_CPU_H
 
+#include <linux/irqdomain.h>
+
 extern void mips_cpu_irq_init(void);
+extern int mips_cpu_get_sw_int(int hwint);
 
 #ifdef CONFIG_IRQ_DOMAIN
 struct device_node;
diff --git a/arch/mips/kernel/irq.c b/arch/mips/kernel/irq.c
index c3ea8d80e0cb..c79504b12134 100644
--- a/arch/mips/kernel/irq.c
+++ b/arch/mips/kernel/irq.c
@@ -26,10 +26,27 @@
 #include <linux/atomic.h>
 #include <linux/uaccess.h>
 
+#include <asm/irq_cpu.h>
 #include <asm/ipi.h>
 
 void *irq_stack[NR_CPUS];
 
+int __weak get_mips_sw_int(int hwint)
+{
+	/* Only SW0 and SW1 */
+	WARN_ON(hwint > 1);
+
+	/* SW int is routed to external source */
+	if (cpu_has_veic)
+		return 0;
+
+#ifdef CONFIG_IRQ_MIPS_CPU
+	return mips_cpu_get_sw_int(hwint);
+#endif
+
+	return MIPS_CPU_IRQ_BASE + hwint;
+}
+
 /*
  * 'what should we do if we get a hw irq event on an illegal vector'.
  * each architecture has to answer this themselves.
diff --git a/drivers/irqchip/irq-mips-cpu.c b/drivers/irqchip/irq-mips-cpu.c
index 0c7ae71a0af0..7b3501485d95 100644
--- a/drivers/irqchip/irq-mips-cpu.c
+++ b/drivers/irqchip/irq-mips-cpu.c
@@ -254,6 +254,17 @@ static inline void mips_cpu_register_ipi_domain(struct device_node *of_node) {}
 
 #endif /* !CONFIG_GENERIC_IRQ_IPI */
 
+int mips_cpu_get_sw_int(int hwint)
+{
+	/* Only 0 and 1 for SW INT */
+	WARN_ON(hwint > 1);
+
+	if (!irq_domain)
+		return 0;
+
+	return irq_create_mapping(irq_domain, hwint);
+}
+
 static void __init __mips_cpu_irq_init(struct device_node *of_node)
 {
 	/* Mask interrupts. */

-- 
2.43.0

[PATCH 08/10] MIPS: GIC: Implement get_sw_int hook

[Jiaxun Yang]

SW0 and SW1 interrupts are routed through GIC in EIC
mode, implement get_sw_int hook for GIC and generic platform
to create IRQ mapping for SW0 and SW1 in such mode.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 arch/mips/generic/irq.c          | 15 +++++++++++++++
 arch/mips/include/asm/mips-gic.h | 10 ++++++++++
 drivers/irqchip/irq-mips-gic.c   | 15 +++++++++++++++
 3 files changed, 40 insertions(+)

diff --git a/arch/mips/generic/irq.c b/arch/mips/generic/irq.c
index 933119262943..bc3599a76014 100644
--- a/arch/mips/generic/irq.c
+++ b/arch/mips/generic/irq.c
@@ -11,6 +11,7 @@
 #include <linux/types.h>
 
 #include <asm/irq.h>
+#include <asm/irq_cpu.h>
 #include <asm/mips-cps.h>
 #include <asm/time.h>
 
@@ -59,3 +60,17 @@ unsigned int get_c0_compare_int(void)
 
 	return mips_cpu_timer_irq;
 }
+
+int get_mips_sw_int(int hwint)
+{
+	int mips_sw_int_irq;
+
+	if (mips_gic_present())
+		mips_sw_int_irq = gic_get_sw_int(hwint);
+	else if (cpu_has_veic)
+		panic("Unimplemented!");
+	else
+		mips_sw_int_irq = mips_cpu_get_sw_int(hwint);
+
+	return mips_sw_int_irq;
+}
diff --git a/arch/mips/include/asm/mips-gic.h b/arch/mips/include/asm/mips-gic.h
index 084cac1c5ea2..83f0d04763bb 100644
--- a/arch/mips/include/asm/mips-gic.h
+++ b/arch/mips/include/asm/mips-gic.h
@@ -370,4 +370,14 @@ extern int gic_get_c0_perfcount_int(void);
  */
 extern int gic_get_c0_fdc_int(void);
 
+/**
+ * gic_get_sw_int() - Return software interrupt virq
+ *
+ * Determine the virq number to use for SWINT0 or SWINT1 interrupts,
+ * which may be routed via the GIC.
+ *
+ * Returns the virq number or a negative error number.
+ */
+extern int gic_get_sw_int(int hwirq);
+
 #endif /* __MIPS_ASM_MIPS_CPS_H__ */
diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
index eb58392f0e66..1fbd7de3796b 100644
--- a/drivers/irqchip/irq-mips-gic.c
+++ b/drivers/irqchip/irq-mips-gic.c
@@ -143,6 +143,21 @@ int gic_get_c0_fdc_int(void)
 				  GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_FDC));
 }
 
+int gic_get_sw_int(int hwint)
+{
+	int local_irq;
+
+	WARN_ON(hwint > 1);
+
+	local_irq = GIC_LOCAL_INT_SWINT0 + hwint;
+
+	if (!gic_local_irq_is_routable(local_irq))
+		return MIPS_CPU_IRQ_BASE + hwint;
+
+	return irq_create_mapping(gic_irq_domain,
+				  GIC_LOCAL_TO_HWIRQ(local_irq));
+}
+
 static void gic_handle_shared_int(bool chained)
 {
 	unsigned int intr;

-- 
2.43.0

[PATCH 09/10] irqchip: irq-mips-cpu: Rework software IRQ handling flow

[Jiaxun Yang]

Remove unnecessary irq_chip hooks for software interrupts,
and don't mask them in ack hook to match kernel's expectation
on handling flow.

Create a irq_chip for regular (non-MT) mode software interrupts
so they will be acked as well.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 drivers/irqchip/irq-mips-cpu.c | 57 +++++++++++++++++++++++++++++-------------
 1 file changed, 39 insertions(+), 18 deletions(-)

diff --git a/drivers/irqchip/irq-mips-cpu.c b/drivers/irqchip/irq-mips-cpu.c
index 7b3501485d95..4854c06ce652 100644
--- a/drivers/irqchip/irq-mips-cpu.c
+++ b/drivers/irqchip/irq-mips-cpu.c
@@ -49,7 +49,21 @@ static inline void mask_mips_irq(struct irq_data *d)
 	irq_disable_hazard();
 }
 
-static struct irq_chip mips_cpu_irq_controller = {
+static unsigned int mips_sw_irq_startup(struct irq_data *d)
+{
+	clear_c0_cause(C_SW0 << d->hwirq);
+	back_to_back_c0_hazard();
+	unmask_mips_irq(d);
+	return 0;
+}
+
+static void mips_sw_irq_ack(struct irq_data *d)
+{
+	clear_c0_cause(C_SW0 << d->hwirq);
+	back_to_back_c0_hazard();
+}
+
+static const struct irq_chip mips_cpu_irq_controller = {
 	.name		= "MIPS",
 	.irq_ack	= mask_mips_irq,
 	.irq_mask	= mask_mips_irq,
@@ -60,11 +74,19 @@ static struct irq_chip mips_cpu_irq_controller = {
 	.irq_enable	= unmask_mips_irq,
 };
 
+static const struct irq_chip mips_cpu_sw_irq_controller = {
+	.name		= "MIPS",
+	.irq_startup	= mips_sw_irq_startup,
+	.irq_ack	= mips_sw_irq_ack,
+	.irq_mask	= mask_mips_irq,
+	.irq_unmask	= unmask_mips_irq,
+};
+
+#ifdef CONFIG_MIPS_MT
 /*
  * Basically the same as above but taking care of all the MT stuff
  */
-
-static unsigned int mips_mt_cpu_irq_startup(struct irq_data *d)
+static unsigned int mips_mt_sw_irq_startup(struct irq_data *d)
 {
 	unsigned int vpflags = dvpe();
 
@@ -76,14 +98,14 @@ static unsigned int mips_mt_cpu_irq_startup(struct irq_data *d)
 
 /*
  * While we ack the interrupt interrupts are disabled and thus we don't need
- * to deal with concurrency issues.  Same for mips_cpu_irq_end.
+ * to deal with concurrency issues.
  */
-static void mips_mt_cpu_irq_ack(struct irq_data *d)
+static void mips_mt_sw_irq_ack(struct irq_data *d)
 {
 	unsigned int vpflags = dvpe();
+
 	clear_c0_cause(C_SW0 << d->hwirq);
 	evpe(vpflags);
-	mask_mips_irq(d);
 }
 
 #ifdef CONFIG_GENERIC_IRQ_IPI
@@ -108,21 +130,17 @@ static void mips_mt_send_ipi(struct irq_data *d, unsigned int cpu)
 }
 
 #endif /* CONFIG_GENERIC_IRQ_IPI */
-
-static struct irq_chip mips_mt_cpu_irq_controller = {
+static const struct irq_chip mips_mt_cpu_irq_controller = {
 	.name		= "MIPS",
-	.irq_startup	= mips_mt_cpu_irq_startup,
-	.irq_ack	= mips_mt_cpu_irq_ack,
+	.irq_startup	= mips_mt_sw_irq_startup,
+	.irq_ack	= mips_mt_sw_irq_ack,
 	.irq_mask	= mask_mips_irq,
-	.irq_mask_ack	= mips_mt_cpu_irq_ack,
 	.irq_unmask	= unmask_mips_irq,
-	.irq_eoi	= unmask_mips_irq,
-	.irq_disable	= mask_mips_irq,
-	.irq_enable	= unmask_mips_irq,
 #ifdef CONFIG_GENERIC_IRQ_IPI
 	.ipi_send_single = mips_mt_send_ipi,
 #endif
 };
+#endif
 
 asmlinkage void __weak plat_irq_dispatch(void)
 {
@@ -152,11 +170,14 @@ asmlinkage void __weak plat_irq_dispatch(void)
 static int mips_cpu_intc_map(struct irq_domain *d, unsigned int irq,
 			     irq_hw_number_t hw)
 {
-	struct irq_chip *chip;
+	const struct irq_chip *chip;
 
-	if (hw < 2 && cpu_has_mipsmt) {
-		/* Software interrupts are used for MT/CMT IPI */
-		chip = &mips_mt_cpu_irq_controller;
+	if (hw < 2) {
+		chip = &mips_cpu_sw_irq_controller;
+#ifdef CONFIG_MIPS_MT
+		if (cpu_has_mipsmt)
+			chip = &mips_mt_cpu_irq_controller;
+#endif
 	} else {
 		chip = &mips_cpu_irq_controller;
 	}

-- 
2.43.0

[PATCH 10/10] MIPS: smp-mt: Rework IPI functions

[Jiaxun Yang]

Move smp IRQ code from irq-mips-cpu to smp-mt as IPI is
not really relavant to CPU intc. In VEIC mode we can have
irq-mips-cpu not registered and SW interrupts comes from
EIC controllers.

Implement IPI with ipi-mux to allow easy extension to number
of IPIs.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 arch/mips/Kconfig              |   2 +
 arch/mips/kernel/smp-mt.c      |  70 +++++++++++++++++++++++
 drivers/irqchip/Kconfig        |   1 -
 drivers/irqchip/irq-mips-cpu.c | 124 +----------------------------------------
 4 files changed, 74 insertions(+), 123 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 1236ea122061..de06c7425e94 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2188,6 +2188,8 @@ config MIPS_MT_SMP
 	depends on SYS_SUPPORTS_MULTITHREADING && !CPU_MICROMIPS
 	select CPU_MIPSR2_IRQ_VI
 	select CPU_MIPSR2_IRQ_EI
+	select GENERIC_IRQ_IPI
+	select GENERIC_IRQ_IPI_MUX
 	select SYNC_R4K
 	select MIPS_MT
 	select SMP
diff --git a/arch/mips/kernel/smp-mt.c b/arch/mips/kernel/smp-mt.c
index 7729cc733421..2f00077dbf07 100644
--- a/arch/mips/kernel/smp-mt.c
+++ b/arch/mips/kernel/smp-mt.c
@@ -10,6 +10,10 @@
 #include <linux/sched.h>
 #include <linux/cpumask.h>
 #include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
 #include <linux/compiler.h>
 #include <linux/sched/task_stack.h>
 #include <linux/smp.h>
@@ -19,6 +23,7 @@
 #include <asm/cpu.h>
 #include <asm/processor.h>
 #include <asm/hardirq.h>
+#include <asm/ipi.h>
 #include <asm/mmu_context.h>
 #include <asm/time.h>
 #include <asm/mipsregs.h>
@@ -26,6 +31,65 @@
 #include <asm/mips_mt.h>
 #include <asm/mips-cps.h>
 
+static int vsmp_sw0_virq __ro_after_init;
+
+static void smvp_handle_ipi_irq(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+
+	chained_irq_enter(chip, desc);
+
+	/* irq-mips-cpu would ack for us, but EIC drivers won't */
+	if (cpu_has_veic) {
+		unsigned int vpflags = dvpe();
+
+		clear_c0_cause(C_SW0);
+		evpe(vpflags);
+	}
+	ipi_mux_process();
+
+	chained_irq_exit(chip, desc);
+}
+
+static void smvp_ipi_send(unsigned int cpu)
+{
+	unsigned long flags;
+	int vpflags;
+
+	local_irq_save(flags);
+
+	/* We can only send IPIs to VPEs within the local core */
+	WARN_ON(!cpus_are_siblings(smp_processor_id(), cpu));
+	vpflags = dvpe();
+	settc(cpu_vpe_id(&cpu_data[cpu]));
+	write_vpe_c0_status(read_vpe_c0_status() | C_SW0);
+	write_vpe_c0_cause(read_vpe_c0_cause() | C_SW0);
+	evpe(vpflags);
+
+	local_irq_restore(flags);
+}
+
+static int __init vsmp_ipi_init(void)
+{
+	int sw0_virq, mux_virq;
+
+	/* SW0 Interrupt for IPI */
+	sw0_virq = get_mips_sw_int(0);
+	if (!sw0_virq)
+		return -EINVAL;
+
+	mux_virq = ipi_mux_create(IPI_MAX, smvp_ipi_send);
+	if (!mux_virq)
+		return -EINVAL;
+
+	irq_set_percpu_devid(sw0_virq);
+	irq_set_chained_handler(sw0_virq, smvp_handle_ipi_irq);
+	mips_smp_ipi_set_virq_range(mux_virq, IPI_MAX);
+	vsmp_sw0_virq = sw0_virq;
+
+	return 0;
+}
+
 static void __init smvp_copy_vpe_config(void)
 {
 	write_vpe_c0_status(
@@ -123,6 +187,8 @@ static void vsmp_smp_finish(void)
 	/* CDFIXME: remove this? */
 	write_c0_compare(read_c0_count() + (8* mips_hpt_frequency/HZ));
 
+	enable_percpu_irq(vsmp_sw0_virq, IRQ_TYPE_NONE);
+
 #ifdef CONFIG_MIPS_MT_FPAFF
 	/* If we have an FPU, enroll ourselves in the FPU-full mask */
 	if (cpu_has_fpu)
@@ -226,7 +292,11 @@ static void __init vsmp_smp_setup(void)
 
 static void __init vsmp_prepare_cpus(unsigned int max_cpus)
 {
+	int rc;
+
 	mips_mt_set_cpuoptions();
+	rc = vsmp_ipi_init();
+	WARN_ON(rc);
 }
 
 const struct plat_smp_ops vsmp_smp_ops = {
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 8665bbf31bb5..bb63b07faa27 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -175,7 +175,6 @@ config MADERA_IRQ
 config IRQ_MIPS_CPU
 	bool
 	select GENERIC_IRQ_CHIP
-	select GENERIC_IRQ_IPI if SMP && SYS_SUPPORTS_MULTITHREADING
 	select IRQ_DOMAIN
 	select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
 
diff --git a/drivers/irqchip/irq-mips-cpu.c b/drivers/irqchip/irq-mips-cpu.c
index 4854c06ce652..456f58729d00 100644
--- a/drivers/irqchip/irq-mips-cpu.c
+++ b/drivers/irqchip/irq-mips-cpu.c
@@ -34,8 +34,7 @@
 #include <asm/mipsmtregs.h>
 #include <asm/setup.h>
 
-static struct irq_domain *irq_domain;
-static struct irq_domain *ipi_domain;
+static struct irq_domain *irq_domain __read_mostly;
 
 static inline void unmask_mips_irq(struct irq_data *d)
 {
@@ -108,37 +107,12 @@ static void mips_mt_sw_irq_ack(struct irq_data *d)
 	evpe(vpflags);
 }
 
-#ifdef CONFIG_GENERIC_IRQ_IPI
-
-static void mips_mt_send_ipi(struct irq_data *d, unsigned int cpu)
-{
-	irq_hw_number_t hwirq = irqd_to_hwirq(d);
-	unsigned long flags;
-	int vpflags;
-
-	local_irq_save(flags);
-
-	/* We can only send IPIs to VPEs within the local core */
-	WARN_ON(!cpus_are_siblings(smp_processor_id(), cpu));
-
-	vpflags = dvpe();
-	settc(cpu_vpe_id(&cpu_data[cpu]));
-	write_vpe_c0_cause(read_vpe_c0_cause() | (C_SW0 << hwirq));
-	evpe(vpflags);
-
-	local_irq_restore(flags);
-}
-
-#endif /* CONFIG_GENERIC_IRQ_IPI */
 static const struct irq_chip mips_mt_cpu_irq_controller = {
 	.name		= "MIPS",
 	.irq_startup	= mips_mt_sw_irq_startup,
 	.irq_ack	= mips_mt_sw_irq_ack,
 	.irq_mask	= mask_mips_irq,
 	.irq_unmask	= unmask_mips_irq,
-#ifdef CONFIG_GENERIC_IRQ_IPI
-	.ipi_send_single = mips_mt_send_ipi,
-#endif
 };
 #endif
 
@@ -154,15 +128,8 @@ asmlinkage void __weak plat_irq_dispatch(void)
 
 	pending >>= CAUSEB_IP;
 	while (pending) {
-		struct irq_domain *d;
-
 		irq = fls(pending) - 1;
-		if (IS_ENABLED(CONFIG_GENERIC_IRQ_IPI) && irq < 2)
-			d = ipi_domain;
-		else
-			d = irq_domain;
-
-		do_domain_IRQ(d, irq);
+		do_domain_IRQ(irq_domain, irq);
 		pending &= ~BIT(irq);
 	}
 }
@@ -195,86 +162,6 @@ static const struct irq_domain_ops mips_cpu_intc_irq_domain_ops = {
 	.xlate = irq_domain_xlate_onecell,
 };
 
-#ifdef CONFIG_GENERIC_IRQ_IPI
-
-struct cpu_ipi_domain_state {
-	DECLARE_BITMAP(allocated, 2);
-};
-
-static int mips_cpu_ipi_alloc(struct irq_domain *domain, unsigned int virq,
-			      unsigned int nr_irqs, void *arg)
-{
-	struct cpu_ipi_domain_state *state = domain->host_data;
-	unsigned int i, hwirq;
-	int ret;
-
-	for (i = 0; i < nr_irqs; i++) {
-		hwirq = find_first_zero_bit(state->allocated, 2);
-		if (hwirq == 2)
-			return -EBUSY;
-		bitmap_set(state->allocated, hwirq, 1);
-
-		ret = irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq,
-						    &mips_mt_cpu_irq_controller,
-						    NULL);
-		if (ret)
-			return ret;
-
-		ret = irq_domain_set_hwirq_and_chip(domain->parent, virq + i, hwirq,
-						    &mips_mt_cpu_irq_controller,
-						    NULL);
-
-		if (ret)
-			return ret;
-
-		ret = irq_set_irq_type(virq + i, IRQ_TYPE_LEVEL_HIGH);
-		if (ret)
-			return ret;
-	}
-
-	return 0;
-}
-
-static int mips_cpu_ipi_match(struct irq_domain *d, struct device_node *node,
-			      enum irq_domain_bus_token bus_token)
-{
-	bool is_ipi;
-
-	switch (bus_token) {
-	case DOMAIN_BUS_IPI:
-		is_ipi = d->bus_token == bus_token;
-		return (!node || (to_of_node(d->fwnode) == node)) && is_ipi;
-	default:
-		return 0;
-	}
-}
-
-static const struct irq_domain_ops mips_cpu_ipi_chip_ops = {
-	.alloc	= mips_cpu_ipi_alloc,
-	.match	= mips_cpu_ipi_match,
-};
-
-static void mips_cpu_register_ipi_domain(struct device_node *of_node)
-{
-	struct cpu_ipi_domain_state *ipi_domain_state;
-
-	ipi_domain_state = kzalloc(sizeof(*ipi_domain_state), GFP_KERNEL);
-	ipi_domain = irq_domain_add_hierarchy(irq_domain,
-					      IRQ_DOMAIN_FLAG_IPI_SINGLE,
-					      2, of_node,
-					      &mips_cpu_ipi_chip_ops,
-					      ipi_domain_state);
-	if (!ipi_domain)
-		panic("Failed to add MIPS CPU IPI domain");
-	irq_domain_update_bus_token(ipi_domain, DOMAIN_BUS_IPI);
-}
-
-#else /* !CONFIG_GENERIC_IRQ_IPI */
-
-static inline void mips_cpu_register_ipi_domain(struct device_node *of_node) {}
-
-#endif /* !CONFIG_GENERIC_IRQ_IPI */
-
 int mips_cpu_get_sw_int(int hwint)
 {
 	/* Only 0 and 1 for SW INT */
@@ -297,13 +184,6 @@ static void __init __mips_cpu_irq_init(struct device_node *of_node)
 					   NULL);
 	if (!irq_domain)
 		panic("Failed to add irqdomain for MIPS CPU");
-
-	/*
-	 * Only proceed to register the software interrupt IPI implementation
-	 * for CPUs which implement the MIPS MT (multi-threading) ASE.
-	 */
-	if (cpu_has_mipsmt)
-		mips_cpu_register_ipi_domain(of_node);
 }
 
 void __init mips_cpu_irq_init(void)

-- 
2.43.0

Re: [PATCH 00/10] MIPS: IPI Improvements

[Jiaxun Yang]

在2024年6月17日六月 上午5:03，Jiaxun Yang写道：
> Hi all,
>
> This series improved general handling to MIPS IPI interrupts, made
> IPI numbers scalable, and switch to IPI-MUX for all GERNERIC_IPI
> users on mux.

Ping :-)

>
> It is a prerequisite for enabling IRQ_WORK for MIPS.
>
> It has been tested on MIPS Boston I6500, malta SOC-It, Loongson-2K,
> Cavium CN7130 (EdgeRouter 4), and an unannounced interaptiv UP MT
> platform with EIC.
>
> I don't really know broadcom platforms and SGI platforms well so
> changes to those platforms are kept minimal (no functional change).
>
> Please review.
> Thanks
>
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
> Jiaxun Yang (10):
>       MIPS: smp: Make IPI interrupts scalable
>       MIPS: smp: Manage IPI interrupts as percpu_devid interrupts
>       MIPS: smp: Provide platform IPI virq & domain hooks
>       MIPS: Move mips_smp_ipi_init call after prepare_cpus
>       MIPS: smp: Implement IPI stats
>       irqchip: irq-mips-gic: Switch to ipi_mux
>       MIPS: Implement get_mips_sw_int hook
>       MIPS: GIC: Implement get_sw_int hook
>       irqchip: irq-mips-cpu: Rework software IRQ handling flow
>       MIPS: smp-mt: Rework IPI functions
>
>  arch/mips/Kconfig                |   2 +
>  arch/mips/cavium-octeon/smp.c    | 109 +++++++-------------
>  arch/mips/generic/irq.c          |  15 +++
>  arch/mips/include/asm/ipi.h      |  71 +++++++++++++
>  arch/mips/include/asm/irq.h      |   1 +
>  arch/mips/include/asm/irq_cpu.h  |   3 +
>  arch/mips/include/asm/mips-gic.h |  10 ++
>  arch/mips/include/asm/smp-ops.h  |   8 +-
>  arch/mips/include/asm/smp.h      |  42 +++-----
>  arch/mips/kernel/irq.c           |  21 ++++
>  arch/mips/kernel/smp-bmips.c     |  43 ++++----
>  arch/mips/kernel/smp-cps.c       |   1 +
>  arch/mips/kernel/smp-mt.c        |  70 +++++++++++++
>  arch/mips/kernel/smp.c           | 216 ++++++++++++++++++++++++---------------
>  arch/mips/loongson64/smp.c       |  51 ++++-----
>  arch/mips/mm/c-octeon.c          |   2 +-
>  arch/mips/sgi-ip27/ip27-smp.c    |  15 +--
>  arch/mips/sgi-ip30/ip30-smp.c    |  15 +--
>  arch/mips/sibyte/bcm1480/smp.c   |  19 ++--
>  arch/mips/sibyte/sb1250/smp.c    |  13 +--
>  drivers/irqchip/Kconfig          |   2 +-
>  drivers/irqchip/irq-mips-cpu.c   | 180 +++++++++-----------------------
>  drivers/irqchip/irq-mips-gic.c   | 213 ++++++++++++++------------------------
>  23 files changed, 594 insertions(+), 528 deletions(-)
> ---
> base-commit: a2a47d53ca1f74f60931487c27eeba3c17fb69c9
> change-id: 20240616-b4-mips-ipi-improvements-f8c86b1dc677
>
> Best regards,
> -- 
> Jiaxun Yang <jiaxun.yang@flygoat.com>

-- 
- Jiaxun