VisionFive2 Linux kernel

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index e095c28d27ae..ec01843cb9f1 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -75,11 +75,12 @@ void hv_remove_vmbus_handler(void)
 DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_stimer0)
 {
 	struct pt_regs *old_regs = set_irq_regs(regs);
+	u64 ip = regs ? instruction_pointer(regs) : 0;
 
 	inc_irq_stat(hyperv_stimer0_count);
 	if (hv_stimer0_handler)
 		hv_stimer0_handler();
-	add_interrupt_randomness(HYPERV_STIMER0_VECTOR, 0);
+	add_interrupt_randomness(HYPERV_STIMER0_VECTOR, 0, ip);
 	ack_APIC_irq();
 
 	set_irq_regs(old_regs);
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 860900470e17..56b2d5a7e2a0 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1242,26 +1242,25 @@ static __u32 get_reg(struct fast_pool *f, struct pt_regs *regs)
 	return *ptr;
 }
 
-void add_interrupt_randomness(int irq, int irq_flags)
+void add_interrupt_randomness(int irq, int irq_flags, __u64 ip)
 {
 	struct entropy_store	*r;
 	struct fast_pool	*fast_pool = this_cpu_ptr(&irq_randomness);
-	struct pt_regs		*regs = get_irq_regs();
 	unsigned long		now = jiffies;
 	cycles_t		cycles = random_get_entropy();
 	__u32			c_high, j_high;
-	__u64			ip;
 
 	if (cycles == 0)
-		cycles = get_reg(fast_pool, regs);
+		cycles = get_reg(fast_pool, NULL);
 	c_high = (sizeof(cycles) > 4) ? cycles >> 32 : 0;
 	j_high = (sizeof(now) > 4) ? now >> 32 : 0;
 	fast_pool->pool[0] ^= cycles ^ j_high ^ irq;
 	fast_pool->pool[1] ^= now ^ c_high;
-	ip = regs ? instruction_pointer(regs) : _RET_IP_;
+	if (!ip)
+		ip = _RET_IP_;
 	fast_pool->pool[2] ^= ip;
 	fast_pool->pool[3] ^= (sizeof(ip) > 4) ? ip >> 32 :
-		get_reg(fast_pool, regs);
+		get_reg(fast_pool, NULL);
 
 	fast_mix(fast_pool);
 	add_interrupt_bench(cycles);
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index d030577ad6a2..ef1db3367df7 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -19,6 +19,7 @@
 #include <linux/atomic.h>
 #include <linux/hyperv.h>
 #include <linux/interrupt.h>
+#include <linux/irq.h>
 
 #include "hv_trace.h"
 
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 392c1ac4f819..c5e9725fb5ff 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -22,6 +22,7 @@
 #include <linux/clockchips.h>
 #include <linux/cpu.h>
 #include <linux/sched/task_stack.h>
+#include <linux/irq.h>
 
 #include <linux/delay.h>
 #include <linux/notifier.h>
@@ -1337,6 +1338,8 @@ static void vmbus_isr(void)
 	void *page_addr = hv_cpu->synic_event_page;
 	struct hv_message *msg;
 	union hv_synic_event_flags *event;
+	struct pt_regs *regs = get_irq_regs();
+	u64 ip = regs ? instruction_pointer(regs) : 0;
 	bool handled = false;
 
 	if (unlikely(page_addr == NULL))
@@ -1381,7 +1384,7 @@ static void vmbus_isr(void)
 			tasklet_schedule(&hv_cpu->msg_dpc);
 	}
 
-	add_interrupt_randomness(vmbus_interrupt, 0);
+	add_interrupt_randomness(vmbus_interrupt, 0, ip);
 }
 
 static irqreturn_t vmbus_percpu_isr(int irq, void *dev_id)
diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h
index 59aea39785bf..ab70314af3d5 100644
--- a/include/linux/irqdesc.h
+++ b/include/linux/irqdesc.h
@@ -68,6 +68,7 @@ struct irq_desc {
 	unsigned int		irqs_unhandled;
 	atomic_t		threads_handled;
 	int			threads_handled_last;
+	u64			random_ip;
 	raw_spinlock_t		lock;
 	struct cpumask		*percpu_enabled;
 	const struct cpumask	*percpu_affinity;
diff --git a/include/linux/random.h b/include/linux/random.h
index f45b8be3e3c4..0e41d0527809 100644
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -35,7 +35,7 @@ static inline void add_latent_entropy(void) {}
 
 extern void add_input_randomness(unsigned int type, unsigned int code,
 				 unsigned int value) __latent_entropy;
-extern void add_interrupt_randomness(int irq, int irq_flags) __latent_entropy;
+extern void add_interrupt_randomness(int irq, int irq_flags, __u64 ip) __latent_entropy;
 
 extern void get_random_bytes(void *buf, int nbytes);
 extern int wait_for_random_bytes(void);
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 221d80c31e94..1543934f26d2 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -190,12 +190,18 @@ irqreturn_t __handle_irq_event_percpu(struct irq_desc *desc, unsigned int *flags
 
 irqreturn_t handle_irq_event_percpu(struct irq_desc *desc)
 {
-	irqreturn_t retval;
+	struct pt_regs *regs = get_irq_regs();
+	u64 ip = regs ? instruction_pointer(regs) : 0;
 	unsigned int flags = 0;
+	irqreturn_t retval;
 
 	retval = __handle_irq_event_percpu(desc, &flags);
 
-	add_interrupt_randomness(desc->irq_data.irq, flags);
+#ifdef CONFIG_PREEMPT_RT
+	desc->random_ip = ip;
+#else
+	add_interrupt_randomness(desc->irq_data.irq, flags, ip);
+#endif
 
 	if (!irq_settings_no_debug(desc))
 		note_interrupt(desc, retval);
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 66d51963e837..0f966288a648 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1281,6 +1281,12 @@ static int irq_thread(void *data)
 		if (action_ret == IRQ_WAKE_THREAD)
 			irq_wake_secondary(desc, action);
 
+		if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
+			migrate_disable();
+			add_interrupt_randomness(action->irq, 0,
+				 desc->random_ip ^ (unsigned long) action);
+			migrate_enable();
+		}
 		wake_threads_waitq(desc);
 	}