Merge branch irq/plic-cleanups into irq/irqchip-next

* irq/plic-cleanups:
  : .
  : SiFive PLIC cleanups from Niklas Cassel:
  :
  : - Clarify some of the namings in the driver
  :
  : - Make sure S-mode interrupts are disabled when running in M-mode
  : .
  irqchip/sifive-plic: Disable S-mode IRQs if running in M-mode
  irqchip/sifive-plic: Improve naming scheme for per context offsets

Signed-off-by: Marc Zyngier <maz@kernel.org>

Author: Marc Zyngier

drivers/irqchip/irq-sifive-plic.c

@@ -44,16 +44,16 @@
  * Each hart context has a vector of interrupt enable bits associated with it.
  * There's one bit for each interrupt source.
  */
-#define ENABLE_BASE			0x2000
-#define     ENABLE_PER_HART		0x80
+#define CONTEXT_ENABLE_BASE		0x2000
+#define     CONTEXT_ENABLE_SIZE		0x80
 
 /*
  * Each hart context has a set of control registers associated with it.  Right
  * now there's only two: a source priority threshold over which the hart will
  * take an interrupt, and a register to claim interrupts.
  */
 #define CONTEXT_BASE			0x200000
-#define     CONTEXT_PER_HART		0x1000
+#define     CONTEXT_SIZE		0x1000
 #define     CONTEXT_THRESHOLD		0x00
 #define     CONTEXT_CLAIM		0x04
 
@@ -81,17 +81,21 @@ static int plic_parent_irq __ro_after_init;
 static bool plic_cpuhp_setup_done __ro_after_init;
 static DEFINE_PER_CPU(struct plic_handler, plic_handlers);
 
-static inline void plic_toggle(struct plic_handler *handler,
-				int hwirq, int enable)
+static void __plic_toggle(void __iomem *enable_base, int hwirq, int enable)
 {
-	u32 __iomem *reg = handler->enable_base + (hwirq / 32) * sizeof(u32);
+	u32 __iomem *reg = enable_base + (hwirq / 32) * sizeof(u32);
 	u32 hwirq_mask = 1 << (hwirq % 32);
 
-	raw_spin_lock(&handler->enable_lock);
 	if (enable)
 		writel(readl(reg) | hwirq_mask, reg);
 	else
 		writel(readl(reg) & ~hwirq_mask, reg);
+}
+
+static void plic_toggle(struct plic_handler *handler, int hwirq, int enable)
+{
+	raw_spin_lock(&handler->enable_lock);
+	__plic_toggle(handler->enable_base, hwirq, enable);
 	raw_spin_unlock(&handler->enable_lock);
 }
 
@@ -324,8 +328,18 @@ static int __init plic_init(struct device_node *node,
 		 * Skip contexts other than external interrupts for our
 		 * privilege level.
 		 */
-		if (parent.args[0] != RV_IRQ_EXT)
+		if (parent.args[0] != RV_IRQ_EXT) {
+			/* Disable S-mode enable bits if running in M-mode. */
+			if (IS_ENABLED(CONFIG_RISCV_M_MODE)) {
+				void __iomem *enable_base = priv->regs +
+					CONTEXT_ENABLE_BASE +
+					i * CONTEXT_ENABLE_SIZE;
+
+				for (hwirq = 1; hwirq <= nr_irqs; hwirq++)
+					__plic_toggle(enable_base, hwirq, 0);
+			}
 			continue;
+		}
 
 		hartid = riscv_of_parent_hartid(parent.np);
 		if (hartid < 0) {
@@ -361,11 +375,11 @@ static int __init plic_init(struct device_node *node,
 
 		cpumask_set_cpu(cpu, &priv->lmask);
 		handler->present = true;
-		handler->hart_base =
-			priv->regs + CONTEXT_BASE + i * CONTEXT_PER_HART;
+		handler->hart_base = priv->regs + CONTEXT_BASE +
+			i * CONTEXT_SIZE;
 		raw_spin_lock_init(&handler->enable_lock);
-		handler->enable_base =
-			priv->regs + ENABLE_BASE + i * ENABLE_PER_HART;
+		handler->enable_base = priv->regs + CONTEXT_ENABLE_BASE +
+			i * CONTEXT_ENABLE_SIZE;
 		handler->priv = priv;
 done:
 		for (hwirq = 1; hwirq <= nr_irqs; hwirq++)