PCI: rcar-host: Convert struct rcar_msi mask_lock into raw spinlock

The rcar_msi_irq_unmask() function may be called from a PCI driver
request_threaded_irq() function. This triggers kernel/irq/manage.c
__setup_irq() which locks raw spinlock &desc->lock descriptor lock
and with that descriptor lock held, calls rcar_msi_irq_unmask().

Since the &desc->lock descriptor lock is a raw spinlock, and the rcar_msi
.mask_lock is not a raw spinlock, this setup triggers 'BUG: Invalid wait
context' with CONFIG_PROVE_RAW_LOCK_NESTING=y.

Use scoped_guard() to simplify the locking.

Fixes: 83ed8d4 ("PCI: rcar: Convert to MSI domains")
Reported-by: Duy Nguyen <[email protected]>
Reported-by: Thuan Nguyen <[email protected]>
Signed-off-by: Marek Vasut <[email protected]>
Signed-off-by: Manivannan Sadhasivam <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Acked-by: Marc Zyngier <[email protected]>
Cc: [email protected]
Link: https://patch.msgid.link/[email protected]

Author: Marek Vasut

drivers/pci/controller/pcie-rcar-host.c

@@ -12,6 +12,7 @@
  */
 
 #include <linux/bitops.h>
+#include <linux/cleanup.h>
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
 #include <linux/delay.h>
@@ -38,7 +39,7 @@ struct rcar_msi {
 	DECLARE_BITMAP(used, INT_PCI_MSI_NR);
 	struct irq_domain *domain;
 	struct mutex map_lock;
-	spinlock_t mask_lock;
+	raw_spinlock_t mask_lock;
 	int irq1;
 	int irq2;
 };
@@ -602,28 +603,26 @@ static void rcar_msi_irq_mask(struct irq_data *d)
 {
 	struct rcar_msi *msi = irq_data_get_irq_chip_data(d);
 	struct rcar_pcie *pcie = &msi_to_host(msi)->pcie;
-	unsigned long flags;
 	u32 value;
 
-	spin_lock_irqsave(&msi->mask_lock, flags);
-	value = rcar_pci_read_reg(pcie, PCIEMSIIER);
-	value &= ~BIT(d->hwirq);
-	rcar_pci_write_reg(pcie, value, PCIEMSIIER);
-	spin_unlock_irqrestore(&msi->mask_lock, flags);
+	scoped_guard(raw_spinlock_irqsave, &msi->mask_lock) {
+		value = rcar_pci_read_reg(pcie, PCIEMSIIER);
+		value &= ~BIT(d->hwirq);
+		rcar_pci_write_reg(pcie, value, PCIEMSIIER);
+	}
 }
 
 static void rcar_msi_irq_unmask(struct irq_data *d)
 {
 	struct rcar_msi *msi = irq_data_get_irq_chip_data(d);
 	struct rcar_pcie *pcie = &msi_to_host(msi)->pcie;
-	unsigned long flags;
 	u32 value;
 
-	spin_lock_irqsave(&msi->mask_lock, flags);
-	value = rcar_pci_read_reg(pcie, PCIEMSIIER);
-	value |= BIT(d->hwirq);
-	rcar_pci_write_reg(pcie, value, PCIEMSIIER);
-	spin_unlock_irqrestore(&msi->mask_lock, flags);
+	scoped_guard(raw_spinlock_irqsave, &msi->mask_lock) {
+		value = rcar_pci_read_reg(pcie, PCIEMSIIER);
+		value |= BIT(d->hwirq);
+		rcar_pci_write_reg(pcie, value, PCIEMSIIER);
+	}
 }
 
 static void rcar_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
@@ -736,7 +735,7 @@ static int rcar_pcie_enable_msi(struct rcar_pcie_host *host)
 	int err;
 
 	mutex_init(&msi->map_lock);
-	spin_lock_init(&msi->mask_lock);
+	raw_spin_lock_init(&msi->mask_lock);
 
 	err = of_address_to_resource(dev->of_node, 0, &res);
 	if (err)