PCI: tegra: Convert struct tegra_msi mask_lock into raw spinlock

commit 26fda92 upstream.

The tegra_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 tegra_msi_irq_unmask().

Since the &desc->lock descriptor lock is a raw spinlock, and the tegra_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: 2c99e55 ("PCI: tegra: Convert to MSI domains")
Reported-by: Geert Uytterhoeven <[email protected]>
Closes: https://patchwork.kernel.org/project/linux-pci/patch/[email protected]/#26574451
Signed-off-by: Marek Vasut <[email protected]>
Signed-off-by: Manivannan Sadhasivam <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Cc: [email protected]
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: Marek Vasut

drivers/pci/controller/pci-tegra.c

@@ -14,6 +14,7 @@
  */
 
 #include <linux/clk.h>
+#include <linux/cleanup.h>
 #include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/export.h>
@@ -270,7 +271,7 @@ struct tegra_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;
 	void *virt;
 	dma_addr_t phys;
 	int irq;
@@ -1581,29 +1582,27 @@ static void tegra_msi_irq_mask(struct irq_data *d)
 	struct tegra_msi *msi = irq_data_get_irq_chip_data(d);
 	struct tegra_pcie *pcie = msi_to_pcie(msi);
 	unsigned int index = d->hwirq / 32;
-	unsigned long flags;
 	u32 value;
 
-	spin_lock_irqsave(&msi->mask_lock, flags);
-	value = afi_readl(pcie, AFI_MSI_EN_VEC(index));
-	value &= ~BIT(d->hwirq % 32);
-	afi_writel(pcie, value, AFI_MSI_EN_VEC(index));
-	spin_unlock_irqrestore(&msi->mask_lock, flags);
+	scoped_guard(raw_spinlock_irqsave, &msi->mask_lock) {
+		value = afi_readl(pcie, AFI_MSI_EN_VEC(index));
+		value &= ~BIT(d->hwirq % 32);
+		afi_writel(pcie, value, AFI_MSI_EN_VEC(index));
+	}
 }
 
 static void tegra_msi_irq_unmask(struct irq_data *d)
 {
 	struct tegra_msi *msi = irq_data_get_irq_chip_data(d);
 	struct tegra_pcie *pcie = msi_to_pcie(msi);
 	unsigned int index = d->hwirq / 32;
-	unsigned long flags;
 	u32 value;
 
-	spin_lock_irqsave(&msi->mask_lock, flags);
-	value = afi_readl(pcie, AFI_MSI_EN_VEC(index));
-	value |= BIT(d->hwirq % 32);
-	afi_writel(pcie, value, AFI_MSI_EN_VEC(index));
-	spin_unlock_irqrestore(&msi->mask_lock, flags);
+	scoped_guard(raw_spinlock_irqsave, &msi->mask_lock) {
+		value = afi_readl(pcie, AFI_MSI_EN_VEC(index));
+		value |= BIT(d->hwirq % 32);
+		afi_writel(pcie, value, AFI_MSI_EN_VEC(index));
+	}
 }
 
 static void tegra_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
@@ -1711,7 +1710,7 @@ static int tegra_pcie_msi_setup(struct tegra_pcie *pcie)
 	int err;
 
 	mutex_init(&msi->map_lock);
-	spin_lock_init(&msi->mask_lock);
+	raw_spin_lock_init(&msi->mask_lock);
 
 	if (IS_ENABLED(CONFIG_PCI_MSI)) {
 		err = tegra_allocate_domains(msi);