[PATCH v2 2/3] PCI: aardvark: Fix masking MSI interrupts

["Pali Rohár" <pali@kernel.org>]

Masking of individual MSI interrupts is done via PCIE_MSI_MASK_REG
register. At the driver probe time mask all MSI interrupts and then let
kernel IRQ chip code to unmask particular MSI interrupt when needed.

Signed-off-by: Pali Rohár <pali@kernel.org>
Cc: stable@vger.kernel.org # f21a8b1b6837 ("PCI: aardvark: Move to MSI handling using generic MSI support")

---
Changes in v2:
* Guard register updates by raw spin lock
---
 drivers/pci/controller/pci-aardvark.c | 52 ++++++++++++++++++++++++---
 1 file changed, 48 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
index 81c4a9ff91a3..0e81d7f37465 100644
--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -241,6 +241,7 @@ struct advk_pcie {
 	struct irq_domain *msi_inner_domain;
 	struct irq_chip msi_bottom_irq_chip;
 	struct irq_chip msi_irq_chip;
+	raw_spinlock_t msi_irq_lock;
 	struct msi_domain_info msi_domain_info;
 	DECLARE_BITMAP(msi_used, MSI_IRQ_NUM);
 	struct mutex msi_used_lock;
@@ -481,12 +482,10 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie)
 	advk_writel(pcie, PCIE_ISR1_ALL_MASK, PCIE_ISR1_REG);
 	advk_writel(pcie, PCIE_IRQ_ALL_MASK, HOST_CTRL_INT_STATUS_REG);
 
-	/* Disable All ISR0/1 Sources */
+	/* Disable All ISR0/1 and MSI Sources */
 	advk_writel(pcie, PCIE_ISR0_ALL_MASK, PCIE_ISR0_MASK_REG);
 	advk_writel(pcie, PCIE_ISR1_ALL_MASK, PCIE_ISR1_MASK_REG);
-
-	/* Unmask all MSIs */
-	advk_writel(pcie, ~(u32)PCIE_MSI_ALL_MASK, PCIE_MSI_MASK_REG);
+	advk_writel(pcie, PCIE_MSI_ALL_MASK, PCIE_MSI_MASK_REG);
 
 	/* Unmask summary MSI interrupt */
 	reg = advk_readl(pcie, PCIE_ISR0_MASK_REG);
@@ -1051,6 +1050,46 @@ static int advk_msi_set_affinity(struct irq_data *irq_data,
 	return -EINVAL;
 }
 
+static void advk_msi_irq_mask(struct irq_data *d)
+{
+	struct advk_pcie *pcie = d->domain->host_data;
+	irq_hw_number_t hwirq = irqd_to_hwirq(d);
+	unsigned long flags;
+	u32 mask;
+
+	raw_spin_lock_irqsave(&pcie->msi_irq_lock, flags);
+	mask = advk_readl(pcie, PCIE_MSI_MASK_REG);
+	mask |= BIT(hwirq);
+	advk_writel(pcie, mask, PCIE_MSI_MASK_REG);
+	raw_spin_unlock_irqrestore(&pcie->msi_irq_lock, flags);
+}
+
+static void advk_msi_irq_unmask(struct irq_data *d)
+{
+	struct advk_pcie *pcie = d->domain->host_data;
+	irq_hw_number_t hwirq = irqd_to_hwirq(d);
+	unsigned long flags;
+	u32 mask;
+
+	raw_spin_lock_irqsave(&pcie->msi_irq_lock, flags);
+	mask = advk_readl(pcie, PCIE_MSI_MASK_REG);
+	mask &= ~BIT(hwirq);
+	advk_writel(pcie, mask, PCIE_MSI_MASK_REG);
+	raw_spin_unlock_irqrestore(&pcie->msi_irq_lock, flags);
+}
+
+static void advk_msi_top_irq_mask(struct irq_data *d)
+{
+	pci_msi_mask_irq(d);
+	irq_chip_mask_parent(d);
+}
+
+static void advk_msi_top_irq_unmask(struct irq_data *d)
+{
+	pci_msi_unmask_irq(d);
+	irq_chip_unmask_parent(d);
+}
+
 static int advk_msi_irq_domain_alloc(struct irq_domain *domain,
 				     unsigned int virq,
 				     unsigned int nr_irqs, void *args)
@@ -1143,6 +1182,7 @@ static int advk_pcie_init_msi_irq_domain(struct advk_pcie *pcie)
 	struct irq_chip *bottom_ic, *msi_ic;
 	struct msi_domain_info *msi_di;
 
+	raw_spin_lock_init(&pcie->msi_irq_lock);
 	mutex_init(&pcie->msi_used_lock);
 
 	bottom_ic = &pcie->msi_bottom_irq_chip;
@@ -1150,9 +1190,13 @@ static int advk_pcie_init_msi_irq_domain(struct advk_pcie *pcie)
 	bottom_ic->name = "MSI";
 	bottom_ic->irq_compose_msi_msg = advk_msi_irq_compose_msi_msg;
 	bottom_ic->irq_set_affinity = advk_msi_set_affinity;
+	bottom_ic->irq_mask = advk_msi_irq_mask;
+	bottom_ic->irq_unmask = advk_msi_irq_unmask;
 
 	msi_ic = &pcie->msi_irq_chip;
 	msi_ic->name = "advk-MSI";
+	msi_ic->irq_mask = advk_msi_top_irq_mask;
+	msi_ic->irq_unmask = advk_msi_top_irq_unmask;
 
 	msi_di = &pcie->msi_domain_info;
 	msi_di->flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
-- 
2.20.1