[PATCH 5.4 1/2] PCI: aardvark: Clear all MSIs at setup

[PATCH 5.4 1/2] PCI: aardvark: Clear all MSIs at setup

[Marek Behún]

From: Pali Rohár <pali@kernel.org>

[ Upstream commit 7d8dc1f7cd007a7ce94c5b4c20d63a8b8d6d7751 ]

We already clear all the other interrupts (ISR0, ISR1, HOST_CTRL_INT).

Define a new macro PCIE_MSI_ALL_MASK and do the same clearing for MSIs,
to ensure that we don't start receiving spurious interrupts.

Use this new mask in advk_pcie_handle_msi();

Link: https://lore.kernel.org/r/20211130172913.9727-5-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Marek Behún <kabel@kernel.org>
---
 drivers/pci/controller/pci-aardvark.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
index 721d2652319c..d43e93eb2fed 100644
--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -108,6 +108,7 @@
 #define PCIE_MSI_ADDR_HIGH_REG			(CONTROL_BASE_ADDR + 0x54)
 #define PCIE_MSI_STATUS_REG			(CONTROL_BASE_ADDR + 0x58)
 #define PCIE_MSI_MASK_REG			(CONTROL_BASE_ADDR + 0x5C)
+#define     PCIE_MSI_ALL_MASK			GENMASK(31, 0)
 #define PCIE_MSI_PAYLOAD_REG			(CONTROL_BASE_ADDR + 0x9C)
 #define     PCIE_MSI_DATA_MASK			GENMASK(15, 0)
 
@@ -561,6 +562,7 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie)
 	advk_writel(pcie, reg, PCIE_CORE_CTRL2_REG);
 
 	/* Clear all interrupts */
+	advk_writel(pcie, PCIE_MSI_ALL_MASK, PCIE_MSI_STATUS_REG);
 	advk_writel(pcie, PCIE_ISR0_ALL_MASK, PCIE_ISR0_REG);
 	advk_writel(pcie, PCIE_ISR1_ALL_MASK, PCIE_ISR1_REG);
 	advk_writel(pcie, PCIE_IRQ_ALL_MASK, HOST_CTRL_INT_STATUS_REG);
@@ -573,7 +575,7 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie)
 	advk_writel(pcie, PCIE_ISR1_ALL_MASK, PCIE_ISR1_MASK_REG);
 
 	/* Unmask all MSIs */
-	advk_writel(pcie, 0, PCIE_MSI_MASK_REG);
+	advk_writel(pcie, ~(u32)PCIE_MSI_ALL_MASK, PCIE_MSI_MASK_REG);
 
 	/* Enable summary interrupt for GIC SPI source */
 	reg = PCIE_IRQ_ALL_MASK & (~PCIE_IRQ_ENABLE_INTS_MASK);
@@ -1374,7 +1376,7 @@ static void advk_pcie_handle_msi(struct advk_pcie *pcie)
 
 	msi_mask = advk_readl(pcie, PCIE_MSI_MASK_REG);
 	msi_val = advk_readl(pcie, PCIE_MSI_STATUS_REG);
-	msi_status = msi_val & ~msi_mask;
+	msi_status = msi_val & ((~msi_mask) & PCIE_MSI_ALL_MASK);
 
 	for (msi_idx = 0; msi_idx < MSI_IRQ_NUM; msi_idx++) {
 		if (!(BIT(msi_idx) & msi_status))
-- 
2.35.1

[PATCH 5.4 2/2] PCI: aardvark: Fix reading MSI interrupt number

[Marek Behún]

From: Pali Rohár <pali@kernel.org>

[ Upstream commit 805dfc18dd3d4dd97a987d4406593b5a225b1253 ]

In advk_pcie_handle_msi() the authors expect that when bit i in the W1C
register PCIE_MSI_STATUS_REG is cleared, the PCIE_MSI_PAYLOAD_REG is
updated to contain the MSI number corresponding to index i.

Experiments show that this is not so, and instead PCIE_MSI_PAYLOAD_REG
always contains the number of the last received MSI, overall.

Do not read PCIE_MSI_PAYLOAD_REG register for determining MSI interrupt
number. Since Aardvark already forbids more than 32 interrupts and uses
own allocated hwirq numbers, the msi_idx already corresponds to the
received MSI number.

Link: https://lore.kernel.org/r/20220110015018.26359-3-kabel@kernel.org
Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Marek Behún <kabel@kernel.org>
---
As explained in https://lore.kernel.org/stable/20220503205434.25275-2-kabel@kernel.org/
for 4.14, this needs to be applied ASAP to stable, since another commit was put into
stable that breaks this driver.

Thx :)
---
 drivers/pci/controller/pci-aardvark.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
index d43e93eb2fed..7219ca39aa90 100644
--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -1372,7 +1372,7 @@ static void advk_pcie_remove_irq_domain(struct advk_pcie *pcie)
 static void advk_pcie_handle_msi(struct advk_pcie *pcie)
 {
 	u32 msi_val, msi_mask, msi_status, msi_idx;
-	u16 msi_data;
+	int virq;
 
 	msi_mask = advk_readl(pcie, PCIE_MSI_MASK_REG);
 	msi_val = advk_readl(pcie, PCIE_MSI_STATUS_REG);
@@ -1382,13 +1382,9 @@ static void advk_pcie_handle_msi(struct advk_pcie *pcie)
 		if (!(BIT(msi_idx) & msi_status))
 			continue;
 
-		/*
-		 * msi_idx contains bits [4:0] of the msi_data and msi_data
-		 * contains 16bit MSI interrupt number
-		 */
 		advk_writel(pcie, BIT(msi_idx), PCIE_MSI_STATUS_REG);
-		msi_data = advk_readl(pcie, PCIE_MSI_PAYLOAD_REG) & PCIE_MSI_DATA_MASK;
-		generic_handle_irq(msi_data);
+		virq = irq_find_mapping(pcie->msi_inner_domain, msi_idx);
+		generic_handle_irq(virq);
 	}
 
 	advk_writel(pcie, PCIE_ISR0_MSI_INT_PENDING,
-- 
2.35.1