irqchip/mbigen: bugfixs

Commit-ID:  5ba9b0a14132d0b8d97affe909f324045a968d03
Gitweb:     http://git.kernel.org/tip/5ba9b0a14132d0b8d97affe909f324045a968d03
Author:     Hanjun Guo <[email protected]>
AuthorDate: Fri, 12 May 2017 11:55:26 +0800
Committer:  Thomas Gleixner <[email protected]>
CommitDate: Fri, 12 May 2017 10:25:37 +0200

irqchip/mbigen: Fix memory mapping code

Some mbigens share memory regions, and devm_ioremap_resource does not allow to share resources which will break the probe of mbigen, in opposition to devm_ioremap.

This patch restores back usage of devm_ioremap function, but with proper error handling and logging.

---
 drivers/irqchip/irq-mbigen.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

index d2306c8..0f5e66e 100644
@@ -337,9 +337,12 @@ static int mbigen_device_probe(struct platform_device *pdev)
 	mgn_chip->pdev = pdev;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	mgn_chip->base = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(mgn_chip->base))
-		return PTR_ERR(mgn_chip->base);
+	mgn_chip->base = devm_ioremap(&pdev->dev, res->start,
+				      resource_size(res));
+	if (!mgn_chip->base) {
+		dev_err(&pdev->dev, "failed to ioremap %pR\n", res);
+		return -ENOMEM;
+	}
 
 	if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node)
 		err = mbigen_of_create_domain(pdev, mgn_chip);

Commit-ID:  ad7cc3c0c57d77b442db323056354d0e49833569
Gitweb:     http://git.kernel.org/tip/ad7cc3c0c57d77b442db323056354d0e49833569
Author:     Hanjun Guo <[email protected]>
AuthorDate: Fri, 12 May 2017 11:55:27 +0800
Committer:  Thomas Gleixner <[email protected]>
CommitDate: Fri, 12 May 2017 10:25:37 +0200

irqchip/mbigen: Fix potential NULL dereferencing

platform_get_resource() may return NULL, add proper check to avoid potential NULL dereferencing.

---
 drivers/irqchip/irq-mbigen.c | 3 +++
 1 file changed, 3 insertions(+)

index 0f5e66e..2fa1e45 100644
@@ -337,6 +337,9 @@ static int mbigen_device_probe(struct platform_device *pdev)
 	mgn_chip->pdev = pdev;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+
 	mgn_chip->base = devm_ioremap(&pdev->dev, res->start,
 				      resource_size(res));
 	if (!mgn_chip->base) {

Commit-ID:  9459a04b6a5a09967eec94a1b66f0a74312819d9
Gitweb:     http://git.kernel.org/tip/9459a04b6a5a09967eec94a1b66f0a74312819d9
Author:     MaJun <[email protected]>
AuthorDate: Fri, 12 May 2017 11:55:28 +0800
Committer:  Thomas Gleixner <[email protected]>
CommitDate: Fri, 12 May 2017 10:25:38 +0200

irqchip/mbigen: Fix the clear register offset calculation

The register array offset for clearing an interrupt is calculated by:

    offset = (hwirq - RESERVED_IRQ_PER_MBIGEN_CHIP) / 32;

This is wrong because the clear register array includes the reserved interrupts. So the clear operation ends up in the wrong register.

This went unnoticed so far, because the hardware clears the real bit through a timeout mechanism when the hardware is configured in debug mode. That debug mode was enabled on early generations of the hardware, so the problem was papered over.

On newer hardware with updated firmware the debug mode was disabled, so the bits did not get cleared which causes the system to malfunction.

Remove the subtraction of RESERVED_IRQ_PER_MBIGEN_CHIP, so the correct register is accessed.

[ tglx: Rewrote changelog ]

---
 drivers/irqchip/irq-mbigen.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

index 2fa1e45..31d6b5a 100644
@@ -106,10 +106,7 @@ static inline void get_mbigen_type_reg(irq_hw_number_t hwirq,
 static inline void get_mbigen_clear_reg(irq_hw_number_t hwirq,
 					u32 *mask, u32 *addr)
 {
-	unsigned int ofst;
-
-	hwirq -= RESERVED_IRQ_PER_MBIGEN_CHIP;
-	ofst = hwirq / 32 * 4;
+	unsigned int ofst = (hwirq / 32) * 4;
 
 	*mask = 1 << (hwirq % 32);
 	*addr = ofst + REG_MBIGEN_CLEAR_OFFSET;