[linux-yocto] [PATCH 4/6] drivers/pci/host: PCIe MSI/MSIx Interrupt Fix

[Daniel Dragomir]

From: Palani <palaniappan.ramanathan at intel.com>

Modified the driver to enable either MSI or MSIx depending
on the first interrupt allocation for each PCIe controllers.
The AXM PCIe supports either MSI or MSIx at any time but not
both. Removed the edge IRQ trigger for the MSI interrupts.

Signed-off-by: Palani <palaniappan.ramanathan at intel.com>
---
 drivers/pci/host/pcie-axxia.c | 80 ++++++++++++++++++++++++++++---------------
 1 file changed, 52 insertions(+), 28 deletions(-)

diff --git a/drivers/pci/host/pcie-axxia.c b/drivers/pci/host/pcie-axxia.c
index 89f0e88..8b5e346 100644
--- a/drivers/pci/host/pcie-axxia.c
+++ b/drivers/pci/host/pcie-axxia.c
@@ -32,7 +32,6 @@
 
 #include "pcie-axxia.h"
 
-#define AXM_LEVEL_MSI
 
 #ifdef CONFIG_PCI_MSI
 #define AXXIA_GENERIC_MSI_DOMAIN_IRQ 1
@@ -528,11 +527,43 @@ static int axxia_check_set_msi_mode(struct pcie_port *pp, u32 is_msix)
 
 	if (pp->msi_mode == AXXIA_MSI_UNCONFIGURED) {
 		if (is_msix) {
+			dev_info(pp->dev, "Enable MSIx for pcie %d...\n",
+								pp->pei_nr);
+			axxia_axi_gpreg_readl(pp,
+				AXI_GPREG_EDG_IRQ_MASK_HI, &val);
+			val |= MSIX_ASSERTED;
+			axxia_axi_gpreg_writel(pp, val,
+				AXI_GPREG_EDG_IRQ_MASK_HI);
+
+			dev_info(pp->dev, "Disable MSI for pcie %d...\n",
+								pp->pei_nr);
+			axxia_cc_gpreg_readl(pp,
+				CC_GPREG_LVL_IRQ_MASK, &val);
+			val &= ~MSI_CNTRL_INT;
+			axxia_cc_gpreg_writel(pp, val,
+				CC_GPREG_LVL_IRQ_MASK);
+
 			axxia_axi_gpreg_readl(pp, AXI_GPREG_MSTR, &val);
 			val &= ~CFG_MSI_MODE;
 			axxia_axi_gpreg_writel(pp, val, AXI_GPREG_MSTR);
 			pp->msi_mode = AXXIA_MSIX_MODE;
 		} else {
+			dev_info(pp->dev, "Enable MSI for pcie %d...\n",
+							pp->pei_nr);
+			axxia_cc_gpreg_readl(pp,
+				CC_GPREG_LVL_IRQ_MASK, &val);
+			val |= MSI_CNTRL_INT;
+			axxia_cc_gpreg_writel(pp, val,
+				CC_GPREG_LVL_IRQ_MASK);
+
+			dev_info(pp->dev, "Disable MSIx for pcie %d...\n",
+							pp->pei_nr);
+			axxia_axi_gpreg_readl(pp,
+				AXI_GPREG_EDG_IRQ_MASK_HI, &val);
+			val &= ~MSIX_ASSERTED;
+			axxia_axi_gpreg_writel(pp, val,
+				AXI_GPREG_EDG_IRQ_MASK_HI);
+
 			axxia_axi_gpreg_readl(pp, AXI_GPREG_MSTR, &val);
 			val |= CFG_MSI_MODE;
 			axxia_axi_gpreg_writel(pp, val, AXI_GPREG_MSTR);
@@ -602,6 +633,7 @@ static int axxia_pcie_irq_domain_alloc(struct irq_domain *domain,
 	msi_alloc_info_t *va = args;
 	struct msi_desc *desc = va->desc;
 	int is_msix = 0;
+	int rc;
 
 	if (desc) {
 		if (desc->msi_attrib.is_msix)
@@ -628,18 +660,26 @@ static int axxia_pcie_irq_domain_alloc(struct irq_domain *domain,
 	if (msi_irq < 0)
 		return msi_irq;
 
-	axxia_check_set_msi_mode(pp, is_msix);
-	for (i = 0; i < nr_irqs; i++) {
-		irq_domain_set_info(domain, virq + i, msi_irq + i,
+	rc = axxia_check_set_msi_mode(pp, is_msix);
+	if (rc == 0) {
+		for (i = 0; i < nr_irqs; i++) {
+			irq_domain_set_info(domain, virq + i, msi_irq + i,
 				    &axxia_msi_bottom_irq_chip,
 				    domain->host_data, handle_simple_irq, NULL,
 				    NULL);
-		if (is_msix)
-			axxia_dw_pcie_msix_set_irq(pp, msi_irq + i, 1);
-		else
-			axxia_dw_pcie_msi_set_irq(pp, msi_irq + i);
+			if (is_msix)
+				axxia_dw_pcie_msix_set_irq(pp, msi_irq + i, 1);
+			else
+				axxia_dw_pcie_msi_set_irq(pp, msi_irq + i);
+		}
+		rc = 0;
+	} else {
+		mutex_lock(&pp->bitmap_lock);
+		bitmap_clear(pp->bitmap, msi_irq, nr_irqs);
+		mutex_unlock(&pp->bitmap_lock);
+		rc = -EINVAL;
 	}
-	return 0;
+	return rc;
 }
 
 static void axxia_pcie_irq_domain_free(struct irq_domain *domain,
@@ -844,24 +884,19 @@ static void axxia_pcie_enable_interrupts(struct pcie_port *pp)
 	if (IS_ENABLED(CONFIG_PCI_MSI)) {
 		/* unmask MSI */
 		if (pp->num_msi_irqs == 0) {
-#ifdef AXM_LEVEL_MSI
+#if 0  /* Delayed. Enabled during irq allocation */
 			axxia_cc_gpreg_readl(pp,
 				CC_GPREG_LVL_IRQ_MASK, &val);
 			val |= MSI_CNTRL_INT;
 			axxia_cc_gpreg_writel(pp, val,
 				CC_GPREG_LVL_IRQ_MASK);
-#else
-			axxia_cc_gpreg_readl(pp,
-				CC_GPREG_EDG_IRQ_MASK_HI, &val);
-			val |= MSI_ASSERTED;
-			axxia_cc_gpreg_writel(pp, val,
-				CC_GPREG_EDG_IRQ_MASK_HI);
-#endif
+
 			axxia_axi_gpreg_readl(pp,
 				AXI_GPREG_EDG_IRQ_MASK_HI, &val);
 			val |= MSIX_ASSERTED;
 			axxia_axi_gpreg_writel(pp, val,
 				AXI_GPREG_EDG_IRQ_MASK_HI);
+#endif
 
 		} else {
 			for (i = 0; i < pp->num_msi_irqs; i++) {
@@ -1335,27 +1370,16 @@ static irqreturn_t axxia_pcie_irq_handler(int irq, void *arg)
 	if (IS_ENABLED(CONFIG_PCI_MSI)) {
 		if (pp->num_msi_irqs == 0) {
 			offset = irq - pp->msi_irqs[0];
-#ifdef AXM_LEVEL_MSI
 			axxia_cc_gpreg_readl(pp,
 				CC_GPREG_LVL_IRQ_STAT, &val);
 			if (val & MSI_CNTRL_INT) {
-#else
-			axxia_cc_gpreg_readl(pp,
-				CC_GPREG_EDG_IRQ_STAT_HI, &val);
-			if (val & MSI_ASSERTED) {
-#endif
 				axxia_pcie_rd_own_conf(pp,
 				PCIE_MSI_INTR0_STATUS, 4, (u32 *)&val1);
 				if (val1)
 					ret = axxia_dw_pcie_handle_msi_irq(pp,
 									 val1);
-#ifdef AXM_LEVEL_MSI
 				axxia_cc_gpreg_writel(pp, MSI_CNTRL_INT,
 					      CC_GPREG_LVL_IRQ_STAT);
-#else
-				axxia_cc_gpreg_writel(pp, MSI_ASSERTED,
-					      CC_GPREG_EDG_IRQ_STAT_HI);
-#endif
 				if (!ret)
 					return IRQ_NONE;
 			}
-- 
2.7.4