1 files changed, 125 insertions, 69 deletions

diff --git a/drivers/xen/xen-pciback/pciback_ops.c b/drivers/xen/xen-pciback/pciback_ops.c
index 64eb0cd8b8af..84e014490950 100644
--- a/drivers/xen/xen-pciback/pciback_ops.c
+++ b/drivers/xen/xen-pciback/pciback_ops.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * PCI Backend Operations - respond to PCI requests from Frontend
  *
@@ -5,17 +6,15 @@
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#define dev_fmt pr_fmt
 
-#include <linux/module.h>
+#include <linux/moduleparam.h>
 #include <linux/wait.h>
 #include <linux/bitops.h>
 #include <xen/events.h>
 #include <linux/sched.h>
 #include "pciback.h"
 
-int verbose_request;
-module_param(verbose_request, int, 0644);
-
 static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id);
 
 /* Ensure a device is has the fake IRQ handler "turned on/off" and is
@@ -70,6 +69,13 @@ static void xen_pcibk_control_isr(struct pci_dev *dev, int reset)
 		enable ? "enable" : "disable");
 
 	if (enable) {
+		/*
+		 * The MSI or MSI-X should not have an IRQ handler. Otherwise
+		 * if the guest terminates we BUG_ON in free_msi_irqs.
+		 */
+		if (dev->msi_enabled || dev->msix_enabled)
+			goto out;
+
 		rc = request_irq(dev_data->irq,
 				xen_pcibk_guest_interrupt, IRQF_SHARED,
 				dev_data->irq_name, dev);
@@ -119,8 +125,6 @@ void xen_pcibk_reset_device(struct pci_dev *dev)
 		if (pci_is_enabled(dev))
 			pci_disable_device(dev);
 
-		pci_write_config_word(dev, PCI_COMMAND, 0);
-
 		dev->is_busmaster = 0;
 	} else {
 		pci_read_config_word(dev, PCI_COMMAND, &cmd);
@@ -141,26 +145,26 @@ int xen_pcibk_enable_msi(struct xen_pcibk_device *pdev,
 	struct xen_pcibk_dev_data *dev_data;
 	int status;
 
-	if (unlikely(verbose_request))
-		printk(KERN_DEBUG DRV_NAME ": %s: enable MSI\n", pci_name(dev));
-
-	status = pci_enable_msi(dev);
+	if (dev->msi_enabled)
+		status = -EALREADY;
+	else if (dev->msix_enabled)
+		status = -ENXIO;
+	else
+		status = pci_enable_msi(dev);
 
 	if (status) {
-		pr_warn_ratelimited("%s: error enabling MSI for guest %u: err %d\n",
-				    pci_name(dev), pdev->xdev->otherend_id,
-				    status);
+		dev_warn_ratelimited(&dev->dev, "error enabling MSI for guest %u: err %d\n",
+				     pdev->xdev->otherend_id, status);
 		op->value = 0;
 		return XEN_PCI_ERR_op_failed;
 	}
 
-	/* The value the guest needs is actually the IDT vector, not the
+	/* The value the guest needs is actually the IDT vector, not
 	 * the local domain's IRQ number. */
 
 	op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
-	if (unlikely(verbose_request))
-		printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev),
-			op->value);
+
+	dev_dbg(&dev->dev, "MSI: %d\n", op->value);
 
 	dev_data = pci_get_drvdata(dev);
 	if (dev_data)
@@ -173,20 +177,19 @@ static
 int xen_pcibk_disable_msi(struct xen_pcibk_device *pdev,
 			  struct pci_dev *dev, struct xen_pci_op *op)
 {
-	struct xen_pcibk_dev_data *dev_data;
+	if (dev->msi_enabled) {
+		struct xen_pcibk_dev_data *dev_data;
 
-	if (unlikely(verbose_request))
-		printk(KERN_DEBUG DRV_NAME ": %s: disable MSI\n",
-		       pci_name(dev));
-	pci_disable_msi(dev);
+		pci_disable_msi(dev);
 
+		dev_data = pci_get_drvdata(dev);
+		if (dev_data)
+			dev_data->ack_intr = 1;
+	}
 	op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
-	if (unlikely(verbose_request))
-		printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev),
-			op->value);
-	dev_data = pci_get_drvdata(dev);
-	if (dev_data)
-		dev_data->ack_intr = 1;
+
+	dev_dbg(&dev->dev, "MSI: %d\n", op->value);
+
 	return 0;
 }
 
@@ -197,14 +200,26 @@ int xen_pcibk_enable_msix(struct xen_pcibk_device *pdev,
 	struct xen_pcibk_dev_data *dev_data;
 	int i, result;
 	struct msix_entry *entries;
+	u16 cmd;
+
+	dev_dbg(&dev->dev, "enable MSI-X\n");
 
-	if (unlikely(verbose_request))
-		printk(KERN_DEBUG DRV_NAME ": %s: enable MSI-X\n",
-		       pci_name(dev));
 	if (op->value > SH_INFO_MAX_VEC)
 		return -EINVAL;
 
-	entries = kmalloc(op->value * sizeof(*entries), GFP_KERNEL);
+	if (dev->msix_enabled)
+		return -EALREADY;
+
+	/*
+	 * PCI_COMMAND_MEMORY must be enabled, otherwise we may not be able
+	 * to access the BARs where the MSI-X entries reside.
+	 * But VF devices are unique in which the PF needs to be checked.
+	 */
+	pci_read_config_word(pci_physfn(dev), PCI_COMMAND, &cmd);
+	if (dev->msi_enabled || !(cmd & PCI_COMMAND_MEMORY))
+		return -ENXIO;
+
+	entries = kmalloc_array(op->value, sizeof(*entries), GFP_KERNEL);
 	if (entries == NULL)
 		return -ENOMEM;
 
@@ -213,24 +228,20 @@ int xen_pcibk_enable_msix(struct xen_pcibk_device *pdev,
 		entries[i].vector = op->msix_entries[i].vector;
 	}
 
-	result = pci_enable_msix(dev, entries, op->value);
-
+	result = pci_enable_msix_exact(dev, entries, op->value);
 	if (result == 0) {
 		for (i = 0; i < op->value; i++) {
 			op->msix_entries[i].entry = entries[i].entry;
-			if (entries[i].vector)
+			if (entries[i].vector) {
 				op->msix_entries[i].vector =
 					xen_pirq_from_irq(entries[i].vector);
-				if (unlikely(verbose_request))
-					printk(KERN_DEBUG DRV_NAME ": %s: " \
-						"MSI-X[%d]: %d\n",
-						pci_name(dev), i,
-						op->msix_entries[i].vector);
+				dev_dbg(&dev->dev, "MSI-X[%d]: %d\n", i,
+					op->msix_entries[i].vector);
+			}
 		}
 	} else
-		pr_warn_ratelimited("%s: error enabling MSI-X for guest %u: err %d!\n",
-				    pci_name(dev), pdev->xdev->otherend_id,
-				    result);
+		dev_warn_ratelimited(&dev->dev, "error enabling MSI-X for guest %u: err %d!\n",
+				     pdev->xdev->otherend_id, result);
 	kfree(entries);
 
 	op->value = result;
@@ -245,46 +256,61 @@ static
 int xen_pcibk_disable_msix(struct xen_pcibk_device *pdev,
 			   struct pci_dev *dev, struct xen_pci_op *op)
 {
-	struct xen_pcibk_dev_data *dev_data;
-	if (unlikely(verbose_request))
-		printk(KERN_DEBUG DRV_NAME ": %s: disable MSI-X\n",
-			pci_name(dev));
-	pci_disable_msix(dev);
+	if (dev->msix_enabled) {
+		struct xen_pcibk_dev_data *dev_data;
 
+		pci_disable_msix(dev);
+
+		dev_data = pci_get_drvdata(dev);
+		if (dev_data)
+			dev_data->ack_intr = 1;
+	}
 	/*
 	 * SR-IOV devices (which don't have any legacy IRQ) have
 	 * an undefined IRQ value of zero.
 	 */
 	op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
-	if (unlikely(verbose_request))
-		printk(KERN_DEBUG DRV_NAME ": %s: MSI-X: %d\n", pci_name(dev),
-			op->value);
-	dev_data = pci_get_drvdata(dev);
-	if (dev_data)
-		dev_data->ack_intr = 1;
+
+	dev_dbg(&dev->dev, "MSI-X: %d\n", op->value);
+
 	return 0;
 }
 #endif
+
+static inline bool xen_pcibk_test_op_pending(struct xen_pcibk_device *pdev)
+{
+	return test_bit(_XEN_PCIF_active,
+			(unsigned long *)&pdev->sh_info->flags) &&
+	       !test_and_set_bit(_PDEVF_op_active, &pdev->flags);
+}
+
 /*
 * Now the same evtchn is used for both pcifront conf_read_write request
 * as well as pcie aer front end ack. We use a new work_queue to schedule
 * xen_pcibk conf_read_write service for avoiding confict with aer_core
 * do_recovery job which also use the system default work_queue
 */
-void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
+static void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
 {
+	bool eoi = true;
+
 	/* Check that frontend is requesting an operation and that we are not
 	 * already processing a request */
-	if (test_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags)
-	    && !test_and_set_bit(_PDEVF_op_active, &pdev->flags)) {
-		queue_work(xen_pcibk_wq, &pdev->op_work);
+	if (xen_pcibk_test_op_pending(pdev)) {
+		schedule_work(&pdev->op_work);
+		eoi = false;
 	}
 	/*_XEN_PCIB_active should have been cleared by pcifront. And also make
 	sure xen_pcibk is waiting for ack by checking _PCIB_op_pending*/
 	if (!test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
 	    && test_bit(_PCIB_op_pending, &pdev->flags)) {
 		wake_up(&xen_pcibk_aer_wait_queue);
+		eoi = false;
 	}
+
+	/* EOI if there was nothing to do. */
+	if (eoi)
+		xen_pcibk_lateeoi(pdev, XEN_EOI_FLAG_SPURIOUS);
 }
 
 /* Performing the configuration space reads/writes must not be done in atomic
@@ -292,15 +318,18 @@ void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
  * use of semaphores). This function is intended to be called from a work
  * queue in process context taking a struct xen_pcibk_device as a parameter */
 
-void xen_pcibk_do_op(struct work_struct *data)
+static void xen_pcibk_do_one_op(struct xen_pcibk_device *pdev)
 {
-	struct xen_pcibk_device *pdev =
-		container_of(data, struct xen_pcibk_device, op_work);
 	struct pci_dev *dev;
 	struct xen_pcibk_dev_data *dev_data = NULL;
-	struct xen_pci_op *op = &pdev->sh_info->op;
+	struct xen_pci_op *op = &pdev->op;
 	int test_intx = 0;
+#ifdef CONFIG_PCI_MSI
+	unsigned int nr = 0;
+#endif
 
+	*op = pdev->sh_info->op;
+	barrier();
 	dev = xen_pcibk_get_pci_dev(pdev, op->domain, op->bus, op->devfn);
 
 	if (dev == NULL)
@@ -326,6 +355,7 @@ void xen_pcibk_do_op(struct work_struct *data)
 			op->err = xen_pcibk_disable_msi(pdev, dev, op);
 			break;
 		case XEN_PCI_OP_enable_msix:
+			nr = op->value;
 			op->err = xen_pcibk_enable_msix(pdev, dev, op);
 			break;
 		case XEN_PCI_OP_disable_msix:
@@ -342,25 +372,51 @@ void xen_pcibk_do_op(struct work_struct *data)
 		if ((dev_data->enable_intx != test_intx))
 			xen_pcibk_control_isr(dev, 0 /* no reset */);
 	}
+	pdev->sh_info->op.err = op->err;
+	pdev->sh_info->op.value = op->value;
+#ifdef CONFIG_PCI_MSI
+	if (op->cmd == XEN_PCI_OP_enable_msix && op->err == 0) {
+		unsigned int i;
+
+		for (i = 0; i < nr; i++)
+			pdev->sh_info->op.msix_entries[i].vector =
+				op->msix_entries[i].vector;
+	}
+#endif
 	/* Tell the driver domain that we're done. */
 	wmb();
 	clear_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags);
 	notify_remote_via_irq(pdev->evtchn_irq);
 
 	/* Mark that we're done. */
-	smp_mb__before_clear_bit(); /* /after/ clearing PCIF_active */
+	smp_mb__before_atomic(); /* /after/ clearing PCIF_active */
 	clear_bit(_PDEVF_op_active, &pdev->flags);
-	smp_mb__after_clear_bit(); /* /before/ final check for work */
+	smp_mb__after_atomic(); /* /before/ final check for work */
+}
 
-	/* Check to see if the driver domain tried to start another request in
-	 * between clearing _XEN_PCIF_active and clearing _PDEVF_op_active.
-	*/
-	xen_pcibk_test_and_schedule_op(pdev);
+void xen_pcibk_do_op(struct work_struct *data)
+{
+	struct xen_pcibk_device *pdev =
+		container_of(data, struct xen_pcibk_device, op_work);
+
+	do {
+		xen_pcibk_do_one_op(pdev);
+	} while (xen_pcibk_test_op_pending(pdev));
+
+	xen_pcibk_lateeoi(pdev, 0);
 }
 
 irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id)
 {
 	struct xen_pcibk_device *pdev = dev_id;
+	bool eoi;
+
+	/* IRQs might come in before pdev->evtchn_irq is written. */
+	if (unlikely(pdev->evtchn_irq != irq))
+		pdev->evtchn_irq = irq;
+
+	eoi = test_and_set_bit(_EOI_pending, &pdev->flags);
+	WARN(eoi, "IRQ while EOI pending\n");
 
 	xen_pcibk_test_and_schedule_op(pdev);
 
@@ -375,7 +431,7 @@ static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id)
 		dev_data->handled++;
 		if ((dev_data->handled % 1000) == 0) {
 			if (xen_test_irq_shared(irq)) {
-				pr_info("%s IRQ line is not shared "
+				dev_info(&dev->dev, "%s IRQ line is not shared "
 					"with other domains. Turning ISR off\n",
 					 dev_data->irq_name);
 				dev_data->ack_intr = 0;