diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index e039b74..73ad9bf 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -102,7 +102,7 @@ int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 	if (type == PCI_CAP_ID_MSI && nvec > 1)
 		return 1;
 
-	for_each_pci_msi_entry(entry, dev) {
+	for_each_pci_msi_entry_from(entry, dev) {
 		ret = arch_setup_msi_irq(dev, entry);
 		if (ret < 0)
 			return ret;
@@ -468,7 +468,7 @@ static int populate_msi_sysfs(struct pci_dev *pdev)
 	int i;
 
 	/* Determine how many msi entries we have */
-	for_each_pci_msi_entry(entry, pdev)
+	for_each_pci_msi_entry_from(entry, pdev)
 		num_msi += entry->nvec_used;
 	if (!num_msi)
 		return 0;
@@ -477,7 +477,7 @@ static int populate_msi_sysfs(struct pci_dev *pdev)
 	msi_attrs = kcalloc(num_msi + 1, sizeof(void *), GFP_KERNEL);
 	if (!msi_attrs)
 		return -ENOMEM;
-	for_each_pci_msi_entry(entry, pdev) {
+	for_each_pci_msi_entry_from(entry, pdev) {
 		for (i = 0; i < entry->nvec_used; i++) {
 			msi_dev_attr = kzalloc(sizeof(*msi_dev_attr), GFP_KERNEL);
 			if (!msi_dev_attr)
@@ -506,7 +506,11 @@ static int populate_msi_sysfs(struct pci_dev *pdev)
 		goto error_irq_group;
 	msi_irq_groups[0] = msi_irq_group;
 
-	ret = sysfs_create_groups(&pdev->dev.kobj, msi_irq_groups);
+	if (!pdev->msix_enabled)
+		ret = sysfs_create_group(&pdev->dev.kobj, msi_irq_group);
+	else
+		ret = sysfs_merge_group(&pdev->dev.kobj, msi_irq_group);
+
 	if (ret)
 		goto error_irq_groups;
 	pdev->msi_irq_groups = msi_irq_groups;
@@ -574,7 +578,7 @@ static int msi_verify_entries(struct pci_dev *dev)
 {
 	struct msi_desc *entry;
 
-	for_each_pci_msi_entry(entry, dev) {
+	for_each_pci_msi_entry_from(entry, dev) {
 		if (!dev->no_64bit_msi || !entry->msg.address_hi)
 			continue;
 		pci_err(dev, "Device has broken 64-bit MSI but arch"
@@ -615,6 +619,9 @@ static int msi_capability_init(struct pci_dev *dev, int nvec,
 
 	list_add_tail(&entry->list, dev_to_msi_list(&dev->dev));
 
+	 dev->dev.grp_first_desc = list_last_entry
+			(dev_to_msi_list(&dev->dev), struct msi_desc, list);
+
 	/* Configure MSI capability structure */
 	ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSI);
 	if (ret) {
@@ -669,7 +676,7 @@ static void __iomem *msix_map_region(struct pci_dev *dev, unsigned nr_entries)
 
 static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
 			      struct msix_entry *entries, int nvec,
-			      struct irq_affinity *affd)
+			      struct irq_affinity *affd, int group)
 {
 	struct irq_affinity_desc *curmsk, *masks = NULL;
 	struct msi_desc *entry;
@@ -698,8 +705,20 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
 			entry->msi_attrib.entry_nr = i;
 		entry->msi_attrib.default_irq	= dev->irq;
 		entry->mask_base		= base;
+		entry->group_id			= group;
 
 		list_add_tail(&entry->list, dev_to_msi_list(&dev->dev));
+
+		/*
+		 * Save the pointer to the first msi_desc entry of every
+		 * MSI-X group. This pointer is used by other functions
+		 * as the starting point to iterate through each of the
+		 * entries in that particular group.
+		 */
+		if (!i)
+			dev->dev.grp_first_desc = list_last_entry
+			(dev_to_msi_list(&dev->dev), struct msi_desc, list);
+
 		if (masks)
 			curmsk++;
 	}
@@ -715,7 +734,7 @@ static void msix_program_entries(struct pci_dev *dev,
 	struct msi_desc *entry;
 	int i = 0;
 
-	for_each_pci_msi_entry(entry, dev) {
+	for_each_pci_msi_entry_from(entry, dev) {
 		if (entries)
 			entries[i++].vector = entry->irq;
 		entry->masked = readl(pci_msix_desc_addr(entry) +
@@ -730,28 +749,31 @@ static void msix_program_entries(struct pci_dev *dev,
  * @entries: pointer to an array of struct msix_entry entries
  * @nvec: number of @entries
  * @affd: Optional pointer to enable automatic affinity assignement
+ * @group: The Group ID to be allocated to the msi-x vectors
  *
  * Setup the MSI-X capability structure of device function with a
  * single MSI-X irq. A return of zero indicates the successful setup of
  * requested MSI-X entries with allocated irqs or non-zero for otherwise.
  **/
 static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
-				int nvec, struct irq_affinity *affd)
+				int nvec, struct irq_affinity *affd, int group)
 {
 	int ret;
 	u16 control;
-	void __iomem *base;
 
 	/* Ensure MSI-X is disabled while it is set up */
 	pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0);
 
 	pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control);
+
 	/* Request & Map MSI-X table region */
-	base = msix_map_region(dev, msix_table_size(control));
-	if (!base)
-		return -ENOMEM;
+	if (!dev->msix_enabled) {
+		dev->base = msix_map_region(dev, msix_table_size(control));
+		if (!dev->base)
+			return -ENOMEM;
+	}
 
-	ret = msix_setup_entries(dev, base, entries, nvec, affd);
+	ret = msix_setup_entries(dev, dev->base, entries, nvec, affd, group);
 	if (ret)
 		return ret;
 
@@ -784,6 +806,7 @@ static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
 	pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0);
 
 	pcibios_free_irq(dev);
+
 	return 0;
 
 out_avail:
@@ -795,7 +818,7 @@ static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
 		struct msi_desc *entry;
 		int avail = 0;
 
-		for_each_pci_msi_entry(entry, dev) {
+		for_each_pci_msi_entry_from(entry, dev) {
 			if (entry->irq != 0)
 				avail++;
 		}
@@ -932,7 +955,8 @@ int pci_msix_vec_count(struct pci_dev *dev)
 EXPORT_SYMBOL(pci_msix_vec_count);
 
 static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
-			     int nvec, struct irq_affinity *affd)
+			     int nvec, struct irq_affinity *affd,
+			     bool one_shot, int group)
 {
 	int nr_entries;
 	int i, j;
@@ -963,7 +987,7 @@ static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
 		pci_info(dev, "can't enable MSI-X (MSI IRQ already assigned)\n");
 		return -EINVAL;
 	}
-	return msix_capability_init(dev, entries, nvec, affd);
+	return msix_capability_init(dev, entries, nvec, affd, group);
 }
 
 static void pci_msix_shutdown(struct pci_dev *dev)
@@ -1079,16 +1103,14 @@ EXPORT_SYMBOL(pci_enable_msi);
 
 static int __pci_enable_msix_range(struct pci_dev *dev,
 				   struct msix_entry *entries, int minvec,
-				   int maxvec, struct irq_affinity *affd)
+				   int maxvec, struct irq_affinity *affd,
+				   bool one_shot, int group)
 {
 	int rc, nvec = maxvec;
 
 	if (maxvec < minvec)
 		return -ERANGE;
 
-	if (WARN_ON_ONCE(dev->msix_enabled))
-		return -EINVAL;
-
 	for (;;) {
 		if (affd) {
 			nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
@@ -1096,7 +1118,8 @@ static int __pci_enable_msix_range(struct pci_dev *dev,
 				return -ENOSPC;
 		}
 
-		rc = __pci_enable_msix(dev, entries, nvec, affd);
+		rc = __pci_enable_msix(dev, entries, nvec, affd, one_shot,
+									group);
 		if (rc == 0)
 			return nvec;
 
@@ -1127,7 +1150,8 @@ static int __pci_enable_msix_range(struct pci_dev *dev,
 int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
 		int minvec, int maxvec)
 {
-	return __pci_enable_msix_range(dev, entries, minvec, maxvec, NULL);
+	return __pci_enable_msix_range(dev, entries, minvec, maxvec, NULL,
+								false, -1);
 }
 EXPORT_SYMBOL(pci_enable_msix_range);
 
@@ -1153,9 +1177,49 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
 				   unsigned int max_vecs, unsigned int flags,
 				   struct irq_affinity *affd)
 {
+	int group = -1;
+
+	dev->one_shot = true;
+
+	return pci_alloc_irq_vectors_affinity_dyn(dev, min_vecs, max_vecs,
+					flags, NULL, &group, dev->one_shot);
+}
+EXPORT_SYMBOL(pci_alloc_irq_vectors_affinity);
+
+/**
+ * pci_alloc_irq_vectors_affinity_dyn - allocate multiple IRQs for a device
+ * dynamically. Can be called multiple times.
+ * @dev:		PCI device to operate on
+ * @min_vecs:		minimum number of vectors required (must be >= 1)
+ * @max_vecs:		maximum (desired) number of vectors
+ * @flags:		flags or quirks for the allocation
+ * @affd:		optional description of the affinity requirements
+ * @group_id:		group ID assigned to vectors allocated
+ * @one_shot:		true if dynamic MSI-X allocation is disabled, else false
+ *
+ * Allocate up to @max_vecs interrupt vectors for @dev, using MSI-X. Return
+ * the number of vectors allocated (which might be smaller than @max_vecs)
+ * if successful, or a negative error code on error. If less than @min_vecs
+ * interrupt vectors are available for @dev the function will fail with -ENOSPC.
+ * Assign a unique group ID to the set of vectors being allocated.
+ *
+ * To get the Linux IRQ number used for a vector that can be passed to
+ * request_irq() use the pci_irq_vector_group() helper.
+ */
+int pci_alloc_irq_vectors_affinity_dyn(struct pci_dev *dev,
+				       unsigned int min_vecs,
+				       unsigned int max_vecs,
+				       unsigned int flags,
+				       struct irq_affinity *affd,
+				       int *group_id, bool one_shot)
+{
+
 	struct irq_affinity msi_default_affd = {0};
-	int msix_vecs = -ENOSPC;
+	int msix_vecs = -ENOSPC, i;
 	int msi_vecs = -ENOSPC;
+	struct msix_entry *entries = NULL;
+	struct msi_desc *entry;
+	int p = 0;
 
 	if (flags & PCI_IRQ_AFFINITY) {
 		if (!affd)
@@ -1166,8 +1230,54 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
 	}
 
 	if (flags & PCI_IRQ_MSIX) {
-		msix_vecs = __pci_enable_msix_range(dev, NULL, min_vecs,
-						    max_vecs, affd);
+		if (dev->msix_enabled) {
+			if (one_shot) {
+				goto err_alloc;
+			} else {
+				for_each_pci_msi_entry(entry, dev) {
+					if (entry->group_id != -1)
+						p = 1;
+				}
+				if (!p)
+					goto err_alloc;
+			}
+		} else {
+			dev->num_msix = pci_msix_vec_count(dev);
+			dev->entry = kcalloc(BITS_TO_LONGS(dev->num_msix),
+					sizeof(unsigned long), GFP_KERNEL);
+			if (!dev->entry)
+				return -ENOMEM;
+		}
+
+		entries = kcalloc(max_vecs, sizeof(struct msix_entry),
+								GFP_KERNEL);
+		if (entries == NULL)
+			return -ENOMEM;
+
+		for (i = 0; i < max_vecs; i++) {
+			entries[i].entry = find_first_zero_bit(
+						dev->entry, dev->num_msix);
+			if (entries[i].entry == dev->num_msix)
+				return -ENOSPC;
+			set_bit(entries[i].entry, dev->entry);
+		}
+
+		if (!one_shot) {
+			/* Assign a unique group ID */
+			*group_id = idr_alloc(dev->grp_idr, NULL,
+						0, dev->num_msix, GFP_KERNEL);
+			if (*group_id < 0) {
+				if (*group_id == -ENOSPC)
+					pci_err(dev, "No free group IDs\n");
+				return *group_id;
+			}
+		}
+
+		msix_vecs = __pci_enable_msix_range(dev, entries, min_vecs,
+					max_vecs, affd, one_shot, *group_id);
+
+		kfree(entries);
+
 		if (msix_vecs > 0)
 			return msix_vecs;
 	}
@@ -1197,8 +1307,12 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
 	if (msix_vecs == -ENOSPC)
 		return -ENOSPC;
 	return msi_vecs;
+
+err_alloc:
+	WARN_ON_ONCE(dev->msix_enabled);
+	return -EINVAL;
 }
-EXPORT_SYMBOL(pci_alloc_irq_vectors_affinity);
+EXPORT_SYMBOL(pci_alloc_irq_vectors_affinity_dyn);
 
 /**
  * pci_free_irq_vectors - free previously allocated IRQs for a device
@@ -1248,6 +1362,43 @@ int pci_irq_vector(struct pci_dev *dev, unsigned int nr)
 EXPORT_SYMBOL(pci_irq_vector);
 
 /**
+ * pci_irq_vector_group - return the IRQ number of a device vector associated
+ * with a group
+ * @dev: PCI device to operate on
+ * @nr: device-relative interrupt vector index (0-based)
+ * @group_id: group from which IRQ number should be returned
+ */
+int pci_irq_vector_group(struct pci_dev *dev, unsigned int nr,
+						unsigned int group_id)
+{
+	if (dev->msix_enabled) {
+		struct msi_desc *entry;
+		int i = 0, grp_present = 0;
+
+		for_each_pci_msi_entry(entry, dev) {
+			if (entry->group_id == group_id) {
+				grp_present = 1;
+				if (i == nr)
+					return entry->irq;
+				i++;
+			}
+		}
+
+		if (!grp_present) {
+			pci_err(dev, "Group %d not present\n", group_id);
+			return -EINVAL;
+		}
+
+		pci_err(dev, "Interrupt vector index %d does not exist in "
+						"group %d\n", nr, group_id);
+	}
+
+	pci_err(dev, "MSI-X not enabled\n");
+	return -EINVAL;
+}
+EXPORT_SYMBOL(pci_irq_vector_group);
+
+/**
  * pci_irq_get_affinity - return the affinity of a particular msi vector
  * @dev:	PCI device to operate on
  * @nr:		device-relative interrupt vector index (0-based).
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 0e8e2c1..491c1cf 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2426,6 +2426,14 @@ struct pci_dev *pci_alloc_dev(struct pci_bus *bus)
 	if (!dev)
 		return NULL;
 
+	/* For dynamic MSI-x */
+	dev->grp_idr = kzalloc(sizeof(struct idr), GFP_KERNEL);
+	if (!dev->grp_idr)
+		return NULL;
+
+	/* Initialise the IDR structures */
+	idr_init(dev->grp_idr);
+
 	INIT_LIST_HEAD(&dev->bus_list);
 	dev->dev.type = &pci_dev_type;
 	dev->bus = pci_bus_get(bus);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index b9a1d41..c56462c 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1411,9 +1411,17 @@ static inline int pci_enable_msix_exact(struct pci_dev *dev,
 int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
 				   unsigned int max_vecs, unsigned int flags,
 				   struct irq_affinity *affd);
+int pci_alloc_irq_vectors_affinity_dyn(struct pci_dev *dev,
+				       unsigned int min_vecs,
+				       unsigned int max_vecs,
+				       unsigned int flags,
+				       struct irq_affinity *affd,
+				       int *group_id, bool one_shot);
 
 void pci_free_irq_vectors(struct pci_dev *dev);
 int pci_irq_vector(struct pci_dev *dev, unsigned int nr);
+int pci_irq_vector_group(struct pci_dev *dev, unsigned int nr,
+						unsigned int group_id);
 const struct cpumask *pci_irq_get_affinity(struct pci_dev *pdev, int vec);
 int pci_irq_get_node(struct pci_dev *pdev, int vec);
 
@@ -1443,6 +1451,17 @@ pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
 	return -ENOSPC;
 }
 
+static inline int
+pci_alloc_irq_vectors_affinity_dyn(struct pci_dev *dev, unsigned int min_vecs,
+				   unsigned int max_vecs, unsigned int flags,
+				   struct irq_affinity *aff_desc,
+				   int *group_id, bool one_shot)
+{
+	if ((flags & PCI_IRQ_LEGACY) && min_vecs == 1 && dev->irq)
+		return 1;
+	return -ENOSPC;
+}
+
 static inline void pci_free_irq_vectors(struct pci_dev *dev)
 {
 }
@@ -1453,6 +1472,15 @@ static inline int pci_irq_vector(struct pci_dev *dev, unsigned int nr)
 		return -EINVAL;
 	return dev->irq;
 }
+
+static inline int pci_irq_vector_group(struct pci_dev *dev, unsigned int nr,
+							unsigned int group_id)
+{
+	if (WARN_ON_ONCE(nr > 0))
+		return -EINVAL;
+	return dev->irq;
+}
+
 static inline const struct cpumask *pci_irq_get_affinity(struct pci_dev *pdev,
 		int vec)
 {
@@ -1473,6 +1501,15 @@ pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
 					      NULL);
 }
 
+static inline int
+pci_alloc_irq_vectors_dyn(struct pci_dev *dev, unsigned int min_vecs,
+			  unsigned int max_vecs, unsigned int flags,
+			  int *group_id)
+{
+	return pci_alloc_irq_vectors_affinity_dyn(dev, min_vecs, max_vecs,
+					  flags, NULL, group_id, false);
+}
+
 /**
  * pci_irqd_intx_xlate() - Translate PCI INTx value to an IRQ domain hwirq
  * @d: the INTx IRQ domain
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index ad26fbc..5cfa931 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -411,7 +411,7 @@ int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
 	if (ret)
 		return ret;
 
-	for_each_msi_entry(desc, dev) {
+	for_each_msi_entry_from(desc, dev) {
 		ops->set_desc(&arg, desc);
 
 		virq = __irq_domain_alloc_irqs(domain, -1, desc->nvec_used,
@@ -437,7 +437,7 @@ int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
 
 	can_reserve = msi_check_reservation_mode(domain, info, dev);
 
-	for_each_msi_entry(desc, dev) {
+	for_each_msi_entry_from(desc, dev) {
 		virq = desc->irq;
 		if (desc->nvec_used == 1)
 			dev_dbg(dev, "irq %d for MSI\n", virq);
@@ -465,7 +465,7 @@ int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
 	 * so request_irq() will assign the final vector.
 	 */
 	if (can_reserve) {
-		for_each_msi_entry(desc, dev) {
+		for_each_msi_entry_from(desc, dev) {
 			irq_data = irq_domain_get_irq_data(domain, desc->irq);
 			irqd_clr_activated(irq_data);
 		}
@@ -473,7 +473,7 @@ int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
 	return 0;
 
 cleanup:
-	for_each_msi_entry(desc, dev) {
+	for_each_msi_entry_from(desc, dev) {
 		struct irq_data *irqd;
 
 		if (desc->irq == virq)
