genirq/msi: Add a new field in msi_desc to store an IOMMU cookie (aaebdf8d) · Commits · 戴 / test

When an MSI doorbell is located downstream of an IOMMU, it is required to swizzle the physical address with an appropriately-mapped IOVA for any device attached to one of our DMA ops domain. At the moment, the allocation of the mapping may be done when composing the message. However, the composing may be done in non-preemtible context while the allocation requires to be called from preemptible context. A follow-up change will split the current logic in two functions requiring to keep an IOMMU cookie per MSI. A new field is introduced in msi_desc to store an IOMMU cookie. As the cookie may not be required in some configuration, the field is protected under a new config CONFIG_IRQ_MSI_IOMMU. A pair of helpers has also been introduced to access the field. Signed-off-by:

Julien Grall <julien.grall@arm.com> Reviewed-by:

Robin Murphy <robin.murphy@arm.com> Reviewed-by:

Eric Auger <eric.auger@redhat.com> Signed-off-by:

Marc Zyngier <marc.zyngier@arm.com>

include/linux/msi.h

+26 −0

Original line number	Diff line number	Diff line
		@@ -86,6 +86,9 @@ struct msi_desc {
		struct device *dev;
		struct msi_msg msg;
		struct irq_affinity_desc *affinity;
		#ifdef CONFIG_IRQ_MSI_IOMMU
		const void *iommu_cookie;
		#endif

		union {
		/* PCI MSI/X specific data */
		@@ -129,6 +132,29 @@ struct msi_desc {
		#define for_each_msi_entry_safe(desc, tmp, dev) \
		list_for_each_entry_safe((desc), (tmp), dev_to_msi_list((dev)), list)

		#ifdef CONFIG_IRQ_MSI_IOMMU
		static inline const void msi_desc_get_iommu_cookie(struct msi_desc desc)
		{
		return desc->iommu_cookie;
		}

		static inline void msi_desc_set_iommu_cookie(struct msi_desc *desc,
		const void *iommu_cookie)
		{
		desc->iommu_cookie = iommu_cookie;
		}
		#else
		static inline const void msi_desc_get_iommu_cookie(struct msi_desc desc)
		{
		return NULL;
		}

		static inline void msi_desc_set_iommu_cookie(struct msi_desc *desc,
		const void *iommu_cookie)
		{
		}
		#endif

		#ifdef CONFIG_PCI_MSI
		#define first_pci_msi_entry(pdev) first_msi_entry(&(pdev)->dev)
		#define for_each_pci_msi_entry(desc, pdev) \

kernel/irq/Kconfig

+3 −0

Original line number	Diff line number	Diff line
		@@ -91,6 +91,9 @@ config GENERIC_MSI_IRQ_DOMAIN
		select IRQ_DOMAIN_HIERARCHY
		select GENERIC_MSI_IRQ

		config IRQ_MSI_IOMMU
		bool

		config HANDLE_DOMAIN_IRQ
		bool

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