Merge tag 'for-linus-5.19a-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from Juergen Gross:

 - a small cleanup removing "export" of an __init function

 - a small series adding a new infrastructure for platform flags

 - a series adding generic virtio support for Xen guests (frontend side)

* tag 'for-linus-5.19a-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: unexport __init-annotated xen_xlate_map_ballooned_pages()
  arm/xen: Assign xen-grant DMA ops for xen-grant DMA devices
  xen/grant-dma-ops: Retrieve the ID of backend's domain for DT devices
  xen/grant-dma-iommu: Introduce stub IOMMU driver
  dt-bindings: Add xen,grant-dma IOMMU description for xen-grant DMA ops
  xen/virtio: Enable restricted memory access using Xen grant mappings
  xen/grant-dma-ops: Add option to restrict memory access under Xen
  xen/grants: support allocating consecutive grants
  arm/xen: Introduce xen_setup_dma_ops()
  virtio: replace arch_has_restricted_virtio_memory_access()
  kernel: add platform_has() infrastructure

8 files changed, 71 insertions, 9 deletions

diff --git a/include/asm-generic/Kbuild b/include/asm-generic/Kbuild
index 302506bbc2a4..8e47d483b524 100644
--- a/include/asm-generic/Kbuild
+++ b/include/asm-generic/Kbuild
@@ -44,6 +44,7 @@ mandatory-y += msi.h
 mandatory-y += pci.h
 mandatory-y += percpu.h
 mandatory-y += pgalloc.h
+mandatory-y += platform-feature.h
 mandatory-y += preempt.h
 mandatory-y += rwonce.h
 mandatory-y += sections.h
diff --git a/include/asm-generic/platform-feature.h b/include/asm-generic/platform-feature.h
new file mode 100644
index 000000000000..4b0af3d51588
--- /dev/null
+++ b/include/asm-generic/platform-feature.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_GENERIC_PLATFORM_FEATURE_H
+#define _ASM_GENERIC_PLATFORM_FEATURE_H
+
+/* Number of arch specific feature flags. */
+#define PLATFORM_ARCH_FEAT_N	0
+
+#endif /* _ASM_GENERIC_PLATFORM_FEATURE_H */
diff --git a/include/linux/platform-feature.h b/include/linux/platform-feature.h
new file mode 100644
index 000000000000..b2f48be999fa
--- /dev/null
+++ b/include/linux/platform-feature.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _PLATFORM_FEATURE_H
+#define _PLATFORM_FEATURE_H
+
+#include <linux/bitops.h>
+#include <asm/platform-feature.h>
+
+/* The platform features are starting with the architecture specific ones. */
+
+/* Used to enable platform specific DMA handling for virtio devices. */
+#define PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS	(0 + PLATFORM_ARCH_FEAT_N)
+
+#define PLATFORM_FEAT_N				(1 + PLATFORM_ARCH_FEAT_N)
+
+void platform_set(unsigned int feature);
+void platform_clear(unsigned int feature);
+bool platform_has(unsigned int feature);
+
+#endif /* _PLATFORM_FEATURE_H */
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 9a36051ceb76..49c7c32815f1 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -604,13 +604,4 @@ static inline void virtio_cwrite64(struct virtio_device *vdev,
 		_r;							\
 	})
 
-#ifdef CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
-int arch_has_restricted_virtio_memory_access(void);
-#else
-static inline int arch_has_restricted_virtio_memory_access(void)
-{
-	return 0;
-}
-#endif /* CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS */
-
 #endif /* _LINUX_VIRTIO_CONFIG_H */
diff --git a/include/xen/arm/xen-ops.h b/include/xen/arm/xen-ops.h
new file mode 100644
index 000000000000..b0766a660338
--- /dev/null
+++ b/include/xen/arm/xen-ops.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_ARM_XEN_OPS_H
+#define _ASM_ARM_XEN_OPS_H
+
+#include <xen/swiotlb-xen.h>
+#include <xen/xen-ops.h>
+
+static inline void xen_setup_dma_ops(struct device *dev)
+{
+#ifdef CONFIG_XEN
+	if (xen_is_grant_dma_device(dev))
+		xen_grant_setup_dma_ops(dev);
+	else if (xen_swiotlb_detect())
+		dev->dma_ops = &xen_swiotlb_dma_ops;
+#endif
+}
+
+#endif /* _ASM_ARM_XEN_OPS_H */
diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h
index 527c9907f99c..e279be353e3f 100644
--- a/include/xen/grant_table.h
+++ b/include/xen/grant_table.h
@@ -127,10 +127,14 @@ int gnttab_try_end_foreign_access(grant_ref_t ref);
  */
 int gnttab_alloc_grant_references(u16 count, grant_ref_t *pprivate_head);
 
+int gnttab_alloc_grant_reference_seq(unsigned int count, grant_ref_t *first);
+
 void gnttab_free_grant_reference(grant_ref_t ref);
 
 void gnttab_free_grant_references(grant_ref_t head);
 
+void gnttab_free_grant_reference_seq(grant_ref_t head, unsigned int count);
+
 int gnttab_empty_grant_references(const grant_ref_t *pprivate_head);
 
 int gnttab_claim_grant_reference(grant_ref_t *pprivate_head);
diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h
index c7c1b46ff4cd..80546960f8b7 100644
--- a/include/xen/xen-ops.h
+++ b/include/xen/xen-ops.h
@@ -214,4 +214,17 @@ static inline void xen_preemptible_hcall_end(void) { }
 
 #endif /* CONFIG_XEN_PV && !CONFIG_PREEMPTION */
 
+#ifdef CONFIG_XEN_GRANT_DMA_OPS
+void xen_grant_setup_dma_ops(struct device *dev);
+bool xen_is_grant_dma_device(struct device *dev);
+#else
+static inline void xen_grant_setup_dma_ops(struct device *dev)
+{
+}
+static inline bool xen_is_grant_dma_device(struct device *dev)
+{
+	return false;
+}
+#endif /* CONFIG_XEN_GRANT_DMA_OPS */
+
 #endif /* INCLUDE_XEN_OPS_H */
diff --git a/include/xen/xen.h b/include/xen/xen.h
index a99bab817523..0780a81e140d 100644
--- a/include/xen/xen.h
+++ b/include/xen/xen.h
@@ -52,6 +52,14 @@ bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
 extern u64 xen_saved_max_mem_size;
 #endif
 
+#include <linux/platform-feature.h>
+
+static inline void xen_set_restricted_virtio_memory_access(void)
+{
+	if (IS_ENABLED(CONFIG_XEN_VIRTIO) && xen_domain())
+		platform_set(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS);
+}
+
 #ifdef CONFIG_XEN_UNPOPULATED_ALLOC
 int xen_alloc_unpopulated_pages(unsigned int nr_pages, struct page **pages);
 void xen_free_unpopulated_pages(unsigned int nr_pages, struct page **pages);