Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
new file mode 100644
index 0000000..ec7a134
--- /dev/null
+++ b/include/linux/io-pgtable.h
@@ -0,0 +1,239 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __IO_PGTABLE_H
+#define __IO_PGTABLE_H
+
+#include <linux/bitops.h>
+#include <linux/iommu.h>
+
+/*
+ * Public API for use by IOMMU drivers
+ */
+enum io_pgtable_fmt {
+	ARM_32_LPAE_S1,
+	ARM_32_LPAE_S2,
+	ARM_64_LPAE_S1,
+	ARM_64_LPAE_S2,
+	ARM_V7S,
+	ARM_MALI_LPAE,
+	IO_PGTABLE_NUM_FMTS,
+};
+
+/**
+ * struct iommu_flush_ops - IOMMU callbacks for TLB and page table management.
+ *
+ * @tlb_flush_all:  Synchronously invalidate the entire TLB context.
+ * @tlb_flush_walk: Synchronously invalidate all intermediate TLB state
+ *                  (sometimes referred to as the "walk cache") for a virtual
+ *                  address range.
+ * @tlb_flush_leaf: Synchronously invalidate all leaf TLB state for a virtual
+ *                  address range.
+ * @tlb_add_page:   Optional callback to queue up leaf TLB invalidation for a
+ *                  single page.  IOMMUs that cannot batch TLB invalidation
+ *                  operations efficiently will typically issue them here, but
+ *                  others may decide to update the iommu_iotlb_gather structure
+ *                  and defer the invalidation until iommu_tlb_sync() instead.
+ *
+ * Note that these can all be called in atomic context and must therefore
+ * not block.
+ */
+struct iommu_flush_ops {
+	void (*tlb_flush_all)(void *cookie);
+	void (*tlb_flush_walk)(unsigned long iova, size_t size, size_t granule,
+			       void *cookie);
+	void (*tlb_flush_leaf)(unsigned long iova, size_t size, size_t granule,
+			       void *cookie);
+	void (*tlb_add_page)(struct iommu_iotlb_gather *gather,
+			     unsigned long iova, size_t granule, void *cookie);
+};
+
+/**
+ * struct io_pgtable_cfg - Configuration data for a set of page tables.
+ *
+ * @quirks:        A bitmap of hardware quirks that require some special
+ *                 action by the low-level page table allocator.
+ * @pgsize_bitmap: A bitmap of page sizes supported by this set of page
+ *                 tables.
+ * @ias:           Input address (iova) size, in bits.
+ * @oas:           Output address (paddr) size, in bits.
+ * @coherent_walk  A flag to indicate whether or not page table walks made
+ *                 by the IOMMU are coherent with the CPU caches.
+ * @tlb:           TLB management callbacks for this set of tables.
+ * @iommu_dev:     The device representing the DMA configuration for the
+ *                 page table walker.
+ */
+struct io_pgtable_cfg {
+	/*
+	 * IO_PGTABLE_QUIRK_ARM_NS: (ARM formats) Set NS and NSTABLE bits in
+	 *	stage 1 PTEs, for hardware which insists on validating them
+	 *	even in	non-secure state where they should normally be ignored.
+	 *
+	 * IO_PGTABLE_QUIRK_NO_PERMS: Ignore the IOMMU_READ, IOMMU_WRITE and
+	 *	IOMMU_NOEXEC flags and map everything with full access, for
+	 *	hardware which does not implement the permissions of a given
+	 *	format, and/or requires some format-specific default value.
+	 *
+	 * IO_PGTABLE_QUIRK_TLBI_ON_MAP: If the format forbids caching invalid
+	 *	(unmapped) entries but the hardware might do so anyway, perform
+	 *	TLB maintenance when mapping as well as when unmapping.
+	 *
+	 * IO_PGTABLE_QUIRK_ARM_MTK_EXT: (ARM v7s format) MediaTek IOMMUs extend
+	 *	to support up to 34 bits PA where the bit32 and bit33 are
+	 *	encoded in the bit9 and bit4 of the PTE respectively.
+	 *
+	 * IO_PGTABLE_QUIRK_NON_STRICT: Skip issuing synchronous leaf TLBIs
+	 *	on unmap, for DMA domains using the flush queue mechanism for
+	 *	delayed invalidation.
+	 */
+	#define IO_PGTABLE_QUIRK_ARM_NS		BIT(0)
+	#define IO_PGTABLE_QUIRK_NO_PERMS	BIT(1)
+	#define IO_PGTABLE_QUIRK_TLBI_ON_MAP	BIT(2)
+	#define IO_PGTABLE_QUIRK_ARM_MTK_EXT	BIT(3)
+	#define IO_PGTABLE_QUIRK_NON_STRICT	BIT(4)
+	unsigned long			quirks;
+	unsigned long			pgsize_bitmap;
+	unsigned int			ias;
+	unsigned int			oas;
+	bool				coherent_walk;
+	const struct iommu_flush_ops	*tlb;
+	struct device			*iommu_dev;
+
+	/* Low-level data specific to the table format */
+	union {
+		struct {
+			u64	ttbr[2];
+			u64	tcr;
+			u64	mair[2];
+		} arm_lpae_s1_cfg;
+
+		struct {
+			u64	vttbr;
+			u64	vtcr;
+		} arm_lpae_s2_cfg;
+
+		struct {
+			u32	ttbr[2];
+			u32	tcr;
+			u32	nmrr;
+			u32	prrr;
+		} arm_v7s_cfg;
+
+		struct {
+			u64	transtab;
+			u64	memattr;
+		} arm_mali_lpae_cfg;
+	};
+};
+
+/**
+ * struct io_pgtable_ops - Page table manipulation API for IOMMU drivers.
+ *
+ * @map:          Map a physically contiguous memory region.
+ * @unmap:        Unmap a physically contiguous memory region.
+ * @iova_to_phys: Translate iova to physical address.
+ *
+ * These functions map directly onto the iommu_ops member functions with
+ * the same names.
+ */
+struct io_pgtable_ops {
+	int (*map)(struct io_pgtable_ops *ops, unsigned long iova,
+		   phys_addr_t paddr, size_t size, int prot);
+	size_t (*unmap)(struct io_pgtable_ops *ops, unsigned long iova,
+			size_t size, struct iommu_iotlb_gather *gather);
+	phys_addr_t (*iova_to_phys)(struct io_pgtable_ops *ops,
+				    unsigned long iova);
+};
+
+/**
+ * alloc_io_pgtable_ops() - Allocate a page table allocator for use by an IOMMU.
+ *
+ * @fmt:    The page table format.
+ * @cfg:    The page table configuration. This will be modified to represent
+ *          the configuration actually provided by the allocator (e.g. the
+ *          pgsize_bitmap may be restricted).
+ * @cookie: An opaque token provided by the IOMMU driver and passed back to
+ *          the callback routines in cfg->tlb.
+ */
+struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
+					    struct io_pgtable_cfg *cfg,
+					    void *cookie);
+
+/**
+ * free_io_pgtable_ops() - Free an io_pgtable_ops structure. The caller
+ *                         *must* ensure that the page table is no longer
+ *                         live, but the TLB can be dirty.
+ *
+ * @ops: The ops returned from alloc_io_pgtable_ops.
+ */
+void free_io_pgtable_ops(struct io_pgtable_ops *ops);
+
+
+/*
+ * Internal structures for page table allocator implementations.
+ */
+
+/**
+ * struct io_pgtable - Internal structure describing a set of page tables.
+ *
+ * @fmt:    The page table format.
+ * @cookie: An opaque token provided by the IOMMU driver and passed back to
+ *          any callback routines.
+ * @cfg:    A copy of the page table configuration.
+ * @ops:    The page table operations in use for this set of page tables.
+ */
+struct io_pgtable {
+	enum io_pgtable_fmt	fmt;
+	void			*cookie;
+	struct io_pgtable_cfg	cfg;
+	struct io_pgtable_ops	ops;
+};
+
+#define io_pgtable_ops_to_pgtable(x) container_of((x), struct io_pgtable, ops)
+
+static inline void io_pgtable_tlb_flush_all(struct io_pgtable *iop)
+{
+	iop->cfg.tlb->tlb_flush_all(iop->cookie);
+}
+
+static inline void
+io_pgtable_tlb_flush_walk(struct io_pgtable *iop, unsigned long iova,
+			  size_t size, size_t granule)
+{
+	iop->cfg.tlb->tlb_flush_walk(iova, size, granule, iop->cookie);
+}
+
+static inline void
+io_pgtable_tlb_flush_leaf(struct io_pgtable *iop, unsigned long iova,
+			  size_t size, size_t granule)
+{
+	iop->cfg.tlb->tlb_flush_leaf(iova, size, granule, iop->cookie);
+}
+
+static inline void
+io_pgtable_tlb_add_page(struct io_pgtable *iop,
+			struct iommu_iotlb_gather * gather, unsigned long iova,
+			size_t granule)
+{
+	if (iop->cfg.tlb->tlb_add_page)
+		iop->cfg.tlb->tlb_add_page(gather, iova, granule, iop->cookie);
+}
+
+/**
+ * struct io_pgtable_init_fns - Alloc/free a set of page tables for a
+ *                              particular format.
+ *
+ * @alloc: Allocate a set of page tables described by cfg.
+ * @free:  Free the page tables associated with iop.
+ */
+struct io_pgtable_init_fns {
+	struct io_pgtable *(*alloc)(struct io_pgtable_cfg *cfg, void *cookie);
+	void (*free)(struct io_pgtable *iop);
+};
+
+extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns;
+extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns;
+extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns;
+extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns;
+extern struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns;
+extern struct io_pgtable_init_fns io_pgtable_arm_mali_lpae_init_fns;
+
+#endif /* __IO_PGTABLE_H */