[PATCH v2 3/6] iommu: add ARM short descriptor page table allocator.

[Yong Wu <yong.wu@mediatek.com>]

This patch is for ARM Short Descriptor Format.It has 2-levels
pagetable and the allocator supports 4K/64K/1M/16M.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
 drivers/iommu/Kconfig                |   7 +
 drivers/iommu/Makefile               |   1 +
 drivers/iommu/io-pgtable-arm-short.c | 490 +++++++++++++++++++++++++++++++++++
 drivers/iommu/io-pgtable.c           |   4 +
 drivers/iommu/io-pgtable.h           |   6 +
 5 files changed, 508 insertions(+)
 create mode 100644 drivers/iommu/io-pgtable-arm-short.c

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 1ae4e54..3d2eac6 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -39,6 +39,13 @@ config IOMMU_IO_PGTABLE_LPAE_SELFTEST
 
 	  If unsure, say N here.
 
+config IOMMU_IO_PGTABLE_SHORT
+	bool "ARMv7/v8 Short Descriptor Format"
+	select IOMMU_IO_PGTABLE
+	help
+	  Enable support for the ARM Short descriptor pagetable format.
+	  It has 2-levels pagetable and The allocator supports 4K/64K/1M/16M.
+
 endmenu
 
 config IOMMU_IOVA
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 080ffab..815b3c8 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -3,6 +3,7 @@ obj-$(CONFIG_IOMMU_API) += iommu-traces.o
 obj-$(CONFIG_IOMMU_API) += iommu-sysfs.o
 obj-$(CONFIG_IOMMU_IO_PGTABLE) += io-pgtable.o
 obj-$(CONFIG_IOMMU_IO_PGTABLE_LPAE) += io-pgtable-arm.o
+obj-$(CONFIG_IOMMU_IO_PGTABLE_SHORT) += io-pgtable-arm-short.o
 obj-$(CONFIG_IOMMU_IOVA) += iova.o
 obj-$(CONFIG_OF_IOMMU)	+= of_iommu.o
 obj-$(CONFIG_MSM_IOMMU) += msm_iommu.o msm_iommu_dev.o
diff --git a/drivers/iommu/io-pgtable-arm-short.c b/drivers/iommu/io-pgtable-arm-short.c
new file mode 100644
index 0000000..cc286ce5
--- /dev/null
+++ b/drivers/iommu/io-pgtable-arm-short.c
@@ -0,0 +1,490 @@
+/*
+ * Copyright (c) 2014-2015 MediaTek Inc.
+ * Author: Yong Wu <yong.wu@mediatek.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#define pr_fmt(fmt)	"arm-short-desc io-pgtable: "fmt
+
+#include <linux/err.h>
+#include <linux/mm.h>
+#include <linux/iommu.h>
+#include <linux/errno.h>
+
+#include "io-pgtable.h"
+
+typedef u32 arm_short_iopte;
+
+struct arm_short_io_pgtable {
+	struct io_pgtable	iop;
+	struct kmem_cache	*ptekmem;
+	size_t			pgd_size;
+	void			*pgd;
+};
+
+#define io_pgtable_short_to_data(x)				\
+	container_of((x), struct arm_short_io_pgtable, iop)
+
+#define io_pgtable_ops_to_pgtable(x)				\
+	container_of((x), struct io_pgtable, ops)
+
+#define io_pgtable_short_ops_to_data(x)				\
+	io_pgtable_short_to_data(io_pgtable_ops_to_pgtable(x))
+
+#define ARM_SHORT_MAX_ADDR_BITS			32
+
+#define ARM_SHORT_PGDIR_SHIFT			20
+#define ARM_SHORT_PAGE_SHIFT			12
+#define ARM_SHORT_PTRS_PER_PTE			256
+#define ARM_SHORT_BYTES_PER_PTE			1024
+
+/* 1 level pagetable */
+#define ARM_SHORT_F_PGD_TYPE_PAGE		(0x1)
+#define ARM_SHORT_F_PGD_TYPE_PAGE_MSK		(0x3)
+#define ARM_SHORT_F_PGD_TYPE_SECTION		(0x2)
+#define ARM_SHORT_F_PGD_TYPE_SUPERSECTION	(0x2 | (1 << 18))
+#define ARM_SHORT_F_PGD_TYPE_SECTION_MSK	(0x3 | (1 << 18))
+#define ARM_SHORT_F_PGD_TYPE_IS_PAGE(pgd)	(((pgd) & 0x3) == 1)
+#define ARM_SHORT_F_PGD_TYPE_IS_SECTION(pgd)		\
+	(((pgd) & ARM_SHORT_F_PGD_TYPE_SECTION_MSK)	\
+		== ARM_SHORT_F_PGD_TYPE_SECTION)
+#define ARM_SHORT_F_PGD_TYPE_IS_SUPERSECTION(pgd)	\
+	(((pgd) & ARM_SHORT_F_PGD_TYPE_SECTION_MSK)	\
+		== ARM_SHORT_F_PGD_TYPE_SUPERSECTION)
+
+#define ARM_SHORT_F_PGD_B_BIT			BIT(2)
+#define ARM_SHORT_F_PGD_C_BIT			BIT(3)
+#define ARM_SHORT_F_PGD_IMPLE_BIT		BIT(9)
+#define ARM_SHORT_F_PGD_S_BIT			BIT(16)
+#define ARM_SHORT_F_PGD_NG_BIT			BIT(17)
+#define ARM_SHORT_F_PGD_NS_BIT_PAGE		BIT(3)
+#define ARM_SHORT_F_PGD_NS_BIT_SECTION		BIT(19)
+
+#define ARM_SHORT_F_PGD_PA_PAGETABLE_MSK	0xfffffc00
+#define ARM_SHORT_F_PGD_PA_SECTION_MSK		0xfff00000
+#define ARM_SHORT_F_PGD_PA_SUPERSECTION_MSK	0xff000000
+
+/* 2 level pagetable */
+#define ARM_SHORT_F_PTE_TYPE_GET(val)		((val) & 0x3)
+#define ARM_SHORT_F_PTE_TYPE_LARGE		BIT(0)
+#define ARM_SHORT_F_PTE_TYPE_SMALL		BIT(1)
+#define ARM_SHORT_F_PTE_B_BIT			BIT(2)
+#define ARM_SHORT_F_PTE_C_BIT			BIT(3)
+#define ARM_SHORT_F_PTE_IMPLE_BIT		BIT(9)
+#define ARM_SHORT_F_PTE_S_BIT			BIT(10)
+#define ARM_SHORT_F_PTE_PA_LARGE_MSK            0xffff0000
+#define ARM_SHORT_F_PTE_PA_SMALL_MSK            0xfffff000
+
+#define ARM_SHORT_PGD_IDX(a)			((a) >> ARM_SHORT_PGDIR_SHIFT)
+#define ARM_SHORT_PTE_IDX(a)			\
+	(((a) >> ARM_SHORT_PAGE_SHIFT) & 0xff)
+#define ARM_SHORT_GET_PTE_VA(pgd)		\
+	(phys_to_virt((unsigned long)pgd & ARM_SHORT_F_PGD_PA_PAGETABLE_MSK))
+
+static arm_short_iopte *
+arm_short_get_pte_in_pgd(arm_short_iopte curpgd, unsigned int iova)
+{
+	arm_short_iopte *pte;
+
+	pte = ARM_SHORT_GET_PTE_VA(curpgd);
+	pte += ARM_SHORT_PTE_IDX(iova);
+	return pte;
+}
+
+static arm_short_iopte *
+arm_short_supersection_start(arm_short_iopte *pgd)
+{
+	return (arm_short_iopte *)(round_down((unsigned long)pgd, (16 * 4)));
+}
+
+static int _arm_short_check_free_pte(struct arm_short_io_pgtable *data,
+				     arm_short_iopte *pgd)
+{
+	arm_short_iopte *pte;
+	int i;
+
+	pte = ARM_SHORT_GET_PTE_VA(*pgd);
+
+	for (i = 0; i < ARM_SHORT_PTRS_PER_PTE; i++) {
+		if (pte[i] != 0)
+			return 1;
+	}
+
+	/* Free PTE */
+	kmem_cache_free(data->ptekmem, pte);
+	*pgd = 0;
+
+	return 0;
+}
+
+static phys_addr_t arm_short_iova_to_phys(struct io_pgtable_ops *ops,
+					  unsigned long iova)
+{
+	struct arm_short_io_pgtable *data = io_pgtable_short_ops_to_data(ops);
+	arm_short_iopte *pte, *pgd = data->pgd;
+	phys_addr_t pa = 0;
+
+	pgd += ARM_SHORT_PGD_IDX(iova);
+
+	if (ARM_SHORT_F_PGD_TYPE_IS_PAGE(*pgd)) {
+		u8 pte_type;
+
+		pte = arm_short_get_pte_in_pgd(*pgd, iova);
+		pte_type = ARM_SHORT_F_PTE_TYPE_GET(*pte);
+
+		if (pte_type == ARM_SHORT_F_PTE_TYPE_LARGE) {
+			pa = (*pte) & ARM_SHORT_F_PTE_PA_LARGE_MSK;
+			pa |= iova & (~ARM_SHORT_F_PTE_PA_LARGE_MSK);
+		} else if (pte_type == ARM_SHORT_F_PTE_TYPE_SMALL) {
+			pa = (*pte) & ARM_SHORT_F_PTE_PA_SMALL_MSK;
+			pa |= iova & (~ARM_SHORT_F_PTE_PA_SMALL_MSK);
+		}
+	} else {
+		if (ARM_SHORT_F_PGD_TYPE_IS_SECTION(*pgd)) {
+			pa = (*pgd) & ARM_SHORT_F_PGD_PA_SECTION_MSK;
+			pa |= iova & (~ARM_SHORT_F_PGD_PA_SECTION_MSK);
+		} else if (ARM_SHORT_F_PGD_TYPE_IS_SUPERSECTION(*pgd)) {
+			pa = (*pgd) & ARM_SHORT_F_PGD_PA_SUPERSECTION_MSK;
+			pa |= iova & (~ARM_SHORT_F_PGD_PA_SUPERSECTION_MSK);
+		}
+	}
+
+	return pa;
+}
+
+static int arm_short_unmap(struct io_pgtable_ops *ops, unsigned long iova,
+			   size_t size)
+{
+	struct arm_short_io_pgtable *data = io_pgtable_short_ops_to_data(ops);
+	arm_short_iopte *pgd;
+	unsigned long iova_start = iova;
+	unsigned long long end_plus_1 = iova + size;
+	const struct iommu_gather_ops *tlb = data->iop.cfg.tlb;
+	void *cookie = data->iop.cookie;
+	int ret;
+
+	do {
+		pgd = (arm_short_iopte *)data->pgd + ARM_SHORT_PGD_IDX(iova);
+
+		if (ARM_SHORT_F_PGD_TYPE_IS_PAGE(*pgd)) {
+			arm_short_iopte *pte;
+			unsigned int pte_offset;
+			unsigned int num_to_clean;
+
+			pte_offset = ARM_SHORT_PTE_IDX(iova);
+			num_to_clean =
+			    min((unsigned int)((end_plus_1 - iova) / PAGE_SIZE),
+				(ARM_SHORT_PTRS_PER_PTE - pte_offset));
+
+			pte = arm_short_get_pte_in_pgd(*pgd, iova);
+
+			memset(pte, 0, num_to_clean * sizeof(arm_short_iopte));
+
+			ret = _arm_short_check_free_pte(data, pgd);
+			if (ret == 1)/* pte is not freed, need to flush pte */
+				tlb->flush_pgtable(
+					pte,
+					num_to_clean * sizeof(arm_short_iopte),
+					cookie);
+			else
+				tlb->flush_pgtable(pgd, sizeof(arm_short_iopte),
+						   cookie);
+
+			iova += num_to_clean << PAGE_SHIFT;
+		} else if (ARM_SHORT_F_PGD_TYPE_IS_SECTION(*pgd)) {
+			*pgd = 0;
+
+			tlb->flush_pgtable(pgd, sizeof(arm_short_iopte),
+					   cookie);
+			iova += SZ_1M;
+		} else if (ARM_SHORT_F_PGD_TYPE_IS_SUPERSECTION(*pgd)) {
+			arm_short_iopte *start;
+
+			start = arm_short_supersection_start(pgd);
+			if (unlikely(start != pgd))
+				pr_warn("%s:suppersection start isn't aligned.iova=0x%lx,pgd=0x%x\n",
+					__func__, iova, *pgd);
+
+			memset(start, 0, 16 * sizeof(arm_short_iopte));
+
+			tlb->flush_pgtable(start, 16 * sizeof(arm_short_iopte),
+					   cookie);
+
+			iova = (iova + SZ_16M) & (~(SZ_16M - 1));
+		} else {
+			break;
+		}
+	} while (iova < end_plus_1 && iova);
+
+	tlb->tlb_add_flush(iova_start, size, true, cookie);
+
+	return 0;
+}
+
+static arm_short_iopte __arm_short_pte_port(unsigned int prot, bool large)
+{
+	arm_short_iopte pteprot;
+
+	pteprot = ARM_SHORT_F_PTE_S_BIT;
+
+	pteprot |= large ? ARM_SHORT_F_PTE_TYPE_LARGE :
+				ARM_SHORT_F_PTE_TYPE_SMALL;
+
+	if (prot & IOMMU_CACHE)
+		pteprot |=  ARM_SHORT_F_PTE_B_BIT | ARM_SHORT_F_PTE_C_BIT;
+
+	return pteprot;
+}
+
+static arm_short_iopte __arm_short_pgd_port(int prot, bool super)
+{
+	arm_short_iopte pgdprot;
+
+	pgdprot = ARM_SHORT_F_PGD_S_BIT;
+	pgdprot |= super ? ARM_SHORT_F_PGD_TYPE_SUPERSECTION :
+				ARM_SHORT_F_PGD_TYPE_SECTION;
+	if (prot & IOMMU_CACHE)
+		pgdprot |= ARM_SHORT_F_PGD_C_BIT | ARM_SHORT_F_PGD_B_BIT;
+
+	return pgdprot;
+}
+
+static int _arm_short_map_page(struct arm_short_io_pgtable *data,
+			       unsigned int iova, phys_addr_t pa,
+			       unsigned int prot, bool largepage)
+{
+	arm_short_iopte *pgd = data->pgd;
+	arm_short_iopte *pte;
+	arm_short_iopte pgdprot, pteprot;
+	arm_short_iopte mask = largepage ? ARM_SHORT_F_PTE_PA_LARGE_MSK :
+						ARM_SHORT_F_PTE_PA_SMALL_MSK;
+	int i, ptenum = largepage ? 16 : 1;
+	bool ptenew = false;
+	void *pte_new_va;
+	void *cookie = data->iop.cookie;
+
+	if ((iova | pa) & (~mask)) {
+		pr_err("IOVA|PA Not Aligned(iova=0x%x pa=0x%pa type=%s)\n",
+		       iova, &pa, largepage ? "large page" : "small page");
+		return -EINVAL;
+	}
+
+	pgdprot = ARM_SHORT_F_PGD_TYPE_PAGE;
+	if (data->iop.cfg.quirks & IO_PGTABLE_QUIRK_ARM_NS)
+		pgdprot |= ARM_SHORT_F_PGD_NS_BIT_PAGE;
+
+	pgd += ARM_SHORT_PGD_IDX(iova);
+
+	if (!(*pgd)) {
+		pte_new_va = kmem_cache_zalloc(data->ptekmem, GFP_KERNEL);
+		if (unlikely(!pte_new_va)) {
+			pr_err("Failed to alloc pte\n");
+			return -ENOMEM;
+		}
+
+		/* Check pte alignment -- must 1K align */
+		if (unlikely((unsigned long)pte_new_va &
+			     (ARM_SHORT_BYTES_PER_PTE - 1))) {
+			pr_err("The new pte is not aligned! (va=0x%p)\n",
+			       pte_new_va);
+			kmem_cache_free(data->ptekmem, (void *)pte_new_va);
+			return -ENOMEM;
+		}
+		ptenew = true;
+		*pgd = virt_to_phys(pte_new_va) | pgdprot;
+		kmemleak_ignore(pte_new_va);
+		data->iop.cfg.tlb->flush_pgtable(pgd, sizeof(arm_short_iopte),
+						 cookie);
+	} else {
+		/* Someone else may have allocated for this pgd */
+		if (((*pgd) & (~ARM_SHORT_F_PGD_PA_PAGETABLE_MSK)) != pgdprot) {
+			pr_err("The prot of old pgd is not Right!iova=0x%x pgd=0x%x pgprot=0x%x\n",
+			       iova, (*pgd), pgdprot);
+			return -EEXIST;
+		}
+	}
+
+	pteprot = (arm_short_iopte)pa;
+	pteprot |= __arm_short_pte_port(prot, largepage);
+
+	pte = arm_short_get_pte_in_pgd(*pgd, iova);
+
+	pr_debug("iova:0x%x,pte:0x%p(0x%x),prot:0x%x-%s\n",
+		 iova, pte, ARM_SHORT_PTE_IDX(iova), pteprot,
+		 largepage ? "large page" : "small page");
+
+	for (i = 0; i < ptenum; i++) {
+		if (pte[i]) {
+			pr_err("The To-Map pte exists!(iova=0x%x pte=0x%x i=%d)\n",
+			       iova, pte[i], i);
+			goto err_out;
+		}
+		pte[i] = pteprot;
+	}
+
+	data->iop.cfg.tlb->flush_pgtable(pte, ptenum * sizeof(arm_short_iopte),
+					 cookie);
+	return 0;
+
+ err_out:
+	for (i--; i >= 0; i--)
+		pte[i] = 0;
+	if (ptenew)
+		kmem_cache_free(data->ptekmem, pte_new_va);
+	return -EEXIST;
+}
+
+static int _arm_short_map_section(struct arm_short_io_pgtable *data,
+				  unsigned int iova, phys_addr_t pa,
+				  int prot, bool supersection)
+{
+	arm_short_iopte pgprot;
+	arm_short_iopte mask = supersection ?
+				ARM_SHORT_F_PGD_PA_SUPERSECTION_MSK :
+				ARM_SHORT_F_PGD_PA_SECTION_MSK;
+	arm_short_iopte *pgd = data->pgd;
+	int i;
+	unsigned int pgdnum = supersection ? 16 : 1;
+
+	if ((iova | pa) & (~mask)) {
+		pr_err("IOVA|PA Not Aligned(iova=0x%x pa=0x%pa type=%s)\n",
+		       iova, &pa, supersection ? "supersection" : "section");
+		return -EINVAL;
+	}
+
+	pgprot = (arm_short_iopte)pa;
+
+	if (data->iop.cfg.quirks & IO_PGTABLE_QUIRK_ARM_NS)
+		pgprot |= ARM_SHORT_F_PGD_NS_BIT_SECTION;
+
+	pgprot |= __arm_short_pgd_port(prot, supersection);
+
+	pgd += ARM_SHORT_PGD_IDX(iova);
+
+	pr_debug("iova:0x%x,pgd:0x%p(0x%p+0x%x),value:0x%x-%s\n",
+		 iova, pgd, data->pgd, ARM_SHORT_PGD_IDX(iova),
+		 pgprot, supersection ? "supersection" : "section");
+
+	for (i = 0; i < pgdnum; i++) {
+		if (unlikely(*pgd)) {
+			pr_err("The To-Map pdg exists!(iova=0x%x pgd=0x%x i=%d)\n",
+			       iova, pgd[i], i);
+			goto err_out;
+		}
+		pgd[i] = pgprot;
+	}
+	data->iop.cfg.tlb->flush_pgtable(pgd,
+					 pgdnum * sizeof(arm_short_iopte),
+					 data->iop.cookie);
+	return 0;
+
+ err_out:
+	for (i--; i >= 0; i--)
+		pgd[i] = 0;
+	return -EEXIST;
+}
+
+static int arm_short_map(struct io_pgtable_ops *ops, unsigned long iova,
+			 phys_addr_t paddr, size_t size, int prot)
+{
+	struct arm_short_io_pgtable *data = io_pgtable_short_ops_to_data(ops);
+	const struct iommu_gather_ops *tlb = data->iop.cfg.tlb;
+	int ret;
+
+	if (!(prot & (IOMMU_READ | IOMMU_WRITE)))
+		return -EINVAL;
+
+	if (size == SZ_4K) {/* most case */
+		ret = _arm_short_map_page(data, iova, paddr, prot, false);
+	} else if (size == SZ_64K) {
+		ret = _arm_short_map_page(data, iova, paddr, prot, true);
+	} else if (size == SZ_1M) {
+		ret = _arm_short_map_section(data, iova, paddr, prot, false);
+	} else if (size == SZ_16M) {
+		ret = _arm_short_map_section(data, iova, paddr, prot, true);
+	} else {
+		ret = -EINVAL;
+	}
+	tlb->tlb_add_flush(iova, size, true, data->iop.cookie);
+	return ret;
+}
+
+static struct io_pgtable *
+arm_short_alloc_pgtable(struct io_pgtable_cfg *cfg, void *cookie)
+{
+	struct arm_short_io_pgtable *data;
+
+	if (cfg->ias != 32)
+		return NULL;
+
+	if (cfg->oas > ARM_SHORT_MAX_ADDR_BITS)
+		return NULL;
+
+	cfg->pgsize_bitmap &= SZ_4K | SZ_64K | SZ_1M | SZ_16M;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return NULL;
+
+	data->pgd_size = SZ_16K;
+
+	data->pgd = alloc_pages_exact(data->pgd_size, GFP_KERNEL | __GFP_ZERO);
+	if (!data->pgd)
+		goto out_free_data;
+
+	cfg->tlb->flush_pgtable(data->pgd, data->pgd_size, cookie);
+
+	/* kmem for pte */
+	data->ptekmem = kmem_cache_create("short-descriptor-pte",
+					   ARM_SHORT_BYTES_PER_PTE,
+					   ARM_SHORT_BYTES_PER_PTE,
+					   0, NULL);
+
+	if (IS_ERR_OR_NULL(data->ptekmem)) {
+		pr_err("Failed to Create cached mem for PTE %ld\n",
+		       PTR_ERR(data->ptekmem));
+		goto out_free_pte;
+	}
+
+	/* TTBRs */
+	cfg->arm_short_cfg.ttbr[0] = virt_to_phys(data->pgd);
+	cfg->arm_short_cfg.ttbr[1] = 0;
+
+	cfg->arm_short_cfg.tcr = 0;
+
+	data->iop.ops = (struct io_pgtable_ops) {
+		.map		= arm_short_map,
+		.unmap		= arm_short_unmap,
+		.iova_to_phys	= arm_short_iova_to_phys,
+	};
+
+	return &data->iop;
+
+out_free_pte:
+	free_pages_exact(data->pgd, data->pgd_size);
+out_free_data:
+	kfree(data);
+	return NULL;
+}
+
+static void arm_short_free_pgtable(struct io_pgtable *iop)
+{
+	struct arm_short_io_pgtable *data = io_pgtable_short_to_data(iop);
+
+	kmem_cache_destroy(data->ptekmem);
+	free_pages_exact(data->pgd, data->pgd_size);
+	kfree(data);
+}
+
+struct io_pgtable_init_fns io_pgtable_arm_short_init_fns = {
+	.alloc	= arm_short_alloc_pgtable,
+	.free	= arm_short_free_pgtable,
+};
+
diff --git a/drivers/iommu/io-pgtable.c b/drivers/iommu/io-pgtable.c
index 6436fe2..14a9b3a 100644
--- a/drivers/iommu/io-pgtable.c
+++ b/drivers/iommu/io-pgtable.c
@@ -28,6 +28,7 @@ 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_short_init_fns;
 
 static const struct io_pgtable_init_fns *
 io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] =
@@ -38,6 +39,9 @@ io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] =
 	[ARM_64_LPAE_S1] = &io_pgtable_arm_64_lpae_s1_init_fns,
 	[ARM_64_LPAE_S2] = &io_pgtable_arm_64_lpae_s2_init_fns,
 #endif
+#ifdef CONFIG_IOMMU_IO_PGTABLE_SHORT
+	[ARM_SHORT_DESC] = &io_pgtable_arm_short_init_fns,
+#endif
 };
 
 struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
diff --git a/drivers/iommu/io-pgtable.h b/drivers/iommu/io-pgtable.h
index 10e32f6..47efaab 100644
--- a/drivers/iommu/io-pgtable.h
+++ b/drivers/iommu/io-pgtable.h
@@ -9,6 +9,7 @@ enum io_pgtable_fmt {
 	ARM_32_LPAE_S2,
 	ARM_64_LPAE_S1,
 	ARM_64_LPAE_S2,
+	ARM_SHORT_DESC,
 	IO_PGTABLE_NUM_FMTS,
 };
 
@@ -62,6 +63,11 @@ struct io_pgtable_cfg {
 			u64	vttbr;
 			u64	vtcr;
 		} arm_lpae_s2_cfg;
+
+		struct {
+			u64	ttbr[2];
+			u64	tcr;
+		} arm_short_cfg;
 	};
 };
 
-- 
1.8.1.1.dirty