drivers/iommu/io-pgtable-fast.c

/* Copyright (c) 2016-2017, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only 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)	"io-pgtable-fast: " fmt

#include <linux/iommu.h>
#include <linux/kernel.h>
#include <linux/scatterlist.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/io-pgtable-fast.h>
#include <asm/cacheflush.h>

#include "io-pgtable.h"

#define AV8L_FAST_MAX_ADDR_BITS		48

/* Struct accessors */
#define iof_pgtable_to_data(x)						\
	container_of((x), struct av8l_fast_io_pgtable, iop)

#define iof_pgtable_ops_to_pgtable(x)					\
	container_of((x), struct io_pgtable, ops)

#define iof_pgtable_ops_to_data(x)					\
	iof_pgtable_to_data(iof_pgtable_ops_to_pgtable(x))

struct av8l_fast_io_pgtable {
	struct io_pgtable	  iop;
	av8l_fast_iopte		 *pgd;
	av8l_fast_iopte		 *puds[4];
	av8l_fast_iopte		 *pmds;
	struct page		**pages; /* page table memory */
};

/* Page table bits */
#define AV8L_FAST_PTE_TYPE_SHIFT	0
#define AV8L_FAST_PTE_TYPE_MASK		0x3

#define AV8L_FAST_PTE_TYPE_BLOCK	1
#define AV8L_FAST_PTE_TYPE_TABLE	3
#define AV8L_FAST_PTE_TYPE_PAGE		3

#define AV8L_FAST_PTE_NSTABLE		(((av8l_fast_iopte)1) << 63)
#define AV8L_FAST_PTE_XN		(((av8l_fast_iopte)3) << 53)
#define AV8L_FAST_PTE_AF		(((av8l_fast_iopte)1) << 10)
#define AV8L_FAST_PTE_SH_NS		(((av8l_fast_iopte)0) << 8)
#define AV8L_FAST_PTE_SH_OS		(((av8l_fast_iopte)2) << 8)
#define AV8L_FAST_PTE_SH_IS		(((av8l_fast_iopte)3) << 8)
#define AV8L_FAST_PTE_NS		(((av8l_fast_iopte)1) << 5)
#define AV8L_FAST_PTE_VALID		(((av8l_fast_iopte)1) << 0)

#define AV8L_FAST_PTE_ATTR_LO_MASK	(((av8l_fast_iopte)0x3ff) << 2)
/* Ignore the contiguous bit for block splitting */
#define AV8L_FAST_PTE_ATTR_HI_MASK	(((av8l_fast_iopte)6) << 52)
#define AV8L_FAST_PTE_ATTR_MASK		(AV8L_FAST_PTE_ATTR_LO_MASK |	\
					 AV8L_FAST_PTE_ATTR_HI_MASK)
#define AV8L_FAST_PTE_ADDR_MASK		((av8l_fast_iopte)0xfffffffff000)


/* Stage-1 PTE */
#define AV8L_FAST_PTE_AP_PRIV_RW	(((av8l_fast_iopte)0) << 6)
#define AV8L_FAST_PTE_AP_RW		(((av8l_fast_iopte)1) << 6)
#define AV8L_FAST_PTE_AP_PRIV_RO	(((av8l_fast_iopte)2) << 6)
#define AV8L_FAST_PTE_AP_RO		(((av8l_fast_iopte)3) << 6)
#define AV8L_FAST_PTE_ATTRINDX_SHIFT	2
#define AV8L_FAST_PTE_nG		(((av8l_fast_iopte)1) << 11)

/* Stage-2 PTE */
#define AV8L_FAST_PTE_HAP_FAULT		(((av8l_fast_iopte)0) << 6)
#define AV8L_FAST_PTE_HAP_READ		(((av8l_fast_iopte)1) << 6)
#define AV8L_FAST_PTE_HAP_WRITE		(((av8l_fast_iopte)2) << 6)
#define AV8L_FAST_PTE_MEMATTR_OIWB	(((av8l_fast_iopte)0xf) << 2)
#define AV8L_FAST_PTE_MEMATTR_NC	(((av8l_fast_iopte)0x5) << 2)
#define AV8L_FAST_PTE_MEMATTR_DEV	(((av8l_fast_iopte)0x1) << 2)

/* Register bits */
#define ARM_32_LPAE_TCR_EAE		(1 << 31)
#define ARM_64_LPAE_S2_TCR_RES1		(1 << 31)

#define AV8L_FAST_TCR_TG0_4K		(0 << 14)
#define AV8L_FAST_TCR_TG0_64K		(1 << 14)
#define AV8L_FAST_TCR_TG0_16K		(2 << 14)

#define AV8L_FAST_TCR_SH0_SHIFT		12
#define AV8L_FAST_TCR_SH0_MASK		0x3
#define AV8L_FAST_TCR_SH_NS		0
#define AV8L_FAST_TCR_SH_OS		2
#define AV8L_FAST_TCR_SH_IS		3

#define AV8L_FAST_TCR_ORGN0_SHIFT	10
#define AV8L_FAST_TCR_IRGN0_SHIFT	8
#define AV8L_FAST_TCR_RGN_MASK		0x3
#define AV8L_FAST_TCR_RGN_NC		0
#define AV8L_FAST_TCR_RGN_WBWA		1
#define AV8L_FAST_TCR_RGN_WT		2
#define AV8L_FAST_TCR_RGN_WB		3

#define AV8L_FAST_TCR_SL0_SHIFT		6
#define AV8L_FAST_TCR_SL0_MASK		0x3

#define AV8L_FAST_TCR_T0SZ_SHIFT	0
#define AV8L_FAST_TCR_SZ_MASK		0xf

#define AV8L_FAST_TCR_PS_SHIFT		16
#define AV8L_FAST_TCR_PS_MASK		0x7

#define AV8L_FAST_TCR_IPS_SHIFT		32
#define AV8L_FAST_TCR_IPS_MASK		0x7

#define AV8L_FAST_TCR_PS_32_BIT		0x0ULL
#define AV8L_FAST_TCR_PS_36_BIT		0x1ULL
#define AV8L_FAST_TCR_PS_40_BIT		0x2ULL
#define AV8L_FAST_TCR_PS_42_BIT		0x3ULL
#define AV8L_FAST_TCR_PS_44_BIT		0x4ULL
#define AV8L_FAST_TCR_PS_48_BIT		0x5ULL

#define AV8L_FAST_TCR_EPD1_SHIFT	23
#define AV8L_FAST_TCR_EPD1_FAULT	1

#define AV8L_FAST_MAIR_ATTR_SHIFT(n)	((n) << 3)
#define AV8L_FAST_MAIR_ATTR_MASK	0xff
#define AV8L_FAST_MAIR_ATTR_DEVICE	0x04
#define AV8L_FAST_MAIR_ATTR_NC		0x44
#define AV8L_FAST_MAIR_ATTR_WBRWA	0xff
#define AV8L_FAST_MAIR_ATTR_UPSTREAM	0xf4
#define AV8L_FAST_MAIR_ATTR_IDX_NC	0
#define AV8L_FAST_MAIR_ATTR_IDX_CACHE	1
#define AV8L_FAST_MAIR_ATTR_IDX_DEV	2
#define AV8L_FAST_MAIR_ATTR_IDX_UPSTREAM	3

#define AV8L_FAST_PAGE_SHIFT		12


#ifdef CONFIG_IOMMU_IO_PGTABLE_FAST_PROVE_TLB

#include <asm/cacheflush.h>
#include <linux/notifier.h>

static ATOMIC_NOTIFIER_HEAD(av8l_notifier_list);

void av8l_register_notify(struct notifier_block *nb)
{
	atomic_notifier_chain_register(&av8l_notifier_list, nb);
}
EXPORT_SYMBOL(av8l_register_notify);

static void __av8l_check_for_stale_tlb(av8l_fast_iopte *ptep)
{
	if (unlikely(*ptep)) {
		atomic_notifier_call_chain(
			&av8l_notifier_list, MAPPED_OVER_STALE_TLB,
			(void *) ptep);
		pr_err("Tried to map over a non-vacant pte: 0x%llx @ %p\n",
		       *ptep, ptep);
		pr_err("Nearby memory:\n");
		print_hex_dump(KERN_ERR, "pgtbl: ", DUMP_PREFIX_ADDRESS,
			       32, 8, ptep - 16, 32 * sizeof(*ptep), false);
	}
}

void av8l_fast_clear_stale_ptes(av8l_fast_iopte *pmds, bool skip_sync)
{
	int i;
	av8l_fast_iopte *pmdp = pmds;

	for (i = 0; i < ((SZ_1G * 4UL) >> AV8L_FAST_PAGE_SHIFT); ++i) {
		if (!(*pmdp & AV8L_FAST_PTE_VALID)) {
			*pmdp = 0;
			if (!skip_sync)
				dmac_clean_range(pmdp, pmdp + 1);
		}
		pmdp++;
	}
}
#else
static void __av8l_check_for_stale_tlb(av8l_fast_iopte *ptep)
{
}
#endif

/* caller must take care of cache maintenance on *ptep */
int av8l_fast_map_public(av8l_fast_iopte *ptep, phys_addr_t paddr, size_t size,
			 int prot)
{
	int i, nptes = size >> AV8L_FAST_PAGE_SHIFT;
	av8l_fast_iopte pte = AV8L_FAST_PTE_XN
		| AV8L_FAST_PTE_TYPE_PAGE
		| AV8L_FAST_PTE_AF
		| AV8L_FAST_PTE_nG
		| AV8L_FAST_PTE_SH_OS;

	if (prot & IOMMU_MMIO)
		pte |= (AV8L_FAST_MAIR_ATTR_IDX_DEV
			<< AV8L_FAST_PTE_ATTRINDX_SHIFT);
	else if (prot & IOMMU_CACHE)
		pte |= (AV8L_FAST_MAIR_ATTR_IDX_CACHE
			<< AV8L_FAST_PTE_ATTRINDX_SHIFT);
	else if (prot & IOMMU_USE_UPSTREAM_HINT)
		pte |= (AV8L_FAST_MAIR_ATTR_IDX_UPSTREAM
			<< AV8L_FAST_PTE_ATTRINDX_SHIFT);

	if (!(prot & IOMMU_WRITE))
		pte |= AV8L_FAST_PTE_AP_RO;
	else
		pte |= AV8L_FAST_PTE_AP_RW;

	paddr &= AV8L_FAST_PTE_ADDR_MASK;
	for (i = 0; i < nptes; i++, paddr += SZ_4K) {
		__av8l_check_for_stale_tlb(ptep + i);
		*(ptep + i) = pte | paddr;
	}

	return 0;
}

static int av8l_fast_map(struct io_pgtable_ops *ops, unsigned long iova,
			 phys_addr_t paddr, size_t size, int prot)
{
	struct av8l_fast_io_pgtable *data = iof_pgtable_ops_to_data(ops);
	av8l_fast_iopte *ptep = iopte_pmd_offset(data->pmds, iova);
	unsigned long nptes = size >> AV8L_FAST_PAGE_SHIFT;

	av8l_fast_map_public(ptep, paddr, size, prot);
	dmac_clean_range(ptep, ptep + nptes);

	return 0;
}

static void __av8l_fast_unmap(av8l_fast_iopte *ptep, size_t size,
			      bool need_stale_tlb_tracking)
{
	unsigned long nptes = size >> AV8L_FAST_PAGE_SHIFT;
	int val = need_stale_tlb_tracking
		? AV8L_FAST_PTE_UNMAPPED_NEED_TLBI
		: 0;

	memset(ptep, val, sizeof(*ptep) * nptes);
}

/* caller must take care of cache maintenance on *ptep */
void av8l_fast_unmap_public(av8l_fast_iopte *ptep, size_t size)
{
	__av8l_fast_unmap(ptep, size, true);
}

/* upper layer must take care of TLB invalidation */
static size_t av8l_fast_unmap(struct io_pgtable_ops *ops, unsigned long iova,
			      size_t size)
{
	struct av8l_fast_io_pgtable *data = iof_pgtable_ops_to_data(ops);
	av8l_fast_iopte *ptep = iopte_pmd_offset(data->pmds, iova);
	unsigned long nptes = size >> AV8L_FAST_PAGE_SHIFT;

	__av8l_fast_unmap(ptep, size, false);
	dmac_clean_range(ptep, ptep + nptes);

	return size;
}

static phys_addr_t av8l_fast_iova_to_phys(struct io_pgtable_ops *ops,
					  unsigned long iova)
{
	struct av8l_fast_io_pgtable *data = iof_pgtable_ops_to_data(ops);
	av8l_fast_iopte pte, *pgdp, *pudp, *pmdp;
	phys_addr_t phys;
	const unsigned long pts = AV8L_FAST_PTE_TYPE_SHIFT;
	const unsigned long ptm = AV8L_FAST_PTE_TYPE_MASK;
	const unsigned long ptt = AV8L_FAST_PTE_TYPE_TABLE;
	const unsigned long ptp = AV8L_FAST_PTE_TYPE_PAGE;
	const av8l_fast_iopte am = AV8L_FAST_PTE_ADDR_MASK;

	/* TODO: clean up some of these magic numbers... */

	pgdp = (av8l_fast_iopte *)
		(((unsigned long)data->pgd) | ((iova & 0x7fc0000000) >> 27));
	pte = *pgdp;
	if (((pte >> pts) & ptm) != ptt)
		return 0;
	pudp = phys_to_virt((pte & am) | ((iova & 0x3fe00000) >> 18));

	pte = *pudp;
	if (((pte >> pts) & ptm) != ptt)
		return 0;
	pmdp = phys_to_virt((pte & am) | ((iova & 0x1ff000) >> 9));

	pte = *pmdp;
	if (((pte >> pts) & ptm) != ptp)
		return 0;
	phys = pte & am;

	return phys | (iova & 0xfff);
}

static int av8l_fast_map_sg(struct io_pgtable_ops *ops, unsigned long iova,
			    struct scatterlist *sg, unsigned int nents,
			    int prot, size_t *size)
{
	return -ENODEV;
}

static struct av8l_fast_io_pgtable *
av8l_fast_alloc_pgtable_data(struct io_pgtable_cfg *cfg)
{
	struct av8l_fast_io_pgtable *data;

	data = kmalloc(sizeof(*data), GFP_KERNEL);
	if (!data)
		return NULL;

	data->iop.ops = (struct io_pgtable_ops) {
		.map		= av8l_fast_map,
		.map_sg		= av8l_fast_map_sg,
		.unmap		= av8l_fast_unmap,
		.iova_to_phys	= av8l_fast_iova_to_phys,
	};

	return data;
}

/*
 * We need 1 page for the pgd, 4 pages for puds (1GB VA per pud page) and
 * 2048 pages for pmds (each pud page contains 512 table entries, each
 * pointing to a pmd).
 */
#define NUM_PGD_PAGES 1
#define NUM_PUD_PAGES 4
#define NUM_PMD_PAGES 2048
#define NUM_PGTBL_PAGES (NUM_PGD_PAGES + NUM_PUD_PAGES + NUM_PMD_PAGES)

static int
av8l_fast_prepopulate_pgtables(struct av8l_fast_io_pgtable *data,
			       struct io_pgtable_cfg *cfg, void *cookie)
{
	int i, j, pg = 0;
	struct page **pages, *page;

	pages = kmalloc(sizeof(*pages) * NUM_PGTBL_PAGES, __GFP_NOWARN |
							__GFP_NORETRY);

	if (!pages)
		pages = vmalloc(sizeof(*pages) * NUM_PGTBL_PAGES);

	if (!pages)
		return -ENOMEM;

	page = alloc_page(GFP_KERNEL | __GFP_ZERO);
	if (!page)
		goto err_free_pages_arr;
	pages[pg++] = page;
	data->pgd = page_address(page);

	/*
	 * We need 2048 entries at level 2 to map 4GB of VA space. A page
	 * can hold 512 entries, so we need 4 pages.
	 */
	for (i = 0; i < 4; ++i) {
		av8l_fast_iopte pte, *ptep;

		page = alloc_page(GFP_KERNEL | __GFP_ZERO);
		if (!page)
			goto err_free_pages;
		pages[pg++] = page;
		data->puds[i] = page_address(page);
		pte = page_to_phys(page) | AV8L_FAST_PTE_TYPE_TABLE;
		ptep = ((av8l_fast_iopte *)data->pgd) + i;
		*ptep = pte;
	}
	dmac_clean_range(data->pgd, data->pgd + 4);

	/*
	 * We have 4 puds, each of which can point to 512 pmds, so we'll
	 * have 2048 pmds, each of which can hold 512 ptes, for a grand
	 * total of 2048*512=1048576 PTEs.
	 */
	for (i = 0; i < 4; ++i) {
		for (j = 0; j < 512; ++j) {
			av8l_fast_iopte pte, *pudp;

			page = alloc_page(GFP_KERNEL | __GFP_ZERO);
			if (!page)
				goto err_free_pages;
			pages[pg++] = page;
			pte = page_to_phys(page) | AV8L_FAST_PTE_TYPE_TABLE;
			pudp = data->puds[i] + j;
			*pudp = pte;
		}
		dmac_clean_range(data->puds[i], data->puds[i] + 512);
	}

	if (WARN_ON(pg != NUM_PGTBL_PAGES))
		goto err_free_pages;

	/*
	 * We map the pmds into a virtually contiguous space so that we
	 * don't have to traverse the first two levels of the page tables
	 * to find the appropriate pud.  Instead, it will be a simple
	 * offset from the virtual base of the pmds.
	 */
	data->pmds = vmap(&pages[NUM_PGD_PAGES + NUM_PUD_PAGES], NUM_PMD_PAGES,
			  VM_IOREMAP, PAGE_KERNEL);
	if (!data->pmds)
		goto err_free_pages;

	data->pages = pages;
	return 0;

err_free_pages:
	for (i = 0; i < pg; ++i)
		__free_page(pages[i]);
err_free_pages_arr:
	kvfree(pages);
	return -ENOMEM;
}

static struct io_pgtable *
av8l_fast_alloc_pgtable(struct io_pgtable_cfg *cfg, void *cookie)
{
	u64 reg;
	struct av8l_fast_io_pgtable *data =
		av8l_fast_alloc_pgtable_data(cfg);

	if (!data)
		return NULL;

	/* restrict according to the fast map requirements */
	cfg->ias = 32;
	cfg->pgsize_bitmap = SZ_4K;

	/* TCR */
	if (cfg->quirks & IO_PGTABLE_QUIRK_QCOM_USE_UPSTREAM_HINT)
		reg = (AV8L_FAST_TCR_SH_OS << AV8L_FAST_TCR_SH0_SHIFT) |
			(AV8L_FAST_TCR_RGN_NC << AV8L_FAST_TCR_IRGN0_SHIFT) |
			(AV8L_FAST_TCR_RGN_WBWA << AV8L_FAST_TCR_ORGN0_SHIFT);
	else if (cfg->quirks & IO_PGTABLE_QUIRK_PAGE_TABLE_COHERENT)
		reg = (AV8L_FAST_TCR_SH_OS << AV8L_FAST_TCR_SH0_SHIFT) |
			(AV8L_FAST_TCR_RGN_WBWA << AV8L_FAST_TCR_IRGN0_SHIFT) |
			(AV8L_FAST_TCR_RGN_WBWA << AV8L_FAST_TCR_ORGN0_SHIFT);
	else
		reg = (AV8L_FAST_TCR_SH_OS << AV8L_FAST_TCR_SH0_SHIFT) |
			(AV8L_FAST_TCR_RGN_NC << AV8L_FAST_TCR_IRGN0_SHIFT) |
			(AV8L_FAST_TCR_RGN_NC << AV8L_FAST_TCR_ORGN0_SHIFT);

	reg |= AV8L_FAST_TCR_TG0_4K;

	switch (cfg->oas) {
	case 32:
		reg |= (AV8L_FAST_TCR_PS_32_BIT << AV8L_FAST_TCR_IPS_SHIFT);
		break;
	case 36:
		reg |= (AV8L_FAST_TCR_PS_36_BIT << AV8L_FAST_TCR_IPS_SHIFT);
		break;
	case 40:
		reg |= (AV8L_FAST_TCR_PS_40_BIT << AV8L_FAST_TCR_IPS_SHIFT);
		break;
	case 42:
		reg |= (AV8L_FAST_TCR_PS_42_BIT << AV8L_FAST_TCR_IPS_SHIFT);
		break;
	case 44:
		reg |= (AV8L_FAST_TCR_PS_44_BIT << AV8L_FAST_TCR_IPS_SHIFT);
		break;
	case 48:
		reg |= (AV8L_FAST_TCR_PS_48_BIT << AV8L_FAST_TCR_IPS_SHIFT);
		break;
	default:
		goto out_free_data;
	}

	reg |= (64ULL - cfg->ias) << AV8L_FAST_TCR_T0SZ_SHIFT;
	reg |= AV8L_FAST_TCR_EPD1_FAULT << AV8L_FAST_TCR_EPD1_SHIFT;
	cfg->av8l_fast_cfg.tcr = reg;

	/* MAIRs */
	reg = (AV8L_FAST_MAIR_ATTR_NC
	       << AV8L_FAST_MAIR_ATTR_SHIFT(AV8L_FAST_MAIR_ATTR_IDX_NC)) |
	      (AV8L_FAST_MAIR_ATTR_WBRWA
	       << AV8L_FAST_MAIR_ATTR_SHIFT(AV8L_FAST_MAIR_ATTR_IDX_CACHE)) |
	      (AV8L_FAST_MAIR_ATTR_DEVICE
	       << AV8L_FAST_MAIR_ATTR_SHIFT(AV8L_FAST_MAIR_ATTR_IDX_DEV)) |
	      (AV8L_FAST_MAIR_ATTR_UPSTREAM
	       << AV8L_FAST_MAIR_ATTR_SHIFT(AV8L_FAST_MAIR_ATTR_IDX_UPSTREAM));

	cfg->av8l_fast_cfg.mair[0] = reg;
	cfg->av8l_fast_cfg.mair[1] = 0;

	/* Allocate all page table memory! */
	if (av8l_fast_prepopulate_pgtables(data, cfg, cookie))
		goto out_free_data;

	cfg->av8l_fast_cfg.pmds = data->pmds;

	/* TTBRs */
	cfg->av8l_fast_cfg.ttbr[0] = virt_to_phys(data->pgd);
	cfg->av8l_fast_cfg.ttbr[1] = 0;
	return &data->iop;

out_free_data:
	kfree(data);
	return NULL;
}

static void av8l_fast_free_pgtable(struct io_pgtable *iop)
{
	int i;
	struct av8l_fast_io_pgtable *data = iof_pgtable_to_data(iop);

	vunmap(data->pmds);
	for (i = 0; i < NUM_PGTBL_PAGES; ++i)
		__free_page(data->pages[i]);
	kvfree(data->pages);
	kfree(data);
}

struct io_pgtable_init_fns io_pgtable_av8l_fast_init_fns = {
	.alloc	= av8l_fast_alloc_pgtable,
	.free	= av8l_fast_free_pgtable,
};


#ifdef CONFIG_IOMMU_IO_PGTABLE_FAST_SELFTEST

#include <linux/dma-contiguous.h>

static struct io_pgtable_cfg *cfg_cookie;

static void dummy_tlb_flush_all(void *cookie)
{
	WARN_ON(cookie != cfg_cookie);
}

static void dummy_tlb_add_flush(unsigned long iova, size_t size, size_t granule,
				bool leaf, void *cookie)
{
	WARN_ON(cookie != cfg_cookie);
	WARN_ON(!(size & cfg_cookie->pgsize_bitmap));
}

static void dummy_tlb_sync(void *cookie)
{
	WARN_ON(cookie != cfg_cookie);
}

static struct iommu_gather_ops dummy_tlb_ops __initdata = {
	.tlb_flush_all	= dummy_tlb_flush_all,
	.tlb_add_flush	= dummy_tlb_add_flush,
	.tlb_sync	= dummy_tlb_sync,
};

/*
 * Returns true if the iova range is successfully mapped to the contiguous
 * phys range in ops.
 */
static bool av8l_fast_range_has_specific_mapping(struct io_pgtable_ops *ops,
						 const unsigned long iova_start,
						 const phys_addr_t phys_start,
						 const size_t size)
{
	unsigned long iova = iova_start;
	phys_addr_t phys = phys_start;

	while (iova < (iova_start + size)) {
		/* + 42 just to make sure offsetting is working */
		if (ops->iova_to_phys(ops, iova + 42) != (phys + 42))
			return false;
		iova += SZ_4K;
		phys += SZ_4K;
	}
	return true;
}

static int __init av8l_fast_positive_testing(void)
{
	int failed = 0;
	unsigned long iova;
	struct io_pgtable_ops *ops;
	struct io_pgtable_cfg cfg;
	struct av8l_fast_io_pgtable *data;
	av8l_fast_iopte *pmds;

	cfg = (struct io_pgtable_cfg) {
		.quirks = 0,
		.tlb = &dummy_tlb_ops,
		.ias = 32,
		.oas = 32,
		.pgsize_bitmap = SZ_4K,
	};

	cfg_cookie = &cfg;
	ops = alloc_io_pgtable_ops(ARM_V8L_FAST, &cfg, &cfg);

	if (WARN_ON(!ops))
		return 1;

	data = iof_pgtable_ops_to_data(ops);
	pmds = data->pmds;

	/* map the entire 4GB VA space with 4K map calls */
	for (iova = 0; iova < SZ_1G * 4UL; iova += SZ_4K) {
		if (WARN_ON(ops->map(ops, iova, iova, SZ_4K, IOMMU_READ))) {
			failed++;
			continue;
		}
	}

	if (WARN_ON(!av8l_fast_range_has_specific_mapping(ops, 0, 0,
							  SZ_1G * 4UL)))
		failed++;

	/* unmap it all */
	for (iova = 0; iova < SZ_1G * 4UL; iova += SZ_4K) {
		if (WARN_ON(ops->unmap(ops, iova, SZ_4K) != SZ_4K))
			failed++;
	}

	/* sweep up TLB proving PTEs */
	av8l_fast_clear_stale_ptes(pmds, false);

	/* map the entire 4GB VA space with 8K map calls */
	for (iova = 0; iova < SZ_1G * 4UL; iova += SZ_8K) {
		if (WARN_ON(ops->map(ops, iova, iova, SZ_8K, IOMMU_READ))) {
			failed++;
			continue;
		}
	}

	if (WARN_ON(!av8l_fast_range_has_specific_mapping(ops, 0, 0,
							  SZ_1G * 4UL)))
		failed++;

	/* unmap it all with 8K unmap calls */
	for (iova = 0; iova < SZ_1G * 4UL; iova += SZ_8K) {
		if (WARN_ON(ops->unmap(ops, iova, SZ_8K) != SZ_8K))
			failed++;
	}

	/* sweep up TLB proving PTEs */
	av8l_fast_clear_stale_ptes(pmds, false);

	/* map the entire 4GB VA space with 16K map calls */
	for (iova = 0; iova < SZ_1G * 4UL; iova += SZ_16K) {
		if (WARN_ON(ops->map(ops, iova, iova, SZ_16K, IOMMU_READ))) {
			failed++;
			continue;
		}
	}

	if (WARN_ON(!av8l_fast_range_has_specific_mapping(ops, 0, 0,
							  SZ_1G * 4UL)))
		failed++;

	/* unmap it all */
	for (iova = 0; iova < SZ_1G * 4UL; iova += SZ_16K) {
		if (WARN_ON(ops->unmap(ops, iova, SZ_16K) != SZ_16K))
			failed++;
	}

	/* sweep up TLB proving PTEs */
	av8l_fast_clear_stale_ptes(pmds, false);

	/* map the entire 4GB VA space with 64K map calls */
	for (iova = 0; iova < SZ_1G * 4UL; iova += SZ_64K) {
		if (WARN_ON(ops->map(ops, iova, iova, SZ_64K, IOMMU_READ))) {
			failed++;
			continue;
		}
	}

	if (WARN_ON(!av8l_fast_range_has_specific_mapping(ops, 0, 0,
							  SZ_1G * 4UL)))
		failed++;

	/* unmap it all at once */
	if (WARN_ON(ops->unmap(ops, 0, SZ_1G * 4UL) != SZ_1G * 4UL))
		failed++;

	free_io_pgtable_ops(ops);
	return failed;
}

static int __init av8l_fast_do_selftests(void)
{
	int failed = 0;

	failed += av8l_fast_positive_testing();

	pr_err("selftest: completed with %d failures\n", failed);

	return 0;
}
subsys_initcall(av8l_fast_do_selftests);
#endif