Initial import

1 files changed, 1050 insertions, 0 deletions

diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
new file mode 100644
index 000000000..cab214544
--- /dev/null
+++ b/drivers/iommu/rockchip-iommu.c
@@ -0,0 +1,1050 @@
+/*
+ * 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.
+ */
+
+#include <asm/cacheflush.h>
+#include <asm/pgtable.h>
+#include <linux/compiler.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iommu.h>
+#include <linux/jiffies.h>
+#include <linux/list.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+/** MMU register offsets */
+#define RK_MMU_DTE_ADDR		0x00	/* Directory table address */
+#define RK_MMU_STATUS		0x04
+#define RK_MMU_COMMAND		0x08
+#define RK_MMU_PAGE_FAULT_ADDR	0x0C	/* IOVA of last page fault */
+#define RK_MMU_ZAP_ONE_LINE	0x10	/* Shootdown one IOTLB entry */
+#define RK_MMU_INT_RAWSTAT	0x14	/* IRQ status ignoring mask */
+#define RK_MMU_INT_CLEAR	0x18	/* Acknowledge and re-arm irq */
+#define RK_MMU_INT_MASK		0x1C	/* IRQ enable */
+#define RK_MMU_INT_STATUS	0x20	/* IRQ status after masking */
+#define RK_MMU_AUTO_GATING	0x24
+
+#define DTE_ADDR_DUMMY		0xCAFEBABE
+#define FORCE_RESET_TIMEOUT	100	/* ms */
+
+/* RK_MMU_STATUS fields */
+#define RK_MMU_STATUS_PAGING_ENABLED       BIT(0)
+#define RK_MMU_STATUS_PAGE_FAULT_ACTIVE    BIT(1)
+#define RK_MMU_STATUS_STALL_ACTIVE         BIT(2)
+#define RK_MMU_STATUS_IDLE                 BIT(3)
+#define RK_MMU_STATUS_REPLAY_BUFFER_EMPTY  BIT(4)
+#define RK_MMU_STATUS_PAGE_FAULT_IS_WRITE  BIT(5)
+#define RK_MMU_STATUS_STALL_NOT_ACTIVE     BIT(31)
+
+/* RK_MMU_COMMAND command values */
+#define RK_MMU_CMD_ENABLE_PAGING    0  /* Enable memory translation */
+#define RK_MMU_CMD_DISABLE_PAGING   1  /* Disable memory translation */
+#define RK_MMU_CMD_ENABLE_STALL     2  /* Stall paging to allow other cmds */
+#define RK_MMU_CMD_DISABLE_STALL    3  /* Stop stall re-enables paging */
+#define RK_MMU_CMD_ZAP_CACHE        4  /* Shoot down entire IOTLB */
+#define RK_MMU_CMD_PAGE_FAULT_DONE  5  /* Clear page fault */
+#define RK_MMU_CMD_FORCE_RESET      6  /* Reset all registers */
+
+/* RK_MMU_INT_* register fields */
+#define RK_MMU_IRQ_PAGE_FAULT    0x01  /* page fault */
+#define RK_MMU_IRQ_BUS_ERROR     0x02  /* bus read error */
+#define RK_MMU_IRQ_MASK          (RK_MMU_IRQ_PAGE_FAULT | RK_MMU_IRQ_BUS_ERROR)
+
+#define NUM_DT_ENTRIES 1024
+#define NUM_PT_ENTRIES 1024
+
+#define SPAGE_ORDER 12
+#define SPAGE_SIZE (1 << SPAGE_ORDER)
+
+ /*
+  * Support mapping any size that fits in one page table:
+  *   4 KiB to 4 MiB
+  */
+#define RK_IOMMU_PGSIZE_BITMAP 0x007ff000
+
+#define IOMMU_REG_POLL_COUNT_FAST 1000
+
+struct rk_iommu_domain {
+	struct list_head iommus;
+	u32 *dt; /* page directory table */
+	spinlock_t iommus_lock; /* lock for iommus list */
+	spinlock_t dt_lock; /* lock for modifying page directory table */
+
+	struct iommu_domain domain;
+};
+
+struct rk_iommu {
+	struct device *dev;
+	void __iomem *base;
+	int irq;
+	struct list_head node; /* entry in rk_iommu_domain.iommus */
+	struct iommu_domain *domain; /* domain to which iommu is attached */
+};
+
+static inline void rk_table_flush(u32 *va, unsigned int count)
+{
+	phys_addr_t pa_start = virt_to_phys(va);
+	phys_addr_t pa_end = virt_to_phys(va + count);
+	size_t size = pa_end - pa_start;
+
+	__cpuc_flush_dcache_area(va, size);
+	outer_flush_range(pa_start, pa_end);
+}
+
+static struct rk_iommu_domain *to_rk_domain(struct iommu_domain *dom)
+{
+	return container_of(dom, struct rk_iommu_domain, domain);
+}
+
+/**
+ * Inspired by _wait_for in intel_drv.h
+ * This is NOT safe for use in interrupt context.
+ *
+ * Note that it's important that we check the condition again after having
+ * timed out, since the timeout could be due to preemption or similar and
+ * we've never had a chance to check the condition before the timeout.
+ */
+#define rk_wait_for(COND, MS) ({ \
+	unsigned long timeout__ = jiffies + msecs_to_jiffies(MS) + 1;	\
+	int ret__ = 0;							\
+	while (!(COND)) {						\
+		if (time_after(jiffies, timeout__)) {			\
+			ret__ = (COND) ? 0 : -ETIMEDOUT;		\
+			break;						\
+		}							\
+		usleep_range(50, 100);					\
+	}								\
+	ret__;								\
+})
+
+/*
+ * The Rockchip rk3288 iommu uses a 2-level page table.
+ * The first level is the "Directory Table" (DT).
+ * The DT consists of 1024 4-byte Directory Table Entries (DTEs), each pointing
+ * to a "Page Table".
+ * The second level is the 1024 Page Tables (PT).
+ * Each PT consists of 1024 4-byte Page Table Entries (PTEs), each pointing to
+ * a 4 KB page of physical memory.
+ *
+ * The DT and each PT fits in a single 4 KB page (4-bytes * 1024 entries).
+ * Each iommu device has a MMU_DTE_ADDR register that contains the physical
+ * address of the start of the DT page.
+ *
+ * The structure of the page table is as follows:
+ *
+ *                   DT
+ * MMU_DTE_ADDR -> +-----+
+ *                 |     |
+ *                 +-----+     PT
+ *                 | DTE | -> +-----+
+ *                 +-----+    |     |     Memory
+ *                 |     |    +-----+     Page
+ *                 |     |    | PTE | -> +-----+
+ *                 +-----+    +-----+    |     |
+ *                            |     |    |     |
+ *                            |     |    |     |
+ *                            +-----+    |     |
+ *                                       |     |
+ *                                       |     |
+ *                                       +-----+
+ */
+
+/*
+ * Each DTE has a PT address and a valid bit:
+ * +---------------------+-----------+-+
+ * | PT address          | Reserved  |V|
+ * +---------------------+-----------+-+
+ *  31:12 - PT address (PTs always starts on a 4 KB boundary)
+ *  11: 1 - Reserved
+ *      0 - 1 if PT @ PT address is valid
+ */
+#define RK_DTE_PT_ADDRESS_MASK    0xfffff000
+#define RK_DTE_PT_VALID           BIT(0)
+
+static inline phys_addr_t rk_dte_pt_address(u32 dte)
+{
+	return (phys_addr_t)dte & RK_DTE_PT_ADDRESS_MASK;
+}
+
+static inline bool rk_dte_is_pt_valid(u32 dte)
+{
+	return dte & RK_DTE_PT_VALID;
+}
+
+static u32 rk_mk_dte(u32 *pt)
+{
+	phys_addr_t pt_phys = virt_to_phys(pt);
+	return (pt_phys & RK_DTE_PT_ADDRESS_MASK) | RK_DTE_PT_VALID;
+}
+
+/*
+ * Each PTE has a Page address, some flags and a valid bit:
+ * +---------------------+---+-------+-+
+ * | Page address        |Rsv| Flags |V|
+ * +---------------------+---+-------+-+
+ *  31:12 - Page address (Pages always start on a 4 KB boundary)
+ *  11: 9 - Reserved
+ *   8: 1 - Flags
+ *      8 - Read allocate - allocate cache space on read misses
+ *      7 - Read cache - enable cache & prefetch of data
+ *      6 - Write buffer - enable delaying writes on their way to memory
+ *      5 - Write allocate - allocate cache space on write misses
+ *      4 - Write cache - different writes can be merged together
+ *      3 - Override cache attributes
+ *          if 1, bits 4-8 control cache attributes
+ *          if 0, the system bus defaults are used
+ *      2 - Writable
+ *      1 - Readable
+ *      0 - 1 if Page @ Page address is valid
+ */
+#define RK_PTE_PAGE_ADDRESS_MASK  0xfffff000
+#define RK_PTE_PAGE_FLAGS_MASK    0x000001fe
+#define RK_PTE_PAGE_WRITABLE      BIT(2)
+#define RK_PTE_PAGE_READABLE      BIT(1)
+#define RK_PTE_PAGE_VALID         BIT(0)
+
+static inline phys_addr_t rk_pte_page_address(u32 pte)
+{
+	return (phys_addr_t)pte & RK_PTE_PAGE_ADDRESS_MASK;
+}
+
+static inline bool rk_pte_is_page_valid(u32 pte)
+{
+	return pte & RK_PTE_PAGE_VALID;
+}
+
+/* TODO: set cache flags per prot IOMMU_CACHE */
+static u32 rk_mk_pte(phys_addr_t page, int prot)
+{
+	u32 flags = 0;
+	flags |= (prot & IOMMU_READ) ? RK_PTE_PAGE_READABLE : 0;
+	flags |= (prot & IOMMU_WRITE) ? RK_PTE_PAGE_WRITABLE : 0;
+	page &= RK_PTE_PAGE_ADDRESS_MASK;
+	return page | flags | RK_PTE_PAGE_VALID;
+}
+
+static u32 rk_mk_pte_invalid(u32 pte)
+{
+	return pte & ~RK_PTE_PAGE_VALID;
+}
+
+/*
+ * rk3288 iova (IOMMU Virtual Address) format
+ *  31       22.21       12.11          0
+ * +-----------+-----------+-------------+
+ * | DTE index | PTE index | Page offset |
+ * +-----------+-----------+-------------+
+ *  31:22 - DTE index   - index of DTE in DT
+ *  21:12 - PTE index   - index of PTE in PT @ DTE.pt_address
+ *  11: 0 - Page offset - offset into page @ PTE.page_address
+ */
+#define RK_IOVA_DTE_MASK    0xffc00000
+#define RK_IOVA_DTE_SHIFT   22
+#define RK_IOVA_PTE_MASK    0x003ff000
+#define RK_IOVA_PTE_SHIFT   12
+#define RK_IOVA_PAGE_MASK   0x00000fff
+#define RK_IOVA_PAGE_SHIFT  0
+
+static u32 rk_iova_dte_index(dma_addr_t iova)
+{
+	return (u32)(iova & RK_IOVA_DTE_MASK) >> RK_IOVA_DTE_SHIFT;
+}
+
+static u32 rk_iova_pte_index(dma_addr_t iova)
+{
+	return (u32)(iova & RK_IOVA_PTE_MASK) >> RK_IOVA_PTE_SHIFT;
+}
+
+static u32 rk_iova_page_offset(dma_addr_t iova)
+{
+	return (u32)(iova & RK_IOVA_PAGE_MASK) >> RK_IOVA_PAGE_SHIFT;
+}
+
+static u32 rk_iommu_read(struct rk_iommu *iommu, u32 offset)
+{
+	return readl(iommu->base + offset);
+}
+
+static void rk_iommu_write(struct rk_iommu *iommu, u32 offset, u32 value)
+{
+	writel(value, iommu->base + offset);
+}
+
+static void rk_iommu_command(struct rk_iommu *iommu, u32 command)
+{
+	writel(command, iommu->base + RK_MMU_COMMAND);
+}
+
+static void rk_iommu_zap_lines(struct rk_iommu *iommu, dma_addr_t iova,
+			       size_t size)
+{
+	dma_addr_t iova_end = iova + size;
+	/*
+	 * TODO(djkurtz): Figure out when it is more efficient to shootdown the
+	 * entire iotlb rather than iterate over individual iovas.
+	 */
+	for (; iova < iova_end; iova += SPAGE_SIZE)
+		rk_iommu_write(iommu, RK_MMU_ZAP_ONE_LINE, iova);
+}
+
+static bool rk_iommu_is_stall_active(struct rk_iommu *iommu)
+{
+	return rk_iommu_read(iommu, RK_MMU_STATUS) & RK_MMU_STATUS_STALL_ACTIVE;
+}
+
+static bool rk_iommu_is_paging_enabled(struct rk_iommu *iommu)
+{
+	return rk_iommu_read(iommu, RK_MMU_STATUS) &
+			     RK_MMU_STATUS_PAGING_ENABLED;
+}
+
+static int rk_iommu_enable_stall(struct rk_iommu *iommu)
+{
+	int ret;
+
+	if (rk_iommu_is_stall_active(iommu))
+		return 0;
+
+	/* Stall can only be enabled if paging is enabled */
+	if (!rk_iommu_is_paging_enabled(iommu))
+		return 0;
+
+	rk_iommu_command(iommu, RK_MMU_CMD_ENABLE_STALL);
+
+	ret = rk_wait_for(rk_iommu_is_stall_active(iommu), 1);
+	if (ret)
+		dev_err(iommu->dev, "Enable stall request timed out, status: %#08x\n",
+			rk_iommu_read(iommu, RK_MMU_STATUS));
+
+	return ret;
+}
+
+static int rk_iommu_disable_stall(struct rk_iommu *iommu)
+{
+	int ret;
+
+	if (!rk_iommu_is_stall_active(iommu))
+		return 0;
+
+	rk_iommu_command(iommu, RK_MMU_CMD_DISABLE_STALL);
+
+	ret = rk_wait_for(!rk_iommu_is_stall_active(iommu), 1);
+	if (ret)
+		dev_err(iommu->dev, "Disable stall request timed out, status: %#08x\n",
+			rk_iommu_read(iommu, RK_MMU_STATUS));
+
+	return ret;
+}
+
+static int rk_iommu_enable_paging(struct rk_iommu *iommu)
+{
+	int ret;
+
+	if (rk_iommu_is_paging_enabled(iommu))
+		return 0;
+
+	rk_iommu_command(iommu, RK_MMU_CMD_ENABLE_PAGING);
+
+	ret = rk_wait_for(rk_iommu_is_paging_enabled(iommu), 1);
+	if (ret)
+		dev_err(iommu->dev, "Enable paging request timed out, status: %#08x\n",
+			rk_iommu_read(iommu, RK_MMU_STATUS));
+
+	return ret;
+}
+
+static int rk_iommu_disable_paging(struct rk_iommu *iommu)
+{
+	int ret;
+
+	if (!rk_iommu_is_paging_enabled(iommu))
+		return 0;
+
+	rk_iommu_command(iommu, RK_MMU_CMD_DISABLE_PAGING);
+
+	ret = rk_wait_for(!rk_iommu_is_paging_enabled(iommu), 1);
+	if (ret)
+		dev_err(iommu->dev, "Disable paging request timed out, status: %#08x\n",
+			rk_iommu_read(iommu, RK_MMU_STATUS));
+
+	return ret;
+}
+
+static int rk_iommu_force_reset(struct rk_iommu *iommu)
+{
+	int ret;
+	u32 dte_addr;
+
+	/*
+	 * Check if register DTE_ADDR is working by writing DTE_ADDR_DUMMY
+	 * and verifying that upper 5 nybbles are read back.
+	 */
+	rk_iommu_write(iommu, RK_MMU_DTE_ADDR, DTE_ADDR_DUMMY);
+
+	dte_addr = rk_iommu_read(iommu, RK_MMU_DTE_ADDR);
+	if (dte_addr != (DTE_ADDR_DUMMY & RK_DTE_PT_ADDRESS_MASK)) {
+		dev_err(iommu->dev, "Error during raw reset. MMU_DTE_ADDR is not functioning\n");
+		return -EFAULT;
+	}
+
+	rk_iommu_command(iommu, RK_MMU_CMD_FORCE_RESET);
+
+	ret = rk_wait_for(rk_iommu_read(iommu, RK_MMU_DTE_ADDR) == 0x00000000,
+			  FORCE_RESET_TIMEOUT);
+	if (ret)
+		dev_err(iommu->dev, "FORCE_RESET command timed out\n");
+
+	return ret;
+}
+
+static void log_iova(struct rk_iommu *iommu, dma_addr_t iova)
+{
+	u32 dte_index, pte_index, page_offset;
+	u32 mmu_dte_addr;
+	phys_addr_t mmu_dte_addr_phys, dte_addr_phys;
+	u32 *dte_addr;
+	u32 dte;
+	phys_addr_t pte_addr_phys = 0;
+	u32 *pte_addr = NULL;
+	u32 pte = 0;
+	phys_addr_t page_addr_phys = 0;
+	u32 page_flags = 0;
+
+	dte_index = rk_iova_dte_index(iova);
+	pte_index = rk_iova_pte_index(iova);
+	page_offset = rk_iova_page_offset(iova);
+
+	mmu_dte_addr = rk_iommu_read(iommu, RK_MMU_DTE_ADDR);
+	mmu_dte_addr_phys = (phys_addr_t)mmu_dte_addr;
+
+	dte_addr_phys = mmu_dte_addr_phys + (4 * dte_index);
+	dte_addr = phys_to_virt(dte_addr_phys);
+	dte = *dte_addr;
+
+	if (!rk_dte_is_pt_valid(dte))
+		goto print_it;
+
+	pte_addr_phys = rk_dte_pt_address(dte) + (pte_index * 4);
+	pte_addr = phys_to_virt(pte_addr_phys);
+	pte = *pte_addr;
+
+	if (!rk_pte_is_page_valid(pte))
+		goto print_it;
+
+	page_addr_phys = rk_pte_page_address(pte) + page_offset;
+	page_flags = pte & RK_PTE_PAGE_FLAGS_MASK;
+
+print_it:
+	dev_err(iommu->dev, "iova = %pad: dte_index: %#03x pte_index: %#03x page_offset: %#03x\n",
+		&iova, dte_index, pte_index, page_offset);
+	dev_err(iommu->dev, "mmu_dte_addr: %pa dte@%pa: %#08x valid: %u pte@%pa: %#08x valid: %u page@%pa flags: %#03x\n",
+		&mmu_dte_addr_phys, &dte_addr_phys, dte,
+		rk_dte_is_pt_valid(dte), &pte_addr_phys, pte,
+		rk_pte_is_page_valid(pte), &page_addr_phys, page_flags);
+}
+
+static irqreturn_t rk_iommu_irq(int irq, void *dev_id)
+{
+	struct rk_iommu *iommu = dev_id;
+	u32 status;
+	u32 int_status;
+	dma_addr_t iova;
+
+	int_status = rk_iommu_read(iommu, RK_MMU_INT_STATUS);
+	if (int_status == 0)
+		return IRQ_NONE;
+
+	iova = rk_iommu_read(iommu, RK_MMU_PAGE_FAULT_ADDR);
+
+	if (int_status & RK_MMU_IRQ_PAGE_FAULT) {
+		int flags;
+
+		status = rk_iommu_read(iommu, RK_MMU_STATUS);
+		flags = (status & RK_MMU_STATUS_PAGE_FAULT_IS_WRITE) ?
+				IOMMU_FAULT_WRITE : IOMMU_FAULT_READ;
+
+		dev_err(iommu->dev, "Page fault at %pad of type %s\n",
+			&iova,
+			(flags == IOMMU_FAULT_WRITE) ? "write" : "read");
+
+		log_iova(iommu, iova);
+
+		/*
+		 * Report page fault to any installed handlers.
+		 * Ignore the return code, though, since we always zap cache
+		 * and clear the page fault anyway.
+		 */
+		if (iommu->domain)
+			report_iommu_fault(iommu->domain, iommu->dev, iova,
+					   flags);
+		else
+			dev_err(iommu->dev, "Page fault while iommu not attached to domain?\n");
+
+		rk_iommu_command(iommu, RK_MMU_CMD_ZAP_CACHE);
+		rk_iommu_command(iommu, RK_MMU_CMD_PAGE_FAULT_DONE);
+	}
+
+	if (int_status & RK_MMU_IRQ_BUS_ERROR)
+		dev_err(iommu->dev, "BUS_ERROR occurred at %pad\n", &iova);
+
+	if (int_status & ~RK_MMU_IRQ_MASK)
+		dev_err(iommu->dev, "unexpected int_status: %#08x\n",
+			int_status);
+
+	rk_iommu_write(iommu, RK_MMU_INT_CLEAR, int_status);
+
+	return IRQ_HANDLED;
+}
+
+static phys_addr_t rk_iommu_iova_to_phys(struct iommu_domain *domain,
+					 dma_addr_t iova)
+{
+	struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
+	unsigned long flags;
+	phys_addr_t pt_phys, phys = 0;
+	u32 dte, pte;
+	u32 *page_table;
+
+	spin_lock_irqsave(&rk_domain->dt_lock, flags);
+
+	dte = rk_domain->dt[rk_iova_dte_index(iova)];
+	if (!rk_dte_is_pt_valid(dte))
+		goto out;
+
+	pt_phys = rk_dte_pt_address(dte);
+	page_table = (u32 *)phys_to_virt(pt_phys);
+	pte = page_table[rk_iova_pte_index(iova)];
+	if (!rk_pte_is_page_valid(pte))
+		goto out;
+
+	phys = rk_pte_page_address(pte) + rk_iova_page_offset(iova);
+out:
+	spin_unlock_irqrestore(&rk_domain->dt_lock, flags);
+
+	return phys;
+}
+
+static void rk_iommu_zap_iova(struct rk_iommu_domain *rk_domain,
+			      dma_addr_t iova, size_t size)
+{
+	struct list_head *pos;
+	unsigned long flags;
+
+	/* shootdown these iova from all iommus using this domain */
+	spin_lock_irqsave(&rk_domain->iommus_lock, flags);
+	list_for_each(pos, &rk_domain->iommus) {
+		struct rk_iommu *iommu;
+		iommu = list_entry(pos, struct rk_iommu, node);
+		rk_iommu_zap_lines(iommu, iova, size);
+	}
+	spin_unlock_irqrestore(&rk_domain->iommus_lock, flags);
+}
+
+static u32 *rk_dte_get_page_table(struct rk_iommu_domain *rk_domain,
+				  dma_addr_t iova)
+{
+	u32 *page_table, *dte_addr;
+	u32 dte;
+	phys_addr_t pt_phys;
+
+	assert_spin_locked(&rk_domain->dt_lock);
+
+	dte_addr = &rk_domain->dt[rk_iova_dte_index(iova)];
+	dte = *dte_addr;
+	if (rk_dte_is_pt_valid(dte))
+		goto done;
+
+	page_table = (u32 *)get_zeroed_page(GFP_ATOMIC | GFP_DMA32);
+	if (!page_table)
+		return ERR_PTR(-ENOMEM);
+
+	dte = rk_mk_dte(page_table);
+	*dte_addr = dte;
+
+	rk_table_flush(page_table, NUM_PT_ENTRIES);
+	rk_table_flush(dte_addr, 1);
+
+	/*
+	 * Zap the first iova of newly allocated page table so iommu evicts
+	 * old cached value of new dte from the iotlb.
+	 */
+	rk_iommu_zap_iova(rk_domain, iova, SPAGE_SIZE);
+
+done:
+	pt_phys = rk_dte_pt_address(dte);
+	return (u32 *)phys_to_virt(pt_phys);
+}
+
+static size_t rk_iommu_unmap_iova(struct rk_iommu_domain *rk_domain,
+				  u32 *pte_addr, dma_addr_t iova, size_t size)
+{
+	unsigned int pte_count;
+	unsigned int pte_total = size / SPAGE_SIZE;
+
+	assert_spin_locked(&rk_domain->dt_lock);
+
+	for (pte_count = 0; pte_count < pte_total; pte_count++) {
+		u32 pte = pte_addr[pte_count];
+		if (!rk_pte_is_page_valid(pte))
+			break;
+
+		pte_addr[pte_count] = rk_mk_pte_invalid(pte);
+	}
+
+	rk_table_flush(pte_addr, pte_count);
+
+	return pte_count * SPAGE_SIZE;
+}
+
+static int rk_iommu_map_iova(struct rk_iommu_domain *rk_domain, u32 *pte_addr,
+			     dma_addr_t iova, phys_addr_t paddr, size_t size,
+			     int prot)
+{
+	unsigned int pte_count;
+	unsigned int pte_total = size / SPAGE_SIZE;
+	phys_addr_t page_phys;
+
+	assert_spin_locked(&rk_domain->dt_lock);
+
+	for (pte_count = 0; pte_count < pte_total; pte_count++) {
+		u32 pte = pte_addr[pte_count];
+
+		if (rk_pte_is_page_valid(pte))
+			goto unwind;
+
+		pte_addr[pte_count] = rk_mk_pte(paddr, prot);
+
+		paddr += SPAGE_SIZE;
+	}
+
+	rk_table_flush(pte_addr, pte_count);
+
+	return 0;
+unwind:
+	/* Unmap the range of iovas that we just mapped */
+	rk_iommu_unmap_iova(rk_domain, pte_addr, iova, pte_count * SPAGE_SIZE);
+
+	iova += pte_count * SPAGE_SIZE;
+	page_phys = rk_pte_page_address(pte_addr[pte_count]);
+	pr_err("iova: %pad already mapped to %pa cannot remap to phys: %pa prot: %#x\n",
+	       &iova, &page_phys, &paddr, prot);
+
+	return -EADDRINUSE;
+}
+
+static int rk_iommu_map(struct iommu_domain *domain, unsigned long _iova,
+			phys_addr_t paddr, size_t size, int prot)
+{
+	struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
+	unsigned long flags;
+	dma_addr_t iova = (dma_addr_t)_iova;
+	u32 *page_table, *pte_addr;
+	int ret;
+
+	spin_lock_irqsave(&rk_domain->dt_lock, flags);
+
+	/*
+	 * pgsize_bitmap specifies iova sizes that fit in one page table
+	 * (1024 4-KiB pages = 4 MiB).
+	 * So, size will always be 4096 <= size <= 4194304.
+	 * Since iommu_map() guarantees that both iova and size will be
+	 * aligned, we will always only be mapping from a single dte here.
+	 */
+	page_table = rk_dte_get_page_table(rk_domain, iova);
+	if (IS_ERR(page_table)) {
+		spin_unlock_irqrestore(&rk_domain->dt_lock, flags);
+		return PTR_ERR(page_table);
+	}
+
+	pte_addr = &page_table[rk_iova_pte_index(iova)];
+	ret = rk_iommu_map_iova(rk_domain, pte_addr, iova, paddr, size, prot);
+	spin_unlock_irqrestore(&rk_domain->dt_lock, flags);
+
+	return ret;
+}
+
+static size_t rk_iommu_unmap(struct iommu_domain *domain, unsigned long _iova,
+			     size_t size)
+{
+	struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
+	unsigned long flags;
+	dma_addr_t iova = (dma_addr_t)_iova;
+	phys_addr_t pt_phys;
+	u32 dte;
+	u32 *pte_addr;
+	size_t unmap_size;
+
+	spin_lock_irqsave(&rk_domain->dt_lock, flags);
+
+	/*
+	 * pgsize_bitmap specifies iova sizes that fit in one page table
+	 * (1024 4-KiB pages = 4 MiB).
+	 * So, size will always be 4096 <= size <= 4194304.
+	 * Since iommu_unmap() guarantees that both iova and size will be
+	 * aligned, we will always only be unmapping from a single dte here.
+	 */
+	dte = rk_domain->dt[rk_iova_dte_index(iova)];
+	/* Just return 0 if iova is unmapped */
+	if (!rk_dte_is_pt_valid(dte)) {
+		spin_unlock_irqrestore(&rk_domain->dt_lock, flags);
+		return 0;
+	}
+
+	pt_phys = rk_dte_pt_address(dte);
+	pte_addr = (u32 *)phys_to_virt(pt_phys) + rk_iova_pte_index(iova);
+	unmap_size = rk_iommu_unmap_iova(rk_domain, pte_addr, iova, size);
+
+	spin_unlock_irqrestore(&rk_domain->dt_lock, flags);
+
+	/* Shootdown iotlb entries for iova range that was just unmapped */
+	rk_iommu_zap_iova(rk_domain, iova, unmap_size);
+
+	return unmap_size;
+}
+
+static struct rk_iommu *rk_iommu_from_dev(struct device *dev)
+{
+	struct iommu_group *group;
+	struct device *iommu_dev;
+	struct rk_iommu *rk_iommu;
+
+	group = iommu_group_get(dev);
+	if (!group)
+		return NULL;
+	iommu_dev = iommu_group_get_iommudata(group);
+	rk_iommu = dev_get_drvdata(iommu_dev);
+	iommu_group_put(group);
+
+	return rk_iommu;
+}
+
+static int rk_iommu_attach_device(struct iommu_domain *domain,
+				  struct device *dev)
+{
+	struct rk_iommu *iommu;
+	struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
+	unsigned long flags;
+	int ret;
+	phys_addr_t dte_addr;
+
+	/*
+	 * Allow 'virtual devices' (e.g., drm) to attach to domain.
+	 * Such a device does not belong to an iommu group.
+	 */
+	iommu = rk_iommu_from_dev(dev);
+	if (!iommu)
+		return 0;
+
+	ret = rk_iommu_enable_stall(iommu);
+	if (ret)
+		return ret;
+
+	ret = rk_iommu_force_reset(iommu);
+	if (ret)
+		return ret;
+
+	iommu->domain = domain;
+
+	ret = devm_request_irq(dev, iommu->irq, rk_iommu_irq,
+			       IRQF_SHARED, dev_name(dev), iommu);
+	if (ret)
+		return ret;
+
+	dte_addr = virt_to_phys(rk_domain->dt);
+	rk_iommu_write(iommu, RK_MMU_DTE_ADDR, dte_addr);
+	rk_iommu_command(iommu, RK_MMU_CMD_ZAP_CACHE);
+	rk_iommu_write(iommu, RK_MMU_INT_MASK, RK_MMU_IRQ_MASK);
+
+	ret = rk_iommu_enable_paging(iommu);
+	if (ret)
+		return ret;
+
+	spin_lock_irqsave(&rk_domain->iommus_lock, flags);
+	list_add_tail(&iommu->node, &rk_domain->iommus);
+	spin_unlock_irqrestore(&rk_domain->iommus_lock, flags);
+
+	dev_info(dev, "Attached to iommu domain\n");
+
+	rk_iommu_disable_stall(iommu);
+
+	return 0;
+}
+
+static void rk_iommu_detach_device(struct iommu_domain *domain,
+				   struct device *dev)
+{
+	struct rk_iommu *iommu;
+	struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
+	unsigned long flags;
+
+	/* Allow 'virtual devices' (eg drm) to detach from domain */
+	iommu = rk_iommu_from_dev(dev);
+	if (!iommu)
+		return;
+
+	spin_lock_irqsave(&rk_domain->iommus_lock, flags);
+	list_del_init(&iommu->node);
+	spin_unlock_irqrestore(&rk_domain->iommus_lock, flags);
+
+	/* Ignore error while disabling, just keep going */
+	rk_iommu_enable_stall(iommu);
+	rk_iommu_disable_paging(iommu);
+	rk_iommu_write(iommu, RK_MMU_INT_MASK, 0);
+	rk_iommu_write(iommu, RK_MMU_DTE_ADDR, 0);
+	rk_iommu_disable_stall(iommu);
+
+	devm_free_irq(dev, iommu->irq, iommu);
+
+	iommu->domain = NULL;
+
+	dev_info(dev, "Detached from iommu domain\n");
+}
+
+static struct iommu_domain *rk_iommu_domain_alloc(unsigned type)
+{
+	struct rk_iommu_domain *rk_domain;
+
+	if (type != IOMMU_DOMAIN_UNMANAGED)
+		return NULL;
+
+	rk_domain = kzalloc(sizeof(*rk_domain), GFP_KERNEL);
+	if (!rk_domain)
+		return NULL;
+
+	/*
+	 * rk32xx iommus use a 2 level pagetable.
+	 * Each level1 (dt) and level2 (pt) table has 1024 4-byte entries.
+	 * Allocate one 4 KiB page for each table.
+	 */
+	rk_domain->dt = (u32 *)get_zeroed_page(GFP_KERNEL | GFP_DMA32);
+	if (!rk_domain->dt)
+		goto err_dt;
+
+	rk_table_flush(rk_domain->dt, NUM_DT_ENTRIES);
+
+	spin_lock_init(&rk_domain->iommus_lock);
+	spin_lock_init(&rk_domain->dt_lock);
+	INIT_LIST_HEAD(&rk_domain->iommus);
+
+	return &rk_domain->domain;
+
+err_dt:
+	kfree(rk_domain);
+	return NULL;
+}
+
+static void rk_iommu_domain_free(struct iommu_domain *domain)
+{
+	struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
+	int i;
+
+	WARN_ON(!list_empty(&rk_domain->iommus));
+
+	for (i = 0; i < NUM_DT_ENTRIES; i++) {
+		u32 dte = rk_domain->dt[i];
+		if (rk_dte_is_pt_valid(dte)) {
+			phys_addr_t pt_phys = rk_dte_pt_address(dte);
+			u32 *page_table = phys_to_virt(pt_phys);
+			free_page((unsigned long)page_table);
+		}
+	}
+
+	free_page((unsigned long)rk_domain->dt);
+	kfree(rk_domain);
+}
+
+static bool rk_iommu_is_dev_iommu_master(struct device *dev)
+{
+	struct device_node *np = dev->of_node;
+	int ret;
+
+	/*
+	 * An iommu master has an iommus property containing a list of phandles
+	 * to iommu nodes, each with an #iommu-cells property with value 0.
+	 */
+	ret = of_count_phandle_with_args(np, "iommus", "#iommu-cells");
+	return (ret > 0);
+}
+
+static int rk_iommu_group_set_iommudata(struct iommu_group *group,
+					struct device *dev)
+{
+	struct device_node *np = dev->of_node;
+	struct platform_device *pd;
+	int ret;
+	struct of_phandle_args args;
+
+	/*
+	 * An iommu master has an iommus property containing a list of phandles
+	 * to iommu nodes, each with an #iommu-cells property with value 0.
+	 */
+	ret = of_parse_phandle_with_args(np, "iommus", "#iommu-cells", 0,
+					 &args);
+	if (ret) {
+		dev_err(dev, "of_parse_phandle_with_args(%s) => %d\n",
+			np->full_name, ret);
+		return ret;
+	}
+	if (args.args_count != 0) {
+		dev_err(dev, "incorrect number of iommu params found for %s (found %d, expected 0)\n",
+			args.np->full_name, args.args_count);
+		return -EINVAL;
+	}
+
+	pd = of_find_device_by_node(args.np);
+	of_node_put(args.np);
+	if (!pd) {
+		dev_err(dev, "iommu %s not found\n", args.np->full_name);
+		return -EPROBE_DEFER;
+	}
+
+	/* TODO(djkurtz): handle multiple slave iommus for a single master */
+	iommu_group_set_iommudata(group, &pd->dev, NULL);
+
+	return 0;
+}
+
+static int rk_iommu_add_device(struct device *dev)
+{
+	struct iommu_group *group;
+	int ret;
+
+	if (!rk_iommu_is_dev_iommu_master(dev))
+		return -ENODEV;
+
+	group = iommu_group_get(dev);
+	if (!group) {
+		group = iommu_group_alloc();
+		if (IS_ERR(group)) {
+			dev_err(dev, "Failed to allocate IOMMU group\n");
+			return PTR_ERR(group);
+		}
+	}
+
+	ret = iommu_group_add_device(group, dev);
+	if (ret)
+		goto err_put_group;
+
+	ret = rk_iommu_group_set_iommudata(group, dev);
+	if (ret)
+		goto err_remove_device;
+
+	iommu_group_put(group);
+
+	return 0;
+
+err_remove_device:
+	iommu_group_remove_device(dev);
+err_put_group:
+	iommu_group_put(group);
+	return ret;
+}
+
+static void rk_iommu_remove_device(struct device *dev)
+{
+	if (!rk_iommu_is_dev_iommu_master(dev))
+		return;
+
+	iommu_group_remove_device(dev);
+}
+
+static const struct iommu_ops rk_iommu_ops = {
+	.domain_alloc = rk_iommu_domain_alloc,
+	.domain_free = rk_iommu_domain_free,
+	.attach_dev = rk_iommu_attach_device,
+	.detach_dev = rk_iommu_detach_device,
+	.map = rk_iommu_map,
+	.unmap = rk_iommu_unmap,
+	.add_device = rk_iommu_add_device,
+	.remove_device = rk_iommu_remove_device,
+	.iova_to_phys = rk_iommu_iova_to_phys,
+	.pgsize_bitmap = RK_IOMMU_PGSIZE_BITMAP,
+};
+
+static int rk_iommu_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct rk_iommu *iommu;
+	struct resource *res;
+
+	iommu = devm_kzalloc(dev, sizeof(*iommu), GFP_KERNEL);
+	if (!iommu)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, iommu);
+	iommu->dev = dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	iommu->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(iommu->base))
+		return PTR_ERR(iommu->base);
+
+	iommu->irq = platform_get_irq(pdev, 0);
+	if (iommu->irq < 0) {
+		dev_err(dev, "Failed to get IRQ, %d\n", iommu->irq);
+		return -ENXIO;
+	}
+
+	return 0;
+}
+
+static int rk_iommu_remove(struct platform_device *pdev)
+{
+	return 0;
+}
+
+static const struct of_device_id rk_iommu_dt_ids[] = {
+	{ .compatible = "rockchip,iommu" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rk_iommu_dt_ids);
+
+static struct platform_driver rk_iommu_driver = {
+	.probe = rk_iommu_probe,
+	.remove = rk_iommu_remove,
+	.driver = {
+		   .name = "rk_iommu",
+		   .of_match_table = rk_iommu_dt_ids,
+	},
+};
+
+static int __init rk_iommu_init(void)
+{
+	struct device_node *np;
+	int ret;
+
+	np = of_find_matching_node(NULL, rk_iommu_dt_ids);
+	if (!np)
+		return 0;
+
+	of_node_put(np);
+
+	ret = bus_set_iommu(&platform_bus_type, &rk_iommu_ops);
+	if (ret)
+		return ret;
+
+	return platform_driver_register(&rk_iommu_driver);
+}
+static void __exit rk_iommu_exit(void)
+{
+	platform_driver_unregister(&rk_iommu_driver);
+}
+
+subsys_initcall(rk_iommu_init);
+module_exit(rk_iommu_exit);
+
+MODULE_DESCRIPTION("IOMMU API for Rockchip");
+MODULE_AUTHOR("Simon Xue <xxm@rock-chips.com> and Daniel Kurtz <djkurtz@chromium.org>");
+MODULE_ALIAS("platform:rockchip-iommu");
+MODULE_LICENSE("GPL v2");