[PATCH v3 0/5] iommu: Add Allwinner H6 IOMMU driver

[PATCH v3 0/5] iommu: Add Allwinner H6 IOMMU driver

[Maxime Ripard]

Hi,

Here's a series adding support for the IOMMU introduced in the Allwinner
H6. The driver from Allwinner hints at more SoCs using it in the future
(with more masters), so we can bet on that IOMMU becoming pretty much
standard in new SoCs from Allwinner.

One thing I wasn't really sure about was how to expose the statistics
reported by the IOMMU PMU (TLB hit rates, latencies, and so on). The
Allwinner driver exposes them through custom sysfs files, while they would
be best represented through perf I guess? Anyway, I'm planning to support
them later on.

Let me know what you think,
Maxime

Changes from v2:
  - Rebased on 5.7
  - Add dt bindings patch
  - Allow the identity domain to be allocated
  - Add an unlikely to the check on whether a PTE already exists in map
  - Remove locking and adjust the PT installation to use an atomic
    operation instead
  - Switch to iotlb_sync / flush_iotlb_all callback instead of flushing by
    ourselves.

Changes from v1:
  - Add a patch to configure the IOMMU on the virtual DRM device
  - Rework the domain allocation / freeing
  - Remove the runtime_pm handling to power up the device and rely on
    refcounting
  - use map gfp argument for kmem cache allocation
  - Removed unused macros
  - Switched from BIT(0) to 1 for the page table entry valid flag to make
    it more obvious that it's over multiple bits.
  - Switch to module_initcall
  - Make accesses to the fwspec more consistant
  - Removed dev_info logs
  - Reworked invalidation / flushing
  - Allow for compilation with COMPILE_TEST

Maxime Ripard (5):
  dt-bindings: iommu: Add Allwinner H6 IOMMU bindings
  dt-bindings: display: sun8i-mixer: Allow for an iommu property
  iommu: Add Allwinner H6 IOMMU driver
  arm64: dts: allwinner: h6: Add IOMMU
  drm/sun4i: mixer: Call of_dma_configure if there's an IOMMU

 Documentation/devicetree/bindings/display/allwinner,sun8i-a83t-de2-mixer.yaml |    3 +-
 Documentation/devicetree/bindings/iommu/allwinner,sun50i-h6-iommu.yaml        |   61 ++++-
 arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi                                  |   10 +-
 drivers/gpu/drm/sun4i/sun8i_mixer.c                                           |   13 +-
 drivers/iommu/Kconfig                                                         |    9 +-
 drivers/iommu/Makefile                                                        |    1 +-
 drivers/iommu/sun50i-iommu.c                                                  | 1065 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 7 files changed, 1162 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iommu/allwinner,sun50i-h6-iommu.yaml
 create mode 100644 drivers/iommu/sun50i-iommu.c

base-commit: 8f3d9f354286745c751374f5f1fcafee6b3f3136
-- 
git-series 0.9.1

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[PATCH v3 1/5] dt-bindings: iommu: Add Allwinner H6 IOMMU bindings

[Maxime Ripard]

The Allwinner H6 has introduced an IOMMU. Let's add a device tree binding
for it.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 Documentation/devicetree/bindings/iommu/allwinner,sun50i-h6-iommu.yaml | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iommu/allwinner,sun50i-h6-iommu.yaml

diff --git a/Documentation/devicetree/bindings/iommu/allwinner,sun50i-h6-iommu.yaml b/Documentation/devicetree/bindings/iommu/allwinner,sun50i-h6-iommu.yaml
new file mode 100644
index 000000000000..5e125cf2a88b
--- /dev/null
+++ b/Documentation/devicetree/bindings/iommu/allwinner,sun50i-h6-iommu.yaml
@@ -0,0 +1,61 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iommu/allwinner,sun50i-h6-iommu.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Allwinner H6 IOMMU Device Tree Bindings
+
+maintainers:
+  - Chen-Yu Tsai <wens@csie.org>
+  - Maxime Ripard <mripard@kernel.org>
+
+properties:
+  "#iommu-cells":
+    const: 1
+    description:
+      The content of the cell is the master ID.
+
+  compatible:
+    const: allwinner,sun50i-h6-iommu
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+required:
+  - "#iommu-cells"
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - resets
+
+additionalProperties: false
+
+examples:
+  - |
+      #include <dt-bindings/interrupt-controller/arm-gic.h>
+      #include <dt-bindings/interrupt-controller/irq.h>
+
+      #include <dt-bindings/clock/sun50i-h6-ccu.h>
+      #include <dt-bindings/reset/sun50i-h6-ccu.h>
+
+      iommu: iommu@30f0000 {
+          compatible = "allwinner,sun50i-h6-iommu";
+          reg = <0x030f0000 0x10000>;
+          interrupts = <GIC_SPI 57 IRQ_TYPE_LEVEL_HIGH>;
+          clocks = <&ccu CLK_BUS_IOMMU>;
+          resets = <&ccu RST_BUS_IOMMU>;
+          #iommu-cells = <1>;
+      };
+
+...
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[PATCH v3 2/5] dt-bindings: display: sun8i-mixer: Allow for an iommu property

[Maxime Ripard]

The H6 mixer is attached to an IOMMU, so let's allow that property to be
set in the bindings.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 Documentation/devicetree/bindings/display/allwinner,sun8i-a83t-de2-mixer.yaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/allwinner,sun8i-a83t-de2-mixer.yaml b/Documentation/devicetree/bindings/display/allwinner,sun8i-a83t-de2-mixer.yaml
index 1dee641e3ea1..c040eef56518 100644
--- a/Documentation/devicetree/bindings/display/allwinner,sun8i-a83t-de2-mixer.yaml
+++ b/Documentation/devicetree/bindings/display/allwinner,sun8i-a83t-de2-mixer.yaml
@@ -36,6 +36,9 @@ properties:
       - const: bus
       - const: mod
 
+  iommus:
+    maxItems: 1
+
   resets:
     maxItems: 1
 
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[PATCH v3 3/5] iommu: Add Allwinner H6 IOMMU driver

[Maxime Ripard]

The Allwinner H6 has introduced an IOMMU for a few DMA controllers, mostly
video related: the display engine, the video decoders / encoders, the
camera capture controller, etc.

The design is pretty simple compared to other IOMMUs found in SoCs: there's
a single instance, controlling all the masters, with a single address
space.

It also features a performance monitoring unit that allows to retrieve
various informations (per-master and global TLB accesses, hits and misses,
access latency, etc) that isn't supported at the moment.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 drivers/iommu/Kconfig        |    9 +-
 drivers/iommu/Makefile       |    1 +-
 drivers/iommu/sun50i-iommu.c | 1065 +++++++++++++++++++++++++++++++++++-
 3 files changed, 1075 insertions(+)
 create mode 100644 drivers/iommu/sun50i-iommu.c

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 58b4a4dbfc78..6e80b0ea7228 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -303,6 +303,15 @@ config ROCKCHIP_IOMMU
 	  Say Y here if you are using a Rockchip SoC that includes an IOMMU
 	  device.
 
+config SUN50I_IOMMU
+	bool "Allwinner H6 IOMMU Support"
+	depends on ARCH_SUNXI || COMPILE_TEST
+	select ARM_DMA_USE_IOMMU
+	select IOMMU_API
+	select IOMMU_DMA
+	help
+	  Support for the IOMMU introduced in the Allwinner H6 SoCs.
+
 config TEGRA_IOMMU_GART
 	bool "Tegra GART IOMMU Support"
 	depends on ARCH_TEGRA_2x_SOC
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 9f33fdb3bb05..57cf4ba5e27c 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_MTK_IOMMU_V1) += mtk_iommu_v1.o
 obj-$(CONFIG_OMAP_IOMMU) += omap-iommu.o
 obj-$(CONFIG_OMAP_IOMMU_DEBUG) += omap-iommu-debug.o
 obj-$(CONFIG_ROCKCHIP_IOMMU) += rockchip-iommu.o
+obj-$(CONFIG_SUN50I_IOMMU) += sun50i-iommu.o
 obj-$(CONFIG_TEGRA_IOMMU_GART) += tegra-gart.o
 obj-$(CONFIG_TEGRA_IOMMU_SMMU) += tegra-smmu.o
 obj-$(CONFIG_EXYNOS_IOMMU) += exynos-iommu.o
diff --git a/drivers/iommu/sun50i-iommu.c b/drivers/iommu/sun50i-iommu.c
new file mode 100644
index 000000000000..d4c3fa2f0f82
--- /dev/null
+++ b/drivers/iommu/sun50i-iommu.c
@@ -0,0 +1,1065 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+// Copyright (C) 2016-2018, Allwinner Technology CO., LTD.
+// Copyright (C) 2019-2020, Cerno
+
+#include <linux/bitfield.h>
+#include <linux/bug.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/dma-direction.h>
+#include <linux/dma-iommu.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/iommu.h>
+#include <linux/iopoll.h>
+#include <linux/ioport.h>
+#include <linux/log2.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#define IOMMU_RESET_REG			0x010
+#define IOMMU_ENABLE_REG		0x020
+#define IOMMU_ENABLE_ENABLE			BIT(0)
+
+#define IOMMU_BYPASS_REG		0x030
+#define IOMMU_AUTO_GATING_REG		0x040
+#define IOMMU_AUTO_GATING_ENABLE		BIT(0)
+
+#define IOMMU_WBUF_CTRL_REG		0x044
+#define IOMMU_OOO_CTRL_REG		0x048
+#define IOMMU_4KB_BDY_PRT_CTRL_REG	0x04c
+#define IOMMU_TTB_REG			0x050
+#define IOMMU_TLB_ENABLE_REG		0x060
+#define IOMMU_TLB_PREFETCH_REG		0x070
+#define IOMMU_TLB_PREFETCH_MASTER_ENABLE(m)	BIT(m)
+
+#define IOMMU_TLB_FLUSH_REG		0x080
+#define IOMMU_TLB_FLUSH_PTW_CACHE		BIT(17)
+#define IOMMU_TLB_FLUSH_MACRO_TLB		BIT(16)
+#define IOMMU_TLB_FLUSH_MICRO_TLB(i)		(BIT(i) & GENMASK(5, 0))
+
+#define IOMMU_TLB_IVLD_ADDR_REG		0x090
+#define IOMMU_TLB_IVLD_ADDR_MASK_REG	0x094
+#define IOMMU_TLB_IVLD_ENABLE_REG	0x098
+#define IOMMU_TLB_IVLD_ENABLE_ENABLE		BIT(0)
+
+#define IOMMU_PC_IVLD_ADDR_REG		0x0a0
+#define IOMMU_PC_IVLD_ENABLE_REG	0x0a8
+#define IOMMU_PC_IVLD_ENABLE_ENABLE		BIT(0)
+
+#define IOMMU_DM_AUT_CTRL_REG(d)	(0x0b0 + ((d) / 2) * 4)
+#define IOMMU_DM_AUT_CTRL_RD_UNAVAIL(d, m)	(1 << (((d & 1) * 16) + ((m) * 2)))
+#define IOMMU_DM_AUT_CTRL_WR_UNAVAIL(d, m)	(1 << (((d & 1) * 16) + ((m) * 2) + 1))
+
+#define IOMMU_DM_AUT_OVWT_REG		0x0d0
+#define IOMMU_INT_ENABLE_REG		0x100
+#define IOMMU_INT_CLR_REG		0x104
+#define IOMMU_INT_STA_REG		0x108
+#define IOMMU_INT_ERR_ADDR_REG(i)	(0x110 + (i) * 4)
+#define IOMMU_INT_ERR_ADDR_L1_REG	0x130
+#define IOMMU_INT_ERR_ADDR_L2_REG	0x134
+#define IOMMU_INT_ERR_DATA_REG(i)	(0x150 + (i) * 4)
+#define IOMMU_L1PG_INT_REG		0x0180
+#define IOMMU_L2PG_INT_REG		0x0184
+
+#define IOMMU_INT_INVALID_L2PG			BIT(17)
+#define IOMMU_INT_INVALID_L1PG			BIT(16)
+#define IOMMU_INT_MASTER_PERMISSION(m)		BIT(m)
+#define IOMMU_INT_MASTER_MASK			(IOMMU_INT_MASTER_PERMISSION(0) | \
+						 IOMMU_INT_MASTER_PERMISSION(1) | \
+						 IOMMU_INT_MASTER_PERMISSION(2) | \
+						 IOMMU_INT_MASTER_PERMISSION(3) | \
+						 IOMMU_INT_MASTER_PERMISSION(4) | \
+						 IOMMU_INT_MASTER_PERMISSION(5))
+#define IOMMU_INT_MASK				(IOMMU_INT_INVALID_L1PG | \
+						 IOMMU_INT_INVALID_L2PG | \
+						 IOMMU_INT_MASTER_MASK)
+
+#define PT_ENTRY_SIZE			sizeof(u32)
+
+#define NUM_DT_ENTRIES			4096
+#define DT_SIZE				(NUM_DT_ENTRIES * PT_ENTRY_SIZE)
+
+#define NUM_PT_ENTRIES			256
+#define PT_SIZE				(NUM_PT_ENTRIES * PT_ENTRY_SIZE)
+
+struct sun50i_iommu {
+	struct iommu_device iommu;
+
+	/* Lock to modify the IOMMU registers */
+	spinlock_t iommu_lock;
+
+	struct device *dev;
+	void __iomem *base;
+	struct reset_control *reset;
+	struct clk *clk;
+
+	struct iommu_domain *domain;
+	struct iommu_group *group;
+	struct kmem_cache *pt_pool;
+};
+
+struct sun50i_iommu_domain {
+	struct iommu_domain domain;
+
+	/* Number of devices attached to the domain */
+	refcount_t refcnt;
+
+	/* L1 Page Table */
+	u32 *dt;
+	dma_addr_t dt_dma;
+
+	struct sun50i_iommu *iommu;
+};
+
+static struct sun50i_iommu_domain *to_sun50i_domain(struct iommu_domain *domain)
+{
+	return container_of(domain, struct sun50i_iommu_domain, domain);
+}
+
+static struct sun50i_iommu *sun50i_iommu_from_dev(struct device *dev)
+{
+	return dev_iommu_priv_get(dev);
+}
+
+static u32 iommu_read(struct sun50i_iommu *iommu, u32 offset)
+{
+	return readl(iommu->base + offset);
+}
+
+static void iommu_write(struct sun50i_iommu *iommu, u32 offset, u32 value)
+{
+	writel(value, iommu->base + offset);
+}
+
+/*
+ * The Allwinner H6 IOMMU uses a 2-level page table.
+ *
+ * The first level is the usual Directory Table (DT), that consists of
+ * 4096 4-bytes Directory Table Entries (DTE), each pointing to a Page
+ * Table (PT).
+ *
+ * Each PT consits of 256 4-bytes Page Table Entries (PTE), each
+ * pointing to a 4kB page of physical memory.
+ *
+ * The IOMMU supports a single DT, pointed by the IOMMU_TTB_REG
+ * register that contains its physical address.
+ */
+
+#define SUN50I_IOVA_DTE_MASK	GENMASK(31, 20)
+#define SUN50I_IOVA_PTE_MASK	GENMASK(19, 12)
+#define SUN50I_IOVA_PAGE_MASK	GENMASK(11, 0)
+
+static u32 sun50i_iova_get_dte_index(dma_addr_t iova)
+{
+	return FIELD_GET(SUN50I_IOVA_DTE_MASK, iova);
+}
+
+static u32 sun50i_iova_get_pte_index(dma_addr_t iova)
+{
+	return FIELD_GET(SUN50I_IOVA_PTE_MASK, iova);
+}
+
+static u32 sun50i_iova_get_page_offset(dma_addr_t iova)
+{
+	return FIELD_GET(SUN50I_IOVA_PAGE_MASK, iova);
+}
+
+/*
+ * Each Directory Table Entry has a Page Table address and a valid
+ * bit:
+
+ * +---------------------+-----------+-+
+ * | PT address          | Reserved  |V|
+ * +---------------------+-----------+-+
+ *  31:10 - Page Table address
+ *   9:2  - Reserved
+ *   1:0  - 1 if the entry is valid
+ */
+
+#define SUN50I_DTE_PT_ADDRESS_MASK	GENMASK(31, 10)
+#define SUN50I_DTE_PT_ATTRS		GENMASK(1, 0)
+#define SUN50I_DTE_PT_VALID		1
+
+static phys_addr_t sun50i_dte_get_pt_address(u32 dte)
+{
+	return (phys_addr_t)dte & SUN50I_DTE_PT_ADDRESS_MASK;
+}
+
+static bool sun50i_dte_is_pt_valid(u32 dte)
+{
+	return (dte & SUN50I_DTE_PT_ATTRS) == SUN50I_DTE_PT_VALID;
+}
+
+static u32 sun50i_mk_dte(dma_addr_t pt_dma)
+{
+	return (pt_dma & SUN50I_DTE_PT_ADDRESS_MASK) | SUN50I_DTE_PT_VALID;
+}
+
+/*
+ * Each PTE has a Page address, an authority index and a valid bit:
+ *
+ * +----------------+-----+-----+-----+---+-----+
+ * | Page address   | Rsv | ACI | Rsv | V | Rsv |
+ * +----------------+-----+-----+-----+---+-----+
+ *  31:12 - Page address
+ *  11:8  - Reserved
+ *   7:4  - Authority Control Index
+ *   3:2  - Reserved
+ *     1  - 1 if the entry is valid
+ *     0  - Reserved
+ *
+ * The way permissions work is that the IOMMU has 16 "domains" that
+ * can be configured to give each masters either read or write
+ * permissions through the IOMMU_DM_AUT_CTRL_REG registers. The domain
+ * 0 seems like the default domain, and its permissions in the
+ * IOMMU_DM_AUT_CTRL_REG are only read-only, so it's not really
+ * useful to enforce any particular permission.
+ *
+ * Each page entry will then have a reference to the domain they are
+ * affected to, so that we can actually enforce them on a per-page
+ * basis.
+ *
+ * In order to make it work with the IOMMU framework, we will be using
+ * 4 different domains, starting at 1: RD_WR, RD, WR and NONE
+ * depending on the permission we want to enforce. Each domain will
+ * have each master setup in the same way, since the IOMMU framework
+ * doesn't seem to restrict page access on a per-device basis. And
+ * then we will use the relevant domain index when generating the page
+ * table entry depending on the permissions we want to be enforced.
+ */
+
+enum sun50i_iommu_aci {
+	SUN50I_IOMMU_ACI_DO_NOT_USE = 0,
+	SUN50I_IOMMU_ACI_NONE,
+	SUN50I_IOMMU_ACI_RD,
+	SUN50I_IOMMU_ACI_WR,
+	SUN50I_IOMMU_ACI_RD_WR,
+};
+
+#define SUN50I_PTE_PAGE_ADDRESS_MASK	GENMASK(31, 12)
+#define SUN50I_PTE_ACI_MASK		GENMASK(7, 4)
+#define SUN50I_PTE_PAGE_VALID		BIT(1)
+
+static phys_addr_t sun50i_pte_get_page_address(u32 pte)
+{
+	return (phys_addr_t)pte & SUN50I_PTE_PAGE_ADDRESS_MASK;
+}
+
+static enum sun50i_iommu_aci sun50i_get_pte_aci(u32 pte)
+{
+	return FIELD_GET(SUN50I_PTE_ACI_MASK, pte);
+}
+
+static bool sun50i_pte_is_page_valid(u32 pte)
+{
+	return pte & SUN50I_PTE_PAGE_VALID;
+}
+
+static u32 sun50i_mk_pte(phys_addr_t page, int prot)
+{
+	enum sun50i_iommu_aci aci;
+	u32 flags = 0;
+
+	if (prot & (IOMMU_READ | IOMMU_WRITE))
+		aci = SUN50I_IOMMU_ACI_RD_WR;
+	else if (prot & IOMMU_READ)
+		aci = SUN50I_IOMMU_ACI_RD;
+	else if (prot & IOMMU_WRITE)
+		aci = SUN50I_IOMMU_ACI_WR;
+	else
+		aci = SUN50I_IOMMU_ACI_NONE;
+
+	flags |= FIELD_PREP(SUN50I_PTE_ACI_MASK, aci);
+	page &= SUN50I_PTE_PAGE_ADDRESS_MASK;
+	return page | flags | SUN50I_PTE_PAGE_VALID;
+}
+
+static void sun50i_table_flush(struct sun50i_iommu_domain *sun50i_domain,
+			       void *vaddr, unsigned int count)
+{
+	struct sun50i_iommu *iommu = sun50i_domain->iommu;
+	dma_addr_t dma = virt_to_phys(vaddr);
+	size_t size = count * PT_ENTRY_SIZE;
+
+	dma_sync_single_for_device(iommu->dev, dma, size, DMA_TO_DEVICE);
+}
+
+static int sun50i_iommu_flush_all_tlb(struct sun50i_iommu *iommu)
+{
+	u32 reg;
+	int ret;
+
+	assert_spin_locked(&iommu->iommu_lock);
+
+	iommu_write(iommu,
+		    IOMMU_TLB_FLUSH_REG,
+		    IOMMU_TLB_FLUSH_PTW_CACHE |
+		    IOMMU_TLB_FLUSH_MACRO_TLB |
+		    IOMMU_TLB_FLUSH_MICRO_TLB(5) |
+		    IOMMU_TLB_FLUSH_MICRO_TLB(4) |
+		    IOMMU_TLB_FLUSH_MICRO_TLB(3) |
+		    IOMMU_TLB_FLUSH_MICRO_TLB(2) |
+		    IOMMU_TLB_FLUSH_MICRO_TLB(1) |
+		    IOMMU_TLB_FLUSH_MICRO_TLB(0));
+
+	ret = readl_poll_timeout(iommu->base + IOMMU_TLB_FLUSH_REG,
+				 reg, !reg,
+				 1, 2000);
+	if (ret)
+		dev_warn(iommu->dev, "TLB Flush timed out!\n");
+
+	return ret;
+}
+
+static int sun50i_iommu_ptw_invalidate(struct sun50i_iommu *iommu,
+				       dma_addr_t iova)
+{
+	int ret;
+	u32 reg;
+
+	assert_spin_locked(&iommu->iommu_lock);
+
+	iommu_write(iommu, IOMMU_PC_IVLD_ADDR_REG, iova);
+	iommu_write(iommu, IOMMU_PC_IVLD_ENABLE_REG,
+		    IOMMU_PC_IVLD_ENABLE_ENABLE);
+
+	ret = readl_poll_timeout(iommu->base + IOMMU_PC_IVLD_ENABLE_REG,
+				 reg, !(reg & IOMMU_PC_IVLD_ENABLE_ENABLE),
+				 1, 2000);
+	if (ret)
+		dev_err(iommu->dev, "PTW cache invalid timed out\n");
+
+	return ret;
+}
+
+static void sun50i_iommu_flush_iotlb_all(struct iommu_domain *domain)
+{
+	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
+	struct sun50i_iommu *iommu = sun50i_domain->iommu;
+	unsigned long flags;
+
+	/*
+	 * At boot, we'll have a first call into .flush_iotlb_all right after
+	 * .add_device, and since we link our (single) domain to our iommu in
+	 * the .attach_device callback, we don't have that pointer set.
+	 *
+	 * It shouldn't really be any trouble to ignore it though since we flush
+	 * all caches as part of the device powerup.
+	 */
+	if (!iommu)
+		return;
+
+	spin_lock_irqsave(&iommu->iommu_lock, flags);
+	sun50i_iommu_flush_all_tlb(iommu);
+	spin_unlock_irqrestore(&iommu->iommu_lock, flags);
+}
+
+static void sun50i_iommu_iotlb_sync(struct iommu_domain *domain,
+				    struct iommu_iotlb_gather *gather)
+{
+	sun50i_iommu_flush_iotlb_all(domain);
+}
+
+static int sun50i_iommu_enable(struct sun50i_iommu *iommu)
+{
+	struct sun50i_iommu_domain *sun50i_domain;
+	unsigned long flags;
+	int ret;
+
+	if (!iommu->domain)
+		return 0;
+
+	sun50i_domain = to_sun50i_domain(iommu->domain);
+
+	ret = reset_control_deassert(iommu->reset);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(iommu->clk);
+	if (ret)
+		goto err_reset_assert;
+
+	spin_lock_irqsave(&iommu->iommu_lock, flags);
+
+	iommu_write(iommu, IOMMU_TTB_REG, sun50i_domain->dt_dma);
+	iommu_write(iommu, IOMMU_TLB_PREFETCH_REG,
+		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(0) |
+		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(1) |
+		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(2) |
+		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(3) |
+		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(4) |
+		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(5));
+	iommu_write(iommu, IOMMU_INT_ENABLE_REG, IOMMU_INT_MASK);
+	iommu_write(iommu, IOMMU_DM_AUT_CTRL_REG(SUN50I_IOMMU_ACI_NONE),
+		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 0) |
+		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 0) |
+		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 1) |
+		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 1) |
+		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 2) |
+		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 2) |
+		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 3) |
+		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 3) |
+		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 4) |
+		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 4) |
+		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 5) |
+		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 5));
+
+	iommu_write(iommu, IOMMU_DM_AUT_CTRL_REG(SUN50I_IOMMU_ACI_RD),
+		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 0) |
+		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 1) |
+		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 2) |
+		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 3) |
+		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 4) |
+		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 5));
+
+	iommu_write(iommu, IOMMU_DM_AUT_CTRL_REG(SUN50I_IOMMU_ACI_WR),
+		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 0) |
+		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 1) |
+		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 2) |
+		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 3) |
+		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 4) |
+		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 5));
+
+	ret = sun50i_iommu_flush_all_tlb(iommu);
+	if (ret) {
+		spin_unlock_irqrestore(&iommu->iommu_lock, flags);
+		goto err_clk_disable;
+	}
+
+	iommu_write(iommu, IOMMU_AUTO_GATING_REG, IOMMU_AUTO_GATING_ENABLE);
+	iommu_write(iommu, IOMMU_ENABLE_REG, IOMMU_ENABLE_ENABLE);
+
+	spin_unlock_irqrestore(&iommu->iommu_lock, flags);
+
+	return 0;
+
+err_clk_disable:
+	clk_disable_unprepare(iommu->clk);
+
+err_reset_assert:
+	reset_control_assert(iommu->reset);
+
+	return ret;
+}
+
+static void sun50i_iommu_disable(struct sun50i_iommu *iommu)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&iommu->iommu_lock, flags);
+
+	iommu_write(iommu, IOMMU_ENABLE_REG, 0);
+	iommu_write(iommu, IOMMU_TTB_REG, 0);
+
+	spin_unlock_irqrestore(&iommu->iommu_lock, flags);
+
+	clk_disable_unprepare(iommu->clk);
+	reset_control_assert(iommu->reset);
+}
+
+static void *sun50i_iommu_alloc_page_table(struct sun50i_iommu *iommu,
+					   gfp_t gfp)
+{
+	dma_addr_t pt_dma;
+	u32 *page_table;
+
+	page_table = kmem_cache_zalloc(iommu->pt_pool, gfp);
+	if (!page_table)
+		return ERR_PTR(-ENOMEM);
+
+	pt_dma = dma_map_single(iommu->dev, page_table, PT_SIZE, DMA_TO_DEVICE);
+	if (dma_mapping_error(iommu->dev, pt_dma)) {
+		dev_err(iommu->dev, "Couldn't map L2 Page Table\n");
+		kmem_cache_free(iommu->pt_pool, page_table);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	/* We rely on the physical address and DMA address being the same */
+	WARN_ON(pt_dma != virt_to_phys(page_table));
+
+	return page_table;
+}
+
+static void sun50i_iommu_free_page_table(struct sun50i_iommu *iommu,
+					 u32 *page_table)
+{
+	phys_addr_t pt_phys = virt_to_phys(page_table);
+
+	dma_unmap_single(iommu->dev, pt_phys, PT_SIZE, DMA_TO_DEVICE);
+	kmem_cache_free(iommu->pt_pool, page_table);
+}
+
+static u32 *sun50i_dte_get_page_table(struct sun50i_iommu_domain *sun50i_domain,
+				      dma_addr_t iova, gfp_t gfp)
+{
+	struct sun50i_iommu *iommu = sun50i_domain->iommu;
+	unsigned long flags;
+	u32 *page_table;
+	u32 *dte_addr;
+	u32 old_dte;
+	u32 dte;
+
+	dte_addr = &sun50i_domain->dt[sun50i_iova_get_dte_index(iova)];
+	dte = *dte_addr;
+	if (sun50i_dte_is_pt_valid(dte)) {
+		phys_addr_t pt_phys = sun50i_dte_get_pt_address(dte);
+		return (u32 *)phys_to_virt(pt_phys);
+	}
+
+	page_table = sun50i_iommu_alloc_page_table(iommu, gfp);
+	if (IS_ERR(page_table))
+		return page_table;
+
+	dte = sun50i_mk_dte(virt_to_phys(page_table));
+	old_dte = cmpxchg(dte_addr, 0, dte);
+	if (old_dte) {
+		phys_addr_t installed_pt_phys =
+			sun50i_dte_get_pt_address(old_dte);
+		u32 *installed_pt = phys_to_virt(installed_pt_phys);
+		u32 *drop_pt = page_table;
+
+		page_table = installed_pt;
+		dte = old_dte;
+		sun50i_iommu_free_page_table(iommu, drop_pt);
+	}
+
+	sun50i_table_flush(sun50i_domain, page_table, PT_SIZE);
+	sun50i_table_flush(sun50i_domain, dte_addr, 1);
+
+	spin_lock_irqsave(&iommu->iommu_lock, flags);
+	sun50i_iommu_ptw_invalidate(iommu, iova);
+	spin_unlock_irqrestore(&iommu->iommu_lock, flags);
+
+	return page_table;
+}
+
+static int sun50i_iommu_map(struct iommu_domain *domain, unsigned long iova,
+			    phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
+{
+	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
+	struct sun50i_iommu *iommu = sun50i_domain->iommu;
+	u32 pte_index;
+	u32 *page_table, *pte_addr;
+	int ret = 0;
+
+	page_table = sun50i_dte_get_page_table(sun50i_domain, iova, gfp);
+	if (IS_ERR(page_table)) {
+		ret = PTR_ERR(page_table);
+		goto out;
+	}
+
+	pte_index = sun50i_iova_get_pte_index(iova);
+	pte_addr = &page_table[pte_index];
+	if (unlikely(sun50i_pte_is_page_valid(*pte_addr))) {
+		phys_addr_t page_phys = sun50i_pte_get_page_address(*pte_addr);
+		dev_err(iommu->dev,
+			"iova %pad already mapped to %pa cannot remap to %pa prot: %#x\n",
+			&iova, &page_phys, &paddr, prot);
+		ret = -EBUSY;
+		goto out;
+	}
+
+	*pte_addr = sun50i_mk_pte(paddr, prot);
+	sun50i_table_flush(sun50i_domain, pte_addr, 1);
+
+out:
+	return ret;
+}
+
+static size_t sun50i_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
+				 size_t size, struct iommu_iotlb_gather *gather)
+{
+	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
+	struct sun50i_iommu *iommu = sun50i_domain->iommu;
+	phys_addr_t pt_phys;
+	dma_addr_t pte_dma;
+	u32 *pte_addr;
+	u32 dte;
+
+	dte = sun50i_domain->dt[sun50i_iova_get_dte_index(iova)];
+	if (!sun50i_dte_is_pt_valid(dte))
+		return 0;
+
+	pt_phys = sun50i_dte_get_pt_address(dte);
+	pte_addr = (u32 *)phys_to_virt(pt_phys) + sun50i_iova_get_pte_index(iova);
+	pte_dma = pt_phys + sun50i_iova_get_pte_index(iova) * PT_ENTRY_SIZE;
+
+	if (!sun50i_pte_is_page_valid(*pte_addr))
+		return 0;
+
+	memset(pte_addr, 0, sizeof(*pte_addr));
+	sun50i_table_flush(sun50i_domain, pte_addr, 1);
+
+	spin_lock(&iommu->iommu_lock);
+	sun50i_iommu_ptw_invalidate(iommu, iova);
+	spin_unlock(&iommu->iommu_lock);
+
+	return SZ_4K;
+}
+
+static phys_addr_t sun50i_iommu_iova_to_phys(struct iommu_domain *domain,
+					     dma_addr_t iova)
+{
+	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
+	phys_addr_t pt_phys;
+	u32 *page_table;
+	u32 dte, pte;
+
+	dte = sun50i_domain->dt[sun50i_iova_get_dte_index(iova)];
+	if (!sun50i_dte_is_pt_valid(dte))
+		return 0;
+
+	pt_phys = sun50i_dte_get_pt_address(dte);
+	page_table = (u32 *)phys_to_virt(pt_phys);
+	pte = page_table[sun50i_iova_get_pte_index(iova)];
+	if (!sun50i_pte_is_page_valid(pte))
+		return 0;
+
+	return sun50i_pte_get_page_address(pte) +
+		sun50i_iova_get_page_offset(iova);
+}
+
+static struct iommu_domain *sun50i_iommu_domain_alloc(unsigned type)
+{
+	struct sun50i_iommu_domain *sun50i_domain;
+
+	if (type != IOMMU_DOMAIN_DMA &&
+	    type != IOMMU_DOMAIN_IDENTITY &&
+	    type != IOMMU_DOMAIN_UNMANAGED)
+		return NULL;
+
+	sun50i_domain = kzalloc(sizeof(*sun50i_domain), GFP_KERNEL);
+	if (!sun50i_domain)
+		return NULL;
+
+	if (type == IOMMU_DOMAIN_DMA &&
+	    iommu_get_dma_cookie(&sun50i_domain->domain))
+		goto err_free_domain;
+
+	sun50i_domain->dt = (u32 *)__get_free_pages(GFP_KERNEL,
+						    get_order(DT_SIZE));
+	if (!sun50i_domain->dt)
+		goto err_put_cookie;
+	memset(sun50i_domain->dt, 0, DT_SIZE);
+
+	refcount_set(&sun50i_domain->refcnt, 1);
+
+	sun50i_domain->domain.geometry.aperture_start = 0;
+	sun50i_domain->domain.geometry.aperture_end = DMA_BIT_MASK(32);
+	sun50i_domain->domain.geometry.force_aperture = true;
+
+	return &sun50i_domain->domain;
+
+err_put_cookie:
+	if (type == IOMMU_DOMAIN_DMA)
+		iommu_put_dma_cookie(&sun50i_domain->domain);
+
+err_free_domain:
+	kfree(sun50i_domain);
+
+	return NULL;
+}
+
+static void sun50i_iommu_domain_free(struct iommu_domain *domain)
+{
+	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
+
+	free_pages((unsigned long)sun50i_domain->dt, get_order(DT_SIZE));
+	sun50i_domain->dt = NULL;
+
+	iommu_put_dma_cookie(domain);
+
+	kfree(sun50i_domain);
+}
+
+static int sun50i_iommu_attach_domain(struct sun50i_iommu *iommu,
+				      struct sun50i_iommu_domain *sun50i_domain)
+{
+	iommu->domain = &sun50i_domain->domain;
+	sun50i_domain->iommu = iommu;
+
+	sun50i_domain->dt_dma = dma_map_single(iommu->dev, sun50i_domain->dt,
+					       DT_SIZE, DMA_TO_DEVICE);
+	if (dma_mapping_error(iommu->dev, sun50i_domain->dt_dma)) {
+		dev_err(iommu->dev, "Couldn't map L1 Page Table\n");
+		return -ENOMEM;
+	}
+
+	return sun50i_iommu_enable(iommu);
+}
+
+static void sun50i_iommu_detach_domain(struct sun50i_iommu *iommu,
+				       struct sun50i_iommu_domain *sun50i_domain)
+{
+	unsigned int i;
+
+	for (i = 0; i < NUM_DT_ENTRIES; i++) {
+		phys_addr_t pt_phys;
+		u32 *page_table;
+		u32 *dte_addr;
+		u32 dte;
+
+		dte_addr = &sun50i_domain->dt[i];
+		dte = *dte_addr;
+		if (!sun50i_dte_is_pt_valid(dte))
+			continue;
+
+		memset(dte_addr, 0, sizeof(*dte_addr));
+		sun50i_table_flush(sun50i_domain, dte_addr, 1);
+
+		pt_phys = sun50i_dte_get_pt_address(dte);
+		page_table = phys_to_virt(pt_phys);
+		sun50i_iommu_free_page_table(iommu, page_table);
+	}
+
+
+	sun50i_iommu_disable(iommu);
+
+	dma_unmap_single(iommu->dev, virt_to_phys(sun50i_domain->dt),
+			 DT_SIZE, DMA_TO_DEVICE);
+
+	iommu->domain = NULL;
+}
+
+static void sun50i_iommu_detach_device(struct iommu_domain *domain,
+				       struct device *dev)
+{
+	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
+	struct sun50i_iommu *iommu = dev_iommu_priv_get(dev);
+
+	dev_dbg(dev, "Detaching from IOMMU domain\n");
+
+	if (iommu->domain != domain)
+		return;
+
+	if (refcount_dec_and_test(&sun50i_domain->refcnt))
+		sun50i_iommu_detach_domain(iommu, sun50i_domain);
+}
+
+static int sun50i_iommu_attach_device(struct iommu_domain *domain,
+				      struct device *dev)
+{
+	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
+	struct sun50i_iommu *iommu;
+
+	iommu = sun50i_iommu_from_dev(dev);
+	if (!iommu)
+		return -ENODEV;
+
+	dev_dbg(dev, "Attaching to IOMMU domain\n");
+
+	refcount_inc(&sun50i_domain->refcnt);
+
+	if (iommu->domain == domain)
+		return 0;
+
+	if (iommu->domain)
+		sun50i_iommu_detach_device(iommu->domain, dev);
+
+	sun50i_iommu_attach_domain(iommu, sun50i_domain);
+
+	return 0;
+}
+
+static int sun50i_iommu_add_device(struct device *dev)
+{
+	struct sun50i_iommu *iommu;
+	struct iommu_group *group;
+
+	iommu = sun50i_iommu_from_dev(dev);
+	if (!iommu)
+		return -ENODEV;
+
+	group = iommu_group_get_for_dev(dev);
+	if (IS_ERR(group))
+		return PTR_ERR(group);
+
+	iommu_group_put(group);
+
+	return 0;
+}
+
+static void sun50i_iommu_remove_device(struct device *dev)
+{
+	iommu_group_remove_device(dev);
+}
+
+static struct iommu_group *sun50i_iommu_device_group(struct device *dev)
+{
+	struct sun50i_iommu *iommu = sun50i_iommu_from_dev(dev);
+
+	return iommu_group_ref_get(iommu->group);
+}
+
+static int sun50i_iommu_of_xlate(struct device *dev,
+				 struct of_phandle_args *args)
+{
+	struct platform_device *iommu_pdev = of_find_device_by_node(args->np);
+	unsigned id = args->args[0];
+
+	dev_iommu_priv_set(dev, platform_get_drvdata(iommu_pdev));
+
+	return iommu_fwspec_add_ids(dev, &id, 1);
+}
+
+static struct iommu_ops sun50i_iommu_ops = {
+	.pgsize_bitmap	= SZ_4K,
+	.add_device	= sun50i_iommu_add_device,
+	.attach_dev	= sun50i_iommu_attach_device,
+	.detach_dev	= sun50i_iommu_detach_device,
+	.device_group	= sun50i_iommu_device_group,
+	.domain_alloc	= sun50i_iommu_domain_alloc,
+	.domain_free	= sun50i_iommu_domain_free,
+	.flush_iotlb_all = sun50i_iommu_flush_iotlb_all,
+	.iotlb_sync	= sun50i_iommu_iotlb_sync,
+	.iova_to_phys	= sun50i_iommu_iova_to_phys,
+	.map		= sun50i_iommu_map,
+	.of_xlate	= sun50i_iommu_of_xlate,
+	.remove_device	= sun50i_iommu_remove_device,
+	.unmap		= sun50i_iommu_unmap,
+};
+
+static void sun50i_iommu_report_fault(struct sun50i_iommu *iommu,
+				      unsigned master, phys_addr_t iova,
+				      unsigned prot)
+{
+	dev_err(iommu->dev, "Page fault for %pad (master %d, dir %s)\n",
+		&iova, master, (prot == IOMMU_FAULT_WRITE) ? "wr" : "rd");
+
+	if (iommu->domain)
+		report_iommu_fault(iommu->domain, iommu->dev, iova, prot);
+	else
+		dev_err(iommu->dev, "Page fault while iommu not attached to any domain?\n");
+}
+
+static phys_addr_t sun50i_iommu_handle_pt_irq(struct sun50i_iommu *iommu,
+					      unsigned addr_reg,
+					      unsigned blame_reg)
+{
+	phys_addr_t iova;
+	unsigned master;
+	u32 blame;
+
+	assert_spin_locked(&iommu->iommu_lock);
+
+	iova = iommu_read(iommu, addr_reg);
+	blame = iommu_read(iommu, blame_reg);
+	master = ilog2(blame & IOMMU_INT_MASTER_MASK);
+
+	/*
+	 * If the address is not in the page table, we can't get what
+	 * operation triggered the fault. Assume it's a read
+	 * operation.
+	 */
+	sun50i_iommu_report_fault(iommu, master, iova, IOMMU_FAULT_READ);
+
+	return iova;
+}
+
+static phys_addr_t sun50i_iommu_handle_perm_irq(struct sun50i_iommu *iommu)
+{
+	enum sun50i_iommu_aci aci;
+	phys_addr_t iova;
+	unsigned master;
+	unsigned dir;
+	u32 blame;
+
+	assert_spin_locked(&iommu->iommu_lock);
+
+	blame = iommu_read(iommu, IOMMU_INT_STA_REG);
+	master = ilog2(blame & IOMMU_INT_MASTER_MASK);
+	iova = iommu_read(iommu, IOMMU_INT_ERR_ADDR_REG(master));
+	aci = sun50i_get_pte_aci(iommu_read(iommu,
+					    IOMMU_INT_ERR_DATA_REG(master)));
+
+	switch (aci) {
+		/*
+		 * If we are in the read-only domain, then it means we
+		 * tried to write.
+		 */
+	case SUN50I_IOMMU_ACI_RD:
+		dir = IOMMU_FAULT_WRITE;
+		break;
+
+		/*
+		 * If we are in the write-only domain, then it means
+		 * we tried to read.
+		 */
+	case SUN50I_IOMMU_ACI_WR:
+
+		/*
+		 * If we are in the domain without any permission, we
+		 * can't really tell. Let's default to a read
+		 * operation.
+		 */
+	case SUN50I_IOMMU_ACI_NONE:
+
+		/* WTF? */
+	case SUN50I_IOMMU_ACI_RD_WR:
+	default:
+		dir = IOMMU_FAULT_READ;
+		break;
+	}
+
+	/*
+	 * If the address is not in the page table, we can't get what
+	 * operation triggered the fault. Assume it's a read
+	 * operation.
+	 */
+	sun50i_iommu_report_fault(iommu, master, iova, dir);
+
+	return iova;
+}
+
+static irqreturn_t sun50i_iommu_irq(int irq, void *dev_id)
+{
+	struct sun50i_iommu *iommu = dev_id;
+	phys_addr_t iova;
+	u32 status;
+
+	spin_lock(&iommu->iommu_lock);
+
+	status = iommu_read(iommu, IOMMU_INT_STA_REG);
+	if (!(status & IOMMU_INT_MASK)) {
+		spin_unlock(&iommu->iommu_lock);
+		return IRQ_NONE;
+	}
+
+	if (status & IOMMU_INT_INVALID_L2PG)
+		iova = sun50i_iommu_handle_pt_irq(iommu,
+						  IOMMU_INT_ERR_ADDR_L2_REG,
+						  IOMMU_L2PG_INT_REG);
+	else if (status & IOMMU_INT_INVALID_L1PG)
+		iova = sun50i_iommu_handle_pt_irq(iommu,
+						  IOMMU_INT_ERR_ADDR_L1_REG,
+						  IOMMU_L1PG_INT_REG);
+	else
+		iova = sun50i_iommu_handle_perm_irq(iommu);
+
+	iommu_write(iommu, IOMMU_INT_CLR_REG, status);
+
+	iommu_write(iommu, IOMMU_RESET_REG, ~status);
+	iommu_write(iommu, IOMMU_RESET_REG, status);
+
+	spin_unlock(&iommu->iommu_lock);
+
+	return IRQ_HANDLED;
+}
+
+static int sun50i_iommu_probe(struct platform_device *pdev)
+{
+	struct sun50i_iommu *iommu;
+	int ret, irq;
+
+	iommu = devm_kzalloc(&pdev->dev, sizeof(*iommu), GFP_KERNEL);
+	if (!iommu)
+		return -ENOMEM;
+	spin_lock_init(&iommu->iommu_lock);
+	platform_set_drvdata(pdev, iommu);
+	iommu->dev = &pdev->dev;
+
+	iommu->pt_pool = kmem_cache_create(dev_name(&pdev->dev),
+					   PT_SIZE, PT_SIZE,
+					   SLAB_HWCACHE_ALIGN,
+					   NULL);
+	if (!iommu->pt_pool)
+		return -ENOMEM;
+
+	iommu->group = iommu_group_alloc();
+	if (IS_ERR(iommu->group)) {
+		ret = PTR_ERR(iommu->group);
+		goto err_free_cache;
+	}
+
+	iommu->base = devm_platform_ioremap_resource(pdev, 0);
+	if (!iommu->base) {
+		ret = PTR_ERR(iommu->base);
+		goto err_free_group;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		ret = irq;
+		goto err_free_group;
+	}
+
+	iommu->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(iommu->clk)) {
+		dev_err(&pdev->dev, "Couldn't get our clock.\n");
+		ret = PTR_ERR(iommu->clk);
+		goto err_free_group;
+	}
+
+	iommu->reset = devm_reset_control_get(&pdev->dev, NULL);
+	if (IS_ERR(iommu->reset)) {
+		dev_err(&pdev->dev, "Couldn't get our reset line.\n");
+		ret = PTR_ERR(iommu->reset);
+		goto err_free_group;
+	}
+
+	ret = iommu_device_sysfs_add(&iommu->iommu, &pdev->dev,
+				     NULL, dev_name(&pdev->dev));
+	if (ret)
+		goto err_free_group;
+
+	iommu_device_set_ops(&iommu->iommu, &sun50i_iommu_ops);
+	iommu_device_set_fwnode(&iommu->iommu, &pdev->dev.of_node->fwnode);
+
+	ret = iommu_device_register(&iommu->iommu);
+	if (ret)
+		goto err_remove_sysfs;
+
+	ret = devm_request_irq(&pdev->dev, irq, sun50i_iommu_irq, 0,
+			       dev_name(&pdev->dev), iommu);
+	if (ret < 0)
+		goto err_unregister;
+
+	bus_set_iommu(&platform_bus_type, &sun50i_iommu_ops);
+
+	return 0;
+
+err_unregister:
+	iommu_device_unregister(&iommu->iommu);
+
+err_remove_sysfs:
+	iommu_device_sysfs_remove(&iommu->iommu);
+
+err_free_group:
+	iommu_group_put(iommu->group);
+
+err_free_cache:
+	kmem_cache_destroy(iommu->pt_pool);
+
+	return ret;
+}
+
+static const struct of_device_id sun50i_iommu_dt[] = {
+	{ .compatible = "allwinner,sun50i-h6-iommu", },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, sun50i_iommu_dt);
+
+static struct platform_driver sun50i_iommu_driver = {
+	.driver		= {
+		.name			= "sun50i-iommu",
+		.of_match_table 	= sun50i_iommu_dt,
+		.suppress_bind_attrs	= true,
+	}
+};
+builtin_platform_driver_probe(sun50i_iommu_driver, sun50i_iommu_probe);
+
+MODULE_DESCRIPTION("Allwinner H6 IOMMU driver");
+MODULE_AUTHOR("Maxime Ripard <maxime@cerno.tech>");
+MODULE_AUTHOR("zhuxianbin <zhuxianbin@allwinnertech.com>");
+MODULE_LICENSE("Dual BSD/GPL");
-- 
git-series 0.9.1

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[PATCH v3 4/5] arm64: dts: allwinner: h6: Add IOMMU

[Maxime Ripard]

Now that we have a driver for the IOMMU, let's start using it.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi
index b9ab7d8fa8af..bba64a4030e2 100644
--- a/arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi
+++ b/arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi
@@ -123,6 +123,7 @@
 				clock-names = "bus",
 					      "mod";
 				resets = <&display_clocks RST_MIXER0>;
+				iommus = <&iommu 0>;
 
 				ports {
 					#address-cells = <1>;
@@ -387,6 +388,15 @@
 			#interrupt-cells = <3>;
 		};
 
+		iommu: iommu@30f0000 {
+			compatible = "allwinner,sun50i-h6-iommu";
+			reg = <0x030f0000 0x10000>;
+			interrupts = <GIC_SPI 57 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&ccu CLK_BUS_IOMMU>;
+			resets = <&ccu RST_BUS_IOMMU>;
+			#iommu-cells = <1>;
+		};
+
 		mmc0: mmc@4020000 {
 			compatible = "allwinner,sun50i-h6-mmc",
 				     "allwinner,sun50i-a64-mmc";
-- 
git-series 0.9.1

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[PATCH v3 5/5] drm/sun4i: mixer: Call of_dma_configure if there's an IOMMU

[Maxime Ripard]

The main DRM device is actually a virtual device so it doesn't have the
iommus property, which is instead on the DMA masters, in this case the
mixers.

Add a call to of_dma_configure with the mixers DT node but on the DRM
virtual device to configure it in the same way than the mixers.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 drivers/gpu/drm/sun4i/sun8i_mixer.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/gpu/drm/sun4i/sun8i_mixer.c b/drivers/gpu/drm/sun4i/sun8i_mixer.c
index 4a64f7ae437a..19b3b4184704 100644
--- a/drivers/gpu/drm/sun4i/sun8i_mixer.c
+++ b/drivers/gpu/drm/sun4i/sun8i_mixer.c
@@ -452,6 +452,19 @@ static int sun8i_mixer_bind(struct device *dev, struct device *master,
 	mixer->engine.ops = &sun8i_engine_ops;
 	mixer->engine.node = dev->of_node;
 
+	if (of_find_property(dev->of_node, "iommus", NULL)) {
+		/*
+		 * This assume we have the same DMA constraints for
+		 * all our the mixers in our pipeline. This sounds
+		 * bad, but it has always been the case for us, and
+		 * DRM doesn't do per-device allocation either, so we
+		 * would need to fix DRM first...
+		 */
+		ret = of_dma_configure(drm->dev, dev->of_node, true);
+		if (ret)
+			return ret;
+	}
+
 	/*
 	 * While this function can fail, we shouldn't do anything
 	 * if this happens. Some early DE2 DT entries don't provide
-- 
git-series 0.9.1

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Re: [PATCH v3 2/5] dt-bindings: display: sun8i-mixer: Allow for an iommu property

[Rob Herring]

On Tue,  5 May 2020 12:09:31 +0200, Maxime Ripard wrote:
> The H6 mixer is attached to an IOMMU, so let's allow that property to be
> set in the bindings.
> 
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> ---
>  Documentation/devicetree/bindings/display/allwinner,sun8i-a83t-de2-mixer.yaml | 3 +++
>  1 file changed, 3 insertions(+)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

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Re: [PATCH v3 3/5] iommu: Add Allwinner H6 IOMMU driver

[Joerg Roedel]

On Tue, May 05, 2020 at 12:09:32PM +0200, Maxime Ripard wrote:
> +static u32 *sun50i_dte_get_page_table(struct sun50i_iommu_domain *sun50i_domain,
> +				      dma_addr_t iova, gfp_t gfp)
> +{
> +	struct sun50i_iommu *iommu = sun50i_domain->iommu;
> +	unsigned long flags;
> +	u32 *page_table;
> +	u32 *dte_addr;
> +	u32 old_dte;
> +	u32 dte;
> +
> +	dte_addr = &sun50i_domain->dt[sun50i_iova_get_dte_index(iova)];
> +	dte = *dte_addr;
> +	if (sun50i_dte_is_pt_valid(dte)) {
> +		phys_addr_t pt_phys = sun50i_dte_get_pt_address(dte);
> +		return (u32 *)phys_to_virt(pt_phys);
> +	}
> +
> +	page_table = sun50i_iommu_alloc_page_table(iommu, gfp);
> +	if (IS_ERR(page_table))
> +		return page_table;
> +
> +	dte = sun50i_mk_dte(virt_to_phys(page_table));
> +	old_dte = cmpxchg(dte_addr, 0, dte);
> +	if (old_dte) {
> +		phys_addr_t installed_pt_phys =
> +			sun50i_dte_get_pt_address(old_dte);
> +		u32 *installed_pt = phys_to_virt(installed_pt_phys);
> +		u32 *drop_pt = page_table;
> +
> +		page_table = installed_pt;
> +		dte = old_dte;
> +		sun50i_iommu_free_page_table(iommu, drop_pt);
> +	}
> +
> +	sun50i_table_flush(sun50i_domain, page_table, PT_SIZE);
> +	sun50i_table_flush(sun50i_domain, dte_addr, 1);
> +
> +	spin_lock_irqsave(&iommu->iommu_lock, flags);
> +	sun50i_iommu_ptw_invalidate(iommu, iova);
> +	spin_unlock_irqrestore(&iommu->iommu_lock, flags);

Why is that needed, does the PTW also cache non-present entries?

> +static size_t sun50i_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
> +				 size_t size, struct iommu_iotlb_gather *gather)
> +{
> +	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
> +	struct sun50i_iommu *iommu = sun50i_domain->iommu;
> +	phys_addr_t pt_phys;
> +	dma_addr_t pte_dma;
> +	u32 *pte_addr;
> +	u32 dte;
> +
> +	dte = sun50i_domain->dt[sun50i_iova_get_dte_index(iova)];
> +	if (!sun50i_dte_is_pt_valid(dte))
> +		return 0;
> +
> +	pt_phys = sun50i_dte_get_pt_address(dte);
> +	pte_addr = (u32 *)phys_to_virt(pt_phys) + sun50i_iova_get_pte_index(iova);
> +	pte_dma = pt_phys + sun50i_iova_get_pte_index(iova) * PT_ENTRY_SIZE;
> +
> +	if (!sun50i_pte_is_page_valid(*pte_addr))
> +		return 0;
> +
> +	memset(pte_addr, 0, sizeof(*pte_addr));
> +	sun50i_table_flush(sun50i_domain, pte_addr, 1);
> +
> +	spin_lock(&iommu->iommu_lock);
> +	sun50i_iommu_ptw_invalidate(iommu, iova);
> +	spin_unlock(&iommu->iommu_lock);

And is that also needed? You clear a PTE here and not a top-level DT
entry. All these spinlocks in the map/unmap paths will truly hurt
performance.

And if it is really needed you can defer it into the iotlb_sync()
call-back.

> +static int sun50i_iommu_add_device(struct device *dev)
> +{
> +	struct sun50i_iommu *iommu;
> +	struct iommu_group *group;
> +
> +	iommu = sun50i_iommu_from_dev(dev);
> +	if (!iommu)
> +		return -ENODEV;
> +
> +	group = iommu_group_get_for_dev(dev);
> +	if (IS_ERR(group))
> +		return PTR_ERR(group);
> +
> +	iommu_group_put(group);
> +
> +	return 0;
> +}
> +
> +static void sun50i_iommu_remove_device(struct device *dev)
> +{
> +	iommu_group_remove_device(dev);
> +}


These two call-backs have been renamed in the iommu-tree to
probe_device() and release_device() with slightly different semantics
and function signatures. I think for this driver they should look like
this:

	static struct iommu_device *sun50i_iommu_probe_device(struct device *dev)
	{
		struct sun50i_iommu *iommu;

		iommu = sun50i_iommu_from_dev(dev);
		if (!iommu)
			return ERR_PTR(-ENODEV);

		return &iommu->iommu;
	}

	static void sun50i_iommu_release_device(struct device *dev)
	{
	}

Can you pleas rebase these patches to the 'core' branch of the
iommu-tree and use these new call-backs?

The rest of your driver looks good to me. Good work!

Thanks,

	Joerg

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Re: [PATCH v3 3/5] iommu: Add Allwinner H6 IOMMU driver

[Maxime Ripard]

[-- Attachment #1.1: Type: text/plain, Size: 3226 bytes --]

Hi Jörg,

On Wed, May 13, 2020 at 11:53:04AM +0200, Joerg Roedel wrote:
> On Tue, May 05, 2020 at 12:09:32PM +0200, Maxime Ripard wrote:
> > +static u32 *sun50i_dte_get_page_table(struct sun50i_iommu_domain *sun50i_domain,
> > +				      dma_addr_t iova, gfp_t gfp)
> > +{
> > +	struct sun50i_iommu *iommu = sun50i_domain->iommu;
> > +	unsigned long flags;
> > +	u32 *page_table;
> > +	u32 *dte_addr;
> > +	u32 old_dte;
> > +	u32 dte;
> > +
> > +	dte_addr = &sun50i_domain->dt[sun50i_iova_get_dte_index(iova)];
> > +	dte = *dte_addr;
> > +	if (sun50i_dte_is_pt_valid(dte)) {
> > +		phys_addr_t pt_phys = sun50i_dte_get_pt_address(dte);
> > +		return (u32 *)phys_to_virt(pt_phys);
> > +	}
> > +
> > +	page_table = sun50i_iommu_alloc_page_table(iommu, gfp);
> > +	if (IS_ERR(page_table))
> > +		return page_table;
> > +
> > +	dte = sun50i_mk_dte(virt_to_phys(page_table));
> > +	old_dte = cmpxchg(dte_addr, 0, dte);
> > +	if (old_dte) {
> > +		phys_addr_t installed_pt_phys =
> > +			sun50i_dte_get_pt_address(old_dte);
> > +		u32 *installed_pt = phys_to_virt(installed_pt_phys);
> > +		u32 *drop_pt = page_table;
> > +
> > +		page_table = installed_pt;
> > +		dte = old_dte;
> > +		sun50i_iommu_free_page_table(iommu, drop_pt);
> > +	}
> > +
> > +	sun50i_table_flush(sun50i_domain, page_table, PT_SIZE);
> > +	sun50i_table_flush(sun50i_domain, dte_addr, 1);
> > +
> > +	spin_lock_irqsave(&iommu->iommu_lock, flags);
> > +	sun50i_iommu_ptw_invalidate(iommu, iova);
> > +	spin_unlock_irqrestore(&iommu->iommu_lock, flags);
> 
> Why is that needed, does the PTW also cache non-present entries?

The documentation is pretty sparse, so I was conservative again. I've removed it
and it seems to be working fine in all the cases I could test, so I guess we're
fine without it :)

> > +static int sun50i_iommu_add_device(struct device *dev)
> > +{
> > +	struct sun50i_iommu *iommu;
> > +	struct iommu_group *group;
> > +
> > +	iommu = sun50i_iommu_from_dev(dev);
> > +	if (!iommu)
> > +		return -ENODEV;
> > +
> > +	group = iommu_group_get_for_dev(dev);
> > +	if (IS_ERR(group))
> > +		return PTR_ERR(group);
> > +
> > +	iommu_group_put(group);
> > +
> > +	return 0;
> > +}
> > +
> > +static void sun50i_iommu_remove_device(struct device *dev)
> > +{
> > +	iommu_group_remove_device(dev);
> > +}
> 
> 
> These two call-backs have been renamed in the iommu-tree to
> probe_device() and release_device() with slightly different semantics
> and function signatures. I think for this driver they should look like
> this:
> 
> 	static struct iommu_device *sun50i_iommu_probe_device(struct device *dev)
> 	{
> 		struct sun50i_iommu *iommu;
> 
> 		iommu = sun50i_iommu_from_dev(dev);
> 		if (!iommu)
> 			return ERR_PTR(-ENODEV);
> 
> 		return &iommu->iommu;
> 	}
> 
> 	static void sun50i_iommu_release_device(struct device *dev)
> 	{
> 	}
> 
> Can you pleas rebase these patches to the 'core' branch of the
> iommu-tree and use these new call-backs?
> 
> The rest of your driver looks good to me. Good work!

I've rebased it on next, and it indeed works with your suggestion. I'll resend a
new version in a short while.

Thanks!
Maxime

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