[PATCH 1/2] iommu/shmobile: Add iommu driver for Renesas IPMMU modules

[Hideki EIRAKU]

This is the Renesas IPMMU driver and IOMMU API implementation.

The IPMMU module supports the MMU function and the PMB function.  The
MMU function provides address translation by pagetable compatible with
ARMv6.  The PMB function provides address translation including
tile-linear translation.  This patch implements the MMU function.

The iommu driver does not register a platform driver directly because:
- the register space of the MMU function and the PMB function
  have a common register (used for settings flush), so they should ideally
  have a way to appropriately share this register.
- the MMU function uses the IOMMU API while the PMB function does not.
- the two functions may be used independently.

Signed-off-by: Hideki EIRAKU <hdk@xxxxxxxxxx>
---
 arch/arm/mach-shmobile/Kconfig              |    6 +
 arch/arm/mach-shmobile/Makefile             |    3 +
 arch/arm/mach-shmobile/include/mach/ipmmu.h |   10 +
 arch/arm/mach-shmobile/ipmmu.c              |  137 ++++++++++++
 drivers/iommu/Kconfig                       |    7 +
 drivers/iommu/Makefile                      |    1 +
 drivers/iommu/shmobile-iommu.c              |  318 +++++++++++++++++++++++++++
 7 files changed, 482 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm/mach-shmobile/include/mach/ipmmu.h
 create mode 100644 arch/arm/mach-shmobile/ipmmu.c
 create mode 100644 drivers/iommu/shmobile-iommu.c

diff --git a/arch/arm/mach-shmobile/Kconfig b/arch/arm/mach-shmobile/Kconfig
index df33909..2ebe04d 100644
--- a/arch/arm/mach-shmobile/Kconfig
+++ b/arch/arm/mach-shmobile/Kconfig
@@ -197,6 +197,12 @@ endmenu
 config SH_CLK_CPG
 	bool
 
+config SHMOBILE_IPMMU
+	bool "IPMMU/IPMMUI driver"
+	default n
+	help
+	  This enables build of the IPMMU/IPMMUI driver.
+
 source "drivers/sh/Kconfig"
 
 endif
diff --git a/arch/arm/mach-shmobile/Makefile b/arch/arm/mach-shmobile/Makefile
index 8aa1962..ffca2b9 100644
--- a/arch/arm/mach-shmobile/Makefile
+++ b/arch/arm/mach-shmobile/Makefile
@@ -58,3 +58,6 @@ obj-$(CONFIG_MACH_KZM9G)	+= board-kzm9g.o
 # Framework support
 obj-$(CONFIG_SMP)		+= $(smp-y)
 obj-$(CONFIG_GENERIC_GPIO)	+= $(pfc-y)
+
+# IPMMU/IPMMUI
+obj-$(CONFIG_SHMOBILE_IPMMU)	+= ipmmu.o
diff --git a/arch/arm/mach-shmobile/include/mach/ipmmu.h b/arch/arm/mach-shmobile/include/mach/ipmmu.h
new file mode 100644
index 0000000..afbd9eb
--- /dev/null
+++ b/arch/arm/mach-shmobile/include/mach/ipmmu.h
@@ -0,0 +1,10 @@
+#ifdef CONFIG_SHMOBILE_IPMMU
+void ipmmu_tlb_flush(void);
+void ipmmu_tlb_set(unsigned long phys, int size, int asid);
+void ipmmu_add_device(struct device *dev);
+int ipmmu_iommu_init(struct device *dev);
+#else
+static inline void ipmmu_add_device(struct device *dev)
+{
+}
+#endif
diff --git a/arch/arm/mach-shmobile/ipmmu.c b/arch/arm/mach-shmobile/ipmmu.c
new file mode 100644
index 0000000..b728a83
--- /dev/null
+++ b/arch/arm/mach-shmobile/ipmmu.c
@@ -0,0 +1,137 @@
+/*
+ * IPMMU/IPMMUI
+ * Copyright (C) 2012  Hideki EIRAKU
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <mach/ipmmu.h>
+
+#define IMCTR1 0x000
+#define IMCTR2 0x004
+#define IMASID 0x010
+#define IMTTBR 0x014
+#define IMTTBCR 0x018
+
+static void __iomem *ipmmu_base;
+static int tlb_enabled;
+static int tlb_asid, tlb_size;
+static unsigned long tlb_phys;
+
+void __attribute__((weak)) ipmmu_add_device(struct device *dev)
+{
+}
+
+void ipmmu_tlb_flush(void)
+{
+	if (!ipmmu_base)
+		return;
+	if (tlb_enabled)
+		iowrite32(0x3, ipmmu_base + IMCTR1); /* flush the TLB */
+	else
+		iowrite32(0x2, ipmmu_base + IMCTR1);
+}
+
+static void update_tlb(void)
+{
+	if (!ipmmu_base)
+		return;
+	switch (tlb_size) {
+	default:
+		tlb_enabled = 0;
+		break;
+	case 0x2000:
+		iowrite32(1, ipmmu_base + IMTTBCR);
+		tlb_enabled = 1;
+		break;
+	case 0x1000:
+		iowrite32(2, ipmmu_base + IMTTBCR);
+		tlb_enabled = 1;
+		break;
+	case 0x800:
+		iowrite32(3, ipmmu_base + IMTTBCR);
+		tlb_enabled = 1;
+		break;
+	case 0x400:
+		iowrite32(4, ipmmu_base + IMTTBCR);
+		tlb_enabled = 1;
+		break;
+	case 0x200:
+		iowrite32(5, ipmmu_base + IMTTBCR);
+		tlb_enabled = 1;
+		break;
+	case 0x100:
+		iowrite32(6, ipmmu_base + IMTTBCR);
+		tlb_enabled = 1;
+		break;
+	case 0x80:
+		iowrite32(7, ipmmu_base + IMTTBCR);
+		tlb_enabled = 1;
+		break;
+	}
+	iowrite32(tlb_phys, ipmmu_base + IMTTBR);
+	iowrite32(tlb_asid, ipmmu_base + IMASID);
+}
+
+void ipmmu_tlb_set(unsigned long phys, int size, int asid)
+{
+	tlb_phys = phys;
+	tlb_size = size;
+	tlb_asid = asid;
+	update_tlb();
+}
+
+int __attribute__((weak)) ipmmu_iommu_init(struct device *dev)
+{
+	return 0;
+}
+
+static int __devinit ipmmu_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "cannot get platform resources\n");
+		return -ENOENT;
+	}
+	ipmmu_base = ioremap_nocache(res->start, resource_size(res));
+	if (!ipmmu_base) {
+		dev_err(&pdev->dev, "ioremap_nocache failed\n");
+		return -ENOMEM;
+	}
+	iowrite32(0x0, ipmmu_base + IMCTR1); /* disable TLB */
+	iowrite32(0x0, ipmmu_base + IMCTR2); /* disable PMB */
+	ipmmu_iommu_init(&pdev->dev);
+	return 0;
+}
+
+static struct platform_driver ipmmu_driver = {
+	.probe = ipmmu_probe,
+	.driver = {
+		.owner = THIS_MODULE,
+		.name = "ipmmu",
+	},
+};
+
+static int __init ipmmu_init(void)
+{
+	return platform_driver_register(&ipmmu_driver);
+}
+subsys_initcall(ipmmu_init);
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 3408937..2b9df1d 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -183,4 +183,11 @@ config EXYNOS_IOMMU_DEBUG
 
 	  Say N unless you need kernel log message for IOMMU debugging
 
+config SHMOBILE_IOMMU
+	bool "IOMMU for Renesas IPMMU/IPMMUI"
+	default n
+	depends on SHMOBILE_IPMMU
+	select IOMMU_API
+	select ARM_DMA_USE_IOMMU
+
 endif # IOMMU_SUPPORT
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 76e54ef..3e0cf7f 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -11,3 +11,4 @@ obj-$(CONFIG_OMAP_IOMMU_DEBUG) += omap-iommu-debug.o
 obj-$(CONFIG_TEGRA_IOMMU_GART) += tegra-gart.o
 obj-$(CONFIG_TEGRA_IOMMU_SMMU) += tegra-smmu.o
 obj-$(CONFIG_EXYNOS_IOMMU) += exynos-iommu.o
+obj-$(CONFIG_SHMOBILE_IOMMU) += shmobile-iommu.o
diff --git a/drivers/iommu/shmobile-iommu.c b/drivers/iommu/shmobile-iommu.c
new file mode 100644
index 0000000..bc2ae1a
--- /dev/null
+++ b/drivers/iommu/shmobile-iommu.c
@@ -0,0 +1,318 @@
+/*
+ * IOMMU for IPMMU/IPMMUI
+ * Copyright (C) 2012  Hideki EIRAKU
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#include <linux/io.h>
+#include <linux/dmapool.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/iommu.h>
+#include <linux/dma-mapping.h>
+#include <mach/ipmmu.h>
+#include <asm/dma-iommu.h>
+
+#define L1_LEN 0x800
+#define L1_SIZE 0x2000
+#define L1_ALIGN 0x2000
+#define L2_LEN 0x100
+#define L2_SIZE 0x400
+#define L2_ALIGN 0x400
+
+struct shmobile_iommu_domain_pgtable {
+	uint32_t *pgtable;
+	dma_addr_t handle;
+};
+
+struct shmobile_iommu_domain {
+	struct shmobile_iommu_domain_pgtable l1, l2[L1_LEN];
+	spinlock_t map_lock;
+	atomic_t active;
+};
+
+static struct dma_iommu_mapping *iommu_mapping;
+static struct device *ipmmu_devices;
+static struct dma_pool *l1p, *l2p;
+static spinlock_t lock;
+static DEFINE_SPINLOCK(lock_add);
+static struct shmobile_iommu_domain *attached;
+static int num_attached_devices;
+
+static int shmobile_iommu_domain_init(struct iommu_domain *domain)
+{
+	struct shmobile_iommu_domain *d;
+	int i;
+
+	d = kmalloc(sizeof *d, GFP_KERNEL);
+	if (!d)
+		return -ENOMEM;
+	d->l1.pgtable = dma_pool_alloc(l1p, GFP_KERNEL, &d->l1.handle);
+	if (!d->l1.pgtable) {
+		kfree(d);
+		return -ENOMEM;
+	}
+	for (i = 0; i < L1_LEN; i++)
+		d->l2[i].pgtable = NULL;
+	memset(d->l1.pgtable, 0, L1_SIZE);
+	spin_lock_init(&d->map_lock);
+	atomic_set(&d->active, 0);
+	domain->priv = d;
+	return 0;
+}
+
+static void shmobile_iommu_domain_destroy(struct iommu_domain *domain)
+{
+	struct shmobile_iommu_domain *d = domain->priv;
+	int i;
+
+	for (i = 0; i < L1_LEN; i++) {
+		if (d->l2[i].pgtable)
+			dma_pool_free(l2p, d->l2[i].pgtable, d->l2[i].handle);
+	}
+	dma_pool_free(l1p, d->l1.pgtable, d->l1.handle);
+	kfree(d);
+}
+
+static int shmobile_iommu_attach_device(struct iommu_domain *domain,
+					struct device *dev)
+{
+	struct shmobile_iommu_domain *d = domain->priv;
+	int ret = -EBUSY;
+
+	spin_lock(&lock);
+	if (attached != d) {
+		if (attached)
+			goto err;
+		atomic_set(&d->active, 1);
+		ipmmu_tlb_set(d->l1.handle, L1_SIZE, 0);
+		wmb();
+		ipmmu_tlb_flush();
+		attached = d;
+		num_attached_devices = 0;
+	}
+	num_attached_devices++;
+	ret = 0;
+err:
+	spin_unlock(&lock);
+	return ret;
+}
+
+static void shmobile_iommu_detach_device(struct iommu_domain *domain,
+					 struct device *dev)
+{
+	struct shmobile_iommu_domain *d = domain->priv;
+
+	spin_lock(&lock);
+	atomic_set(&d->active, 0);
+	num_attached_devices--;
+	if (!num_attached_devices) {
+		ipmmu_tlb_set(0, 0, 0);
+		ipmmu_tlb_flush();
+		attached = NULL;
+	}
+	spin_unlock(&lock);
+}
+
+static int
+l2alloc(struct shmobile_iommu_domain *d, unsigned int n)
+{
+	if (!d->l2[n].pgtable) {
+		d->l2[n].pgtable = dma_pool_alloc(l2p, GFP_KERNEL,
+						  &d->l2[n].handle);
+		if (!d->l2[n].pgtable)
+			return -ENOMEM;
+		memset(d->l2[n].pgtable, 0, L2_SIZE);
+	}
+	d->l1.pgtable[n] = d->l2[n].handle | 0x1;
+	return 0;
+}
+
+static int shmobile_iommu_map(struct iommu_domain *domain, unsigned long iova,
+			      phys_addr_t paddr, size_t size, int prot)
+{
+	struct shmobile_iommu_domain *d = domain->priv;
+	unsigned int l1n, l2n, i;
+	int ret;
+
+	l1n = iova >> 20;
+	switch (size) {
+	case 0x1000:
+		l2n = (iova >> 12) & 0xff;
+		spin_lock(&d->map_lock);
+		ret = l2alloc(d, l1n);
+		if (!ret)
+			d->l2[l1n].pgtable[l2n] = paddr | 0xff2;
+		spin_unlock(&d->map_lock);
+		break;
+	case 0x10000:
+		l2n = (iova >> 12) & 0xf0;
+		spin_lock(&d->map_lock);
+		ret = l2alloc(d, l1n);
+		if (!ret) {
+			for (i = 0; i < 0x10; i++)
+				d->l2[l1n].pgtable[l2n + i] = paddr | 0xff1;
+		}
+		spin_unlock(&d->map_lock);
+		break;
+	case 0x100000:
+		spin_lock(&d->map_lock);
+		d->l1.pgtable[l1n] = paddr | 0xc02;
+		spin_unlock(&d->map_lock);
+		ret = 0;
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	if (!ret && atomic_read(&d->active)) {
+		wmb();
+		ipmmu_tlb_flush();
+	}
+	return ret;
+}
+
+static size_t shmobile_iommu_unmap(struct iommu_domain *domain,
+				   unsigned long iova, size_t size)
+{
+	struct shmobile_iommu_domain *d = domain->priv;
+	unsigned int l1n, l2n, i;
+
+	l1n = iova >> 20;
+	switch (size) {
+	case 0x1000:
+		l2n = (iova >> 12) & 0xff;
+		spin_lock(&d->map_lock);
+		if (d->l2[l1n].pgtable)
+			d->l2[l1n].pgtable[l2n] = 0;
+		spin_unlock(&d->map_lock);
+		break;
+	case 0x10000:
+		l2n = (iova >> 12) & 0xf0;
+		spin_lock(&d->map_lock);
+		if (d->l2[l1n].pgtable) {
+			for (i = 0; i < 0x10; i++)
+				d->l2[l1n].pgtable[l2n + i] = 0;
+		}
+		spin_unlock(&d->map_lock);
+		break;
+	case 0x100000:
+		spin_lock(&d->map_lock);
+		d->l1.pgtable[l1n] = 0;
+		spin_unlock(&d->map_lock);
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (atomic_read(&d->active)) {
+		wmb();
+		ipmmu_tlb_flush();
+	}
+	return size;
+}
+
+static phys_addr_t shmobile_iommu_iova_to_phys(struct iommu_domain *domain,
+					       unsigned long iova)
+{
+	struct shmobile_iommu_domain *d = domain->priv;
+	uint32_t l1d = 0, l2d = 0;
+	unsigned int l1n, l2n;
+
+	l1n = iova >> 20;
+	l2n = (iova >> 12) & 0xff;
+	spin_lock(&d->map_lock);
+	if (d->l2[l1n].pgtable)
+		l2d = d->l2[l1n].pgtable[l2n];
+	else
+		l1d = d->l1.pgtable[l1n];
+	spin_unlock(&d->map_lock);
+	switch (l2d & 3) {
+	case 1:
+		return (l2d & ~0xffff) | (iova & 0xffff);
+	case 2:
+		return (l2d & ~0xfff) | (iova & 0xfff);
+	default:
+		if ((l1d & 3) == 2)
+			return (l1d & ~0xfffff) | (iova & 0xfffff);
+		return 0;
+	}
+}
+
+static struct iommu_ops shmobile_iommu_ops = {
+	.domain_init = shmobile_iommu_domain_init,
+	.domain_destroy = shmobile_iommu_domain_destroy,
+	.attach_dev = shmobile_iommu_attach_device,
+	.detach_dev = shmobile_iommu_detach_device,
+	.map = shmobile_iommu_map,
+	.unmap = shmobile_iommu_unmap,
+	.iova_to_phys = shmobile_iommu_iova_to_phys,
+	.pgsize_bitmap = 0x111000,
+};
+
+static int shmobile_iommu_attach_all_devices(void)
+{
+	struct device *dev;
+	int ret = 0;
+
+	spin_lock(&lock_add);
+	iommu_mapping = arm_iommu_create_mapping(&platform_bus_type, 0x0,
+						 0x80000000, 0);
+	if (IS_ERR_OR_NULL(iommu_mapping)) {
+		ret = PTR_ERR(iommu_mapping);
+		goto err;
+	}
+	for (dev = ipmmu_devices; dev; dev = dev->archdata.iommu) {
+		if (arm_iommu_attach_device(dev, iommu_mapping))
+			pr_err("arm_iommu_attach_device failed\n");
+	}
+err:
+	spin_unlock(&lock_add);
+	return 0;
+}
+
+void ipmmu_add_device(struct device *dev)
+{
+	spin_lock(&lock_add);
+	dev->archdata.iommu = ipmmu_devices;
+	ipmmu_devices = dev;
+	if (!IS_ERR_OR_NULL(iommu_mapping)) {
+		if (arm_iommu_attach_device(dev, iommu_mapping))
+			pr_err("arm_iommu_attach_device failed\n");
+	}
+	spin_unlock(&lock_add);
+}
+
+int ipmmu_iommu_init(struct device *dev)
+{
+	dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
+	l1p = dma_pool_create("shmobile-iommu-pgtable1", dev,
+			      L1_SIZE, L1_ALIGN, 0);
+	if (!l1p)
+		goto nomem_pool1;
+	l2p = dma_pool_create("shmobile-iommu-pgtable2", dev,
+			      L2_SIZE, L2_ALIGN, 0);
+	if (!l2p)
+		goto nomem_pool2;
+	spin_lock_init(&lock);
+	attached = NULL;
+	bus_set_iommu(&platform_bus_type, &shmobile_iommu_ops);
+	if (shmobile_iommu_attach_all_devices())
+		pr_err("shmobile_iommu_attach_all_devices failed\n");
+	return 0;
+nomem_pool2:
+	dma_pool_destroy(l1p);
+nomem_pool1:
+	return -ENOMEM;
+}
-- 
1.7.0.4

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