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* [PATCH v2 3/5] iommu/exynos: Add iommu driver for Exynos4 Platforms
@ 2011-09-30  7:31 Kukjin Kim
  2011-09-30 12:06 ` Roedel, Joerg
  0 siblings, 1 reply; 3+ messages in thread
From: Kukjin Kim @ 2011-09-30  7:31 UTC (permalink / raw)
  To: linux-arm-kernel

From: KyongHo Cho <pullip.cho@samsung.com>

This is the System MMU driver and IOMMU API implementation for
Exynos4 SOC platforms. Exynos4 platforms has more than 10 System
MMUs dedicated for each multimedia accellerators.

Signed-off-by: KyongHo Cho <pullip.cho@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
---
 drivers/iommu/Kconfig        |   14 +
 drivers/iommu/Makefile       |    1 +
 drivers/iommu/exynos_iommu.c |  914 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 929 insertions(+), 0 deletions(-)
 create mode 100644 drivers/iommu/exynos_iommu.c

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index b57b3fa..1c754cd 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -107,4 +107,18 @@ config INTR_REMAP
 	  To use x2apic mode in the CPU's which support x2APIC enhancements or
 	  to support platforms with CPU's having > 8 bit APIC ID, say Y.
 
+# EXYNOS IOMMU support
+config EXYNOS_IOMMU
+	bool "Exynos IOMMU Support"
+	depends on ARCH_EXYNOS4
+	select IOMMU_API
+	select EXYNOS4_DEV_SYSMMU
+	help
+	  Support for the IOMMUs (System MMUs) Samsung Exynos application
+	  processor family. This enables H/W multimedia accellerators to view
+	  non-linear physical memory chunks as a linear memory in their virtual
+	  address spaces.
+
+	  If unsure, say N here.
+
 endif # IOMMU_SUPPORT
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 4d4d77d..1eb924f 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -3,3 +3,4 @@ obj-$(CONFIG_MSM_IOMMU) += msm_iommu.o msm_iommu_dev.o
 obj-$(CONFIG_AMD_IOMMU) += amd_iommu.o amd_iommu_init.o
 obj-$(CONFIG_DMAR) += dmar.o iova.o intel-iommu.o
 obj-$(CONFIG_INTR_REMAP) += dmar.o intr_remapping.o
+obj-$(CONFIG_EXYNOS_IOMMU) += exynos_iommu.o
diff --git a/drivers/iommu/exynos_iommu.c b/drivers/iommu/exynos_iommu.c
new file mode 100644
index 0000000..33fa4a8
--- /dev/null
+++ b/drivers/iommu/exynos_iommu.c
@@ -0,0 +1,914 @@
+/* linux/drivers/iommu/exynos_iommu.c
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/io.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/iommu.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/list.h>
+#include <linux/atomic.h>
+
+#include <asm/cacheflush.h>
+#include <asm/pgtable.h>
+
+#include <mach/map.h>
+#include <mach/regs-sysmmu.h>
+#include <mach/sysmmu.h>
+
+#define CTRL_ENABLE	0x5
+#define CTRL_BLOCK	0x7
+#define CTRL_DISABLE	0x0
+
+enum S5P_SYSMMU_INTERRUPT_TYPE {
+	SYSMMU_PAGEFAULT,
+	SYSMMU_AR_MULTIHIT,
+	SYSMMU_AW_MULTIHIT,
+	SYSMMU_BUSERROR,
+	SYSMMU_AR_SECURITY,
+	SYSMMU_AR_ACCESS,
+	SYSMMU_AW_SECURITY,
+	SYSMMU_AW_PROTECTION, /* 7 */
+	SYSMMU_FAULT_UNKNOWN,
+	SYSMMU_FAULTS_NUM
+};
+
+static unsigned short fault_reg_offset[SYSMMU_FAULTS_NUM] = {
+	S5P_PAGE_FAULT_ADDR,
+	S5P_AR_FAULT_ADDR,
+	S5P_AW_FAULT_ADDR,
+	S5P_DEFAULT_SLAVE_ADDR,
+	S5P_AR_FAULT_ADDR,
+	S5P_AR_FAULT_ADDR,
+	S5P_AW_FAULT_ADDR,
+	S5P_AW_FAULT_ADDR
+};
+
+static char *sysmmu_fault_name[SYSMMU_FAULTS_NUM + 1] = {
+	"PAGE FAULT",
+	"AR MULTI-HIT FAULT",
+	"AW MULTI-HIT FAULT",
+	"BUS ERROR",
+	"AR SECURITY PROTECTION FAULT",
+	"AR ACCESS PROTECTION FAULT",
+	"AW SECURITY PROTECTION FAULT",
+	"AW ACCESS PROTECTION FAULT",
+	"UNKOWN FAULT"
+};
+
+struct exynos_iommu_domain {
+	struct device *dev;
+	unsigned long *pgtable;
+	spinlock_t lock;
+	spinlock_t pgtablelock;
+};
+
+struct sysmmu_drvdata {
+	struct list_head node;
+	struct device *dev;
+	struct device *owner;
+	void __iomem *sfrbase;
+	struct clk *clk;
+	int activations;
+	struct iommu_domain *domain;
+	int (*fault_handler)(enum S5P_SYSMMU_INTERRUPT_TYPE itype,
+			unsigned long pgtable_base,
+			unsigned long fault_addr);
+};
+
+/* List of sysmmu_drvdata */
+static LIST_HEAD(sysmmu_list);
+
+static inline struct sysmmu_drvdata *get_sysmmu_data(struct device *owner,
+						struct sysmmu_drvdata *start)
+{
+	struct list_head *pos, *head;
+
+	head = (start) ? &start->node : &sysmmu_list;
+
+	list_for_each(pos, head) {
+		struct sysmmu_drvdata *data =
+				container_of(pos, struct sysmmu_drvdata, node);
+
+		if (pos == &sysmmu_list)
+			return NULL;
+
+		if (data->owner == owner)
+			return data;
+	}
+
+	return NULL;
+}
+
+static inline bool set_sysmmu_active(struct sysmmu_drvdata *data)
+{
+	/* return true if the System MMU was not active previously
+	   and it needs to be initialized */
+
+	data->activations++;
+	return data->activations == 1;
+}
+
+static inline bool set_sysmmu_inactive(struct sysmmu_drvdata *data)
+{
+	/* return true if the System MMU is needed to be disabled */
+	data->activations--;
+
+	if (data->activations == 0)
+		return true;
+
+	if (WARN_ON(data->activations < 0))
+		/* System MMU is already disabled */
+		data->activations = 0;
+
+	return false;
+}
+
+static inline bool is_sysmmu_active(struct sysmmu_drvdata *data)
+{
+	return data->activations != 0;
+}
+
+static inline void sysmmu_block(void __iomem *sfrbase)
+{
+	__raw_writel(CTRL_BLOCK, sfrbase + S5P_MMU_CTRL);
+}
+
+static inline void sysmmu_unblock(void __iomem *sfrbase)
+{
+	__raw_writel(CTRL_ENABLE, sfrbase + S5P_MMU_CTRL);
+}
+
+static inline void __sysmmu_tlb_invalidate(void __iomem *sfrbase)
+{
+	__raw_writel(0x1, sfrbase + S5P_MMU_FLUSH);
+}
+
+static inline void __sysmmu_set_ptbase(void __iomem *sfrbase,
+				       unsigned long pgd)
+{
+	if (unlikely(pgd == 0)) {
+		pgd = (unsigned long)ZERO_PAGE(0);
+		__raw_writel(0x20, sfrbase + S5P_MMU_CFG); /* 4KB LV1 */
+	} else {
+		__raw_writel(0x0, sfrbase + S5P_MMU_CFG); /* 16KB LV1 */
+	}
+
+	__raw_writel(pgd, sfrbase + S5P_PT_BASE_ADDR);
+
+	__sysmmu_tlb_invalidate(sfrbase);
+}
+
+static inline void __set_fault_handler(struct sysmmu_drvdata *data,
+			int (*handler)(enum S5P_SYSMMU_INTERRUPT_TYPE itype,
+					unsigned long pgtable_base,
+					unsigned long fault_addr))
+{
+	data->fault_handler = handler;
+}
+
+void s5p_sysmmu_set_fault_handler(struct device *owner,
+			int (*handler)(enum S5P_SYSMMU_INTERRUPT_TYPE itype,
+					unsigned long pgtable_base,
+					unsigned long fault_addr))
+{
+	struct sysmmu_drvdata *data = NULL;
+
+	while ((data = get_sysmmu_data(owner, data)))
+		__set_fault_handler(data, handler);
+}
+
+static int default_fault_handler(enum S5P_SYSMMU_INTERRUPT_TYPE itype,
+			unsigned long pgtable_base, unsigned long fault_addr)
+{
+	if ((itype > SYSMMU_FAULTS_NUM) || (itype < SYSMMU_PAGEFAULT))
+		itype = SYSMMU_FAULTS_NUM;
+
+	pr_err("%s occured@0x%08lx(Page table base: 0x%08lx)\n",
+			sysmmu_fault_name[itype], fault_addr, pgtable_base);
+	pr_err("\t\tGenerating Kernel OOPS... because it is unrecoverable.\n");
+
+	BUG();
+
+	return 0;
+}
+
+static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
+{
+	/* SYSMMU is in blocked when interrupt occurred. */
+	struct sysmmu_drvdata *data = dev_id;
+	enum S5P_SYSMMU_INTERRUPT_TYPE itype;
+	bool handled = false;
+
+	WARN_ON(!is_sysmmu_active(data));
+
+	itype = (enum S5P_SYSMMU_INTERRUPT_TYPE)
+		__ffs(__raw_readl(data->sfrbase + S5P_INT_STATUS));
+
+	if (WARN_ON((itype < 0) && (itype >= 8))) {
+		itype = SYSMMU_FAULT_UNKNOWN;
+	} else if (data->fault_handler) {
+		unsigned long base;
+		unsigned long addr;
+		addr = __raw_readl(data->sfrbase + fault_reg_offset[itype]);
+		base = __raw_readl(data->sfrbase + S5P_PT_BASE_ADDR);
+
+		if (!data->fault_handler(itype, base, addr))
+			handled = true;
+	}
+
+	if (handled)
+		__raw_writel(1 << itype, data->sfrbase + S5P_INT_CLEAR);
+	else
+		dev_dbg(data->dev, "%s is not handled.\n",
+						sysmmu_fault_name[itype]);
+
+	sysmmu_unblock(data->sfrbase);
+
+	return IRQ_HANDLED;
+}
+
+void exynos_sysmmu_set_tablebase_pgd(struct device *owner, unsigned long pgd)
+{
+	struct sysmmu_drvdata *data = NULL;
+
+	while ((data = get_sysmmu_data(owner, data))) {
+		if (is_sysmmu_active(data)) {
+			sysmmu_block(data->sfrbase);
+			__sysmmu_set_ptbase(data->sfrbase, pgd);
+			sysmmu_unblock(data->sfrbase);
+			dev_dbg(data->dev,
+				"New page table base is 0x%08lx\n", pgd);
+		} else {
+			dev_dbg(data->dev,
+			"Disabled: Skipping setting page table base.\n");
+		}
+	}
+}
+
+static int __exynos_sysmmu_enable(struct device *owner, unsigned long pgtable,
+						struct iommu_domain *domain)
+{
+	struct sysmmu_drvdata *data = NULL;
+	bool enabled = false;
+
+	/* There are some devices that control more System MMUs than one such
+	 * as MFC.
+	 */
+	while ((data = get_sysmmu_data(owner, data))) {
+		enabled = true;
+
+		if (!set_sysmmu_active(data)) {
+			dev_dbg(data->dev, "Already enabled.\n");
+			continue;
+		}
+
+		pm_runtime_get_sync(data->dev);
+
+		clk_enable(data->clk);
+
+		__sysmmu_set_ptbase(data->sfrbase, pgtable);
+
+		__raw_writel(CTRL_ENABLE, data->sfrbase + S5P_MMU_CTRL);
+
+		data->domain = domain;
+
+		dev_dbg(data->dev, "Enabled.\n");
+	}
+
+	return (enabled) ? 0 : -ENODEV;
+}
+
+static inline int exynos_iommu_enable(struct iommu_domain *domain)
+{
+	struct exynos_iommu_domain *priv = domain->priv;
+
+	if (!priv || !priv->dev)
+		return -EINVAL;
+
+	return __exynos_sysmmu_enable(priv->dev, __pa(priv->pgtable), domain);
+}
+
+int exynos_sysmmu_enable(struct device *owner, unsigned long pgtable)
+{
+	return __exynos_sysmmu_enable(owner, pgtable, NULL);
+}
+
+void exynos_sysmmu_disable(struct device *owner)
+{
+	struct sysmmu_drvdata *data = NULL;
+	bool disabled = false;
+
+	while ((data = get_sysmmu_data(owner, data))) {
+		disabled = true;
+
+		if (!set_sysmmu_inactive(data)) {
+			dev_dbg(data->dev, "Inactivation request ignorred\n");
+			continue;
+		}
+
+		__raw_writel(CTRL_DISABLE, data->sfrbase + S5P_MMU_CTRL);
+
+		clk_disable(data->clk);
+
+		pm_runtime_put_sync(data->dev);
+
+		data->domain = NULL;
+
+		dev_dbg(data->dev, "Disabled.\n");
+	}
+
+	BUG_ON(!disabled);
+}
+
+static inline void exynos_iommu_disable(struct iommu_domain *domain)
+{
+	struct exynos_iommu_domain *priv = domain->priv;
+
+	if (priv && priv->dev)
+		exynos_sysmmu_disable(priv->dev);
+}
+
+void exynos_sysmmu_tlb_invalidate(struct device *owner)
+{
+	struct sysmmu_drvdata *data = NULL;
+
+	while ((data = get_sysmmu_data(owner, data))) {
+		if (is_sysmmu_active(data)) {
+			sysmmu_block(data->sfrbase);
+			__sysmmu_tlb_invalidate(data->sfrbase);
+			sysmmu_unblock(data->sfrbase);
+		} else {
+			dev_dbg(data->dev,
+				"Disabled: Skipping invalidating TLB.\n");
+		}
+	}
+}
+
+static int exynos_sysmmu_probe(struct platform_device *pdev)
+{
+	struct resource *res, *ioarea;
+	int ret = 0;
+	int irq;
+	struct device *dev;
+	void *sfr;
+	struct sysmmu_drvdata *data;
+	struct clk *clk;
+
+	dev = &pdev->dev;
+
+	data = kzalloc(GFP_KERNEL, sizeof(*data));
+	if (!data) {
+		dev_err(dev, "Failed to probing System MMU: "
+					"Not enough memory");
+		return -ENOMEM;
+	}
+
+	if (!dev_get_platdata(dev)) {
+		dev_err(dev, "Failed to probing system MMU: "
+						"Owner device is not set.");
+
+		ret = -ENODEV;
+		goto err_init;
+	}
+
+	ret = dev_set_drvdata(dev, data);
+	if (ret) {
+		dev_err(dev, "Failed to probing system MMU: "
+						"Unable to set driver data.");
+		goto err_init;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev,
+			"Failed probing system MMU: failed to get resource.");
+		ret = -ENOENT;
+		goto err_init;
+	}
+
+	ioarea = request_mem_region(res->start, resource_size(res), pdev->name);
+	if (ioarea == NULL) {
+		dev_err(dev, "Failed probing system MMU: "
+					"failed to request memory region.");
+		ret = -ENOENT;
+		goto err_init;
+	}
+
+	sfr = ioremap(res->start, resource_size(res));
+	if (!sfr) {
+		dev_err(dev, "Failed probing system MMU: "
+						"failed to call ioremap().");
+		ret = -ENOENT;
+		goto err_ioremap;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq <= 0) {
+		dev_err(dev, "Failed probing system MMU: "
+						"failed to get irq resource.");
+		ret = irq;
+		goto err_irq;
+	}
+
+	ret = request_irq(irq, exynos_sysmmu_irq, 0, dev_name(dev), data);
+	if (ret) {
+		dev_err(dev, "Failed probing system MMU: "
+						"failed to request irq.");
+		goto err_irq;
+	}
+
+	clk = clk_get(dev, "sysmmu");
+	if (IS_ERR(clk)) {
+		dev_err(dev, "Failed to probing System MMU: "
+					"failed to get clock descriptor");
+		ret = PTR_ERR(clk);
+		goto err_clk;
+	}
+
+	data->dev = dev;
+	data->owner = dev_get_platdata(dev);
+	data->clk = clk;
+	data->sfrbase = sfr;
+	data->fault_handler = &default_fault_handler;
+	INIT_LIST_HEAD(&data->node);
+
+	list_add(&data->node, &sysmmu_list);
+
+	if (dev->parent)
+		pm_runtime_enable(dev);
+
+	dev_dbg(dev, "Initialized for %s.\n", dev_name(data->owner));
+	return 0;
+err_clk:
+	free_irq(irq, data);
+err_irq:
+	iounmap(sfr);
+err_ioremap:
+	release_resource(ioarea);
+	kfree(ioarea);
+err_init:
+	kfree(data);
+	dev_err(dev, "Probing system MMU failed.");
+	return ret;
+}
+
+int exynos_sysmmu_runtime_suspend(struct device *dev)
+{
+	if (WARN_ON(is_sysmmu_active(dev_get_drvdata(dev))))
+		return -EFAULT;
+
+	return 0;
+}
+
+int exynos_sysmmu_runtime_resume(struct device *dev)
+{
+	if (WARN_ON(is_sysmmu_active(dev_get_drvdata(dev))))
+		return -EFAULT;
+
+	return 0;
+}
+
+const struct dev_pm_ops exynos_sysmmu_pm_ops = {
+	.runtime_suspend	= exynos_sysmmu_runtime_suspend,
+	.runtime_resume		= exynos_sysmmu_runtime_resume,
+};
+
+static struct platform_driver exynos_sysmmu_driver = {
+	.probe		= exynos_sysmmu_probe,
+	.driver		= {
+		.owner		= THIS_MODULE,
+		.name		= "s5p-sysmmu",
+		.pm		= &exynos_sysmmu_pm_ops,
+	}
+};
+
+static int __init exynos_sysmmu_init(void)
+{
+	return platform_driver_register(&exynos_sysmmu_driver);
+}
+arch_initcall(exynos_sysmmu_init);
+
+/* We does not consider super section mapping (16MB) */
+#define S5P_SPAGE_SHIFT		12
+#define S5P_LPAGE_SHIFT		16
+#define S5P_SECTION_SHIFT	20
+
+#define S5P_SPAGE_SIZE		(1 << S5P_SPAGE_SHIFT)
+#define S5P_LPAGE_SIZE		(1 << S5P_LPAGE_SHIFT)
+#define S5P_SECTION_SIZE	(1 << S5P_SECTION_SHIFT)
+
+#define S5P_SPAGE_MASK		(~(S5P_SPAGE_SIZE - 1))
+#define S5P_LPAGE_MASK		(~(S5P_LPAGE_SIZE - 1))
+#define S5P_SECTION_MASK	(~(S5P_SECTION_SIZE - 1))
+
+#define S5P_SPAGE_ORDER		(S5P_SPAGE_SHIFT - PAGE_SHIFT)
+#define S5P_LPAGE_ORDER		(S5P_LPAGE_SHIFT - S5P_SPAGE_SHIFT)
+#define S5P_SECTION_ORDER	(S5P_SECTION_SHIFT - S5P_SPAGE_SHIFT)
+
+#define S5P_LV1TABLE_ENTRIES	(1 << (BITS_PER_LONG - S5P_SECTION_SHIFT))
+
+#define S5P_LV2TABLE_ENTRIES	(1 << S5P_SECTION_ORDER)
+#define S5P_LV2TABLE_SIZE	(S5P_LV2TABLE_ENTRIES * sizeof(long))
+#define S5P_LV2TABLE_MASK	(~(S5P_LV2TABLE_SIZE - 1)) /* 0xFFFFFC00 */
+
+#define S5P_SECTION_LV1_ENTRY(entry)	((entry & 0x40003) == 2)
+#define S5P_SUPSECT_LV1_ENTRY(entry)	((entry & 0x40003) == 0x40002)
+#define S5P_PAGE_LV1_ENTRY(entry)	((entry & 3) == 1)
+#define S5P_FAULT_LV1_ENTRY(entry) (((entry & 3) == 0) || (entry & 3) == 3)
+
+#define S5P_LPAGE_LV2_ENTRY(entry)	((entry & 3) == 1)
+#define S5P_SPAGE_LV2_ENTRY(entry)	((entry & 2) == 2)
+#define S5P_FAULT_LV2_ENTRY(entry)	((entry & 3) == 0)
+
+#define MAKE_FAULT_ENTRY(entry)		do { entry = 0; } while (0)
+#define MAKE_SECTION_ENTRY(entry, pa)	do { entry = pa | 2; } while (0)
+#define MAKE_SUPSECT_ENTRY(entry, pa)	do { entry = pa | 0x40002; } while (0)
+#define MAKE_LV2TABLE_ENTRY(entry, pa)	do { entry = pa | 1; } while (0)
+
+#define MAKE_LPAGE_ENTRY(entry, pa)	do { entry = pa | 1; } while (0)
+#define MAKE_SPAGE_ENTRY(entry, pa)	do { entry = pa | 3; } while (0)
+
+#define GET_LV2ENTRY(entry, iova) (\
+	(unsigned long *)phys_to_virt(entry & S5P_LV2TABLE_MASK) +\
+	((iova & (~S5P_SECTION_MASK)) >> S5P_SPAGE_SHIFT))
+
+/* slab cache for level 2 page tables */
+static struct kmem_cache *l2table_cachep;
+
+static inline void pgtable_flush(void *vastart, void *vaend)
+{
+	dmac_flush_range(vastart, vaend);
+	outer_flush_range(virt_to_phys(vastart),
+				virt_to_phys(vaend));
+}
+
+static int exynos_iommu_domain_init(struct iommu_domain *domain)
+{
+	struct exynos_iommu_domain *priv;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->pgtable = (unsigned long *)__get_free_pages(GFP_KERNEL,
+		(S5P_LV1TABLE_ENTRIES * sizeof(unsigned long)) >> PAGE_SHIFT);
+	if (!priv->pgtable) {
+		kfree(priv);
+		return -ENOMEM;
+	}
+
+	memset(priv->pgtable, 0, S5P_LV1TABLE_ENTRIES * sizeof(unsigned long));
+	pgtable_flush(priv->pgtable, priv->pgtable + S5P_LV1TABLE_ENTRIES);
+
+	spin_lock_init(&priv->lock);
+
+	domain->priv = priv;
+
+	iommu_set_fault_handler(domain, &exynos_iommu_fault_handler);
+
+	return 0;
+}
+
+static void exynos_iommu_domain_destroy(struct iommu_domain *domain)
+{
+	struct exynos_iommu_domain *priv = domain->priv;
+
+	free_pages((unsigned long)priv->pgtable,
+		(S5P_LV1TABLE_ENTRIES * sizeof(unsigned long)) >> PAGE_SHIFT);
+
+	kfree(priv);
+
+	domain->priv = NULL;
+}
+
+static int exynos_iommu_attach_device(struct iommu_domain *domain,
+				   struct device *dev)
+{
+	struct exynos_iommu_domain *priv = domain->priv;
+	int ret;
+
+	spin_lock(&priv->lock);
+
+	priv->dev = dev;
+
+	ret = exynos_iommu_enable(domain);
+
+	spin_unlock(&priv->lock);
+
+	return ret;
+}
+
+static void exynos_iommu_detach_device(struct iommu_domain *domain,
+				    struct device *dev)
+{
+	struct exynos_iommu_domain *priv = domain->priv;
+
+	spin_lock(&priv->lock);
+
+	if (priv->dev == dev) {
+		exynos_iommu_disable(domain);
+		priv->dev = NULL;
+	}
+
+	spin_unlock(&priv->lock);
+}
+
+static bool section_available(struct iommu_domain *domain,
+			      unsigned long *lv1entry)
+{
+	struct exynos_iommu_domain *priv = domain->priv;
+
+	if (S5P_SECTION_LV1_ENTRY(*lv1entry)) {
+		dev_err(priv->dev, "1MB entry alread exists at 0x%08x\n",
+				(lv1entry - priv->pgtable) * SZ_1M);
+		return false;
+	}
+
+	if (S5P_PAGE_LV1_ENTRY(*lv1entry)) {
+		unsigned long *lv2end, *lv2base;
+
+		lv2base = phys_to_virt(*lv1entry & S5P_LV2TABLE_MASK);
+		lv2end = lv2base + S5P_LV2TABLE_ENTRIES;
+		while (lv2base != lv2end) {
+			if (!S5P_FAULT_LV2_ENTRY(*lv2base)) {
+				dev_err(priv->dev, "Failed to free L2 page "
+						"table for section mapping.\n");
+				return false;
+			}
+			lv2base++;
+		}
+
+		kmem_cache_free(l2table_cachep,
+				phys_to_virt(*lv1entry & S5P_LV2TABLE_MASK));
+
+		MAKE_FAULT_ENTRY(*lv1entry);
+	}
+
+	return true;
+}
+
+static bool write_lpage(unsigned long *head_entry, unsigned long phys_addr)
+{
+	unsigned long *entry, *end;
+
+	entry = head_entry;
+	end = entry + (1 << S5P_LPAGE_ORDER);
+
+	while (entry != end) {
+		if (!S5P_FAULT_LV2_ENTRY(*entry))
+			break;
+
+		MAKE_LPAGE_ENTRY(*entry, phys_addr);
+
+		entry++;
+	}
+
+	if (entry != end) {
+		end = entry;
+		while (entry != head_entry)
+			MAKE_FAULT_ENTRY(*(--entry));
+
+		return false;
+	}
+
+	return true;
+}
+
+static int exynos_iommu_map(struct iommu_domain *domain, unsigned long iova,
+			 phys_addr_t paddr, int gfp_order, int prot)
+{
+	struct exynos_iommu_domain *priv = domain->priv;
+	unsigned long *start_entry, *entry, *end_entry;
+	int num_entry;
+	int ret = 0;
+	unsigned long flags;
+
+	BUG_ON(priv->pgtable == NULL);
+
+	spin_lock_irqsave(&priv->pgtablelock, flags);
+
+	start_entry = entry = priv->pgtable + (iova >> S5P_SECTION_SHIFT);
+
+	if (gfp_order >= S5P_SECTION_ORDER) {
+		BUG_ON((paddr | iova) & ~S5P_SECTION_MASK);
+		/* 1MiB mapping */
+
+		num_entry = 1 << (gfp_order - S5P_SECTION_ORDER);
+		end_entry = entry + num_entry;
+
+		while (entry != end_entry) {
+			if (!section_available(domain, entry))
+				break;
+
+			MAKE_SECTION_ENTRY(*entry, paddr);
+
+			paddr += S5P_SECTION_SIZE;
+			entry++;
+		}
+
+		if (entry != end_entry)
+			goto mapping_error;
+
+		pgtable_flush(start_entry, entry);
+		goto mapping_done;
+	}
+
+	if (S5P_FAULT_LV1_ENTRY(*entry)) {
+		unsigned long *l2table;
+
+		l2table = kmem_cache_zalloc(l2table_cachep, GFP_KERNEL);
+		if (!l2table) {
+			ret = -ENOMEM;
+			goto nomem_error;
+		}
+
+		pgtable_flush(entry, entry + S5P_LV2TABLE_ENTRIES);
+
+		MAKE_LV2TABLE_ENTRY(*entry, virt_to_phys(l2table));
+		pgtable_flush(entry, entry + 1);
+	}
+
+	/* 'entry' points level 2 entries, hereafter */
+	entry = GET_LV2ENTRY(*entry, iova);
+
+	start_entry = entry;
+	num_entry = 1 << gfp_order;
+	end_entry = entry + num_entry;
+
+	if (gfp_order >= S5P_LPAGE_ORDER) {
+		/* large page(64KiB) mapping */
+		BUG_ON((paddr | iova) & ~S5P_LPAGE_MASK);
+
+		while (entry != end_entry) {
+			if (!write_lpage(entry, paddr)) {
+				pr_err("%s: "
+					"Failed to allocate large page entry."
+					"\n", __func__);
+				break;
+			}
+
+			paddr += S5P_LPAGE_SIZE;
+			entry += (1 << S5P_LPAGE_ORDER);
+		}
+
+		if (entry != end_entry) {
+			entry -= 1 << S5P_LPAGE_ORDER;
+			goto mapping_error;
+		}
+	} else {
+		/* page (4KiB) mapping */
+		while (entry != end_entry && S5P_FAULT_LV2_ENTRY(*entry)) {
+
+			MAKE_SPAGE_ENTRY(*entry, paddr);
+
+			entry++;
+			paddr += S5P_SPAGE_SIZE;
+		}
+
+		if (entry != end_entry) {
+			pr_err("%s: Failed to allocate small page entry.\n",
+								__func__);
+			goto mapping_error;
+		}
+	}
+
+	pgtable_flush(start_entry, entry);
+mapping_error:
+	if (entry != end_entry) {
+		unsigned long *current_entry = entry;
+		while (entry != start_entry)
+			MAKE_FAULT_ENTRY(*(--entry));
+		pgtable_flush(start_entry, current_entry);
+		ret = -EADDRINUSE;
+	}
+
+nomem_error:
+mapping_done:
+	spin_unlock_irqrestore(&priv->pgtablelock, flags);
+
+	return 0;
+}
+
+static int exynos_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
+			   int gfp_order)
+{
+	struct exynos_iommu_domain *priv = domain->priv;
+	unsigned long *entry;
+	int num_entry;
+	unsigned long flags;
+
+	BUG_ON(priv->pgtable == NULL);
+
+	spin_lock_irqsave(&priv->pgtablelock, flags);
+
+	entry = priv->pgtable + (iova >> S5P_SECTION_SHIFT);
+
+	if (gfp_order >= S5P_SECTION_ORDER) {
+		gfp_order -= S5P_SECTION_ORDER;
+		num_entry = 1 << (gfp_order - S5P_SECTION_ORDER);
+		while (num_entry--) {
+			if (S5P_SECTION_LV1_ENTRY(*entry)) {
+				MAKE_FAULT_ENTRY(*entry);
+			} else if (S5P_PAGE_LV1_ENTRY(*entry)) {
+				unsigned long *lv2beg, *lv2end;
+				lv2beg = phys_to_virt(
+						*entry & S5P_LV2TABLE_MASK);
+				lv2end = lv2beg + S5P_LV2TABLE_ENTRIES;
+				while (lv2beg != lv2end) {
+					MAKE_FAULT_ENTRY(*lv2beg);
+					lv2beg++;
+				}
+			}
+			entry++;
+		}
+	} else {
+		entry = GET_LV2ENTRY(*entry, iova);
+
+		BUG_ON(S5P_LPAGE_LV2_ENTRY(*entry) &&
+						(gfp_order < S5P_LPAGE_ORDER));
+
+		num_entry = 1 << gfp_order;
+
+		while (num_entry--) {
+			MAKE_FAULT_ENTRY(*entry);
+			entry++;
+		}
+	}
+
+	if (priv->dev)
+		exynos_sysmmu_tlb_invalidate(priv->dev);
+
+	spin_unlock_irqrestore(&priv->pgtablelock, flags);
+
+	return 0;
+}
+
+static phys_addr_t exynos_iommu_iova_to_phys(struct iommu_domain *domain,
+					  unsigned long iova)
+{
+	struct exynos_iommu_domain *priv = domain->priv;
+	unsigned long *entry;
+	unsigned long offset;
+
+	entry = priv->pgtable + (iova >> S5P_SECTION_SHIFT);
+
+	if (S5P_FAULT_LV1_ENTRY(*entry))
+		return 0;
+
+	offset = iova & ~S5P_SECTION_MASK;
+
+	if (S5P_SECTION_LV1_ENTRY(*entry))
+		return (*entry & S5P_SECTION_MASK) + offset;
+
+	entry = GET_LV2ENTRY(*entry, iova);
+
+	if (S5P_SPAGE_LV2_ENTRY(*entry))
+		return (*entry & S5P_SPAGE_MASK) + (iova & ~S5P_SPAGE_MASK);
+
+	if (S5P_LPAGE_LV2_ENTRY(*entry))
+		return (*entry & S5P_LPAGE_MASK) + (iova & ~S5P_LPAGE_MASK);
+
+	return 0;
+}
+
+static int exynos_iommu_domain_has_cap(struct iommu_domain *domain,
+				    unsigned long cap)
+{
+	return 0;
+}
+
+static struct iommu_ops exynos_iommu_ops = {
+	.domain_init = &exynos_iommu_domain_init,
+	.domain_destroy = &exynos_iommu_domain_destroy,
+	.attach_dev = &exynos_iommu_attach_device,
+	.detach_dev = &exynos_iommu_detach_device,
+	.map = &exynos_iommu_map,
+	.unmap = &exynos_iommu_unmap,
+	.iova_to_phys = &exynos_iommu_iova_to_phys,
+	.domain_has_cap = &exynos_iommu_domain_has_cap,
+};
+
+static int __init exynos_iommu_init(void)
+{
+	l2table_cachep = kmem_cache_create("SysMMU Lv2 Tables",
+				S5P_LV2TABLE_SIZE, S5P_LV2TABLE_SIZE, 0, NULL);
+	if (!l2table_cachep)
+		return -ENOMEM;
+
+	register_iommu(&exynos_iommu_ops);
+
+	return 0;
+}
+arch_initcall(exynos_iommu_init);
-- 
1.7.1

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* [PATCH v2 3/5] iommu/exynos: Add iommu driver for Exynos4 Platforms
  2011-09-30  7:31 [PATCH v2 3/5] iommu/exynos: Add iommu driver for Exynos4 Platforms Kukjin Kim
@ 2011-09-30 12:06 ` Roedel, Joerg
  2011-09-30 23:46   ` KyongHo Cho
  0 siblings, 1 reply; 3+ messages in thread
From: Roedel, Joerg @ 2011-09-30 12:06 UTC (permalink / raw)
  To: linux-arm-kernel

On Fri, Sep 30, 2011 at 03:31:30AM -0400, Kukjin Kim wrote:
> From: KyongHo Cho <pullip.cho@samsung.com>
> 
> This is the System MMU driver and IOMMU API implementation for
> Exynos4 SOC platforms. Exynos4 platforms has more than 10 System
> MMUs dedicated for each multimedia accellerators.
> 
> Signed-off-by: KyongHo Cho <pullip.cho@samsung.com>
> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

First comment: Pleas remove the 'inline' annotations in this patch. It
is better to let the compiler decide what to inline and what not.

> ---
>  drivers/iommu/Kconfig        |   14 +
>  drivers/iommu/Makefile       |    1 +
>  drivers/iommu/exynos_iommu.c |  914 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 929 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/iommu/exynos_iommu.c
> +

> +static inline struct sysmmu_drvdata *get_sysmmu_data(struct device *owner,
> +                                               struct sysmmu_drvdata *start)
> +{
> +       struct list_head *pos, *head;
> +
> +       head = (start) ? &start->node : &sysmmu_list;
> +
> +       list_for_each(pos, head) {
> +               struct sysmmu_drvdata *data =
> +                               container_of(pos, struct sysmmu_drvdata, node);
> +
> +               if (pos == &sysmmu_list)
> +                       return NULL;
> +
> +               if (data->owner == owner)
> +                       return data;
> +       }
> +
> +       return NULL;
> +}

Hmm, may it make sense to store data directly in dev->arch.iommu? This
will save you the list traversals to get the information.

> +
> +static inline bool set_sysmmu_active(struct sysmmu_drvdata *data)
> +{
> +       /* return true if the System MMU was not active previously
> +          and it needs to be initialized */
> +
> +       data->activations++;

Is this variable only accessed under a lock? If not it should be an
atomic.

> +       return data->activations == 1;

Is that right? Shouldn't it be 'data->activations > 0'?

> +}
> +
> +static inline bool set_sysmmu_inactive(struct sysmmu_drvdata *data)
> +{
> +       /* return true if the System MMU is needed to be disabled */
> +       data->activations--;
> +
> +       if (data->activations == 0)
> +               return true;
> +
> +       if (WARN_ON(data->activations < 0))
> +               /* System MMU is already disabled */
> +               data->activations = 0;
> +
> +       return false;
> +}
> +
> +static inline bool is_sysmmu_active(struct sysmmu_drvdata *data)
> +{
> +       return data->activations != 0;
> +}
> +
> +static inline void sysmmu_block(void __iomem *sfrbase)
> +{
> +       __raw_writel(CTRL_BLOCK, sfrbase + S5P_MMU_CTRL);
> +}
> +
> +static inline void sysmmu_unblock(void __iomem *sfrbase)
> +{
> +       __raw_writel(CTRL_ENABLE, sfrbase + S5P_MMU_CTRL);
> +}
> +
> +static inline void __sysmmu_tlb_invalidate(void __iomem *sfrbase)
> +{
> +       __raw_writel(0x1, sfrbase + S5P_MMU_FLUSH);
> +}
> +
> +static inline void __sysmmu_set_ptbase(void __iomem *sfrbase,
> +                                      unsigned long pgd)
> +{
> +       if (unlikely(pgd == 0)) {
> +               pgd = (unsigned long)ZERO_PAGE(0);
> +               __raw_writel(0x20, sfrbase + S5P_MMU_CFG); /* 4KB LV1 */
> +       } else {
> +               __raw_writel(0x0, sfrbase + S5P_MMU_CFG); /* 16KB LV1 */
> +       }
> +
> +       __raw_writel(pgd, sfrbase + S5P_PT_BASE_ADDR);
> +
> +       __sysmmu_tlb_invalidate(sfrbase);
> +}
> +
> +static inline void __set_fault_handler(struct sysmmu_drvdata *data,
> +                       int (*handler)(enum S5P_SYSMMU_INTERRUPT_TYPE itype,
> +                                       unsigned long pgtable_base,
> +                                       unsigned long fault_addr))

Please typedef the function signature.

> +{
> +       data->fault_handler = handler;
> +}
> +
> +void s5p_sysmmu_set_fault_handler(struct device *owner,
> +                       int (*handler)(enum S5P_SYSMMU_INTERRUPT_TYPE itype,
> +                                       unsigned long pgtable_base,
> +                                       unsigned long fault_addr))
> +{
> +       struct sysmmu_drvdata *data = NULL;
> +
> +       while ((data = get_sysmmu_data(owner, data)))
> +               __set_fault_handler(data, handler);
> +}
> +
> +static int default_fault_handler(enum S5P_SYSMMU_INTERRUPT_TYPE itype,
> +                       unsigned long pgtable_base, unsigned long fault_addr)
> +{
> +       if ((itype > SYSMMU_FAULTS_NUM) || (itype < SYSMMU_PAGEFAULT))
> +               itype = SYSMMU_FAULTS_NUM;
> +
> +       pr_err("%s occured at 0x%08lx(Page table base: 0x%08lx)\n",
> +                       sysmmu_fault_name[itype], fault_addr, pgtable_base);
> +       pr_err("\t\tGenerating Kernel OOPS... because it is unrecoverable.\n");
> +
> +       BUG();
> +
> +       return 0;
> +}
> +
> +static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
> +{
> +       /* SYSMMU is in blocked when interrupt occurred. */
> +       struct sysmmu_drvdata *data = dev_id;
> +       enum S5P_SYSMMU_INTERRUPT_TYPE itype;
> +       bool handled = false;
> +
> +       WARN_ON(!is_sysmmu_active(data));
> +
> +       itype = (enum S5P_SYSMMU_INTERRUPT_TYPE)
> +               __ffs(__raw_readl(data->sfrbase + S5P_INT_STATUS));
> +
> +       if (WARN_ON((itype < 0) && (itype >= 8))) {
> +               itype = SYSMMU_FAULT_UNKNOWN;
> +       } else if (data->fault_handler) {
> +               unsigned long base;
> +               unsigned long addr;
> +               addr = __raw_readl(data->sfrbase + fault_reg_offset[itype]);
> +               base = __raw_readl(data->sfrbase + S5P_PT_BASE_ADDR);
> +
> +               if (!data->fault_handler(itype, base, addr))
> +                       handled = true;
> +       }
> +
> +       if (handled)
> +               __raw_writel(1 << itype, data->sfrbase + S5P_INT_CLEAR);
> +       else
> +               dev_dbg(data->dev, "%s is not handled.\n",
> +                                               sysmmu_fault_name[itype]);
> +
> +       sysmmu_unblock(data->sfrbase);
> +
> +       return IRQ_HANDLED;
> +}
> +
> +void exynos_sysmmu_set_tablebase_pgd(struct device *owner, unsigned long pgd)
> +{
> +       struct sysmmu_drvdata *data = NULL;
> +
> +       while ((data = get_sysmmu_data(owner, data))) {
> +               if (is_sysmmu_active(data)) {
> +                       sysmmu_block(data->sfrbase);
> +                       __sysmmu_set_ptbase(data->sfrbase, pgd);
> +                       sysmmu_unblock(data->sfrbase);
> +                       dev_dbg(data->dev,
> +                               "New page table base is 0x%08lx\n", pgd);
> +               } else {
> +                       dev_dbg(data->dev,
> +                       "Disabled: Skipping setting page table base.\n");
> +               }
> +       }
> +}
> +
> +static int __exynos_sysmmu_enable(struct device *owner, unsigned long pgtable,
> +                                               struct iommu_domain *domain)
> +{
> +       struct sysmmu_drvdata *data = NULL;
> +       bool enabled = false;
> +
> +       /* There are some devices that control more System MMUs than one such
> +        * as MFC.
> +        */
> +       while ((data = get_sysmmu_data(owner, data))) {
> +               enabled = true;
> +
> +               if (!set_sysmmu_active(data)) {
> +                       dev_dbg(data->dev, "Already enabled.\n");
> +                       continue;
> +               }
> +
> +               pm_runtime_get_sync(data->dev);
> +
> +               clk_enable(data->clk);
> +
> +               __sysmmu_set_ptbase(data->sfrbase, pgtable);
> +
> +               __raw_writel(CTRL_ENABLE, data->sfrbase + S5P_MMU_CTRL);
> +
> +               data->domain = domain;
> +
> +               dev_dbg(data->dev, "Enabled.\n");
> +       }
> +
> +       return (enabled) ? 0 : -ENODEV;
> +}
> +
> +static inline int exynos_iommu_enable(struct iommu_domain *domain)
> +{
> +       struct exynos_iommu_domain *priv = domain->priv;
> +
> +       if (!priv || !priv->dev)
> +               return -EINVAL;
> +
> +       return __exynos_sysmmu_enable(priv->dev, __pa(priv->pgtable), domain);
> +}
> +
> +int exynos_sysmmu_enable(struct device *owner, unsigned long pgtable)
> +{
> +       return __exynos_sysmmu_enable(owner, pgtable, NULL);
> +}
> +
> +void exynos_sysmmu_disable(struct device *owner)
> +{
> +       struct sysmmu_drvdata *data = NULL;
> +       bool disabled = false;
> +
> +       while ((data = get_sysmmu_data(owner, data))) {
> +               disabled = true;
> +
> +               if (!set_sysmmu_inactive(data)) {
> +                       dev_dbg(data->dev, "Inactivation request ignorred\n");
> +                       continue;
> +               }
> +
> +               __raw_writel(CTRL_DISABLE, data->sfrbase + S5P_MMU_CTRL);
> +
> +               clk_disable(data->clk);
> +
> +               pm_runtime_put_sync(data->dev);
> +
> +               data->domain = NULL;
> +
> +               dev_dbg(data->dev, "Disabled.\n");
> +       }
> +
> +       BUG_ON(!disabled);
> +}
> +
> +static inline void exynos_iommu_disable(struct iommu_domain *domain)
> +{
> +       struct exynos_iommu_domain *priv = domain->priv;
> +
> +       if (priv && priv->dev)
> +               exynos_sysmmu_disable(priv->dev);
> +}
> +
> +void exynos_sysmmu_tlb_invalidate(struct device *owner)
> +{
> +       struct sysmmu_drvdata *data = NULL;
> +
> +       while ((data = get_sysmmu_data(owner, data))) {
> +               if (is_sysmmu_active(data)) {
> +                       sysmmu_block(data->sfrbase);
> +                       __sysmmu_tlb_invalidate(data->sfrbase);
> +                       sysmmu_unblock(data->sfrbase);
> +               } else {
> +                       dev_dbg(data->dev,
> +                               "Disabled: Skipping invalidating TLB.\n");
> +               }
> +       }
> +}
> +
> +static int exynos_sysmmu_probe(struct platform_device *pdev)
> +{
> +       struct resource *res, *ioarea;
> +       int ret = 0;
> +       int irq;
> +       struct device *dev;
> +       void *sfr;
> +       struct sysmmu_drvdata *data;
> +       struct clk *clk;
> +
> +       dev = &pdev->dev;
> +
> +       data = kzalloc(GFP_KERNEL, sizeof(*data));
> +       if (!data) {
> +               dev_err(dev, "Failed to probing System MMU: "
> +                                       "Not enough memory");
> +               return -ENOMEM;
> +       }
> +
> +       if (!dev_get_platdata(dev)) {
> +               dev_err(dev, "Failed to probing system MMU: "
> +                                               "Owner device is not set.");
> +
> +               ret = -ENODEV;
> +               goto err_init;
> +       }
> +
> +       ret = dev_set_drvdata(dev, data);
> +       if (ret) {
> +               dev_err(dev, "Failed to probing system MMU: "
> +                                               "Unable to set driver data.");
> +               goto err_init;
> +       }
> +
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       if (!res) {
> +               dev_err(dev,
> +                       "Failed probing system MMU: failed to get resource.");
> +               ret = -ENOENT;
> +               goto err_init;
> +       }
> +
> +       ioarea = request_mem_region(res->start, resource_size(res), pdev->name);
> +       if (ioarea == NULL) {
> +               dev_err(dev, "Failed probing system MMU: "
> +                                       "failed to request memory region.");
> +               ret = -ENOENT;
> +               goto err_init;
> +       }
> +
> +       sfr = ioremap(res->start, resource_size(res));
> +       if (!sfr) {
> +               dev_err(dev, "Failed probing system MMU: "
> +                                               "failed to call ioremap().");
> +               ret = -ENOENT;
> +               goto err_ioremap;
> +       }
> +
> +       irq = platform_get_irq(pdev, 0);
> +       if (irq <= 0) {
> +               dev_err(dev, "Failed probing system MMU: "
> +                                               "failed to get irq resource.");
> +               ret = irq;
> +               goto err_irq;
> +       }
> +
> +       ret = request_irq(irq, exynos_sysmmu_irq, 0, dev_name(dev), data);
> +       if (ret) {
> +               dev_err(dev, "Failed probing system MMU: "
> +                                               "failed to request irq.");
> +               goto err_irq;
> +       }
> +
> +       clk = clk_get(dev, "sysmmu");
> +       if (IS_ERR(clk)) {
> +               dev_err(dev, "Failed to probing System MMU: "
> +                                       "failed to get clock descriptor");
> +               ret = PTR_ERR(clk);
> +               goto err_clk;
> +       }
> +
> +       data->dev = dev;
> +       data->owner = dev_get_platdata(dev);
> +       data->clk = clk;
> +       data->sfrbase = sfr;
> +       data->fault_handler = &default_fault_handler;
> +       INIT_LIST_HEAD(&data->node);
> +
> +       list_add(&data->node, &sysmmu_list);
> +
> +       if (dev->parent)
> +               pm_runtime_enable(dev);
> +
> +       dev_dbg(dev, "Initialized for %s.\n", dev_name(data->owner));
> +       return 0;
> +err_clk:
> +       free_irq(irq, data);
> +err_irq:
> +       iounmap(sfr);
> +err_ioremap:
> +       release_resource(ioarea);
> +       kfree(ioarea);
> +err_init:
> +       kfree(data);
> +       dev_err(dev, "Probing system MMU failed.");
> +       return ret;
> +}
> +
> +int exynos_sysmmu_runtime_suspend(struct device *dev)
> +{
> +       if (WARN_ON(is_sysmmu_active(dev_get_drvdata(dev))))
> +               return -EFAULT;
> +
> +       return 0;
> +}
> +
> +int exynos_sysmmu_runtime_resume(struct device *dev)
> +{
> +       if (WARN_ON(is_sysmmu_active(dev_get_drvdata(dev))))
> +               return -EFAULT;
> +
> +       return 0;
> +}
> +
> +const struct dev_pm_ops exynos_sysmmu_pm_ops = {
> +       .runtime_suspend        = exynos_sysmmu_runtime_suspend,
> +       .runtime_resume         = exynos_sysmmu_runtime_resume,
> +};
> +
> +static struct platform_driver exynos_sysmmu_driver = {
> +       .probe          = exynos_sysmmu_probe,
> +       .driver         = {
> +               .owner          = THIS_MODULE,
> +               .name           = "s5p-sysmmu",
> +               .pm             = &exynos_sysmmu_pm_ops,
> +       }
> +};
> +
> +static int __init exynos_sysmmu_init(void)
> +{
> +       return platform_driver_register(&exynos_sysmmu_driver);
> +}
> +arch_initcall(exynos_sysmmu_init);
> +
> +/* We does not consider super section mapping (16MB) */
> +#define S5P_SPAGE_SHIFT                12
> +#define S5P_LPAGE_SHIFT                16
> +#define S5P_SECTION_SHIFT      20
> +
> +#define S5P_SPAGE_SIZE         (1 << S5P_SPAGE_SHIFT)
> +#define S5P_LPAGE_SIZE         (1 << S5P_LPAGE_SHIFT)
> +#define S5P_SECTION_SIZE       (1 << S5P_SECTION_SHIFT)
> +
> +#define S5P_SPAGE_MASK         (~(S5P_SPAGE_SIZE - 1))
> +#define S5P_LPAGE_MASK         (~(S5P_LPAGE_SIZE - 1))
> +#define S5P_SECTION_MASK       (~(S5P_SECTION_SIZE - 1))
> +
> +#define S5P_SPAGE_ORDER                (S5P_SPAGE_SHIFT - PAGE_SHIFT)
> +#define S5P_LPAGE_ORDER                (S5P_LPAGE_SHIFT - S5P_SPAGE_SHIFT)
> +#define S5P_SECTION_ORDER      (S5P_SECTION_SHIFT - S5P_SPAGE_SHIFT)
> +
> +#define S5P_LV1TABLE_ENTRIES   (1 << (BITS_PER_LONG - S5P_SECTION_SHIFT))
> +
> +#define S5P_LV2TABLE_ENTRIES   (1 << S5P_SECTION_ORDER)
> +#define S5P_LV2TABLE_SIZE      (S5P_LV2TABLE_ENTRIES * sizeof(long))
> +#define S5P_LV2TABLE_MASK      (~(S5P_LV2TABLE_SIZE - 1)) /* 0xFFFFFC00 */
> +
> +#define S5P_SECTION_LV1_ENTRY(entry)   ((entry & 0x40003) == 2)
> +#define S5P_SUPSECT_LV1_ENTRY(entry)   ((entry & 0x40003) == 0x40002)
> +#define S5P_PAGE_LV1_ENTRY(entry)      ((entry & 3) == 1)
> +#define S5P_FAULT_LV1_ENTRY(entry) (((entry & 3) == 0) || (entry & 3) == 3)
> +
> +#define S5P_LPAGE_LV2_ENTRY(entry)     ((entry & 3) == 1)
> +#define S5P_SPAGE_LV2_ENTRY(entry)     ((entry & 2) == 2)
> +#define S5P_FAULT_LV2_ENTRY(entry)     ((entry & 3) == 0)
> +
> +#define MAKE_FAULT_ENTRY(entry)                do { entry = 0; } while (0)
> +#define MAKE_SECTION_ENTRY(entry, pa)  do { entry = pa | 2; } while (0)
> +#define MAKE_SUPSECT_ENTRY(entry, pa)  do { entry = pa | 0x40002; } while (0)
> +#define MAKE_LV2TABLE_ENTRY(entry, pa) do { entry = pa | 1; } while (0)
> +
> +#define MAKE_LPAGE_ENTRY(entry, pa)    do { entry = pa | 1; } while (0)
> +#define MAKE_SPAGE_ENTRY(entry, pa)    do { entry = pa | 3; } while (0)
> +
> +#define GET_LV2ENTRY(entry, iova) (\
> +       (unsigned long *)phys_to_virt(entry & S5P_LV2TABLE_MASK) +\
> +       ((iova & (~S5P_SECTION_MASK)) >> S5P_SPAGE_SHIFT))
> +
> +/* slab cache for level 2 page tables */
> +static struct kmem_cache *l2table_cachep;
> +
> +static inline void pgtable_flush(void *vastart, void *vaend)
> +{
> +       dmac_flush_range(vastart, vaend);
> +       outer_flush_range(virt_to_phys(vastart),
> +                               virt_to_phys(vaend));
> +}
> +
> +static int exynos_iommu_domain_init(struct iommu_domain *domain)
> +{
> +       struct exynos_iommu_domain *priv;
> +
> +       priv = kzalloc(sizeof(*priv), GFP_KERNEL);
> +       if (!priv)
> +               return -ENOMEM;
> +
> +       priv->pgtable = (unsigned long *)__get_free_pages(GFP_KERNEL,
> +               (S5P_LV1TABLE_ENTRIES * sizeof(unsigned long)) >> PAGE_SHIFT);

For __get_free_pages you can't just pass in the number of pages, you
need the order. Please use get_order.

> +       if (!priv->pgtable) {
> +               kfree(priv);
> +               return -ENOMEM;
> +       }
> +
> +       memset(priv->pgtable, 0, S5P_LV1TABLE_ENTRIES * sizeof(unsigned long));
> +       pgtable_flush(priv->pgtable, priv->pgtable + S5P_LV1TABLE_ENTRIES);
> +
> +       spin_lock_init(&priv->lock);

No init for the page-table lock?

> +
> +       domain->priv = priv;
> +
> +       iommu_set_fault_handler(domain, &exynos_iommu_fault_handler);
> +
> +       return 0;
> +}
> +
> +static void exynos_iommu_domain_destroy(struct iommu_domain *domain)
> +{
> +       struct exynos_iommu_domain *priv = domain->priv;
> +
> +       free_pages((unsigned long)priv->pgtable,
> +               (S5P_LV1TABLE_ENTRIES * sizeof(unsigned long)) >> PAGE_SHIFT);

Same here, please use get_order.

> +
> +       kfree(priv);
> +
> +       domain->priv = NULL;
> +}
> +
> +static int exynos_iommu_attach_device(struct iommu_domain *domain,
> +                                  struct device *dev)
> +{
> +       struct exynos_iommu_domain *priv = domain->priv;
> +       int ret;
> +
> +       spin_lock(&priv->lock);
> +
> +       priv->dev = dev;
> +
> +       ret = exynos_iommu_enable(domain);
> +
> +       spin_unlock(&priv->lock);
> +
> +       return ret;
> +}
> +
> +static void exynos_iommu_detach_device(struct iommu_domain *domain,
> +                                   struct device *dev)
> +{
> +       struct exynos_iommu_domain *priv = domain->priv;
> +
> +       spin_lock(&priv->lock);
> +
> +       if (priv->dev == dev) {
> +               exynos_iommu_disable(domain);
> +               priv->dev = NULL;
> +       }
> +
> +       spin_unlock(&priv->lock);
> +}
> +
> +static bool section_available(struct iommu_domain *domain,
> +                             unsigned long *lv1entry)
> +{
> +       struct exynos_iommu_domain *priv = domain->priv;
> +
> +       if (S5P_SECTION_LV1_ENTRY(*lv1entry)) {
> +               dev_err(priv->dev, "1MB entry alread exists at 0x%08x\n",
> +                               (lv1entry - priv->pgtable) * SZ_1M);
> +               return false;
> +       }
> +
> +       if (S5P_PAGE_LV1_ENTRY(*lv1entry)) {
> +               unsigned long *lv2end, *lv2base;
> +
> +               lv2base = phys_to_virt(*lv1entry & S5P_LV2TABLE_MASK);
> +               lv2end = lv2base + S5P_LV2TABLE_ENTRIES;
> +               while (lv2base != lv2end) {
> +                       if (!S5P_FAULT_LV2_ENTRY(*lv2base)) {
> +                               dev_err(priv->dev, "Failed to free L2 page "
> +                                               "table for section mapping.\n");
> +                               return false;
> +                       }
> +                       lv2base++;
> +               }
> +
> +               kmem_cache_free(l2table_cachep,
> +                               phys_to_virt(*lv1entry & S5P_LV2TABLE_MASK));
> +
> +               MAKE_FAULT_ENTRY(*lv1entry);
> +       }
> +
> +       return true;
> +}
> +
> +static bool write_lpage(unsigned long *head_entry, unsigned long phys_addr)
> +{
> +       unsigned long *entry, *end;
> +
> +       entry = head_entry;
> +       end = entry + (1 << S5P_LPAGE_ORDER);
> +
> +       while (entry != end) {
> +               if (!S5P_FAULT_LV2_ENTRY(*entry))
> +                       break;
> +
> +               MAKE_LPAGE_ENTRY(*entry, phys_addr);
> +
> +               entry++;
> +       }
> +
> +       if (entry != end) {
> +               end = entry;
> +               while (entry != head_entry)
> +                       MAKE_FAULT_ENTRY(*(--entry));
> +
> +               return false;
> +       }
> +
> +       return true;
> +}
> +
> +static int exynos_iommu_map(struct iommu_domain *domain, unsigned long iova,
> +                        phys_addr_t paddr, int gfp_order, int prot)
> +{
> +       struct exynos_iommu_domain *priv = domain->priv;
> +       unsigned long *start_entry, *entry, *end_entry;
> +       int num_entry;
> +       int ret = 0;
> +       unsigned long flags;
> +
> +       BUG_ON(priv->pgtable == NULL);
> +
> +       spin_lock_irqsave(&priv->pgtablelock, flags);
> +
> +       start_entry = entry = priv->pgtable + (iova >> S5P_SECTION_SHIFT);
> +
> +       if (gfp_order >= S5P_SECTION_ORDER) {
> +               BUG_ON((paddr | iova) & ~S5P_SECTION_MASK);
> +               /* 1MiB mapping */
> +
> +               num_entry = 1 << (gfp_order - S5P_SECTION_ORDER);
> +               end_entry = entry + num_entry;
> +
> +               while (entry != end_entry) {
> +                       if (!section_available(domain, entry))
> +                               break;
> +
> +                       MAKE_SECTION_ENTRY(*entry, paddr);
> +
> +                       paddr += S5P_SECTION_SIZE;
> +                       entry++;
> +               }
> +
> +               if (entry != end_entry)
> +                       goto mapping_error;
> +
> +               pgtable_flush(start_entry, entry);
> +               goto mapping_done;
> +       }
> +
> +       if (S5P_FAULT_LV1_ENTRY(*entry)) {
> +               unsigned long *l2table;
> +
> +               l2table = kmem_cache_zalloc(l2table_cachep, GFP_KERNEL);
> +               if (!l2table) {
> +                       ret = -ENOMEM;
> +                       goto nomem_error;
> +               }
> +
> +               pgtable_flush(entry, entry + S5P_LV2TABLE_ENTRIES);
> +
> +               MAKE_LV2TABLE_ENTRY(*entry, virt_to_phys(l2table));
> +               pgtable_flush(entry, entry + 1);
> +       }
> +
> +       /* 'entry' points level 2 entries, hereafter */
> +       entry = GET_LV2ENTRY(*entry, iova);
> +
> +       start_entry = entry;
> +       num_entry = 1 << gfp_order;
> +       end_entry = entry + num_entry;
> +
> +       if (gfp_order >= S5P_LPAGE_ORDER) {
> +               /* large page(64KiB) mapping */
> +               BUG_ON((paddr | iova) & ~S5P_LPAGE_MASK);
> +
> +               while (entry != end_entry) {
> +                       if (!write_lpage(entry, paddr)) {
> +                               pr_err("%s: "
> +                                       "Failed to allocate large page entry."
> +                                       "\n", __func__);
> +                               break;
> +                       }
> +
> +                       paddr += S5P_LPAGE_SIZE;
> +                       entry += (1 << S5P_LPAGE_ORDER);
> +               }
> +
> +               if (entry != end_entry) {
> +                       entry -= 1 << S5P_LPAGE_ORDER;
> +                       goto mapping_error;
> +               }
> +       } else {
> +               /* page (4KiB) mapping */
> +               while (entry != end_entry && S5P_FAULT_LV2_ENTRY(*entry)) {
> +
> +                       MAKE_SPAGE_ENTRY(*entry, paddr);
> +
> +                       entry++;
> +                       paddr += S5P_SPAGE_SIZE;
> +               }
> +
> +               if (entry != end_entry) {
> +                       pr_err("%s: Failed to allocate small page entry.\n",
> +                                                               __func__);
> +                       goto mapping_error;
> +               }
> +       }
> +
> +       pgtable_flush(start_entry, entry);
> +mapping_error:
> +       if (entry != end_entry) {
> +               unsigned long *current_entry = entry;
> +               while (entry != start_entry)
> +                       MAKE_FAULT_ENTRY(*(--entry));
> +               pgtable_flush(start_entry, current_entry);
> +               ret = -EADDRINUSE;
> +       }
> +
> +nomem_error:
> +mapping_done:
> +       spin_unlock_irqrestore(&priv->pgtablelock, flags);
> +
> +       return 0;
> +}
> +
> +static int exynos_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
> +                          int gfp_order)
> +{
> +       struct exynos_iommu_domain *priv = domain->priv;
> +       unsigned long *entry;
> +       int num_entry;
> +       unsigned long flags;
> +
> +       BUG_ON(priv->pgtable == NULL);
> +
> +       spin_lock_irqsave(&priv->pgtablelock, flags);
> +
> +       entry = priv->pgtable + (iova >> S5P_SECTION_SHIFT);
> +
> +       if (gfp_order >= S5P_SECTION_ORDER) {
> +               gfp_order -= S5P_SECTION_ORDER;
> +               num_entry = 1 << (gfp_order - S5P_SECTION_ORDER);
> +               while (num_entry--) {
> +                       if (S5P_SECTION_LV1_ENTRY(*entry)) {
> +                               MAKE_FAULT_ENTRY(*entry);
> +                       } else if (S5P_PAGE_LV1_ENTRY(*entry)) {
> +                               unsigned long *lv2beg, *lv2end;
> +                               lv2beg = phys_to_virt(
> +                                               *entry & S5P_LV2TABLE_MASK);
> +                               lv2end = lv2beg + S5P_LV2TABLE_ENTRIES;
> +                               while (lv2beg != lv2end) {
> +                                       MAKE_FAULT_ENTRY(*lv2beg);
> +                                       lv2beg++;
> +                               }
> +                       }
> +                       entry++;
> +               }
> +       } else {
> +               entry = GET_LV2ENTRY(*entry, iova);
> +
> +               BUG_ON(S5P_LPAGE_LV2_ENTRY(*entry) &&
> +                                               (gfp_order < S5P_LPAGE_ORDER));
> +
> +               num_entry = 1 << gfp_order;
> +
> +               while (num_entry--) {
> +                       MAKE_FAULT_ENTRY(*entry);
> +                       entry++;
> +               }
> +       }
> +
> +       if (priv->dev)
> +               exynos_sysmmu_tlb_invalidate(priv->dev);
> +
> +       spin_unlock_irqrestore(&priv->pgtablelock, flags);
> +
> +       return 0;
> +}
> +
> +static phys_addr_t exynos_iommu_iova_to_phys(struct iommu_domain *domain,
> +                                         unsigned long iova)
> +{
> +       struct exynos_iommu_domain *priv = domain->priv;
> +       unsigned long *entry;
> +       unsigned long offset;
> +
> +       entry = priv->pgtable + (iova >> S5P_SECTION_SHIFT);
> +
> +       if (S5P_FAULT_LV1_ENTRY(*entry))
> +               return 0;
> +
> +       offset = iova & ~S5P_SECTION_MASK;
> +
> +       if (S5P_SECTION_LV1_ENTRY(*entry))
> +               return (*entry & S5P_SECTION_MASK) + offset;
> +
> +       entry = GET_LV2ENTRY(*entry, iova);
> +
> +       if (S5P_SPAGE_LV2_ENTRY(*entry))
> +               return (*entry & S5P_SPAGE_MASK) + (iova & ~S5P_SPAGE_MASK);
> +
> +       if (S5P_LPAGE_LV2_ENTRY(*entry))
> +               return (*entry & S5P_LPAGE_MASK) + (iova & ~S5P_LPAGE_MASK);
> +
> +       return 0;
> +}
> +
> +static int exynos_iommu_domain_has_cap(struct iommu_domain *domain,
> +                                   unsigned long cap)
> +{
> +       return 0;
> +}
> +
> +static struct iommu_ops exynos_iommu_ops = {
> +       .domain_init = &exynos_iommu_domain_init,
> +       .domain_destroy = &exynos_iommu_domain_destroy,
> +       .attach_dev = &exynos_iommu_attach_device,
> +       .detach_dev = &exynos_iommu_detach_device,
> +       .map = &exynos_iommu_map,
> +       .unmap = &exynos_iommu_unmap,
> +       .iova_to_phys = &exynos_iommu_iova_to_phys,
> +       .domain_has_cap = &exynos_iommu_domain_has_cap,
> +};
> +
> +static int __init exynos_iommu_init(void)
> +{
> +       l2table_cachep = kmem_cache_create("SysMMU Lv2 Tables",
> +                               S5P_LV2TABLE_SIZE, S5P_LV2TABLE_SIZE, 0, NULL);

Any reason you allocate a seperate slab-cache? It doesn't have a
constructor so it would be merged into the kmalloc-slabs anyway (at
least with SLUB).

> +       if (!l2table_cachep)
> +               return -ENOMEM;
> +
> +       register_iommu(&exynos_iommu_ops);
> +
> +       return 0;
> +}
> +arch_initcall(exynos_iommu_init);
> --
> 1.7.1
> 
> 

-- 
AMD Operating System Research Center

Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach
General Managers: Alberto Bozzo, Andrew Bowd
Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632

^ permalink raw reply	[flat|nested] 3+ messages in thread

* [PATCH v2 3/5] iommu/exynos: Add iommu driver for Exynos4 Platforms
  2011-09-30 12:06 ` Roedel, Joerg
@ 2011-09-30 23:46   ` KyongHo Cho
  0 siblings, 0 replies; 3+ messages in thread
From: KyongHo Cho @ 2011-09-30 23:46 UTC (permalink / raw)
  To: linux-arm-kernel

On Fri, Sep 30, 2011 at 9:06 PM, Roedel, Joerg <Joerg.Roedel@amd.com> wrote:
> First comment: Pleas remove the 'inline' annotations in this patch. It
> is better to let the compiler decide what to inline and what not.
Ok. Thanks :)

>
> Hmm, may it make sense to store data directly in dev->arch.iommu? This
> will save you the list traversals to get the information.
>
That looks better.
However, adding features to dev_archdata of ARM is actively discussed
in Linaro-mm-sig and the features also include iommu_domain.

On the other hand,
I was not able to determine what will be accepted to the mainline kernel
between Linaro's one that is suggested by Marek and Ohad's one.

>> +
>> +static inline bool set_sysmmu_active(struct sysmmu_drvdata *data)
>> +{
>> + ? ? ? /* return true if the System MMU was not active previously
>> + ? ? ? ? ?and it needs to be initialized */
>> +
>> + ? ? ? data->activations++;
>
> Is this variable only accessed under a lock? If not it should be an
> atomic.
>
All 'sysmmu' functions must be called under a lock because a System MMU
(Samsung's IOMMU) is a shared resource.
I the first patch, I declared the 'data->activations' as atomic_t but
Russell King pointed
that atomic operations on data->activations is not helpful for
preventing to become
a System MMU enabled when its data->activations is 0.

>> + ? ? ? return data->activations == 1;
>
> Is that right? Shouldn't it be 'data->activations > 0'?
>
The value returned by set_sysmmu_active() means "The System MMU must be
initialized".
System MMU is initialized when its state is changed from
'inactive(disabled)' to active(enabled).
If data->activations++ becomes 2 or more, the System MMU is already enabled and
must not be initialized again.

>> +static inline void __set_fault_handler(struct sysmmu_drvdata *data,
>> + ? ? ? ? ? ? ? ? ? ? ? int (*handler)(enum S5P_SYSMMU_INTERRUPT_TYPE itype,
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? unsigned long pgtable_base,
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? unsigned long fault_addr))
>
> Please typedef the function signature.
>
Ok. thanks.

>> +static int exynos_iommu_domain_init(struct iommu_domain *domain)
>> +{
>> + ? ? ? struct exynos_iommu_domain *priv;
>> +
>> + ? ? ? priv = kzalloc(sizeof(*priv), GFP_KERNEL);
>> + ? ? ? if (!priv)
>> + ? ? ? ? ? ? ? return -ENOMEM;
>> +
>> + ? ? ? priv->pgtable = (unsigned long *)__get_free_pages(GFP_KERNEL,
>> + ? ? ? ? ? ? ? (S5P_LV1TABLE_ENTRIES * sizeof(unsigned long)) >> PAGE_SHIFT);
>
> For __get_free_pages you can't just pass in the number of pages, you
> need the order. Please use get_order.
>
Oh! Thank you.
I didn't notice the problem.
It allocated too large memory so far.

>> + ? ? ? if (!priv->pgtable) {
>> + ? ? ? ? ? ? ? kfree(priv);
>> + ? ? ? ? ? ? ? return -ENOMEM;
>> + ? ? ? }
>> +
>> + ? ? ? memset(priv->pgtable, 0, S5P_LV1TABLE_ENTRIES * sizeof(unsigned long));
>> + ? ? ? pgtable_flush(priv->pgtable, priv->pgtable + S5P_LV1TABLE_ENTRIES);
>> +
>> + ? ? ? spin_lock_init(&priv->lock);
>
> No init for the page-table lock?
>
Thank you. I forgot that.


>> +static void exynos_iommu_domain_destroy(struct iommu_domain *domain)
>> +{
>> + ? ? ? struct exynos_iommu_domain *priv = domain->priv;
>> +
>> + ? ? ? free_pages((unsigned long)priv->pgtable,
>> + ? ? ? ? ? ? ? (S5P_LV1TABLE_ENTRIES * sizeof(unsigned long)) >> PAGE_SHIFT);
>
> Same here, please use get_order.
>
True. I will fix that immediately.

>> +static int __init exynos_iommu_init(void)
>> +{
>> + ? ? ? l2table_cachep = kmem_cache_create("SysMMU Lv2 Tables",
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? S5P_LV2TABLE_SIZE, S5P_LV2TABLE_SIZE, 0, NULL);
>
> Any reason you allocate a seperate slab-cache? It doesn't have a
> constructor so it would be merged into the kmalloc-slabs anyway (at
> least with SLUB).
>
I found that kmalloc(SZ_1K) returned an address that is not aligned by SZ_1K.
I did not understand why it happened and I changed it to the slab cache.
I will try it again with kmalloc().


Regards,
KyongHo

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2011-09-30 23:46 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-09-30  7:31 [PATCH v2 3/5] iommu/exynos: Add iommu driver for Exynos4 Platforms Kukjin Kim
2011-09-30 12:06 ` Roedel, Joerg
2011-09-30 23:46   ` KyongHo Cho

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