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Date:	Tue, 28 Feb 2012 16:53:52 +0900
From:	Kyungmin Park <kyungmin.park@...sung.com>
To:	pullip.cho@...sung.com
Cc:	linux-arm-kernel@...ts.infradead.org,
	linux-samsung-soc@...r.kernel.org,
	iommu@...ts.linux-foundation.org, linux-kernel@...r.kernel.org,
	Joerg Roedel <joro@...tes.org>,
	Sanghyun Lee <sanghyun75.lee@...sung.com>,
	Kukjin Kim <kgene.kim@...sung.com>,
	Younglak Kim <younglak1004.kim@...sung.com>,
	Marek Szyprowski <m.szyprowski@...sung.com>,
	Subash Patel <subash.ramaswamy@...aro.org>
Subject: Re: [PATCH v9 2/2] iommu/exynos: Add iommu driver for Exynos Platforms

On 2/28/12, KyongHo Cho <pullip.cho@...sung.com> wrote:
> QBtAHMAdQBuAGcALgBjAG8AbQA=;Tue,
>  28 Feb 2012 06:37:18
> GMT;WwBQAEEAVABDAEgAIAB2ADkAIAAyAC8AMgBdACAAaQBvAG0AbQB1AC8AZQB4AHkAbgBvAHMAOgAgAEEAZABkACAAaQBvAG0AbQB1ACAAZAByAGkAdgBlAHIAIABmAG8AcgAgAEUAeAB5AG4AbwBzACAAUABsAGEAdABmAG8AcgBtAHMA
> x-cr-puzzleid: {A7DCA01D-7357-496D-8A82-82B25CF0E1C3}
>
> This is the System MMU driver and IOMMU API implementation for
> Exynos SOC platforms. Exynos platforms has more than 10 System
> MMUs dedicated for each multimedia accelerators.
>
> The System MMU driver is already in arc/arm/plat-s5p but it is
> moved to drivers/iommu due to Ohad Ben-Cohen gathered IOMMU drivers
> there
>
> Any device driver in Exynos platforms that needs to control its
> System MMU must call platform_set_sysmmu() to inform System MMU
> driver who will control it.
> platform_set_sysmmu() is defined in <mach/sysmmu.h>
>
> Cc: Joerg Roedel <joerg.roedel@....com>
> Cc: Kukjin Kim <kgene.kim@...sung.com>
> Signed-off-by: KyongHo Cho <pullip.cho@...sung.com>
> ---
>  arch/arm/plat-s5p/Kconfig                   |    8 -
>  arch/arm/plat-s5p/Makefile                  |    1 -
>  arch/arm/plat-s5p/sysmmu.c                  |  324 --------
>  arch/arm/plat-samsung/include/plat/sysmmu.h |   95 ---
>  drivers/iommu/Kconfig                       |   21 +
>  drivers/iommu/Makefile                      |    1 +
>  drivers/iommu/exynos-iommu.c                | 1076
> +++++++++++++++++++++++++++
>  7 files changed, 1098 insertions(+), 428 deletions(-)
>  delete mode 100644 arch/arm/plat-s5p/sysmmu.c
>  delete mode 100644 arch/arm/plat-samsung/include/plat/sysmmu.h
>  create mode 100644 drivers/iommu/exynos-iommu.c
>
> diff --git a/arch/arm/plat-s5p/Kconfig b/arch/arm/plat-s5p/Kconfig
> index 88795ea..f905905 100644
> --- a/arch/arm/plat-s5p/Kconfig
> +++ b/arch/arm/plat-s5p/Kconfig
> @@ -50,14 +50,6 @@ config S5P_PM
>  	  Common code for power management support on S5P and newer SoCs
>  	  Note: Do not select this for S5P6440 and S5P6450.
>
> -comment "System MMU"
> -
> -config S5P_SYSTEM_MMU
> -	bool "S5P SYSTEM MMU"
> -	depends on ARCH_EXYNOS4
> -	help
> -	  Say Y here if you want to enable System MMU
> -
>  config S5P_SLEEP
>  	bool
>  	help
> diff --git a/arch/arm/plat-s5p/Makefile b/arch/arm/plat-s5p/Makefile
> index 4bd8241..4953d50 100644
> --- a/arch/arm/plat-s5p/Makefile
> +++ b/arch/arm/plat-s5p/Makefile
> @@ -16,7 +16,6 @@ obj-y				+= clock.o
>  obj-y				+= irq.o
>  obj-$(CONFIG_S5P_EXT_INT)	+= irq-eint.o
>  obj-$(CONFIG_S5P_GPIO_INT)	+= irq-gpioint.o
> -obj-$(CONFIG_S5P_SYSTEM_MMU)	+= sysmmu.o
>  obj-$(CONFIG_S5P_PM)		+= pm.o irq-pm.o
>  obj-$(CONFIG_S5P_SLEEP)		+= sleep.o
>  obj-$(CONFIG_S5P_HRT) 		+= s5p-time.o
> diff --git a/arch/arm/plat-s5p/sysmmu.c b/arch/arm/plat-s5p/sysmmu.c
> deleted file mode 100644
> index 98b87c1..0000000
> --- a/arch/arm/plat-s5p/sysmmu.c
> +++ /dev/null
> @@ -1,324 +0,0 @@
> -/* linux/arch/arm/plat-s5p/sysmmu.c
> - *
> - * Copyright (c) 2010 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/interrupt.h>
> -#include <linux/platform_device.h>
> -#include <linux/export.h>
> -
> -#include <asm/pgtable.h>
> -
> -#include <mach/map.h>
> -#include <plat/sysmmu.h>
> -
> -#define CTRL_ENABLE	0x5
> -#define CTRL_BLOCK	0x7
> -#define CTRL_DISABLE	0x0
> -
> -static struct device *dev;
> -
> -#define EXYNOS_MMU_CTRL			0x000
> -#define EXYNOS_MMU_CFG			0x004
> -#define EXYNOS_MMU_STATUS		0x008
> -#define EXYNOS_MMU_FLUSH		0x00C
> -#define EXYNOS_PT_BASE_ADDR		0x014
> -#define EXYNOS_INT_STATUS		0x018
> -#define EXYNOS_INT_CLEAR		0x01C
> -#define EXYNOS_PAGE_FAULT_ADDR		0x024
> -#define EXYNOS_AW_FAULT_ADDR		0x028
> -#define EXYNOS_AR_FAULT_ADDR		0x02C
> -#define EXYNOS_DEFAULT_SLAVE_ADDR	0x030
> -
> -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] = {
> -	"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"
> -};
> -
> -static int (*fault_handlers[S5P_SYSMMU_TOTAL_IPNUM])(
> -		enum S5P_SYSMMU_INTERRUPT_TYPE itype,
> -		unsigned long pgtable_base,
> -		unsigned long fault_addr);
> -
> -/*
> - * If adjacent 2 bits are true, the system MMU is enabled.
> - * The system MMU is disabled, otherwise.
> - */
> -static unsigned long sysmmu_states;
> -
> -static inline void set_sysmmu_active(sysmmu_ips ips)
> -{
> -	sysmmu_states |= 3 << (ips * 2);
> -}
> -
> -static inline void set_sysmmu_inactive(sysmmu_ips ips)
> -{
> -	sysmmu_states &= ~(3 << (ips * 2));
> -}
> -
> -static inline int is_sysmmu_active(sysmmu_ips ips)
> -{
> -	return sysmmu_states & (3 << (ips * 2));
> -}
> -
> -static void __iomem *sysmmusfrs[S5P_SYSMMU_TOTAL_IPNUM];
> -
> -static inline void sysmmu_block(sysmmu_ips ips)
> -{
> -	__raw_writel(CTRL_BLOCK, sysmmusfrs[ips] + S5P_MMU_CTRL);
> -	dev_dbg(dev, "%s is blocked.\n", sysmmu_ips_name[ips]);
> -}
> -
> -static inline void sysmmu_unblock(sysmmu_ips ips)
> -{
> -	__raw_writel(CTRL_ENABLE, sysmmusfrs[ips] + S5P_MMU_CTRL);
> -	dev_dbg(dev, "%s is unblocked.\n", sysmmu_ips_name[ips]);
> -}
> -
> -static inline void __sysmmu_tlb_invalidate(sysmmu_ips ips)
> -{
> -	__raw_writel(0x1, sysmmusfrs[ips] + S5P_MMU_FLUSH);
> -	dev_dbg(dev, "TLB of %s is invalidated.\n", sysmmu_ips_name[ips]);
> -}
> -
> -static inline void __sysmmu_set_ptbase(sysmmu_ips ips, unsigned long pgd)
> -{
> -	if (unlikely(pgd == 0)) {
> -		pgd = (unsigned long)ZERO_PAGE(0);
> -		__raw_writel(0x20, sysmmusfrs[ips] + S5P_MMU_CFG); /* 4KB LV1 */
> -	} else {
> -		__raw_writel(0x0, sysmmusfrs[ips] + S5P_MMU_CFG); /* 16KB LV1 */
> -	}
> -
> -	__raw_writel(pgd, sysmmusfrs[ips] + S5P_PT_BASE_ADDR);
> -
> -	dev_dbg(dev, "Page table base of %s is initialized with 0x%08lX.\n",
> -						sysmmu_ips_name[ips], pgd);
> -	__sysmmu_tlb_invalidate(ips);
> -}
> -
> -void sysmmu_set_fault_handler(sysmmu_ips ips,
> -			int (*handler)(enum S5P_SYSMMU_INTERRUPT_TYPE itype,
> -					unsigned long pgtable_base,
> -					unsigned long fault_addr))
> -{
> -	BUG_ON(!((ips >= SYSMMU_MDMA) && (ips < S5P_SYSMMU_TOTAL_IPNUM)));
> -	fault_handlers[ips] = handler;
> -}
> -
> -static irqreturn_t s5p_sysmmu_irq(int irq, void *dev_id)
> -{
> -	/* SYSMMU is in blocked when interrupt occurred. */
> -	unsigned long base = 0;
> -	sysmmu_ips ips = (sysmmu_ips)dev_id;
> -	enum S5P_SYSMMU_INTERRUPT_TYPE itype;
> -
> -	itype = (enum S5P_SYSMMU_INTERRUPT_TYPE)
> -		__ffs(__raw_readl(sysmmusfrs[ips] + S5P_INT_STATUS));
> -
> -	BUG_ON(!((itype >= 0) && (itype < 8)));
> -
> -	dev_alert(dev, "%s occurred by %s.\n", sysmmu_fault_name[itype],
> -							sysmmu_ips_name[ips]);
> -
> -	if (fault_handlers[ips]) {
> -		unsigned long addr;
> -
> -		base = __raw_readl(sysmmusfrs[ips] + S5P_PT_BASE_ADDR);
> -		addr = __raw_readl(sysmmusfrs[ips] + fault_reg_offset[itype]);
> -
> -		if (fault_handlers[ips](itype, base, addr)) {
> -			__raw_writel(1 << itype,
> -					sysmmusfrs[ips] + S5P_INT_CLEAR);
> -			dev_notice(dev, "%s from %s is resolved."
> -					" Retrying translation.\n",
> -				sysmmu_fault_name[itype], sysmmu_ips_name[ips]);
> -		} else {
> -			base = 0;
> -		}
> -	}
> -
> -	sysmmu_unblock(ips);
> -
> -	if (!base)
> -		dev_notice(dev, "%s from %s is not handled.\n",
> -			sysmmu_fault_name[itype], sysmmu_ips_name[ips]);
> -
> -	return IRQ_HANDLED;
> -}
> -
> -void s5p_sysmmu_set_tablebase_pgd(sysmmu_ips ips, unsigned long pgd)
> -{
> -	if (is_sysmmu_active(ips)) {
> -		sysmmu_block(ips);
> -		__sysmmu_set_ptbase(ips, pgd);
> -		sysmmu_unblock(ips);
> -	} else {
> -		dev_dbg(dev, "%s is disabled. "
> -			"Skipping initializing page table base.\n",
> -						sysmmu_ips_name[ips]);
> -	}
> -}
> -
> -void s5p_sysmmu_enable(sysmmu_ips ips, unsigned long pgd)
> -{
> -	if (!is_sysmmu_active(ips)) {
> -		sysmmu_clk_enable(ips);
> -
> -		__sysmmu_set_ptbase(ips, pgd);
> -
> -		__raw_writel(CTRL_ENABLE, sysmmusfrs[ips] + S5P_MMU_CTRL);
> -
> -		set_sysmmu_active(ips);
> -		dev_dbg(dev, "%s is enabled.\n", sysmmu_ips_name[ips]);
> -	} else {
> -		dev_dbg(dev, "%s is already enabled.\n", sysmmu_ips_name[ips]);
> -	}
> -}
> -
> -void s5p_sysmmu_disable(sysmmu_ips ips)
> -{
> -	if (is_sysmmu_active(ips)) {
> -		__raw_writel(CTRL_DISABLE, sysmmusfrs[ips] + S5P_MMU_CTRL);
> -		set_sysmmu_inactive(ips);
> -		sysmmu_clk_disable(ips);
> -		dev_dbg(dev, "%s is disabled.\n", sysmmu_ips_name[ips]);
> -	} else {
> -		dev_dbg(dev, "%s is already disabled.\n", sysmmu_ips_name[ips]);
> -	}
> -}
> -
> -void s5p_sysmmu_tlb_invalidate(sysmmu_ips ips)
> -{
> -	if (is_sysmmu_active(ips)) {
> -		sysmmu_block(ips);
> -		__sysmmu_tlb_invalidate(ips);
> -		sysmmu_unblock(ips);
> -	} else {
> -		dev_dbg(dev, "%s is disabled. "
> -			"Skipping invalidating TLB.\n", sysmmu_ips_name[ips]);
> -	}
> -}
> -
> -static int s5p_sysmmu_probe(struct platform_device *pdev)
> -{
> -	int i, ret;
> -	struct resource *res, *mem;
> -
> -	dev = &pdev->dev;
> -
> -	for (i = 0; i < S5P_SYSMMU_TOTAL_IPNUM; i++) {
> -		int irq;
> -
> -		sysmmu_clk_init(dev, i);
> -		sysmmu_clk_disable(i);
> -
> -		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
> -		if (!res) {
> -			dev_err(dev, "Failed to get the resource of %s.\n",
> -							sysmmu_ips_name[i]);
> -			ret = -ENODEV;
> -			goto err_res;
> -		}
> -
> -		mem = request_mem_region(res->start, resource_size(res),
> -					 pdev->name);
> -		if (!mem) {
> -			dev_err(dev, "Failed to request the memory region of %s.\n",
> -							sysmmu_ips_name[i]);
> -			ret = -EBUSY;
> -			goto err_res;
> -		}
> -
> -		sysmmusfrs[i] = ioremap(res->start, resource_size(res));
> -		if (!sysmmusfrs[i]) {
> -			dev_err(dev, "Failed to ioremap() for %s.\n",
> -							sysmmu_ips_name[i]);
> -			ret = -ENXIO;
> -			goto err_reg;
> -		}
> -
> -		irq = platform_get_irq(pdev, i);
> -		if (irq <= 0) {
> -			dev_err(dev, "Failed to get the IRQ resource of %s.\n",
> -							sysmmu_ips_name[i]);
> -			ret = -ENOENT;
> -			goto err_map;
> -		}
> -
> -		if (request_irq(irq, s5p_sysmmu_irq, IRQF_DISABLED,
> -						pdev->name, (void *)i)) {
> -			dev_err(dev, "Failed to request IRQ for %s.\n",
> -							sysmmu_ips_name[i]);
> -			ret = -ENOENT;
> -			goto err_map;
> -		}
> -	}
> -
> -	return 0;
> -
> -err_map:
> -	iounmap(sysmmusfrs[i]);
> -err_reg:
> -	release_mem_region(mem->start, resource_size(mem));
> -err_res:
> -	return ret;
> -}
> -
> -static int s5p_sysmmu_remove(struct platform_device *pdev)
> -{
> -	return 0;
> -}
> -int s5p_sysmmu_runtime_suspend(struct device *dev)
> -{
> -	return 0;
> -}
> -
> -int s5p_sysmmu_runtime_resume(struct device *dev)
> -{
> -	return 0;
> -}
> -
> -const struct dev_pm_ops s5p_sysmmu_pm_ops = {
> -	.runtime_suspend	= s5p_sysmmu_runtime_suspend,
> -	.runtime_resume		= s5p_sysmmu_runtime_resume,
> -};
> -
> -static struct platform_driver s5p_sysmmu_driver = {
> -	.probe		= s5p_sysmmu_probe,
> -	.remove		= s5p_sysmmu_remove,
> -	.driver		= {
> -		.owner		= THIS_MODULE,
> -		.name		= "s5p-sysmmu",
> -		.pm		= &s5p_sysmmu_pm_ops,
> -	}
> -};
> -
> -static int __init s5p_sysmmu_init(void)
> -{
> -	return platform_driver_register(&s5p_sysmmu_driver);
> -}
> -arch_initcall(s5p_sysmmu_init);
> diff --git a/arch/arm/plat-samsung/include/plat/sysmmu.h
> b/arch/arm/plat-samsung/include/plat/sysmmu.h
> deleted file mode 100644
> index 5fe8ee0..0000000
> --- a/arch/arm/plat-samsung/include/plat/sysmmu.h
> +++ /dev/null
> @@ -1,95 +0,0 @@
> -/* linux/arch/arm/plat-samsung/include/plat/sysmmu.h
> - *
> - * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
> - *		http://www.samsung.com
> - *
> - * Samsung System MMU driver for S5P platform
> - *
> - * 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.
> -*/
> -
> -#ifndef __PLAT_SAMSUNG_SYSMMU_H
> -#define __PLAT_SAMSUNG_SYSMMU_H __FILE__
> -
> -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_FAULTS_NUM
> -};
> -
> -#ifdef CONFIG_S5P_SYSTEM_MMU
> -
> -#include <mach/sysmmu.h>
> -
> -/**
> - * s5p_sysmmu_enable() - enable system mmu of ip
> - * @ips: The ip connected system mmu.
> - * #pgd: Base physical address of the 1st level page table
> - *
> - * This function enable system mmu to transfer address
> - * from virtual address to physical address
> - */
> -void s5p_sysmmu_enable(sysmmu_ips ips, unsigned long pgd);
> -
> -/**
> - * s5p_sysmmu_disable() - disable sysmmu mmu of ip
> - * @ips: The ip connected system mmu.
> - *
> - * This function disable system mmu to transfer address
> - * from virtual address to physical address
> - */
> -void s5p_sysmmu_disable(sysmmu_ips ips);
> -
> -/**
> - * s5p_sysmmu_set_tablebase_pgd() - set page table base address to refer
> page table
> - * @ips: The ip connected system mmu.
> - * @pgd: The page table base address.
> - *
> - * This function set page table base address
> - * When system mmu transfer address from virtaul address to physical
> address,
> - * system mmu refer address information from page table
> - */
> -void s5p_sysmmu_set_tablebase_pgd(sysmmu_ips ips, unsigned long pgd);
> -
> -/**
> - * s5p_sysmmu_tlb_invalidate() - flush all TLB entry in system mmu
> - * @ips: The ip connected system mmu.
> - *
> - * This function flush all TLB entry in system mmu
> - */
> -void s5p_sysmmu_tlb_invalidate(sysmmu_ips ips);
> -
> -/** s5p_sysmmu_set_fault_handler() - Fault handler for System MMUs
> - * @itype: type of fault.
> - * @pgtable_base: the physical address of page table base. This is 0 if
> @ips is
> - *               SYSMMU_BUSERROR.
> - * @fault_addr: the device (virtual) address that the System MMU tried to
> - *             translated. This is 0 if @ips is SYSMMU_BUSERROR.
> - * Called when interrupt occurred by the System MMUs
> - * The device drivers of peripheral devices that has a System MMU can
> implement
> - * a fault handler to resolve address translation fault by System MMU.
> - * The meanings of return value and parameters are described below.
> -
> - * return value: non-zero if the fault is correctly resolved.
> - *         zero if the fault is not handled.
> - */
> -void s5p_sysmmu_set_fault_handler(sysmmu_ips ips,
> -			int (*handler)(enum S5P_SYSMMU_INTERRUPT_TYPE itype,
> -					unsigned long pgtable_base,
> -					unsigned long fault_addr));
> -#else
> -#define s5p_sysmmu_enable(ips, pgd) do { } while (0)
> -#define s5p_sysmmu_disable(ips) do { } while (0)
> -#define s5p_sysmmu_set_tablebase_pgd(ips, pgd) do { } while (0)
> -#define s5p_sysmmu_tlb_invalidate(ips) do { } while (0)
> -#define s5p_sysmmu_set_fault_handler(ips, handler) do { } while (0)
> -#endif
> -#endif /* __ASM_PLAT_SYSMMU_H */
> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
> index 6bea696..25d3eed 100644
> --- a/drivers/iommu/Kconfig
> +++ b/drivers/iommu/Kconfig
> @@ -142,4 +142,25 @@ config OMAP_IOMMU_DEBUG
>
>           Say N unless you know you need this.
>
> +config EXYNOS_IOMMU
> +	bool "Exynos IOMMU Support"
> +	depends on EXYNOS_DEV_SYSMMU
> +	select IOMMU_API
> +	help
> +	  Support for the IOMMU(System MMU) of Samsung Exynos application
> +	  processor family. This enables H/W multimedia accellerators to see
> +	  non-linear physical memory chunks as a linear memory in their
> +	  address spaces
> +
> +	  If unsure, say N here.
> +
> +config EXYNOS_IOMMU_DEBUG
> +	bool "Debugging log for Exynos IOMMU"
> +	depends on EXYNOS_IOMMU
> +	help
> +	  Select this to see the detailed log message that shows what
> +	  happens in the IOMMU driver
> +
> +	  Say N unless you need kernel log message for IOMMU debugging
> +
>  endif # IOMMU_SUPPORT
> diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
> index 0e36b49..5a8fd97 100644
> --- a/drivers/iommu/Makefile
> +++ b/drivers/iommu/Makefile
> @@ -8,3 +8,4 @@ obj-$(CONFIG_IRQ_REMAP) += intr_remapping.o
>  obj-$(CONFIG_OMAP_IOMMU) += omap-iommu.o
>  obj-$(CONFIG_OMAP_IOVMM) += omap-iovmm.o
>  obj-$(CONFIG_OMAP_IOMMU_DEBUG) += omap-iommu-debug.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..87b5c0f
> --- /dev/null
> +++ b/drivers/iommu/exynos-iommu.c
> @@ -0,0 +1,1076 @@
> +/* 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.
> + */
> +
> +#ifdef CONFIG_EXYNOS_IOMMU_DEBUG
> +#define DEBUG
> +#endif
> +
> +#include <linux/io.h>
> +#include <linux/interrupt.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +#include <linux/mm.h>
> +#include <linux/iommu.h>
> +#include <linux/errno.h>
> +#include <linux/list.h>
> +#include <linux/memblock.h>
> +#include <linux/export.h>
> +
> +#include <asm/cacheflush.h>
> +#include <asm/pgtable.h>
> +
> +#include <mach/sysmmu.h>
> +
> +#define S5P_MMU_CTRL			0x000
> +#define S5P_MMU_CFG			0x004
> +#define S5P_MMU_STATUS			0x008
> +#define S5P_MMU_FLUSH			0x00C
> +#define S5P_PT_BASE_ADDR		0x014
> +#define S5P_INT_STATUS			0x018
> +#define S5P_INT_CLEAR			0x01C
> +#define S5P_PAGE_FAULT_ADDR		0x024
> +#define S5P_AW_FAULT_ADDR		0x028
> +#define S5P_AR_FAULT_ADDR		0x02C
> +#define S5P_DEFAULT_SLAVE_ADDR		0x030
> +#define S5P_MMU_VERSION			0x034
> +#define S5P_PB0_SADDR			0x04C
> +#define S5P_PB0_EADDR			0x050
> +#define S5P_PB1_SADDR			0x054
> +#define S5P_PB1_EADDR			0x058
> +
> +#define SECT_ORDER 20
> +#define LPAGE_ORDER 16
> +#define SPAGE_ORDER 12
> +
> +#define SECT_SIZE (1 << SECT_ORDER)
> +#define LPAGE_SIZE (1 << LPAGE_ORDER)
> +#define SPAGE_SIZE (1 << SPAGE_ORDER)
> +
> +#define SECT_MASK (~(SECT_SIZE - 1))
> +#define LPAGE_MASK (~(LPAGE_SIZE - 1))
> +#define SPAGE_MASK (~(SPAGE_SIZE - 1))
> +
> +#define lv1ent_fault(sent) (((*(sent) & 3) == 0) || ((*(sent) & 3) == 3))
> +#define lv1ent_page(sent) ((*(sent) & 3) == 1)
> +#define lv1ent_section(sent) ((*(sent) & 3) == 2)
> +
> +#define lv2ent_fault(pent) ((*(pent) & 3) == 0)
> +#define lv2ent_small(pent) ((*(pent) & 2) == 2)
> +#define lv2ent_large(pent) ((*(pent) & 3) == 1)
> +
> +#define section_phys(sent) (*(sent) & SECT_MASK)
> +#define section_offs(iova) ((iova) & 0xFFFFF)
> +#define lpage_phys(pent) (*(pent) & LPAGE_MASK)
> +#define lpage_offs(iova) ((iova) & 0xFFFF)
> +#define spage_phys(pent) (*(pent) & SPAGE_MASK)
> +#define spage_offs(iova) ((iova) & 0xFFF)
> +
> +#define lv1ent_offset(iova) ((iova) >> SECT_ORDER)
> +#define lv2ent_offset(iova) (((iova) & 0xFF000) >> SPAGE_ORDER)
> +
> +#define NUM_LV1ENTRIES 4096
> +#define NUM_LV2ENTRIES 256
> +
> +#define LV2TABLE_SIZE (NUM_LV2ENTRIES * sizeof(long))
> +
> +#define SPAGES_PER_LPAGE (LPAGE_SIZE / SPAGE_SIZE)
> +
> +#define lv2table_base(sent) (*(sent) & 0xFFFFFC00)
> +
> +#define mk_lv1ent_sect(pa) ((pa) | 2)
> +#define mk_lv1ent_page(pa) ((pa) | 1)
> +#define mk_lv2ent_lpage(pa) ((pa) | 1)
> +#define mk_lv2ent_spage(pa) ((pa) | 2)
> +
> +#define CTRL_ENABLE	0x5
> +#define CTRL_BLOCK	0x7
> +#define CTRL_DISABLE	0x0
> +
> +#define REG_MMU_CTRL		0x000
> +#define REG_MMU_CFG		0x004
> +#define REG_MMU_STATUS		0x008
> +#define REG_MMU_FLUSH		0x00C
> +#define REG_MMU_FLUSH_ENTRY	0x010
> +#define REG_PT_BASE_ADDR	0x014
> +#define REG_INT_STATUS		0x018
> +#define REG_INT_CLEAR		0x01C
> +#define REG_MMU_VERSION		0x034
> +
> +#define REG_PAGE_FAULT_ADDR	0x024
> +#define REG_AW_FAULT_ADDR	0x028
> +#define REG_AR_FAULT_ADDR	0x02C
> +#define REG_DEFAULT_SLAVE_ADDR	0x030
> +
> +static unsigned long *section_entry(unsigned long *pgtable, unsigned long
> iova)
> +{
> +	return pgtable + lv1ent_offset(iova);
> +}
> +
> +static unsigned long *page_entry(unsigned long *sent, unsigned long iova)
> +{
> +	return (unsigned long *)__va(lv2table_base(sent)) + lv2ent_offset(iova);
> +}
> +
> +enum EXYNOS_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
> +};
> +
> +typedef int (*sysmmu_fault_handler_t)(enum EXYNOS_SYSMMU_INTERRUPT_TYPE
> itype,
> +			unsigned long pgtable_base, unsigned long fault_addr);
> +
> +static unsigned short fault_reg_offset[SYSMMU_FAULTS_NUM] = {
> +	REG_PAGE_FAULT_ADDR,
> +	REG_AR_FAULT_ADDR,
> +	REG_AW_FAULT_ADDR,
> +	REG_DEFAULT_SLAVE_ADDR,
> +	REG_AR_FAULT_ADDR,
> +	REG_AR_FAULT_ADDR,
> +	REG_AW_FAULT_ADDR,
> +	REG_AW_FAULT_ADDR
> +};
> +
> +static char *sysmmu_fault_name[SYSMMU_FAULTS_NUM] = {
> +	"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",
> +	"UNKNOWN FAULT"
> +};
> +
> +struct exynos_iommu_domain;
> +
> +struct sysmmu_drvdata {
> +	struct device *dev;
> +	char *dbgname;
> +	int nsfrs;
> +	void __iomem **sfrbases;
> +	struct clk *clk[2];
> +	bool active;
> +	rwlock_t lock;
> +	struct iommu_domain *domain;
> +	sysmmu_fault_handler_t fault_handler;
> +	unsigned long pgtable;
> +};
> +
> +static bool set_sysmmu_active(struct sysmmu_drvdata *data)
> +{
> +	/* return true if the System MMU was not active previously
> +	   and it needs to be initialized */
> +	if (WARN_ON_ONCE(data->active))
> +		return false;
> +	data->active = true;
> +	return true;
> +}
> +
> +static bool set_sysmmu_inactive(struct sysmmu_drvdata *data)
> +{
> +	/* return true if the System MMU is needed to be disabled */
> +	if (WARN_ON_ONCE(!data->active))
> +		return false;
> +	data->active = false;
> +	return true;
> +}
> +
> +static bool is_sysmmu_active(struct sysmmu_drvdata *data)
> +{
> +	return data->active;
> +}
> +
> +static void sysmmu_block(void __iomem *sfrbase)
> +{
> +	__raw_writel(CTRL_BLOCK, sfrbase + REG_MMU_CTRL);
> +}
> +
> +static void sysmmu_unblock(void __iomem *sfrbase)
> +{
> +	__raw_writel(CTRL_ENABLE, sfrbase + REG_MMU_CTRL);
> +}
> +
> +static void __sysmmu_tlb_invalidate(void __iomem *sfrbase)
> +{
> +	__raw_writel(0x1, sfrbase + REG_MMU_FLUSH);
> +}
> +
> +static void __sysmmu_tlb_invalidate_entry(void __iomem *sfrbase,
> +						unsigned long iova)
> +{
> +	__raw_writel((iova & SPAGE_MASK) | 1, sfrbase + REG_MMU_FLUSH_ENTRY);
> +}
> +
> +static void __sysmmu_set_ptbase(void __iomem *sfrbase,
> +				       unsigned long pgd)
> +{
> +	__raw_writel(0x1, sfrbase + REG_MMU_CFG); /* 16KB LV1, LRU */
> +	__raw_writel(pgd, sfrbase + REG_PT_BASE_ADDR);
> +
> +	__sysmmu_tlb_invalidate(sfrbase);
> +}
> +
> +static void __sysmmu_set_prefbuf(void __iomem *sfrbase, unsigned long base,
> +						unsigned long size, int idx)
> +{
> +	__raw_writel(base, sfrbase + S5P_PB0_SADDR + idx * 8);
> +	__raw_writel(size - 1 + base,  sfrbase + S5P_PB0_EADDR + idx * 8);
> +}
> +
> +void exynos_sysmmu_set_prefbuf(struct device *owner,
> +				unsigned long base0, unsigned long size0,
> +				unsigned long base1, unsigned long size1)
> +{
> +	struct sysmmu_drvdata *data = dev_get_drvdata(owner->archdata.iommu);
> +	unsigned long flags;
> +	int i;
> +
> +	BUG_ON((base0 + (size0 - 1)) <= base0);
> +	BUG_ON((base1 + (size1 - 1)) <= base1);
Do you want to check size? BUG_ON(size <= 1);?
> +
> +	read_lock_irqsave(&data->lock, flags);
> +	if (!is_sysmmu_active(data))
> +		goto finish;
> +
> +	for (i = 0; i < data->nsfrs; i++) {
> +		if ((readl(data->sfrbases[i] + S5P_MMU_VERSION) >> 28) == 3) {
> +			sysmmu_block(data->sfrbases[i]);
> +
> +			if (size1 == 0) {
Is it possible? if size1 is '0', it can't pass the BUG_ON condition.
> +				if (size0 <= SZ_128K) {
> +					base1 = base0;
> +					size1 = size0;
> +				} else {
> +					size1 = size0 -
> +						ALIGN(size0 / 2, SZ_64K);
> +					size0 = size0 - size1;
> +					base1 = base0 + size0;
> +				}
> +			}
> +
> +			__sysmmu_set_prefbuf(
> +					data->sfrbases[i], base0, size0, 0);
> +			__sysmmu_set_prefbuf(
> +					data->sfrbases[i], base1, size1, 1);
> +
> +			sysmmu_unblock(data->sfrbases[i]);
> +		}
> +	}
> +finish:
> +	read_unlock_irqrestore(&data->lock, flags);
> +}
> +
> +static void __set_fault_handler(struct sysmmu_drvdata *data,
> +					sysmmu_fault_handler_t handler)
> +{
> +	unsigned long flags;
> +
> +	write_lock_irqsave(&data->lock, flags);
> +	data->fault_handler = handler;
> +	write_unlock_irqrestore(&data->lock, flags);
> +}
> +
> +void exynos_sysmmu_set_fault_handler(struct device *owner,
> +					sysmmu_fault_handler_t handler)
> +{
> +	struct sysmmu_drvdata *data = dev_get_drvdata(owner->archdata.iommu);
> +
> +	__set_fault_handler(data, handler);
> +}
> +
> +static int default_fault_handler(enum EXYNOS_SYSMMU_INTERRUPT_TYPE itype,
> +		     unsigned long pgtable_base, unsigned long fault_addr)
> +{
> +	unsigned long *ent;
> +
> +	if ((itype >= SYSMMU_FAULTS_NUM) || (itype < SYSMMU_PAGEFAULT))
> +		itype = SYSMMU_FAULT_UNKNOWN;
> +
> +	pr_err("%s occured at 0x%lx(Page table base: 0x%lx)\n",
> +			sysmmu_fault_name[itype], fault_addr, pgtable_base);
> +
> +	ent = section_entry(__va(pgtable_base), fault_addr);
> +	pr_err("\tLv1 entry: 0x%lx\n", *ent);
> +
> +	if (lv1ent_page(ent)) {
> +		ent = page_entry(ent, fault_addr);
> +		pr_err("\t Lv2 entry: 0x%lx\n", *ent);
> +	}
> +
> +	pr_err("Generating 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;
> +	struct resource *irqres;
> +	struct platform_device *pdev;
> +	enum EXYNOS_SYSMMU_INTERRUPT_TYPE itype;
> +	unsigned long addr = -1;
> +
> +	int i, ret = -ENOSYS;
> +
> +	read_lock(&data->lock);
> +
> +	WARN_ON(!is_sysmmu_active(data));
> +
> +	pdev = to_platform_device(data->dev);
> +	for (i = 0; i < pdev->num_resources; i++) {
> +		irqres = platform_get_resource(pdev, IORESOURCE_IRQ, i);
> +		if (irqres && ((int)irqres->start == irq))
> +			break;
> +	}
> +
> +	if (i == pdev->num_resources) {
> +		itype = SYSMMU_FAULT_UNKNOWN;
> +	} else {
> +		i /= 2;
> +
> +		itype = (enum EXYNOS_SYSMMU_INTERRUPT_TYPE)
> +			__ffs(__raw_readl(data->sfrbases[i] + REG_INT_STATUS));
> +		if (WARN_ON(!((itype >= 0) && (itype < SYSMMU_FAULT_UNKNOWN))))
> +			itype = SYSMMU_FAULT_UNKNOWN;
> +		else
> +			addr = __raw_readl(
> +				data->sfrbases[i] + fault_reg_offset[itype]);
> +	}
> +
> +	if (data->domain)
> +		ret = report_iommu_fault(data->domain, data->dev, addr, itype);
> +
> +	if ((ret == -ENOSYS) && data->fault_handler) {
> +		unsigned long base = data->pgtable;
> +		if (itype != SYSMMU_FAULT_UNKNOWN)
> +			base = __raw_readl(
> +					data->sfrbases[i] + REG_PT_BASE_ADDR);
> +		ret = data->fault_handler(itype, base, addr);
> +	}
> +
> +	if (!ret && (itype != SYSMMU_FAULT_UNKNOWN))
> +		__raw_writel(1 << itype, data->sfrbases[i] + REG_INT_CLEAR);
> +	else
> +		dev_dbg(data->dev, "(%s) %s is not handled.\n",
> +				data->dbgname, sysmmu_fault_name[itype]);
> +
> +	if (itype != SYSMMU_FAULT_UNKNOWN)
> +		sysmmu_unblock(data->sfrbases[i]);
> +
> +	read_unlock(&data->lock);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static bool __sysmmu_disable(struct sysmmu_drvdata *data)
> +{
> +	unsigned long flags;
> +	bool disabled = false;
> +	int i;
> +
> +	write_lock_irqsave(&data->lock, flags);
> +
> +	if (!set_sysmmu_inactive(data))
> +		goto finish;
> +
> +	for (i = 0; i < data->nsfrs; i++) {
> +		__raw_writel(CTRL_DISABLE, data->sfrbases[i] + REG_MMU_CTRL);
> +		if (data->clk[0])
> +			clk_disable(data->clk[0]);
> +		if (data->clk[1])
> +			clk_disable(data->clk[1]);
To make it clear, disable the clk[1] first. to match enable order.
> +		disabled = true;
> +		data->pgtable = 0;
> +		data->domain = NULL;
> +		pm_runtime_put(data->dev);
> +	}
> +
> +finish:
> +	write_unlock_irqrestore(&data->lock, flags);
> +
> +	return disabled;
> +}
> +
> +static int __exynos_sysmmu_enable(struct device *owner, unsigned long
> pgtable,
> +						struct iommu_domain *domain)
> +{
> +	int i, ret = 0;
> +	unsigned long flags;
> +	struct sysmmu_drvdata *data = dev_get_drvdata(owner->archdata.iommu);
> +
> +	BUG_ON(!memblock_is_memory(pgtable));
> +
> +	ret = pm_runtime_get_sync(data->dev);
> +	if (ret < 0)
> +		return ret;
> +
> +	write_lock_irqsave(&data->lock, flags);
> +
> +	if (!set_sysmmu_active(data)) {
> +		/* RPM of sysmmu won't be refcounted */
> +		if (ret > 0)
> +			pm_runtime_put(data->dev);
> +
> +		if (WARN_ON(pgtable != data->pgtable)) {
> +			set_sysmmu_inactive(data);
> +			ret = -EBUSY;
> +		}
> +
> +		dev_dbg(data->dev, "(%s) Already enabled.\n", data->dbgname);
> +		goto finish;
> +	}
> +
> +	if (data->clk[0])
> +		clk_enable(data->clk[0]);
> +	if (data->clk[1])
> +		clk_enable(data->clk[1]);
> +
> +	data->pgtable = pgtable;
> +
> +	for (i = 0; i < data->nsfrs; i++) {
> +		__sysmmu_set_ptbase(data->sfrbases[i], pgtable);
> +
> +		if ((readl(data->sfrbases[i] + S5P_MMU_VERSION) >> 28) == 3) {
> +			/* System MMU version is 3.x */
> +			__raw_writel((1 << 12) | (2 << 28),
Can you use the DEFINE instead of hard-code?
> +					data->sfrbases[i] + S5P_MMU_CFG);
> +			__sysmmu_set_prefbuf(data->sfrbases[i], 0, -1, 0);
> +			__sysmmu_set_prefbuf(data->sfrbases[i], 0, -1, 1);
> +		}
> +
> +		__raw_writel(CTRL_ENABLE, data->sfrbases[i] + REG_MMU_CTRL);
> +	}
> +
> +	data->domain = domain;
> +
> +	dev_dbg(data->dev, "(%s) Enabled.\n", data->dbgname);
> +finish:
> +	write_unlock_irqrestore(&data->lock, flags);
> +
> +	if (ret < 0) {
> +		__sysmmu_disable(data);
> +		dev_dbg(data->dev, "(%s) Failed to enable.\n", data->dbgname);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +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 = dev_get_drvdata(owner->archdata.iommu);
> +	bool disabled;
> +
> +	disabled = __sysmmu_disable(data);
> +	dev_dbg(data->dev,
> +			disabled ? "(%s) Disabled.\n" :
> +				"(%s) Deactivation request ignorred.\n",
> +			data->dbgname);
> +}
> +
> +static void sysmmu_tlb_invalidate_entry(struct device *owner,
> +						unsigned long iova)
> +{
> +	unsigned long flags;
> +	struct sysmmu_drvdata *data = dev_get_drvdata(owner->archdata.iommu);
> +
> +	read_lock_irqsave(&data->lock, flags);
> +
> +	if (is_sysmmu_active(data)) {
> +		int i;
> +		for (i = 0; i < data->nsfrs; i++) {
> +			sysmmu_block(data->sfrbases[i]);
> +			__sysmmu_tlb_invalidate_entry(data->sfrbases[i], iova);
> +			sysmmu_unblock(data->sfrbases[i]);
> +		}
> +	} else {
> +		dev_dbg(data->dev,
> +			"(%s) Disabled. Skipping invalidating TLB.\n",
> +			data->dbgname);
> +	}
> +
> +	read_unlock_irqrestore(&data->lock, flags);
> +}
> +
> +void exynos_sysmmu_tlb_invalidate(struct device *owner)
> +{
> +	unsigned long flags;
> +	struct sysmmu_drvdata *data = dev_get_drvdata(owner->archdata.iommu);
> +
> +	read_lock_irqsave(&data->lock, flags);
> +
> +	if (is_sysmmu_active(data)) {
> +		int i;
> +		for (i = 0; i < data->nsfrs; i++) {
> +			sysmmu_block(data->sfrbases[i]);
> +			__sysmmu_tlb_invalidate(data->sfrbases[i]);
> +			sysmmu_unblock(data->sfrbases[i]);
> +		}
> +	} else {
> +		dev_dbg(data->dev,
> +			"(%s) Disabled. Skipping invalidating TLB.\n",
> +			data->dbgname);
> +	}
> +
> +	read_unlock_irqrestore(&data->lock, flags);
> +}
> +
> +static int exynos_sysmmu_probe(struct platform_device *pdev)
> +{
> +	int i, ret;
> +	struct device *dev;
> +	struct sysmmu_drvdata *data;
> +
> +	dev = &pdev->dev;
> +
> +	data = kzalloc(sizeof(*data), GFP_KERNEL);
> +	if (!data) {
> +		dev_dbg(dev, "Not enough memory\n");
> +		ret = -ENOMEM;
> +		goto err_alloc;
> +	}
> +
> +	ret = dev_set_drvdata(dev, data);
> +	if (ret) {
> +		dev_dbg(dev, "Unabled to initialize driver data\n");
> +		goto err_init;
> +	}
> +
> +	data->nsfrs = pdev->num_resources / 2;
> +	data->sfrbases = kmalloc(sizeof(*data->sfrbases) * data->nsfrs,
> +								GFP_KERNEL);
> +	if (data->sfrbases == NULL) {
> +		dev_dbg(dev, "Not enough memory\n");
> +		ret = -ENOMEM;
> +		goto err_init;
> +	}
> +
> +	for (i = 0; i < data->nsfrs; i++) {
> +		struct resource *res;
> +		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
> +		if (!res) {
> +			dev_dbg(dev, "Unable to find IOMEM region\n");
> +			ret = -ENOENT;
> +			goto err_res;
> +		}
> +
> +		data->sfrbases[i] = ioremap(res->start, resource_size(res));
> +		if (!data->sfrbases[i]) {
> +			dev_dbg(dev, "Unable to map IOMEM @ PA:%#x\n",
> +							res->start);
> +			ret = -ENOENT;
> +			goto err_res;
> +		}
> +	}
> +
> +	for (i = 0; i < data->nsfrs; i++) {
> +		ret = platform_get_irq(pdev, i);
> +		if (ret <= 0) {
> +			dev_dbg(dev, "Unable to find IRQ resource\n");
> +			goto err_irq;
> +		}
> +
> +		ret = request_irq(ret, exynos_sysmmu_irq, 0,
> +					dev_name(dev), data);
> +		if (ret) {
> +			dev_dbg(dev, "Unabled to register interrupt handler\n");
> +			goto err_irq;
> +		}
> +	}
> +
> +	if (dev_get_platdata(dev)) {
> +		char *deli, *beg;
> +		struct sysmmu_platform_data *platdata = dev_get_platdata(dev);
> +
> +		beg = platdata->clockname;
> +
> +		for (deli = beg; (*deli != '\0') && (*deli != ','); deli++)
> +			/* NOTHING */;
> +
> +		if (*deli == '\0')
> +			deli = NULL;
> +		else
> +			*deli = '\0';
> +
> +		data->clk[0] = clk_get(dev, beg);
> +		if (IS_ERR(data->clk[0])) {
> +			data->clk[0] = NULL;
> +			dev_dbg(dev, "No clock descriptor registered\n");
> +		}
> +
> +		if (data->clk[0] && deli) {
> +			*deli = ',';
> +			data->clk[1] = clk_get(dev, deli + 1);
> +			if (IS_ERR(data->clk[1]))
> +				data->clk[1] = NULL;
> +		}
> +
> +		data->dbgname = platdata->dbgname;
> +	}
> +
> +	data->dev = dev;
> +	rwlock_init(&data->lock);
> +
> +	__set_fault_handler(data, &default_fault_handler);
> +
> +	if (dev->parent)
> +		pm_runtime_enable(dev);
> +
> +	dev_dbg(dev, "(%s) Initialized\n", data->dbgname);
> +	return 0;
> +err_irq:
> +	while (i-- > 0) {
> +		int irq;
> +
> +		irq = platform_get_irq(pdev, i);
> +		free_irq(irq, data);
> +	}
> +err_res:
> +	while (data->nsfrs-- > 0)
> +		iounmap(data->sfrbases[data->nsfrs]);
> +	kfree(data->sfrbases);
> +err_init:
> +	kfree(data);
> +err_alloc:
> +	dev_err(dev, "(%s) Failed to initialize\n", data->dbgname);
> +	return ret;
> +}
> +
> +static struct platform_driver exynos_sysmmu_driver = {
> +	.probe		= exynos_sysmmu_probe,
> +	.driver		= {
> +		.owner		= THIS_MODULE,
> +		.name		= "exynos-sysmmu",
> +	}
> +};
> +
> +/* We does not consider super section mapping (16MB) */
> +struct iommu_client {
> +	struct list_head node;
> +	struct device *dev;
> +	int refcnt;
> +};
> +
> +struct exynos_iommu_domain {
> +	struct list_head clients; /* list of iommu_client */
> +	unsigned long *pgtable; /* lv1 page table, 16KB */
> +	short *lv2entcnt; /* free lv2 entry counter for each section */
> +	spinlock_t lock; /* lock for this structure */
> +	spinlock_t pgtablelock; /* lock for modifying page table @ pgtable */
> +};
> +
> +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 | __GFP_ZERO, 2);
> +	if (!priv->pgtable)
> +		goto err_pgtable;
> +
> +	priv->lv2entcnt = (short *)__get_free_pages(
> +						GFP_KERNEL | __GFP_ZERO, 1);
> +	if (!priv->lv2entcnt)
> +		goto err_counter;
> +
> +	pgtable_flush(priv->pgtable, priv->pgtable + NUM_LV1ENTRIES);
> +
> +	spin_lock_init(&priv->lock);
> +	spin_lock_init(&priv->pgtablelock);
> +	INIT_LIST_HEAD(&priv->clients);
> +
> +	domain->priv = priv;
> +	return 0;
> +
> +err_counter:
> +	free_pages((unsigned long)priv->pgtable, 2);
> +err_pgtable:
> +	kfree(priv);
> +	return -ENOMEM;
> +}
> +
> +static void exynos_iommu_domain_destroy(struct iommu_domain *domain)
> +{
> +	struct exynos_iommu_domain *priv = domain->priv;
> +	struct list_head *pos, *n;
> +	unsigned long flags;
> +	int i;
> +
> +	WARN_ON(!list_empty(&priv->clients));
> +
> +	spin_lock_irqsave(&priv->lock, flags);
> +
> +	list_for_each_safe(pos, n, &priv->clients) {
> +		struct iommu_client *client;
> +
> +		client = list_entry(pos, struct iommu_client, node);
> +		exynos_sysmmu_disable(client->dev);
> +		kfree(client);
> +	}
> +
> +	spin_unlock_irqrestore(&priv->lock, flags);
> +
> +	for (i = 0; i < NUM_LV1ENTRIES; i++)
> +		if (lv1ent_page(priv->pgtable + i))
> +			kfree(__va(lv2table_base(priv->pgtable + i)));
> +
> +	free_pages((unsigned long)priv->pgtable, 2);
> +	free_pages((unsigned long)priv->lv2entcnt, 1);
> +	kfree(domain->priv);
> +	domain->priv = NULL;
> +}
> +
> +static int exynos_iommu_attach_device(struct iommu_domain *domain,
> +				   struct device *dev)
> +{
> +	int ret;
> +	struct exynos_iommu_domain *priv = domain->priv;
> +	struct iommu_client *client = NULL;
> +	struct list_head *pos;
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&priv->lock, flags);
> +
> +	list_for_each(pos, &priv->clients) {
Simply list_for_each_entry.
> +		struct iommu_client *cur;
> +
> +		cur = list_entry(pos, struct iommu_client, node);
> +		if (cur->dev == dev) {
> +			client = cur;
> +			break;
> +		}
> +	}
> +
> +	if (client != NULL) {
> +		dev_dbg(dev, "%s: IOMMU with pgtable 0x%lx already attached\n",
> +					__func__, __pa(priv->pgtable));
> +		client->refcnt++;
> +	}
> +
> +	spin_unlock_irqrestore(&priv->lock, flags);
> +
> +	if (client != NULL)
> +		return 0;
> +
> +	client = kmalloc(sizeof(*client), GFP_KERNEL);
Maybe attach called frequently. how about to use kmem_cache-*?
> +	if (!client)
> +		return -ENOMEM;
> +
> +	INIT_LIST_HEAD(&client->node);
> +	client->dev = dev;
> +	client->refcnt = 1;
Dose it possible attach more than one? OMAP has multiple attach codes.
> +
> +	ret = __exynos_sysmmu_enable(dev, __pa(priv->pgtable), domain);
> +	if (ret) {
> +		kfree(client);
> +		return ret;
> +	}
> +
> +	spin_lock_irqsave(&priv->lock, flags);
> +	list_add_tail(&client->node, &priv->clients);
> +	spin_unlock_irqrestore(&priv->lock, flags);
> +
> +	dev_dbg(dev, "%s: Attached new IOMMU with pgtable 0x%lx\n", __func__,
> +						__pa(priv->pgtable));
> +	return 0;
> +}
> +
> +static void exynos_iommu_detach_device(struct iommu_domain *domain,
> +				    struct device *dev)
> +{
> +	struct exynos_iommu_domain *priv = domain->priv;
> +	struct iommu_client *client = NULL;
> +	struct list_head *pos;
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&priv->lock, flags);
> +
> +	list_for_each(pos, &priv->clients) {
> +		struct iommu_client *cur;
> +
> +		cur = list_entry(pos, struct iommu_client, node);
> +		if (cur->dev == dev) {
> +			cur->refcnt--;
> +			client = cur;
> +			break;
> +		}
> +	}
> +
> +	spin_unlock_irqrestore(&priv->lock, flags);
> +
> +	if (WARN_ON(client == NULL))
> +		return;
> +
> +	if (client->refcnt > 0) {
It never triggered. as you use true/false scheme. I remember you said
previous patch. use the refcount but actual meaning is true/false.
> +		dev_dbg(dev, "%s: Detaching IOMMU with pgtable 0x%lx delayed\n",
> +					__func__, __pa(priv->pgtable));
> +		return;
> +	}
> +
> +	BUG_ON(client->refcnt != 0);
Do you think "minus value"?
> +
> +	list_del(&client->node);
> +	exynos_sysmmu_disable(client->dev);
> +	kfree(client);
> +	dev_dbg(dev, "%s: Detached IOMMU with pgtable 0x%lx\n", __func__,
> +						__pa(priv->pgtable));
> +}
> +
> +static unsigned long *alloc_lv2entry(unsigned long *sent, unsigned long
> iova,
> +					short *pgcounter)
> +{
> +	if (lv1ent_fault(sent)) {
> +		unsigned long *pent;
> +
> +		pent = kzalloc(LV2TABLE_SIZE, GFP_ATOMIC);
> +		BUG_ON((unsigned long)pent & (LV2TABLE_SIZE - 1));
> +		if (!pent)
> +			return NULL;
> +
> +		*sent = mk_lv1ent_page(__pa(pent));
> +		*pgcounter = NUM_LV2ENTRIES;
> +		pgtable_flush(pent, pent + NUM_LV2ENTRIES);
> +		pgtable_flush(sent, sent + 1);
> +	}
> +
> +	return page_entry(sent, iova);
> +}
> +
> +static int lv1set_section(unsigned long *sent, phys_addr_t paddr, short
> *pgcnt)
> +{
> +	if (lv1ent_section(sent))
> +		return -EADDRINUSE;
> +
> +	if (lv1ent_page(sent)) {
> +		if (*pgcnt != NUM_LV2ENTRIES)
> +			return -EADDRINUSE;
> +
> +		kfree(page_entry(sent, 0));
> +
> +		*pgcnt = 0;
> +	}
> +
> +	*sent = mk_lv1ent_sect(paddr);
> +
> +	pgtable_flush(sent, sent + 1);
> +
> +	return 0;
> +}
> +
> +static int lv2set_page(unsigned long *pent, phys_addr_t paddr, size_t size,
> +								short *pgcnt)
> +{
> +	if (size == SPAGE_SIZE) {
> +		if (!lv2ent_fault(pent))
> +			return -EADDRINUSE;
> +
> +		*pent = mk_lv2ent_spage(paddr);
> +		pgtable_flush(pent, pent + 1);
> +		*pgcnt -= 1;
> +	} else { /* size == LPAGE_SIZE */
> +		int i;
> +		for (i = 0; i < SPAGES_PER_LPAGE; i++, pent++) {
> +			if (!lv2ent_fault(pent)) {
> +				memset(pent, 0, sizeof(*pent) * i);
> +				return -EADDRINUSE;
> +			}
> +
> +			*pent = mk_lv2ent_lpage(paddr);
> +		}
> +		pgtable_flush(pent - SPAGES_PER_LPAGE, pent);
> +		*pgcnt -= SPAGES_PER_LPAGE;
> +	}
> +
> +	return 0;
> +}
> +
> +static int exynos_iommu_map(struct iommu_domain *domain, unsigned long
> iova,
> +			 phys_addr_t paddr, size_t size, int prot)
> +{
> +	struct exynos_iommu_domain *priv = domain->priv;
> +	unsigned long *entry;
> +	unsigned long flags;
> +	int ret = -ENOMEM;
> +
> +	BUG_ON(priv->pgtable == NULL);
> +
> +	spin_lock_irqsave(&priv->pgtablelock, flags);
> +
> +	entry = section_entry(priv->pgtable, iova);
> +
> +	if (size == SECT_SIZE) {
> +		ret = lv1set_section(entry, paddr,
> +					&priv->lv2entcnt[lv1ent_offset(iova)]);
> +	} else {
> +		unsigned long *pent;
> +
> +		pent = alloc_lv2entry(entry, iova,
> +					&priv->lv2entcnt[lv1ent_offset(iova)]);
> +
> +		if (!pent)
> +			ret = -ENOMEM;
> +		else
> +			ret = lv2set_page(pent, paddr, size,
> +					&priv->lv2entcnt[lv1ent_offset(iova)]);
> +	}
> +
> +	if (ret) {
> +		pr_debug("%s: Failed to map iova 0x%lx/0x%x bytes\n",
> +							__func__, iova, size);
> +	}
> +
> +	spin_unlock_irqrestore(&priv->pgtablelock, flags);
> +
> +	return ret;
> +}
> +
> +static size_t exynos_iommu_unmap(struct iommu_domain *domain,
> +					       unsigned long iova, size_t size)
> +{
> +	struct exynos_iommu_domain *priv = domain->priv;
> +	struct iommu_client *client;
> +	unsigned long flags;
> +	unsigned long *ent;
> +
> +	BUG_ON(priv->pgtable == NULL);
> +
> +	spin_lock_irqsave(&priv->pgtablelock, flags);
> +
> +	ent = section_entry(priv->pgtable, iova);
> +
> +	if (lv1ent_section(ent)) {
> +		BUG_ON(size < SECT_SIZE);
> +
> +		*ent = 0;
> +		pgtable_flush(ent, ent + 1);
> +		size = SECT_SIZE;
> +		goto done;
> +	}
> +
> +	if (unlikely(lv1ent_fault(ent))) {
> +		if (size > SECT_SIZE)
> +			size = SECT_SIZE;
> +		goto done;
> +	}
> +
> +	/* lv1ent_page(sent) == true here */
> +
> +	ent = page_entry(ent, iova);
> +
> +	if (unlikely(lv2ent_fault(ent))) {
> +		size = SPAGE_SIZE;
> +		goto done;
> +	}
> +
> +	if (lv2ent_small(ent)) {
> +		*ent = 0;
> +		size = SPAGE_SIZE;
> +		priv->lv2entcnt[lv1ent_offset(iova)] -= 1;
> +		goto done;
> +	}
> +
> +	/* lv1ent_large(ent) == true here */
> +	BUG_ON(size < LPAGE_SIZE);
> +
> +	memset(ent, 0, sizeof(*ent) * SPAGES_PER_LPAGE);
> +
> +	size = LPAGE_SIZE;
> +	priv->lv2entcnt[lv1ent_offset(iova)] -= SPAGES_PER_LPAGE;
> +done:
> +	list_for_each_entry(client, &priv->clients, node)
> +		sysmmu_tlb_invalidate_entry(client->dev, iova);
> +
> +	spin_unlock_irqrestore(&priv->pgtablelock, flags);
> +
> +	return size;
> +}
> +
> +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 flags;
> +	phys_addr_t phys = -1;
> +
> +	spin_lock_irqsave(&priv->pgtablelock, flags);
> +
> +	entry = section_entry(priv->pgtable, iova);
> +
> +	if (lv1ent_section(entry)) {
> +		phys = section_phys(entry) + section_offs(iova);
> +	} else if (lv1ent_page(entry)) {
> +		entry = page_entry(entry, iova);
> +
> +		if (lv2ent_large(entry))
> +			phys = lpage_phys(entry) + lpage_offs(iova);
> +		else if (lv2ent_small(entry))
> +			phys = spage_phys(entry) + spage_offs(iova);
> +	}
> +
> +	spin_unlock_irqrestore(&priv->pgtablelock, flags);
> +
> +	return phys;
> +}
> +
> +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,
> +	.pgsize_bitmap = SECT_SIZE | LPAGE_SIZE | SPAGE_SIZE,
> +};
> +
> +static int __init exynos_iommu_init(void)
> +{
> +	int ret;
> +
> +	ret = platform_driver_register(&exynos_sysmmu_driver);
> +
> +	if (ret == 0)
> +		bus_set_iommu(&platform_bus_type, &exynos_iommu_ops);
> +
> +	return ret;
> +}
> +arch_initcall(exynos_iommu_init);
Thank you,
Kyungmin Park
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