linux/arch/arm/mach-msm/include/mach/iommu.h

/* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

#ifndef MSM_IOMMU_H
#define MSM_IOMMU_H

#include <linux/interrupt.h>

/* Maximum number of Machine IDs that we are allowing to be mapped to the same
 * context bank. The number of MIDs mapped to the same CB does not affect
 * performance, but there is a practical limit on how many distinct MIDs may
 * be present. These mappings are typically determined at design time and are
 * not expected to change at run time.
 */
#define MAX_NUM_MIDS	16

/**
 * struct msm_iommu_dev - a single IOMMU hardware instance
 * name		Human-readable name given to this IOMMU HW instance
 * clk_rate	Rate to set for this IOMMU's clock, if applicable to this
 *		particular IOMMU. 0 means don't set a rate.
 *		-1 means it is an AXI clock with no valid rate
 *
 */
struct msm_iommu_dev {
	const char *name;
	int clk_rate;
};

/**
 * struct msm_iommu_ctx_dev - an IOMMU context bank instance
 * name		Human-readable name given to this context bank
 * num		Index of this context bank within the hardware
 * mids		List of Machine IDs that are to be mapped into this context
 *		bank, terminated by -1. The MID is a set of signals on the
 *		AXI bus that identifies the function associated with a specific
 *		memory request. (See ARM spec).
 */
struct msm_iommu_ctx_dev {
	const char *name;
	int num;
	int mids[MAX_NUM_MIDS];
};


/**
 * struct msm_iommu_drvdata - A single IOMMU hardware instance
 * @base:	IOMMU config port base address (VA)
 * @irq:	Interrupt number
  *
 * A msm_iommu_drvdata holds the global driver data about a single piece
 * of an IOMMU hardware instance.
 */
struct msm_iommu_drvdata {
	void __iomem *base;
	int irq;
};

/**
 * struct msm_iommu_ctx_drvdata - an IOMMU context bank instance
 * @num:		Hardware context number of this context
 * @pdev:		Platform device associated wit this HW instance
 * @attached_elm:	List element for domains to track which devices are
 *			attached to them
 *
 * A msm_iommu_ctx_drvdata holds the driver data for a single context bank
 * within each IOMMU hardware instance
 */
struct msm_iommu_ctx_drvdata {
	int num;
	struct platform_device *pdev;
	struct list_head attached_elm;
};

/*
 * Look up an IOMMU context device by its context name. NULL if none found.
 * Useful for testing and drivers that do not yet fully have IOMMU stuff in
 * their platform devices.
 */
struct device *msm_iommu_get_ctx(const char *ctx_name);

/*
 * Interrupt handler for the IOMMU context fault interrupt. Hooking the
 * interrupt is not supported in the API yet, but this will print an error
 * message and dump useful IOMMU registers.
 */
irqreturn_t msm_iommu_fault_handler(int irq, void *dev_id);

#endif