include/linux/vcm_types.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.
 *
 */

#ifndef VCM_TYPES_H
#define VCM_TYPES_H

#include <linux/device.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/genalloc.h>
#include <linux/list.h>

/*
 * Reservation Attributes
 *
 * Used in vcm_reserve(), vcm_reserve_at(), vcm_set_res_attr() and
 * vcm_reserve_bound().
 *
 *	VCM_READ	Specifies that the reservation can be read.
 *	VCM_WRITE	Specifies that the reservation can be written.
 *	VCM_EXECUTE	Specifies that the reservation can be executed.
 *	VCM_USER	Specifies that this reservation is used for
 *			userspace access.
 *	VCM_SUPERVISOR	Specifies that this reservation is used for
 *				supervisor access.
 *	VCM_SECURE	Specifies that the target of the reservation is
 *			secure. The usage of this setting is TBD.
 *
 *	Caching behavior as a 4 bit field:
 *		VCM_NOTCACHED		The VCM region is not cached.
 *		VCM_INNER_WB_WA		The VCM region is inner cached
 *					and is write-back and write-allocate.
 *		VCM_INNER_WT_NWA	The VCM region is inner cached and is
 *					write-through and no-write-allocate.
 *		VCM_INNER_WB_NWA	The VCM region is inner cached and is
 *					write-back and no-write-allocate.
 *		VCM_OUTER_WB_WA		The VCM region is outer cached and is
 *					write-back and write-allocate.
 *		VCM_OUTER_WT_NWA	The VCM region is outer cached and is
 *					write-through and no-write-allocate.
 *		VCM_OUTER_WB_NWA	The VCM region is outer cached and is
 *					write-back and no-write-allocate.
 *		VCM_WB_WA		The VCM region is cached and is write
 *					-back and write-allocate.
 *		VCM_WT_NWA		The VCM region is cached and is write
 *					-through and no-write-allocate.
 *		VCM_WB_NWA		The VCM region is cached and is write
 *					-back and no-write-allocate.
 */

/* Order of alignment (power of 2). Ie, 12 = 4k, 13 = 8k, 14 = 16k
 * Alignments of less than 1MB on buffers of size 1MB or greater should be
 * avoided. Alignments of less than 64KB on buffers of size 64KB or greater
 * should be avoided. Strictly speaking, it will work, but will result in
 * suboptimal performance, and a warning will be printed to that effect if
 * VCM_PERF_WARN is enabled.
 */
#define VCM_ALIGN_SHIFT		10
#define VCM_ALIGN_MASK		0x1F
#define VCM_ALIGN_ATTR(order)	(((order) & VCM_ALIGN_MASK) << VCM_ALIGN_SHIFT)

#define VCM_ALIGN_DEFAULT	0
#define VCM_ALIGN_4K		(VCM_ALIGN_ATTR(12))
#define VCM_ALIGN_8K		(VCM_ALIGN_ATTR(13))
#define VCM_ALIGN_16K		(VCM_ALIGN_ATTR(14))
#define VCM_ALIGN_32K		(VCM_ALIGN_ATTR(15))
#define VCM_ALIGN_64K		(VCM_ALIGN_ATTR(16))
#define VCM_ALIGN_128K		(VCM_ALIGN_ATTR(17))
#define VCM_ALIGN_256K		(VCM_ALIGN_ATTR(18))
#define VCM_ALIGN_512K		(VCM_ALIGN_ATTR(19))
#define VCM_ALIGN_1M		(VCM_ALIGN_ATTR(20))
#define VCM_ALIGN_2M		(VCM_ALIGN_ATTR(21))
#define VCM_ALIGN_4M		(VCM_ALIGN_ATTR(22))
#define VCM_ALIGN_8M		(VCM_ALIGN_ATTR(23))
#define VCM_ALIGN_16M		(VCM_ALIGN_ATTR(24))
#define VCM_ALIGN_32M		(VCM_ALIGN_ATTR(25))
#define VCM_ALIGN_64M		(VCM_ALIGN_ATTR(26))
#define VCM_ALIGN_128M		(VCM_ALIGN_ATTR(27))
#define VCM_ALIGN_256M		(VCM_ALIGN_ATTR(28))
#define VCM_ALIGN_512M		(VCM_ALIGN_ATTR(29))
#define VCM_ALIGN_1GB		(VCM_ALIGN_ATTR(30))


#define VCM_CACHE_POLICY	(0xF << 0)
#define VCM_READ		(1UL << 9)
#define VCM_WRITE		(1UL << 8)
#define VCM_EXECUTE		(1UL << 7)
#define VCM_USER		(1UL << 6)
#define VCM_SUPERVISOR		(1UL << 5)
#define VCM_SECURE		(1UL << 4)
#define VCM_NOTCACHED		(0UL << 0)
#define VCM_WB_WA		(1UL << 0)
#define VCM_WB_NWA		(2UL << 0)
#define VCM_WT			(3UL << 0)


/*
 * Physical Allocation Attributes
 *
 * Used in vcm_phys_alloc().
 *
 *	Alignment as a power of 2 starting at 4 KB. 5 bit field.
 *	1 = 4KB, 2 = 8KB, etc.
 *
 *			Specifies that the reservation should have the
 *			alignment specified.
 *
 *	VCM_4KB		Specifies that the reservation should use 4KB pages.
 *	VCM_64KB	Specifies that the reservation should use 64KB pages.
 *	VCM_1MB		specifies that the reservation should use 1MB pages.
 *	VCM_ALL		Specifies that the reservation should use all
 *			available page sizes.
 *	VCM_PHYS_CONT	Specifies that a reservation should be backed with
 *			physically contiguous memory.
 *	VCM_COHERENT	Specifies that the reservation must be kept coherent
 *			because it's shared.
 */

#define VCM_4KB			(1UL << 5)
#define VCM_64KB		(1UL << 4)
#define VCM_1MB			(1UL << 3)
#define VCM_ALL			(1UL << 2)
#define VCM_PAGE_SEL_MASK       (0xFUL << 2)
#define VCM_PHYS_CONT		(1UL << 1)
#define VCM_COHERENT		(1UL << 0)


#define SHIFT_4KB               (12)

#define ALIGN_REQ_BYTES(attr) (1UL << (((attr & VCM_ALIGNMENT_MASK) >> 6) + 12))
/* set the alignment in pow 2, 0 = 4KB */
#define SET_ALIGN_REQ_BYTES(attr, align) \
	((attr & ~VCM_ALIGNMENT_MASK) | ((align << 6) & VCM_ALIGNMENT_MASK))

/*
 * Association Attributes
 *
 * Used in vcm_assoc(), vcm_set_assoc_attr().
 *
 *	VCM_USE_LOW_BASE	Use the low base register.
 *	VCM_USE_HIGH_BASE	Use the high base register.
 *
 *	VCM_SPLIT		A 5 bit field that defines the
 *				high/low split.  This value defines
 *				the number of 0's left-filled into the
 *				split register. Addresses that match
 *				this will use VCM_USE_LOW_BASE
 *				otherwise they'll use
 *				VCM_USE_HIGH_BASE. An all 0's value
 *				directs all translations to
 *				VCM_USE_LOW_BASE.
 */

#define VCM_SPLIT		(1UL << 3)
#define VCM_USE_LOW_BASE	(1UL << 2)
#define VCM_USE_HIGH_BASE	(1UL << 1)


/*
 * External VCMs
 *
 * Used in vcm_create_from_prebuilt()
 *
 * Externally created VCM IDs for creating kernel and user space
 * mappings to VCMs and kernel and user space buffers out of
 * VCM_MEMTYPE_0,1,2, etc.
 *
 */
#define VCM_PREBUILT_KERNEL		1
#define VCM_PREBUILT_USER		2

/**
 * enum memtarget_t - A logical location in a VCM.
 * @VCM_START:			Indicates the start of a VCM_REGION.
 */
enum memtarget_t {
	VCM_START
};


/**
 * enum memtype_t - A logical location in a VCM.
 * @VCM_MEMTYPE_0:		Generic memory type 0
 * @VCM_MEMTYPE_1:		Generic memory type 1
 * @VCM_MEMTYPE_2:		Generic memory type 2
 *
 * A memtype encapsulates a platform specific memory arrangement. The
 * memtype needn't refer to a single type of memory, it can refer to a
 * set of memories that can back a reservation.
 *
 */
enum memtype_t {
	VCM_MEMTYPE_0 = 0,
	VCM_MEMTYPE_1 = 1,
	VCM_MEMTYPE_2 = 2,
	VCM_MEMTYPE_3 = 3,
	VCM_INVALID = 4,
};

/**
 * vcm_handler - The signature of the fault hook.
 * @dev:			The device id of the faulting device.
 * @data:			The generic data pointer.
 * @fault_data:			System specific common fault data.
 *
 * The handler should return 0 for success. This indicates that the
 * fault was handled. A non-zero return value is an error and will be
 * propagated up the stack.
 */
typedef int (*vcm_handler)(struct device *dev, void *data, void *fault_data);


/**
 * enum vcm_type - The type of VCM.
 * @VCM_DEVICE:			VCM used for device mappings
 * @VCM_EXT_KERNEL:		VCM used for kernel-side mappings
 * @VCM_EXT_USER:		VCM used for userspace mappings
 * @VCM_ONE_TO_ONE:		VCM used for devices without SMMUs
 *
 */
enum vcm_type {
	VCM_DEVICE,
	VCM_EXT_KERNEL,
	VCM_EXT_USER,
	VCM_ONE_TO_ONE,
};


/**
 * struct vcm - A Virtually Contiguous Memory region.
 * @start_addr:		The starting address of the VCM region.
 * @len:		The len of the VCM region. This must be at least
 *			vcm_min() bytes.
 */
struct vcm {
	/* public */
	unsigned long start_addr;
	size_t len;

	/* private */
	enum vcm_type type;

	struct device *dev; /* opaque device control */

	struct iommu_domain *domain;

	/* allocator dependent */
	struct gen_pool *pool;

	struct list_head res_head;

	/* this will be a very short list */
	struct list_head assoc_head;
};

/**
 * struct avcm - A VCM to device association
 * @vcm:		The VCM region of interest.
 * @dev:		The device to associate the VCM with.
 * @attr:		See 'Association Attributes'.
 */
struct avcm {
	/* public */
	struct vcm *vcm;
	struct device *dev;
	u32 attr;

	/* private */
	struct list_head assoc_elm;

	int is_active; /* is this particular association active */
};

/**
 * struct bound - A boundary to reserve from in a VCM region.
 * @vcm:		The VCM that needs a bound.
 * @len:		The len of the bound.
 */
struct bound {
	struct vcm *vcm;
	size_t len;
};

struct phys_chunk {
	struct list_head list;
	struct list_head allocated; /* used to record is allocated */

	struct list_head refers_to;
	phys_addr_t pa;
	int pool_idx;
	int size;
};

/**
 * struct physmem - A physical memory allocation.
 * @memtype:		The memory type of the VCM region.
 * @len:		The len of the physical memory allocation.
 * @attr:		See 'Physical Allocation Attributes'.
 */
struct physmem {
	/* public */
	enum memtype_t memtype;
	size_t len;
	u32 attr;

	/* private */
	struct phys_chunk alloc_head;

	/* if the physmem is cont then use the built in VCM */
	int is_cont;
	struct res *res;
};


/**
 * struct res - A reservation in a VCM region.
 * @vcm:		The VCM region to reserve from.
 * @len:		The length of the reservation. Must be at least
 *			vcm_min() bytes.
 * @attr:		See 'Reservation Attributes'.
 * @dev_addr:		The device-side address.
 */
struct res {
	/* public */
	struct vcm *vcm;
	size_t len;
	u32 attr;
	unsigned long dev_addr;

	/* private */
	struct physmem *physmem;
	/* allocator dependent */
	size_t alignment_req;
	size_t aligned_len;
	unsigned long ptr;

	struct list_head res_elm;

	/* type VCM_EXT_KERNEL */
	struct vm_struct *vm_area;
	int mapped;
};

#endif /* VCM_TYPES_H */