/include/linux/vcm_mm.h

  1/* Copyright (c) 2010, The Linux Foundation. All rights reserved.
  2 *
  3 * This program is free software; you can redistribute it and/or modify
  4 * it under the terms of the GNU General Public License version 2 and
  5 * only version 2 as published by the Free Software Foundation.
  6 *
  7 * This program is distributed in the hope that it will be useful,
  8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 10 * GNU General Public License for more details.
 11 *
 12 */
 13
 14/* Architecture-specific VCM functions */
 15
 16/* Device attributes */
 17
 18/*
 19 * Sharing attributes. Pick only one.
 20 */
 21#define VCM_DEV_ATTR_NON_SH 	(0x00)
 22#define VCM_DEV_ATTR_SH		(0x04)
 23
 24/*
 25 * Caching attributes. Pick only one.
 26 */
 27#define VCM_DEV_ATTR_NONCACHED		(0x00)
 28#define VCM_DEV_ATTR_CACHED_WB_WA	(0x01)
 29#define VCM_DEV_ATTR_CACHED_WB_NWA	(0x02)
 30#define VCM_DEV_ATTR_CACHED_WT		(0x03)
 31
 32/*
 33 * A "good" default set of attributes: shareable and non-cacheable.
 34 */
 35#define VCM_DEV_DEFAULT_ATTR	(VCM_DEV_ATTR_SH | VCM_DEV_ATTR_NONCACHED)
 36
 37/**
 38 * set_arm7_pte_attr() - Set ARMv7 page table attributes
 39 * pt_base	Virtual address of the first-level page table
 40 * @va		Virtual address whose attributes are to be set
 41 * @len		Page size used to map the given virtual address
 42 * @attr	Attributes to set for this mapping.
 43 *
 44 * Modify a mapping attribute. The base address of the page table must
 45 * be a virtual address containing a valid ARMv7 page table.  The
 46 * virtual address must refer to an existing mapping and must be
 47 * aligned to the length with which it was mapped. The mapping length
 48 * must similarly be the same as was specified when the mapping was
 49 * made (one of 4KB, 64KB, 1MB, or 16MB). The attribute must be one of
 50 * the shareability attributes above ORed with one of the cacheability
 51 * attributes. Any previous attributes are completely replaced by the
 52 * most recent call to this function. This function only sets the
 53 * cacheability and shareability attributes. This is accomplished by
 54 * modifying the TEX class and the S bit in the PTE. It is an error to
 55 * call this function without having called vcm_setup_tex_classes at
 56 * least once.
 57 *
 58 * The return value is zero on success and non-zero on failure.
 59 */
 60int set_arm7_pte_attr(unsigned long pt_base, unsigned long va,
 61		     unsigned long len,	unsigned int attr);
 62
 63
 64/**
 65 * cpu_set_attr() - Set page table attributes on the CPU's page tables
 66 * @va		Virtual address whose attributes are to be set
 67 * @len		Page size used to map the given virtual address
 68 * @attr	Attributes to set for this mapping.
 69 *
 70 * Modify a mapping attribute within the ARM page tables. The va must
 71 * refer to an existing mapping and must be aligned to the length with
 72 * which it was mapped. The mapping length must similarly be the same
 73 * as was specified when the mapping was made (one of 4KB, 64KB, 1MB,
 74 * or 16MB). The attribute must be one of the shareability attributes
 75 * above ORed with one of the cacheability attributes. Any previous
 76 * attributes are completely replaced by the most recent call to this
 77 * function. This function only sets the cacheability and shareability
 78 * attributes. This is accomplished by modifying the TEX class and the
 79 * S bit in the PTE. It is an error to call this function without
 80 * having called vcm_setup_tex_classes at least once. It is an error
 81 * to call this function on any system using a memory configuration
 82 * that is anything OTHER than ARMv7 with TEX remap enabled. Only the
 83 * HW page tables are modified; the Linux page tables are left
 84 * untouched.
 85 *
 86 * The return value is zero on success and non-zero on failure.
 87 */
 88int cpu_set_attr(unsigned long va, unsigned long len, unsigned int attr);
 89
 90
 91/**
 92 * vcm_setup_tex_classes() - Prepare TEX class table for use
 93 *
 94 * Initialize the attribute mapping table by examining the TEX classes
 95 * used by the CPU and finding the classes that match the device
 96 * attributes (VCM_DEV_xx) defined above. This function is only
 97 * relevant if TEX remap is enabled. The results will be unpredictable
 98 * and irrelevant if TEX remap is not in use. It is an error to call
 99 * this function in any system using a memory configuration of
100 * anything OTHER than ARMv7 with TEX remap enabled.
101 *
102 * The return value is zero on success or non-zero on failure. In the
103 * present version, a failure will result in a panic.
104 */
105int vcm_setup_tex_classes(void);