/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
*
* (C) COPYRIGHT 2019-2022 ARM Limited. All rights reserved.
*
* This program is free software and is provided to you under the terms of the
* GNU General Public License version 2 as published by the Free Software
* Foundation, and any use by you of this program is subject to the terms
* of such GNU license.
*
* 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, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*
*/
#ifndef _MEMORY_GROUP_MANAGER_H_
#define _MEMORY_GROUP_MANAGER_H_
#include <linux/mm.h>
#include <linux/of.h>
#include <linux/version.h>
#if (KERNEL_VERSION(4, 17, 0) > LINUX_VERSION_CODE)
typedef int vm_fault_t;
#endif
#define MEMORY_GROUP_MANAGER_NR_GROUPS (16)
struct memory_group_manager_device;
struct memory_group_manager_import_data;
/**
* struct memory_group_manager_ops - Callbacks for memory group manager
* operations
*
* @mgm_alloc_page: Callback to allocate physical memory in a group
* @mgm_free_page: Callback to free physical memory in a group
* @mgm_get_import_memory_id: Callback to get the group ID for imported memory
* @mgm_update_gpu_pte: Callback to modify a GPU page table entry
* @mgm_pte_to_original_pte: Callback to get the original PTE entry as given
* to mgm_update_gpu_pte
* @mgm_vmf_insert_pfn_prot: Callback to map a physical memory page for the CPU
*/
struct memory_group_manager_ops {
/*
* mgm_alloc_page - Allocate a physical memory page in a group
*
* @mgm_dev: The memory group manager through which the request is
* being made.
* @group_id: A physical memory group ID. The meaning of this is defined
* by the systems integrator. Its valid range is
* 0 .. MEMORY_GROUP_MANAGER_NR_GROUPS-1.
* @gfp_mask: Bitmask of Get Free Page flags affecting allocator
* behavior.
* @order: Page order for physical page size (order=0 means 4 KiB,
* order=9 means 2 MiB).
*
* Return: Pointer to allocated page, or NULL if allocation failed.
*/
struct page *(*mgm_alloc_page)(
struct memory_group_manager_device *mgm_dev, int group_id,
gfp_t gfp_mask, unsigned int order);
/*
* mgm_free_page - Free a physical memory page in a group
*
* @mgm_dev: The memory group manager through which the request
* is being made.
* @group_id: A physical memory group ID. The meaning of this is
* defined by the systems integrator. Its valid range is
* 0 .. MEMORY_GROUP_MANAGER_NR_GROUPS-1.
* @page: Address of the struct associated with a page of physical
* memory that was allocated by calling the mgm_alloc_page
* method of the same memory pool with the same values of
* @group_id and @order.
* @order: Page order for physical page size (order=0 means 4 KiB,
* order=9 means 2 MiB).
*/
void (*mgm_free_page)(
struct memory_group_manager_device *mgm_dev, int group_id,
struct page *page, unsigned int order);
/*
* mgm_get_import_memory_id - Get the physical memory group ID for the
* imported memory
*
* @mgm_dev: The memory group manager through which the request
* is being made.
* @import_data: Pointer to the data which describes imported memory.
*
* Note that provision of this call back is optional, where it is not
* provided this call back pointer must be set to NULL to indicate it
* is not in use.
*
* Return: The memory group ID to use when mapping pages from this
* imported memory.
*/
int (*mgm_get_import_memory_id)(
struct memory_group_manager_device *mgm_dev,
struct memory_group_manager_import_data *import_data);
/*
* mgm_update_gpu_pte - Modify a GPU page table entry for a memory group
*
* @mgm_dev: The memory group manager through which the request
* is being made.
* @group_id: A physical memory group ID. The meaning of this is
* defined by the systems integrator. Its valid range is
* 0 .. MEMORY_GROUP_MANAGER_NR_GROUPS-1.
* @mmu_level: The level of the page table entry in @ate.
* @pte: The page table entry to modify, in LPAE or AArch64 format
* (depending on the driver's configuration). This should be
* decoded to determine the physical address and any other
* properties of the mapping the manager requires.
*
* This function allows the memory group manager to modify a GPU page
* table entry before it is stored by the kbase module (controller
* driver). It may set certain bits in the page table entry attributes
* or in the physical address, based on the physical memory group ID.
*
* Return: A modified GPU page table entry to be stored in a page table.
*/
u64 (*mgm_update_gpu_pte)(struct memory_group_manager_device *mgm_dev,
int group_id, int mmu_level, u64 pte);
/*
* mgm_pte_to_original_pte - Undo any modification done during mgm_update_gpu_pte()
*
* @mgm_dev: The memory group manager through which the request
* is being made.
* @group_id: A physical memory group ID. The meaning of this is
* defined by the systems integrator. Its valid range is
* 0 .. MEMORY_GROUP_MANAGER_NR_GROUPS-1.
* @mmu_level: The level of the page table entry in @ate.
* @pte: The page table entry to restore the original representation for,
* in LPAE or AArch64 format (depending on the driver's configuration).
*
* Undo any modifications done during mgm_update_gpu_pte().
* This function allows getting back the original PTE entry as given
* to mgm_update_gpu_pte().
*
* Return: PTE entry as originally specified to mgm_update_gpu_pte()
*/
u64 (*mgm_pte_to_original_pte)(struct memory_group_manager_device *mgm_dev, int group_id,
int mmu_level, u64 pte);
/*
* mgm_vmf_insert_pfn_prot - Map a physical page in a group for the CPU
*
* @mgm_dev: The memory group manager through which the request
* is being made.
* @group_id: A physical memory group ID. The meaning of this is
* defined by the systems integrator. Its valid range is
* 0 .. MEMORY_GROUP_MANAGER_NR_GROUPS-1.
* @vma: The virtual memory area to insert the page into.
* @addr: A virtual address (in @vma) to assign to the page.
* @pfn: The kernel Page Frame Number to insert at @addr in @vma.
* @pgprot: Protection flags for the inserted page.
*
* Called from a CPU virtual memory page fault handler. This function
* creates a page table entry from the given parameter values and stores
* it at the appropriate location (unlike mgm_update_gpu_pte, which
* returns a modified entry).
*
* Return: Type of fault that occurred or VM_FAULT_NOPAGE if the page
* table entry was successfully installed.
*/
vm_fault_t (*mgm_vmf_insert_pfn_prot)(
struct memory_group_manager_device *mgm_dev, int group_id,
struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn, pgprot_t pgprot);
};
/**
* struct memory_group_manager_device - Device structure for a memory group
* manager
*
* @ops: Callbacks associated with this device
* @data: Pointer to device private data
* @owner: pointer to owning module
*
* In order for a systems integrator to provide custom behaviors for memory
* operations performed by the kbase module (controller driver), they must
* provide a platform-specific driver module which implements this interface.
*
* This structure should be registered with the platform device using
* platform_set_drvdata().
*/
struct memory_group_manager_device {
struct memory_group_manager_ops ops;
void *data;
struct module *owner;
};
enum memory_group_manager_import_type {
MEMORY_GROUP_MANAGER_IMPORT_TYPE_DMA_BUF
};
/**
* struct memory_group_manager_import_data - Structure describing the imported
* memory
*
* @type: type of imported memory
* @u: Union describing the imported memory
* @u.dma_buf: imported memory
*
*/
struct memory_group_manager_import_data {
enum memory_group_manager_import_type type;
union {
struct dma_buf *dma_buf;
} u;
};
#endif /* _MEMORY_GROUP_MANAGER_H_ */