/*
* Copyright (c) Red Hat Inc.
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sub license,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
* Authors: Dave Airlie <airlied@redhat.com>
* Jerome Glisse <jglisse@redhat.com>
* Pauli Nieminen <suokkos@gmail.com>
*/
/* simple list based uncached page pool
* - Pool collects resently freed pages for reuse
* - Use page->lru to keep a free list
* - doesn't track currently in use pages
*/
#define pr_fmt(fmt) "[TTM] " fmt
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/highmem.h>
#include <linux/mm_types.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/seq_file.h> /* for seq_printf */
#include <linux/slab.h>
#include <linux/dma-mapping.h>
#include <linux/atomic.h>
#include <drm/ttm/ttm_bo_driver.h>
#include <drm/ttm/ttm_page_alloc.h>
#if IS_ENABLED(CONFIG_AGP)
#include <asm/agp.h>
#endif
#ifdef CONFIG_X86
#include <asm/set_memory.h>
#endif
#define NUM_PAGES_TO_ALLOC (PAGE_SIZE/sizeof(struct page *))
#define SMALL_ALLOCATION 16
#define FREE_ALL_PAGES (~0U)
/* times are in msecs */
#define PAGE_FREE_INTERVAL 1000
/**
* struct ttm_page_pool - Pool to reuse recently allocated uc/wc pages.
*
* @lock: Protects the shared pool from concurrnet access. Must be used with
* irqsave/irqrestore variants because pool allocator maybe called from
* delayed work.
* @fill_lock: Prevent concurrent calls to fill.
* @list: Pool of free uc/wc pages for fast reuse.
* @gfp_flags: Flags to pass for alloc_page.
* @npages: Number of pages in pool.
*/
struct ttm_page_pool {
spinlock_t lock;
bool fill_lock;
struct list_head list;
gfp_t gfp_flags;
unsigned npages;
char *name;
unsigned long nfrees;
unsigned long nrefills;
};
/**
* Limits for the pool. They are handled without locks because only place where
* they may change is in sysfs store. They won't have immediate effect anyway
* so forcing serialization to access them is pointless.
*/
struct ttm_pool_opts {
unsigned alloc_size;
unsigned max_size;
unsigned small;
};
#define NUM_POOLS 6
/**
* struct ttm_pool_manager - Holds memory pools for fst allocation
*
* Manager is read only object for pool code so it doesn't need locking.
*
* @free_interval: minimum number of jiffies between freeing pages from pool.
* @page_alloc_inited: reference counting for pool allocation.
* @work: Work that is used to shrink the pool. Work is only run when there is
* some pages to free.
* @small_allocation: Limit in number of pages what is small allocation.
*
* @pools: All pool objects in use.
**/
struct ttm_pool_manager {
struct kobject kobj;
struct shrinker mm_shrink;
struct ttm_pool_opts options;
union {
struct ttm_page_pool pools[NUM_POOLS];
struct {
struct ttm_page_pool wc_pool;
struct ttm_page_pool uc_pool;
struct ttm_page_pool wc_pool_dma32;
struct ttm_page_pool uc_pool_dma32;
struct ttm_page_pool wc_pool_huge;
struct ttm_page_pool uc_pool_huge;
} ;
};
};
static struct attribute ttm_page_pool_max = {
.name = "pool_max_size",
.mode = S_IRUGO | S_IWUSR
};
static struct attribute ttm_page_pool_small = {
.name = "pool_small_allocation",
.mode = S_IRUGO | S_IWUSR
};
static struct attribute ttm_page_pool_alloc_size = {
.name = "pool_allocation_size",
.mode = S_IRUGO | S_IWUSR
};
static struct attribute *ttm_pool_attrs[] = {
&ttm_page_pool_max,
&ttm_page_pool_small,
&ttm_page_pool_alloc_size,
NULL
};
static void ttm_pool_kobj_release(struct kobject *kobj)
{
struct ttm_pool_manager *m =
container_of(kobj, struct ttm_pool_manager, kobj);
kfree(m);
}
static ssize_t ttm_pool_store(struct kobject *kobj,
struct attribute *attr, const char *buffer, size_t size)
{
struct ttm_pool_manager *m =
container_of(kobj, struct ttm_pool_manager, kobj);
int chars;
unsigned val;
chars =