linux/drivers/gpu/drm/vmwgfx/vmwgfx_thp.c
Thomas Hellstrom (VMware) 7546f7ffdb drm/vmwgfx: Introduce a huge page aligning TTM range manager
Using huge page-table entries requires that the physical address of the
start of a buffer object is huge page size aligned.
Make a special version of the TTM range manager that accomplishes this,
but falls back to a smaller page size alignment (PUD->PMD, PMD->NORMAL)
to avoid eviction.
If other drivers want to use it in the future, it can be made a
TTM generic helper. Note that drivers can force eviction for a certain
alignment by assigning the TTM GPU alignment correspondingly.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Thomas Hellstrom (VMware) <thomas_os@shipmail.org>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Acked-by: Christian König <christian.koenig@amd.com>
2020-03-24 18:50:12 +01:00

167 lines
3.8 KiB
C

// SPDX-License-Identifier: GPL-2.0 OR MIT
/*
* Huge page-table-entry support for IO memory.
*
* Copyright (C) 2007-2019 Vmware, Inc. All rights reservedd.
*/
#include "vmwgfx_drv.h"
#include <drm/ttm/ttm_module.h>
#include <drm/ttm/ttm_bo_driver.h>
#include <drm/ttm/ttm_placement.h>
/**
* struct vmw_thp_manager - Range manager implementing huge page alignment
*
* @mm: The underlying range manager. Protected by @lock.
* @lock: Manager lock.
*/
struct vmw_thp_manager {
struct drm_mm mm;
spinlock_t lock;
};
static int vmw_thp_insert_aligned(struct drm_mm *mm, struct drm_mm_node *node,
unsigned long align_pages,
const struct ttm_place *place,
struct ttm_mem_reg *mem,
unsigned long lpfn,
enum drm_mm_insert_mode mode)
{
if (align_pages >= mem->page_alignment &&
(!mem->page_alignment || align_pages % mem->page_alignment == 0)) {
return drm_mm_insert_node_in_range(mm, node,
mem->num_pages,
align_pages, 0,
place->fpfn, lpfn, mode);
}
return -ENOSPC;
}
static int vmw_thp_get_node(struct ttm_mem_type_manager *man,
struct ttm_buffer_object *bo,
const struct ttm_place *place,
struct ttm_mem_reg *mem)
{
struct vmw_thp_manager *rman = (struct vmw_thp_manager *) man->priv;
struct drm_mm *mm = &rman->mm;
struct drm_mm_node *node;
unsigned long align_pages;
unsigned long lpfn;
enum drm_mm_insert_mode mode = DRM_MM_INSERT_BEST;
int ret;
node = kzalloc(sizeof(*node), GFP_KERNEL);
if (!node)
return -ENOMEM;
lpfn = place->lpfn;
if (!lpfn)
lpfn = man->size;
mode = DRM_MM_INSERT_BEST;
if (place->flags & TTM_PL_FLAG_TOPDOWN)
mode = DRM_MM_INSERT_HIGH;
spin_lock(&rman->lock);
if (IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)) {
align_pages = (HPAGE_PUD_SIZE >> PAGE_SHIFT);
if (mem->num_pages >= align_pages) {
ret = vmw_thp_insert_aligned(mm, node, align_pages,
place, mem, lpfn, mode);
if (!ret)
goto found_unlock;
}
}
align_pages = (HPAGE_PMD_SIZE >> PAGE_SHIFT);
if (mem->num_pages >= align_pages) {
ret = vmw_thp_insert_aligned(mm, node, align_pages, place, mem,
lpfn, mode);
if (!ret)
goto found_unlock;
}
ret = drm_mm_insert_node_in_range(mm, node, mem->num_pages,
mem->page_alignment, 0,
place->fpfn, lpfn, mode);
found_unlock:
spin_unlock(&rman->lock);
if (unlikely(ret)) {
kfree(node);
} else {
mem->mm_node = node;
mem->start = node->start;
}
return 0;
}
static void vmw_thp_put_node(struct ttm_mem_type_manager *man,
struct ttm_mem_reg *mem)
{
struct vmw_thp_manager *rman = (struct vmw_thp_manager *) man->priv;
if (mem->mm_node) {
spin_lock(&rman->lock);
drm_mm_remove_node(mem->mm_node);
spin_unlock(&rman->lock);
kfree(mem->mm_node);
mem->mm_node = NULL;
}
}
static int vmw_thp_init(struct ttm_mem_type_manager *man,
unsigned long p_size)
{
struct vmw_thp_manager *rman;
rman = kzalloc(sizeof(*rman), GFP_KERNEL);
if (!rman)
return -ENOMEM;
drm_mm_init(&rman->mm, 0, p_size);
spin_lock_init(&rman->lock);
man->priv = rman;
return 0;
}
static int vmw_thp_takedown(struct ttm_mem_type_manager *man)
{
struct vmw_thp_manager *rman = (struct vmw_thp_manager *) man->priv;
struct drm_mm *mm = &rman->mm;
spin_lock(&rman->lock);
if (drm_mm_clean(mm)) {
drm_mm_takedown(mm);
spin_unlock(&rman->lock);
kfree(rman);
man->priv = NULL;
return 0;
}
spin_unlock(&rman->lock);
return -EBUSY;
}
static void vmw_thp_debug(struct ttm_mem_type_manager *man,
struct drm_printer *printer)
{
struct vmw_thp_manager *rman = (struct vmw_thp_manager *) man->priv;
spin_lock(&rman->lock);
drm_mm_print(&rman->mm, printer);
spin_unlock(&rman->lock);
}
const struct ttm_mem_type_manager_func vmw_thp_func = {
.init = vmw_thp_init,
.takedown = vmw_thp_takedown,
.get_node = vmw_thp_get_node,
.put_node = vmw_thp_put_node,
.debug = vmw_thp_debug
};