Commit 7546f7ff authored by Thomas Hellstrom (VMware)'s avatar Thomas Hellstrom (VMware)
Browse files

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: default avatarThomas Hellstrom (VMware) <thomas_os@shipmail.org>
Reviewed-by: default avatarRoland Scheidegger <sroland@vmware.com>
Acked-by: default avatarChristian König <christian.koenig@amd.com>
parent b1823416

drivers/gpu/drm/vmwgfx/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -11,4 +11,5 @@ vmwgfx-y := vmwgfx_execbuf.o vmwgfx_gmr.o vmwgfx_kms.o vmwgfx_drv.o \ 
	    vmwgfx_validation.o vmwgfx_page_dirty.o \

	    ttm_object.o ttm_lock.o



vmwgfx-$(CONFIG_TRANSPARENT_HUGEPAGE) += vmwgfx_thp.o

obj-$(CONFIG_DRM_VMWGFX) := vmwgfx.o

drivers/gpu/drm/vmwgfx/vmwgfx_drv.h

+7 −0
Original line number Diff line number Diff line
@@ -1407,6 +1407,13 @@ vm_fault_t vmw_bo_vm_huge_fault(struct vm_fault *vmf, 
				enum page_entry_size pe_size);

#endif



/* Transparent hugepage support - vmwgfx_thp.c */

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

extern const struct ttm_mem_type_manager_func vmw_thp_func;

#else

#define vmw_thp_func ttm_bo_manager_func

#endif



/**

 * VMW_DEBUG_KMS - Debug output for kernel mode-setting

 *

drivers/gpu/drm/vmwgfx/vmwgfx_thp.c

0 → 100644
+166 −0
Original line number Diff line number Diff line 
// 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

};

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