linux_dsm_epyc7002/drivers/gpu/drm/panfrost/panfrost_gem.c
Rob Herring 187d292920 drm/panfrost: Add support for GPU heap allocations
The midgard/bifrost GPUs need to allocate GPU heap memory which is
allocated on GPU page faults and not pinned in memory. The vendor driver
calls this functionality GROW_ON_GPF.

This implementation assumes that BOs allocated with the
PANFROST_BO_NOEXEC flag are never mmapped or exported. Both of those may
actually work, but I'm unsure if there's some interaction there. It
would cause the whole object to be pinned in memory which would defeat
the point of this.

On faults, we map in 2MB at a time in order to utilize huge pages (if
enabled). Currently, once we've mapped pages in, they are only unmapped
if the BO is freed. Once we add shrinker support, we can unmap pages
with the shrinker.

Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Acked-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190808222200.13176-9-robh@kernel.org
2019-08-12 14:21:37 -06:00

188 lines
4.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright 2019 Linaro, Ltd, Rob Herring <robh@kernel.org> */
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/dma-buf.h>
#include <linux/dma-mapping.h>
#include <drm/panfrost_drm.h>
#include "panfrost_device.h"
#include "panfrost_gem.h"
#include "panfrost_mmu.h"
/* Called DRM core on the last userspace/kernel unreference of the
* BO.
*/
static void panfrost_gem_free_object(struct drm_gem_object *obj)
{
struct panfrost_gem_object *bo = to_panfrost_bo(obj);
struct panfrost_device *pfdev = obj->dev->dev_private;
if (bo->sgts) {
int i;
int n_sgt = bo->base.base.size / SZ_2M;
for (i = 0; i < n_sgt; i++) {
if (bo->sgts[i].sgl) {
dma_unmap_sg(pfdev->dev, bo->sgts[i].sgl,
bo->sgts[i].nents, DMA_BIDIRECTIONAL);
sg_free_table(&bo->sgts[i]);
}
}
kfree(bo->sgts);
}
mutex_lock(&pfdev->shrinker_lock);
if (!list_empty(&bo->base.madv_list))
list_del(&bo->base.madv_list);
mutex_unlock(&pfdev->shrinker_lock);
drm_gem_shmem_free_object(obj);
}
static int panfrost_gem_open(struct drm_gem_object *obj, struct drm_file *file_priv)
{
int ret;
size_t size = obj->size;
u64 align;
struct panfrost_gem_object *bo = to_panfrost_bo(obj);
struct panfrost_device *pfdev = obj->dev->dev_private;
unsigned long color = bo->noexec ? PANFROST_BO_NOEXEC : 0;
/*
* Executable buffers cannot cross a 16MB boundary as the program
* counter is 24-bits. We assume executable buffers will be less than
* 16MB and aligning executable buffers to their size will avoid
* crossing a 16MB boundary.
*/
if (!bo->noexec)
align = size >> PAGE_SHIFT;
else
align = size >= SZ_2M ? SZ_2M >> PAGE_SHIFT : 0;
spin_lock(&pfdev->mm_lock);
ret = drm_mm_insert_node_generic(&pfdev->mm, &bo->node,
size >> PAGE_SHIFT, align, color, 0);
if (ret)
goto out;
if (!bo->is_heap) {
ret = panfrost_mmu_map(bo);
if (ret)
drm_mm_remove_node(&bo->node);
}
out:
spin_unlock(&pfdev->mm_lock);
return ret;
}
static void panfrost_gem_close(struct drm_gem_object *obj, struct drm_file *file_priv)
{
struct panfrost_gem_object *bo = to_panfrost_bo(obj);
struct panfrost_device *pfdev = obj->dev->dev_private;
if (bo->is_mapped)
panfrost_mmu_unmap(bo);
spin_lock(&pfdev->mm_lock);
if (drm_mm_node_allocated(&bo->node))
drm_mm_remove_node(&bo->node);
spin_unlock(&pfdev->mm_lock);
}
static int panfrost_gem_pin(struct drm_gem_object *obj)
{
if (to_panfrost_bo(obj)->is_heap)
return -EINVAL;
return drm_gem_shmem_pin(obj);
}
static const struct drm_gem_object_funcs panfrost_gem_funcs = {
.free = panfrost_gem_free_object,
.open = panfrost_gem_open,
.close = panfrost_gem_close,
.print_info = drm_gem_shmem_print_info,
.pin = panfrost_gem_pin,
.unpin = drm_gem_shmem_unpin,
.get_sg_table = drm_gem_shmem_get_sg_table,
.vmap = drm_gem_shmem_vmap,
.vunmap = drm_gem_shmem_vunmap,
.vm_ops = &drm_gem_shmem_vm_ops,
};
/**
* panfrost_gem_create_object - Implementation of driver->gem_create_object.
* @dev: DRM device
* @size: Size in bytes of the memory the object will reference
*
* This lets the GEM helpers allocate object structs for us, and keep
* our BO stats correct.
*/
struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t size)
{
struct panfrost_gem_object *obj;
obj = kzalloc(sizeof(*obj), GFP_KERNEL);
if (!obj)
return NULL;
obj->base.base.funcs = &panfrost_gem_funcs;
return &obj->base.base;
}
struct panfrost_gem_object *
panfrost_gem_create_with_handle(struct drm_file *file_priv,
struct drm_device *dev, size_t size,
u32 flags,
uint32_t *handle)
{
int ret;
struct drm_gem_shmem_object *shmem;
struct panfrost_gem_object *bo;
/* Round up heap allocations to 2MB to keep fault handling simple */
if (flags & PANFROST_BO_HEAP)
size = roundup(size, SZ_2M);
shmem = drm_gem_shmem_create(dev, size);
if (IS_ERR(shmem))
return ERR_CAST(shmem);
bo = to_panfrost_bo(&shmem->base);
bo->noexec = !!(flags & PANFROST_BO_NOEXEC);
bo->is_heap = !!(flags & PANFROST_BO_HEAP);
/*
* Allocate an id of idr table where the obj is registered
* and handle has the id what user can see.
*/
ret = drm_gem_handle_create(file_priv, &shmem->base, handle);
/* drop reference from allocate - handle holds it now. */
drm_gem_object_put_unlocked(&shmem->base);
if (ret)
return ERR_PTR(ret);
return bo;
}
struct drm_gem_object *
panfrost_gem_prime_import_sg_table(struct drm_device *dev,
struct dma_buf_attachment *attach,
struct sg_table *sgt)
{
struct drm_gem_object *obj;
struct panfrost_gem_object *bo;
obj = drm_gem_shmem_prime_import_sg_table(dev, attach, sgt);
if (IS_ERR(obj))
return ERR_CAST(obj);
bo = to_panfrost_bo(obj);
bo->noexec = true;
return obj;
}