This adds a library for shmem backed GEM objects with the
necessary drm_driver callbacks.
Signed-off-by: Noralf Trønnes <noralf@xxxxxxxxxxx>
---
drivers/gpu/drm/Kconfig | 6 +
drivers/gpu/drm/Makefile | 1 +
drivers/gpu/drm/drm_gem_shmem_helper.c | 628 +++++++++++++++++++++++++++++++++
include/drm/drm_gem_shmem_helper.h | 131 +++++++
4 files changed, 766 insertions(+)
create mode 100644 drivers/gpu/drm/drm_gem_shmem_helper.c
create mode 100644 include/drm/drm_gem_shmem_helper.h
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 83cb2a8..8e709c2 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -145,6 +145,12 @@ config DRM_KMS_CMA_HELPER
help
Choose this if you need the KMS CMA helper functions
+config DRM_GEM_SHMEM_HELPER
+ bool
+ depends on DRM
+ help
+ Choose this if you need the GEM SHMEM helper functions
+
config DRM_VM
bool
depends on DRM && MMU
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 83d8b09..598c247 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -23,6 +23,7 @@ drm-$(CONFIG_DRM_LIB_RANDOM) += lib/drm_random.o
drm-$(CONFIG_DRM_VM) += drm_vm.o
drm-$(CONFIG_COMPAT) += drm_ioc32.o
drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o
+drm-$(CONFIG_DRM_GEM_SHMEM_HELPER) += drm_gem_shmem_helper.o
drm-$(CONFIG_PCI) += ati_pcigart.o
drm-$(CONFIG_DRM_PANEL) += drm_panel.o
drm-$(CONFIG_OF) += drm_of.o
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
new file mode 100644
index 0000000..137badc
--- /dev/null
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -0,0 +1,628 @@
+/*
+ * drm gem shmem (shared memory) helper functions
+ *
+ * Copyright (C) 2017 Noralf Trønnes
+ *
+ * Based on drm_gem_cma_helper.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/dma-buf.h>
+#include <linux/shmem_fs.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_gem_shmem_helper.h>
+#include <drm/drm_vma_manager.h>
+
+/**
+ * DOC: shmem helpers
+ *
+ * The Contiguous Memory Allocator reserves a pool of memory at early boot
+ * that is used to service requests for large blocks of contiguous memory.
+ *
+ * The DRM GEM/SHMEM helpers use this allocator as a means to provide buffer
+ * objects that are physically contiguous in memory. This is useful for
+ * display drivers that are unable to map scattered buffers via an IOMMU.
+ */
+
+static struct drm_gem_shmem_object *
+__drm_gem_shmem_create(struct drm_device *drm, size_t size)
+{
+ struct drm_gem_shmem_object *obj;
+ struct drm_gem_object *gem_obj;
+ int ret;
+
+ if (drm->driver->gem_create_object)
+ gem_obj = drm->driver->gem_create_object(drm, size);
+ else
+ gem_obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+ if (!gem_obj)
+ return ERR_PTR(-ENOMEM);
+
+ obj = to_drm_gem_shmem_obj(gem_obj);
+
+ if (!drm->driver->gem_create_object)
+ obj->cache_mode = DRM_GEM_SHMEM_BO_WRITECOMBINED;
+
+ ret = drm_gem_object_init(drm, gem_obj, size);
+ if (ret)
+ goto error;
+
+ ret = drm_gem_create_mmap_offset(gem_obj);
+ if (ret) {
+ drm_gem_object_release(gem_obj);
+ goto error;
+ }
+
+ return obj;
+
+error:
+ kfree(obj);
+
+ return ERR_PTR(ret);
+}
+
+/**
+ * drm_gem_shmem_create - allocate an object with the given size
+ * @drm: DRM device
+ * @size: size of the object to allocate
+ *
+ * This function creates a shmem GEM object and uses drm_gem_get_pages() to get
+ * the backing pages.
+ *
+ * Returns:
+ * A struct drm_gem_shmem_object * on success or an ERR_PTR()-encoded negative
+ * error code on failure.
+ */
+struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *drm,
+ size_t size)
+{
+ struct drm_gem_shmem_object *obj;
+ int ret;
+
+ size = round_up(size, PAGE_SIZE);
+
+ obj = __drm_gem_shmem_create(drm, size);
+ if (IS_ERR(obj))
+ return obj;
+
+ obj->pages = drm_gem_get_pages(&obj->base);
+ if (IS_ERR(obj->pages)) {
+ dev_err(drm->dev, "failed to allocate buffer with size %zu\n",
+ size);
+ ret = PTR_ERR(obj->pages);
+ goto error;
+ }
+
+ return obj;
+
+error:
+ drm_gem_object_put_unlocked(&obj->base);
+
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_create);
+
+static struct drm_gem_shmem_object *
+drm_gem_shmem_create_with_handle(struct drm_file *file_priv,
+ struct drm_device *drm, size_t size,
+ uint32_t *handle)
+{
+ struct drm_gem_shmem_object *obj;
+ struct drm_gem_object *gem_obj;
+ int ret;
+
+ obj = drm_gem_shmem_create(drm, size);
+ if (IS_ERR(obj))
+ return obj;
+
+ gem_obj = &obj->base;
+
+ /*
+ * allocate a 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, gem_obj, handle);
+ /* drop reference from allocate - handle holds it now. */
+ drm_gem_object_put_unlocked(gem_obj);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return obj;
+}
+
+/**
+ * drm_gem_shmem_free_object - free resources associated with a shmem GEM object
+ * @gem_obj: GEM object to free
+ *
+ * This function frees the backing memory of the shmem GEM object, cleans up
+ * the GEM object state and frees the memory used to store the object itself.
+ * Drivers using the shmem helpers should set this as their
+ * &drm_driver.gem_free_object callback.
+ */
+void drm_gem_shmem_free_object(struct drm_gem_object *gem_obj)
+{
+ struct drm_gem_shmem_object *obj = to_drm_gem_shmem_obj(gem_obj);
+
+ drm_gem_shmem_vunmap(obj);
+
+ if (gem_obj->import_attach) {
+ drm_prime_gem_destroy(gem_obj, obj->sgt);
+ kvfree(obj->pages);
+ } else {
+ drm_gem_put_pages(&obj->base, obj->pages, false, false);
+ }
+
+ drm_gem_object_release(gem_obj);
+
+ kfree(obj);
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_free_object);
+
+/*
+ * drm_gem_shmem_vmap - vmap a shmem GEM object
+ * @obj: shmem GEM object
+ *
+ * This function makes sure that a virtual address exists for
+ * the shmem GEM object.
+ *
+ * Returns:
+ * Zero on success, negative error code on failure.
+ */
+int drm_gem_shmem_vmap(struct drm_gem_shmem_object *obj)
+{
+ struct drm_gem_object *gem_obj = &obj->base;
+
+ if (obj->vaddr)
+ return 0;
+
+ /* TODO: locking? */
+
+ if (gem_obj->import_attach) {
+ obj->vaddr = dma_buf_vmap(gem_obj->import_attach->dmabuf);
+ } else {
+ pgprot_t prot;
+
+ switch (obj->cache_mode) {
+ case DRM_GEM_SHMEM_BO_WRITECOMBINED:
+ prot = pgprot_writecombine(PAGE_KERNEL);
+ break;
+
+ case DRM_GEM_SHMEM_BO_UNCACHED:
+ prot = pgprot_noncached(PAGE_KERNEL);
+ break;
+
+ case DRM_GEM_SHMEM_BO_CACHED:
+ prot = PAGE_KERNEL;
+ break;
+ }
+
+ obj->vaddr = vmap(obj->pages, gem_obj->size >> PAGE_SHIFT,
+ VM_MAP, prot);
+ }
+
+ if (!obj->vaddr)
+ return -ENOMEM;
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_gem_shmem_vmap);
+
+/*
+ * drm_gem_shmem_vunmap - vunmap a shmem GEM object
+ * @obj: shmem GEM object
+ *
+ * This function makes sure that the virtual address is removed for
+ * the shmem GEM object.
+ */
+void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *obj)
+{
+ struct drm_gem_object *gem_obj = &obj->base;
+
+ if (!obj->vaddr)
+ return;
+
+ if (gem_obj->import_attach)
+ dma_buf_vunmap(gem_obj->import_attach->dmabuf, obj->vaddr);
+ else
+ vunmap(obj->vaddr);
+
+ obj->vaddr = NULL;
+}
+EXPORT_SYMBOL(drm_gem_shmem_vunmap);
+
+/**
+ * drm_gem_shmem_dumb_create - create a dumb shmem buffer object
+ * @file_priv: DRM file structure to create the dumb buffer for
+ * @drm: DRM device
+ * @args: IOCTL data
+ *
+ * This function computes the pitch of the dumb buffer and rounds it up to an
+ * integer number of bytes per pixel. Drivers for hardware that doesn't have
+ * any additional restrictions on the pitch can directly use this function as
+ * their &drm_driver.dumb_create callback.
+ *
+ * For hardware with additional restrictions, drivers can adjust the fields
+ * set up by userspace before calling into this function.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_shmem_dumb_create(struct drm_file *file_priv,
+ struct drm_device *drm,
+ struct drm_mode_create_dumb *args)
+{
+ struct drm_gem_shmem_object *obj;
+
+ if (!args->pitch || !args->size) {
+ args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
+ args->size = args->pitch * args->height;
+ } else {
+ /* ensure sane minimum values */
+ args->pitch = max(args->pitch,
+ DIV_ROUND_UP(args->width * args->bpp, 8));
+ args->size = max_t(typeof(args->size), args->size,
+ args->pitch * args->height);
+ }
+
+ obj = drm_gem_shmem_create_with_handle(file_priv, drm, args->size,
+ &args->handle);
+ return PTR_ERR_OR_ZERO(obj);
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_dumb_create);
+
+static int drm_gem_shmem_fault(struct vm_fault *vmf)
+{
+ struct vm_area_struct *vma = vmf->vma;
+ struct drm_gem_shmem_object *obj = to_drm_gem_shmem_obj(vma->vm_private_data);
+ /* We don't use vmf->pgoff since that has the fake offset */
+ unsigned long vaddr = vmf->address;
+ struct page *page;
+
+ page = shmem_read_mapping_page(file_inode(obj->base.filp)->i_mapping,
+ (vaddr - vma->vm_start) >> PAGE_SHIFT);
+ if (!IS_ERR(page)) {
+ vmf->page = page;
+ return 0;
+ } else switch (PTR_ERR(page)) {
+ case -ENOSPC:
+ case -ENOMEM:
+ return VM_FAULT_OOM;
+ case -EBUSY:
+ return VM_FAULT_RETRY;
+ case -EFAULT:
+ case -EINVAL:
+ return VM_FAULT_SIGBUS;
+ default:
+ WARN_ON_ONCE(PTR_ERR(page));
+ return VM_FAULT_SIGBUS;
+ }
+}
+
+const struct vm_operations_struct drm_gem_shmem_vm_ops = {
+ .fault = drm_gem_shmem_fault,
+ .open = drm_gem_vm_open,
+ .close = drm_gem_vm_close,
+};
+EXPORT_SYMBOL_GPL(drm_gem_shmem_vm_ops);
+
+static int drm_gem_shmem_mmap_obj(struct drm_gem_shmem_object *obj,
+ struct vm_area_struct *vma)
+{
+ /* VM_PFNMAP was set by drm_gem_mmap() */
+ vma->vm_flags &= ~VM_PFNMAP;
+ vma->vm_flags |= VM_MIXEDMAP;
+
+ switch (obj->cache_mode) {
+ case DRM_GEM_SHMEM_BO_WRITECOMBINED:
+ vma->vm_page_prot =
+ pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
+ break;
+
+ case DRM_GEM_SHMEM_BO_UNCACHED:
+ vma->vm_page_prot =
+ pgprot_noncached(vm_get_page_prot(vma->vm_flags));
+ break;
+
+ case DRM_GEM_SHMEM_BO_CACHED:
+ /*
+ * Shunt off cached objs to shmem file so they have their own
+ * address_space (so unmap_mapping_range does what we want,
+ * in particular in the case of mmap'd dmabufs)
+ */
+ fput(vma->vm_file);
+ get_file(obj->base.filp);
+ vma->vm_pgoff = 0;
+ vma->vm_file = obj->base.filp;
+
+ vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
+ break;
+ }
+
+ return 0;
+}
+
+/**
+ * drm_gem_shmem_mmap - memory-map a shmem GEM object
+ * @filp: file object
+ * @vma: VMA for the area to be mapped
+ *
+ * This function implements an augmented version of the GEM DRM file mmap
+ * operation for shmem objects. Drivers which employ the shmem helpers should
+ * use this function as their ->mmap() handler in the DRM device file's
+ * file_operations structure.
+ *
+ * Instead of directly referencing this function, drivers should use the
+ * DEFINE_DRM_GEM_SHMEM_FOPS().macro.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_shmem_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+
+ struct drm_gem_shmem_object *obj;
+ struct drm_gem_object *gem_obj;
+ int ret;
+
+ ret = drm_gem_mmap(filp, vma);
+ if (ret)
+ return ret;
+
+ gem_obj = vma->vm_private_data;
+ obj = to_drm_gem_shmem_obj(gem_obj);
+
+ return drm_gem_shmem_mmap_obj(obj, vma);
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_mmap);
+
+#ifndef CONFIG_MMU
+/**
+ * drm_gem_shmem_get_unmapped_area - propose address for mapping in noMMU cases
+ * @filp: file object
+ * @addr: memory address
+ * @len: buffer size
+ * @pgoff: page offset
+ * @flags: memory flags
+ *
+ * This function is used in noMMU platforms to propose address mapping
+ * for a given buffer.
+ * It's intended to be used as a direct handler for the struct
+ * &file_operations.get_unmapped_area operation.
+ *
+ * Returns:
+ * mapping address on success or a negative error code on failure.
+ */
+unsigned long drm_gem_shmem_get_unmapped_area(struct file *filp,
+ unsigned long addr,
+ unsigned long len,
+ unsigned long pgoff,
+ unsigned long flags)
+{
+ struct drm_file *priv = filp->private_data;
+ struct drm_device *dev = priv->minor->dev;
+ struct drm_gem_object *gem_obj = NULL;
+ struct drm_vma_offset_node *node;
+ struct drm_gem_shmem_object *obj;
+
+ if (drm_device_is_unplugged(dev))
+ return -ENODEV;
+
+ drm_vma_offset_lock_lookup(dev->vma_offset_manager);
+ node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager,
+ pgoff,
+ len >> PAGE_SHIFT);
+ if (likely(node)) {
+ gem_obj = container_of(node, struct drm_gem_object, vma_node);
+ /*
+ * When the object is being freed, after it hits 0-refcnt it
+ * proceeds to tear down the object. In the process it will
+ * attempt to remove the VMA offset and so acquire this
+ * mgr->vm_lock. Therefore if we find an object with a 0-refcnt
+ * that matches our range, we know it is in the process of being
+ * destroyed and will be freed as soon as we release the lock -
+ * so we have to check for the 0-refcnted object and treat it as
+ * invalid.
+ */
+ if (!kref_get_unless_zero(&gem_obj->refcount))
+ gem_obj = NULL;
+ }
+
+ drm_vma_offset_unlock_lookup(dev->vma_offset_manager);
+
+ if (!gem_obj)
+ return -EINVAL;
+
+ if (!drm_vma_node_is_allowed(node, priv)) {
+ drm_gem_object_put_unlocked(gem_obj);
+ return -EACCES;
+ }
+
+ obj = to_drm_gem_shmem_obj(gem_obj);
+
+ drm_gem_object_put_unlocked(gem_obj);
+
+ /* TODO: should we call drm_gem_shmem_vmap() here? */
+
+ return obj->vaddr ? (unsigned long)obj->vaddr : -EINVAL;
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_get_unmapped_area);
+#endif
+
+#ifdef CONFIG_DEBUG_FS
+static const char *cache_mode_str[] = {
+ [DRM_GEM_SHMEM_BO_UNCACHED] = "uncached",
+ [DRM_GEM_SHMEM_BO_CACHED] = "cached",
+ [DRM_GEM_SHMEM_BO_WRITECOMBINED] = "writecombined",
+};
+
+/**
+ * drm_gem_shmem_describe - describe a shmem GEM object for debugfs
+ * @obj: shmem GEM object
+ * @m: debugfs file handle
+ *
+ * This function can be used to dump a human-readable representation of the
+ * shmem GEM object into a synthetic file.
+ */
+void drm_gem_shmem_describe(struct drm_gem_shmem_object *obj,
+ struct seq_file *m)
+{
+ struct drm_gem_object *gem_obj = &obj->base;
+ uint64_t off;
+
+ off = drm_vma_node_start(&gem_obj->vma_node);
+ seq_printf(m, "name=%d refcount=%d off=%08llx vaddr=%p size=%zu mode=%s",
+ gem_obj->name, kref_read(&gem_obj->refcount), off,
+ obj->vaddr, gem_obj->size, cache_mode_str[obj->cache_mode]);
+
+ seq_printf(m, "\n");
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_describe);
+#endif
+
+/**
+ * drm_gem_shmem_prime_get_sg_table - provide a scatter/gather table of pinned
+ * pages for a SHMEM GEM object
+ * @obj: GEM object
+ *
+ * This function exports a scatter/gather table suitable for PRIME usage by
+ * calling the standard DMA mapping API. Drivers using the shmem helpers should
+ * set this as their &drm_driver.gem_prime_get_sg_table callback.
+ *
+ * Returns:
+ * A pointer to the scatter/gather table of pinned pages or NULL on failure.
+ */
+struct sg_table *
+drm_gem_shmem_prime_get_sg_table(struct drm_gem_object *gem_obj)
+{
+ struct drm_gem_shmem_object *obj = to_drm_gem_shmem_obj(gem_obj);
+
+ return drm_prime_pages_to_sg(obj->pages, gem_obj->size >> PAGE_SHIFT);
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_get_sg_table);
+
+/**
+ * drm_gem_shmem_prime_import_sg_table - produce a shmem GEM object from
+ * another driver's scatter/gather table of pinned pages
+ * @dev: device to import into
+ * @attach: DMA-BUF attachment
+ * @sgt: scatter/gather table of pinned pages
+ *
+ * This function imports a scatter/gather table exported via DMA-BUF by
+ * another driver. Drivers that use the shmem helpers should set this as their
+ * &drm_driver.gem_prime_import_sg_table callback.
+ *
+ * Returns:
+ * A pointer to a newly created GEM object or an ERR_PTR-encoded negative
+ * error code on failure.
+ */
+struct drm_gem_object *
+drm_gem_shmem_prime_import_sg_table(struct drm_device *dev,
+ struct dma_buf_attachment *attach,
+ struct sg_table *sgt)
+{
+ int npages = attach->dmabuf->size >> PAGE_SHIFT;
+ struct drm_gem_shmem_object *obj;
+ int ret;
+
+ obj = __drm_gem_shmem_create(dev, attach->dmabuf->size);
+ if (IS_ERR(obj))
+ return ERR_CAST(obj);
+
+ obj->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
+ if (!obj->pages) {
+ ret = -ENOMEM;
+ goto err_free_gem;
+ }
+
+ ret = drm_prime_sg_to_page_addr_arrays(sgt, obj->pages, NULL, npages);
+ if (ret < 0)
+ goto err_free_array;
+
+ obj->sgt = sgt;
+
+ DRM_DEBUG_PRIME("size = %zu\n", attach->dmabuf->size);
+
+ return &obj->base;
+
+err_free_array:
+ kvfree(obj->pages);
+err_free_gem:
+ drm_gem_object_put_unlocked(&obj->base);
+
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_import_sg_table);
+
+/**
+ * drm_gem_shmem_prime_mmap - memory-map an exported shmem GEM object
+ * @obj: GEM object
+ * @vma: VMA for the area to be mapped
+ *
+ * This function maps a buffer imported via DRM PRIME into a userspace
+ * process's address space. Drivers that use the shmem helpers should set this
+ * as their &drm_driver.gem_prime_mmap callback.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_shmem_prime_mmap(struct drm_gem_object *gem_obj,
+ struct vm_area_struct *vma)
+{
+ struct drm_gem_shmem_object *obj = to_drm_gem_shmem_obj(gem_obj);
+ int ret;
+
+ ret = drm_gem_mmap_obj(gem_obj, gem_obj->size, vma);
+ if (ret < 0)
+ return ret;
+
+ return drm_gem_shmem_mmap_obj(obj, vma);
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_mmap);
+
+/**
+ * drm_gem_shmem_prime_vmap - map a shmem GEM object into the kernel's virtual
+ * address space
+ * @obj: GEM object
+ *
+ * This function maps a buffer exported via DRM PRIME into the kernel's
+ * virtual address space. Drivers using the SHMEM helpers should set this as
+ * their DRM driver's &drm_driver.gem_prime_vmap callback.
+ *
+ * Returns:
+ * The kernel virtual address of the SHMEM GEM object's backing store.
+ */
+void *drm_gem_shmem_prime_vmap(struct drm_gem_object *gem_obj)
+{
+ struct drm_gem_shmem_object *obj = to_drm_gem_shmem_obj(gem_obj);
+
+ drm_gem_shmem_vmap(obj);
+
+ return obj->vaddr;
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_vmap);
+
+/**
+ * drm_gem_shmem_prime_vunmap - unmap a shmem GEM object from the kernel's
+ * virtual address space
+ * @obj: GEM object
+ * @vaddr: kernel virtual address where the shmem GEM object was mapped
+ *
+ * This function removes a buffer exported via DRM PRIME from the kernel's
+ * virtual address space. Drivers using the SHMEM helpers should set this as
+ * their &drm_driver.gem_prime_vunmap callback.
+ */
+void drm_gem_shmem_prime_vunmap(struct drm_gem_object *gem_obj, void *vaddr)
+{
+ struct drm_gem_shmem_object *obj = to_drm_gem_shmem_obj(gem_obj);
+
+ drm_gem_shmem_vunmap(obj);
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_vunmap);
diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
new file mode 100644
index 0000000..5cbd990
--- /dev/null
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -0,0 +1,131 @@
+#ifndef __DRM_GEM_SHMEM_HELPER_H__
+#define __DRM_GEM_SHMEM_HELPER_H__
+
+#include <drm/drmP.h>
+#include <drm/drm_gem.h>
+
+enum drm_gem_shmem_cache_mode {
+ DRM_GEM_SHMEM_BO_UNCACHED,
+ DRM_GEM_SHMEM_BO_CACHED,
+ DRM_GEM_SHMEM_BO_WRITECOMBINED,
+};
+
+/**
+ * struct drm_gem_shmem_object - GEM object backed by shmem
+ * @base: base GEM object
+ * @pages: page table
+ * @cache_mode: Cache mode
+ * @sgt: scatter/gather table for imported PRIME buffers
+ * @vaddr: kernel virtual address of the backing memory
+ */
+struct drm_gem_shmem_object {
+ struct drm_gem_object base;
+ struct page **pages;
+ enum drm_gem_shmem_cache_mode cache_mode;
+ struct sg_table *sgt;
+ void *vaddr;
+};
+
+static inline struct drm_gem_shmem_object *
+to_drm_gem_shmem_obj(struct drm_gem_object *gem_obj)
+{
+ return container_of(gem_obj, struct drm_gem_shmem_object, base);
+}
+
+#ifndef CONFIG_MMU
+#define DRM_GEM_SHMEM_UNMAPPED_AREA_FOPS \
+ .get_unmapped_area = drm_gem_shmem_get_unmapped_area,
+#else
+#define DRM_GEM_SHMEM_UNMAPPED_AREA_FOPS
+#endif
+
+/**
+ * DEFINE_DRM_GEM_SHMEM_FOPS() - macro to generate file operations for shmem
+ * drivers
+ * @name: name for the generated structure
+ *
+ * This macro autogenerates a suitable &struct file_operations for shmem based
+ * drivers, which can be assigned to &drm_driver.fops. Note that this structure
+ * cannot be shared between drivers, because it contains a reference to the
+ * current module using THIS_MODULE.
+ *
+ * Note that the declaration is already marked as static - if you need a
+ * non-static version of this you're probably doing it wrong and will break the
+ * THIS_MODULE reference by accident.
+ */
+#define DEFINE_DRM_GEM_SHMEM_FOPS(name) \
+ static const struct file_operations name = {\
+ .owner = THIS_MODULE,\
+ .open = drm_open,\
+ .release = drm_release,\
+ .unlocked_ioctl = drm_ioctl,\
+ .compat_ioctl = drm_compat_ioctl,\
+ .poll = drm_poll,\
+ .read = drm_read,\
+ .llseek = noop_llseek,\
+ .mmap = drm_gem_shmem_mmap,\
+ DRM_GEM_SHMEM_UNMAPPED_AREA_FOPS \
+ }
+
+struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *drm,
+ size_t size);
+void drm_gem_shmem_free_object(struct drm_gem_object *gem_obj);
+
+int drm_gem_shmem_vmap(struct drm_gem_shmem_object *obj);
+void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *obj);
+
+int drm_gem_shmem_dumb_create(struct drm_file *file_priv,
+ struct drm_device *drm,
+ struct drm_mode_create_dumb *args);
+
+int drm_gem_shmem_mmap(struct file *filp, struct vm_area_struct *vma);
+
+extern const struct vm_operations_struct drm_gem_shmem_vm_ops;
+
+#ifndef CONFIG_MMU
+unsigned long drm_gem_shmem_get_unmapped_area(struct file *filp,
+ unsigned long addr,
+ unsigned long len,
+ unsigned long pgoff,
+ unsigned long flags);
+#endif
+
+#ifdef CONFIG_DEBUG_FS
+void drm_gem_shmem_describe(struct drm_gem_shmem_object *obj,
+ struct seq_file *m);
+#endif
+
+struct sg_table *
+drm_gem_shmem_prime_get_sg_table(struct drm_gem_object *gem_obj);
+struct drm_gem_object *
+drm_gem_shmem_prime_import_sg_table(struct drm_device *dev,
+ struct dma_buf_attachment *attach,
+ struct sg_table *sgt);
+int drm_gem_shmem_prime_mmap(struct drm_gem_object *gem_obj,
+ struct vm_area_struct *vma);
+void *drm_gem_shmem_prime_vmap(struct drm_gem_object *gem_obj);
+void drm_gem_shmem_prime_vunmap(struct drm_gem_object *gem_obj, void *vaddr);
+
+/**
+ * DRM_GEM_SHMEM_DRIVER_OPS - default shmem gem operations
+ *
+ * This macro provides a shortcut for setting the shmem GEM operations in
+ * the &drm_driver structure.
+ */
+#define DRM_GEM_SHMEM_DRIVER_OPS \
+ .gem_free_object = drm_gem_shmem_free_object, \
+ .gem_vm_ops = &drm_gem_shmem_vm_ops, \
+ .prime_handle_to_fd = drm_gem_prime_handle_to_fd, \
+ .prime_fd_to_handle = drm_gem_prime_fd_to_handle, \
+ .gem_prime_import = drm_gem_prime_import, \
+ .gem_prime_export = drm_gem_prime_export, \
+ .gem_prime_get_sg_table = drm_gem_shmem_prime_get_sg_table, \
+ .gem_prime_import_sg_table = drm_gem_shmem_prime_import_sg_table, \
+ .gem_prime_vmap = drm_gem_shmem_prime_vmap, \
+ .gem_prime_vunmap = drm_gem_shmem_prime_vunmap, \
+ .gem_prime_mmap = drm_gem_shmem_prime_mmap, \
+ .dumb_create = drm_gem_shmem_dumb_create, \
+ .dumb_map_offset = drm_gem_dumb_map_offset, \
+ .dumb_destroy = drm_gem_dumb_destroy
+
+#endif /* __DRM_GEM_SHMEM_HELPER_H__ */
--
2.7.4
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