fbdev.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/**************************************************************************
  3 * Copyright (c) 2007-2011, Intel Corporation.
  4 * All Rights Reserved.
  5 *
  6 **************************************************************************/
  7
  8#include <linux/fb.h>
  9
 10#include <drm/drm_crtc_helper.h>
 11#include <drm/drm_drv.h>
 12#include <drm/drm_fb_helper.h>
 13#include <drm/drm_framebuffer.h>
 14
 15#include "gem.h"
 16#include "psb_drv.h"
 17
 18/*
 19 * VM area struct
 20 */
 21
 22static vm_fault_t psb_fbdev_vm_fault(struct vm_fault *vmf)
 23{
 24	struct vm_area_struct *vma = vmf->vma;
 25	struct fb_info *info = vma->vm_private_data;
 26	unsigned long address = vmf->address - (vmf->pgoff << PAGE_SHIFT);
 27	unsigned long pfn = info->fix.smem_start >> PAGE_SHIFT;
 28	vm_fault_t err = VM_FAULT_SIGBUS;
 29	unsigned long page_num = vma_pages(vma);
 30	unsigned long i;
 31
 32	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 33
 34	for (i = 0; i < page_num; ++i) {
 35		err = vmf_insert_mixed(vma, address, pfn);
 36		if (unlikely(err & VM_FAULT_ERROR))
 37			break;
 38		address += PAGE_SIZE;
 39		++pfn;
 40	}
 41
 42	return err;
 43}
 44
 45static const struct vm_operations_struct psb_fbdev_vm_ops = {
 46	.fault	= psb_fbdev_vm_fault,
 47};
 48
 49/*
 50 * struct fb_ops
 51 */
 52
 53static int psb_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 54{
 55	if (vma->vm_pgoff != 0)
 56		return -EINVAL;
 57	if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT))
 58		return -EINVAL;
 59
 60	/*
 61	 * If this is a GEM object then info->screen_base is the virtual
 62	 * kernel remapping of the object. FIXME: Review if this is
 63	 * suitable for our mmap work
 64	 */
 65	vma->vm_ops = &psb_fbdev_vm_ops;
 66	vma->vm_private_data = info;
 67	vm_flags_set(vma, VM_IO | VM_MIXEDMAP | VM_DONTEXPAND | VM_DONTDUMP);
 68
 69	return 0;
 70}
 71
 72static void psb_fbdev_fb_destroy(struct fb_info *info)
 73{
 74	struct drm_fb_helper *fb_helper = info->par;
 75	struct drm_framebuffer *fb = fb_helper->fb;
 76	struct drm_gem_object *obj = fb->obj[0];
 77
 78	drm_fb_helper_fini(fb_helper);
 79
 80	drm_framebuffer_unregister_private(fb);
 81	drm_framebuffer_cleanup(fb);
 82	kfree(fb);
 83
 84	drm_gem_object_put(obj);
 85
 86	drm_client_release(&fb_helper->client);
 87}
 88
 89static const struct fb_ops psb_fbdev_fb_ops = {
 90	.owner = THIS_MODULE,
 91	__FB_DEFAULT_IOMEM_OPS_RDWR,
 92	DRM_FB_HELPER_DEFAULT_OPS,
 93	__FB_DEFAULT_IOMEM_OPS_DRAW,
 94	.fb_mmap = psb_fbdev_fb_mmap,
 95	.fb_destroy = psb_fbdev_fb_destroy,
 96};
 97
 98static const struct drm_fb_helper_funcs psb_fbdev_fb_helper_funcs = {
 99};
100
101/*
102 * struct drm_driver
103 */
104
105int psb_fbdev_driver_fbdev_probe(struct drm_fb_helper *fb_helper,
106				 struct drm_fb_helper_surface_size *sizes)
107{
108	struct drm_device *dev = fb_helper->dev;
109	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
110	struct pci_dev *pdev = to_pci_dev(dev->dev);
111	struct fb_info *info = fb_helper->info;
112	struct drm_framebuffer *fb;
113	struct drm_mode_fb_cmd2 mode_cmd = { };
114	int size;
115	int ret;
116	struct psb_gem_object *backing;
117	struct drm_gem_object *obj;
118	u32 bpp, depth;
119
120	/* No 24-bit packed mode */
121	if (sizes->surface_bpp == 24) {
122		sizes->surface_bpp = 32;
123		sizes->surface_depth = 24;
124	}
125	bpp = sizes->surface_bpp;
126	depth = sizes->surface_depth;
127
128	/*
129	 * If the mode does not fit in 32 bit then switch to 16 bit to get
130	 * a console on full resolution. The X mode setting server will
131	 * allocate its own 32-bit GEM framebuffer.
132	 */
133	size = ALIGN(sizes->surface_width * DIV_ROUND_UP(bpp, 8), 64) *
134		     sizes->surface_height;
135	size = ALIGN(size, PAGE_SIZE);
136
137	if (size > dev_priv->vram_stolen_size) {
138		sizes->surface_bpp = 16;
139		sizes->surface_depth = 16;
140	}
141	bpp = sizes->surface_bpp;
142	depth = sizes->surface_depth;
143
144	mode_cmd.width = sizes->surface_width;
145	mode_cmd.height = sizes->surface_height;
146	mode_cmd.pitches[0] = ALIGN(mode_cmd.width * DIV_ROUND_UP(bpp, 8), 64);
147	mode_cmd.pixel_format = drm_mode_legacy_fb_format(bpp, depth);
148
149	size = mode_cmd.pitches[0] * mode_cmd.height;
150	size = ALIGN(size, PAGE_SIZE);
151
152	/* Allocate the framebuffer in the GTT with stolen page backing */
153	backing = psb_gem_create(dev, size, "fb", true, PAGE_SIZE);
154	if (IS_ERR(backing))
155		return PTR_ERR(backing);
156	obj = &backing->base;
157
158	fb = psb_framebuffer_create(dev,
159				    drm_get_format_info(dev, mode_cmd.pixel_format,
160							mode_cmd.modifier[0]),
161				    &mode_cmd, obj);
162	if (IS_ERR(fb)) {
163		ret = PTR_ERR(fb);
164		goto err_drm_gem_object_put;
165	}
166
167	fb_helper->funcs = &psb_fbdev_fb_helper_funcs;
168	fb_helper->fb = fb;
169
170	info->fbops = &psb_fbdev_fb_ops;
171
172	/* Accessed stolen memory directly */
173	info->screen_base = dev_priv->vram_addr + backing->offset;
174	info->screen_size = size;
175
176	drm_fb_helper_fill_info(info, fb_helper, sizes);
177
178	info->fix.smem_start = dev_priv->stolen_base + backing->offset;
179	info->fix.smem_len = size;
180	info->fix.ywrapstep = 0;
181	info->fix.ypanstep = 0;
182	info->fix.mmio_start = pci_resource_start(pdev, 0);
183	info->fix.mmio_len = pci_resource_len(pdev, 0);
184
185	fb_memset_io(info->screen_base, 0, info->screen_size);
186
187	/* Use default scratch pixmap (info->pixmap.flags = FB_PIXMAP_SYSTEM) */
188
189	dev_dbg(dev->dev, "allocated %dx%d fb\n", fb->width, fb->height);
190
191	return 0;
192
193err_drm_gem_object_put:
194	drm_gem_object_put(obj);
195	return ret;
196}