xref: /linux/drivers/gpu/drm/gma500/fbdev.c (revision 38f7e5450ebfc6f2e046a249a3f629ea7bec8c31)
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 
22 static 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 
45 static const struct vm_operations_struct psb_fbdev_vm_ops = {
46 	.fault	= psb_fbdev_vm_fault,
47 };
48 
49 /*
50  * struct fb_ops
51  */
52 
53 static 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 
72 static void psb_fbdev_fb_destroy(struct fb_info *info)
73 {
74 	struct drm_fb_helper *fb_helper = info->par;
75 
76 	drm_fb_helper_fini(fb_helper);
77 
78 	drm_client_buffer_delete(fb_helper->buffer);
79 	drm_client_release(&fb_helper->client);
80 }
81 
82 static const struct fb_ops psb_fbdev_fb_ops = {
83 	.owner = THIS_MODULE,
84 	__FB_DEFAULT_IOMEM_OPS_RDWR,
85 	DRM_FB_HELPER_DEFAULT_OPS,
86 	__FB_DEFAULT_IOMEM_OPS_DRAW,
87 	.fb_mmap = psb_fbdev_fb_mmap,
88 	.fb_destroy = psb_fbdev_fb_destroy,
89 };
90 
91 static const struct drm_fb_helper_funcs psb_fbdev_fb_helper_funcs = {
92 };
93 
94 /*
95  * struct drm_driver
96  */
97 
98 int psb_fbdev_driver_fbdev_probe(struct drm_fb_helper *fb_helper,
99 				 struct drm_fb_helper_surface_size *sizes)
100 {
101 	struct drm_client_dev *client = &fb_helper->client;
102 	struct drm_device *dev = client->dev;
103 	struct drm_file *file = client->file;
104 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
105 	struct pci_dev *pdev = to_pci_dev(dev->dev);
106 	struct fb_info *info = fb_helper->info;
107 	u32 fourcc, pitch;
108 	u64 size;
109 	const struct drm_format_info *format;
110 	struct drm_client_buffer *buffer;
111 	struct psb_gem_object *backing;
112 	struct drm_gem_object *obj;
113 	u32 handle;
114 	int ret;
115 
116 	/* No 24-bit packed mode */
117 	if (sizes->surface_bpp == 24) {
118 		sizes->surface_bpp = 32;
119 		sizes->surface_depth = 24;
120 	}
121 
122 try_psb_gem_create:
123 	fourcc = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
124 	format = drm_get_format_info(dev, fourcc, DRM_FORMAT_MOD_LINEAR);
125 	pitch = ALIGN(drm_format_info_min_pitch(format, 0, sizes->surface_width), SZ_64);
126 	size = ALIGN(pitch * sizes->surface_height, PAGE_SIZE);
127 
128 	/* Allocate the framebuffer in the GTT with stolen page backing */
129 	backing = psb_gem_create(dev, size, "fb", true, PAGE_SIZE);
130 	if (IS_ERR(backing)) {
131 		ret = PTR_ERR(backing);
132 		if (ret == -EBUSY && sizes->surface_bpp > 16) {
133 			/*
134 			 * If the mode does not fit in 32 bit then switch to 16 bit to
135 			 * get a console on full resolution. User-space compositors will
136 			 * allocate their own 32-bit framebuffers.
137 			 */
138 			sizes->surface_bpp = 16;
139 			sizes->surface_depth = 16;
140 			goto try_psb_gem_create;
141 		}
142 		return ret;
143 	}
144 	obj = &backing->base;
145 
146 	ret = drm_gem_handle_create(file, obj, &handle);
147 	if (ret)
148 		goto err_drm_gem_object_put;
149 
150 	buffer = drm_client_buffer_create(client, sizes->surface_width, sizes->surface_height,
151 					  fourcc, handle, pitch);
152 	if (IS_ERR(buffer)) {
153 		ret = PTR_ERR(buffer);
154 		goto err_drm_gem_handle_delete;
155 	}
156 
157 	fb_helper->funcs = &psb_fbdev_fb_helper_funcs;
158 	fb_helper->buffer = buffer;
159 	fb_helper->fb = buffer->fb;
160 
161 	info->fbops = &psb_fbdev_fb_ops;
162 
163 	/* Accessed stolen memory directly */
164 	info->screen_base = dev_priv->vram_addr + backing->offset;
165 	info->screen_size = obj->size;
166 
167 	drm_fb_helper_fill_info(info, fb_helper, sizes);
168 
169 	info->fix.smem_start = dev_priv->stolen_base + backing->offset;
170 	info->fix.smem_len = obj->size;
171 	info->fix.ywrapstep = 0;
172 	info->fix.ypanstep = 0;
173 	info->fix.mmio_start = pci_resource_start(pdev, 0);
174 	info->fix.mmio_len = pci_resource_len(pdev, 0);
175 
176 	fb_memset_io(info->screen_base, 0, info->screen_size);
177 
178 	/* Use default scratch pixmap (info->pixmap.flags = FB_PIXMAP_SYSTEM) */
179 
180 	dev_dbg(dev->dev, "allocated %dx%d fb\n", buffer->fb->width, buffer->fb->height);
181 
182 	/* The handle is only needed for creating the framebuffer.*/
183 	drm_gem_handle_delete(file, handle);
184 
185 	/* The framebuffer still holds a references on the GEM object. */
186 	drm_gem_object_put(obj);
187 
188 	return 0;
189 
190 err_drm_gem_handle_delete:
191 	drm_gem_handle_delete(file, handle);
192 err_drm_gem_object_put:
193 	drm_gem_object_put(obj);
194 	return ret;
195 }
196