xref: /openbmc/linux/drivers/firmware/efi/libstub/gop.c (revision 99ea8b1d)
1 // SPDX-License-Identifier: GPL-2.0
2 /* -----------------------------------------------------------------------
3  *
4  *   Copyright 2011 Intel Corporation; author Matt Fleming
5  *
6  * ----------------------------------------------------------------------- */
7 
8 #include <linux/efi.h>
9 #include <linux/screen_info.h>
10 #include <asm/efi.h>
11 #include <asm/setup.h>
12 
13 #include "efistub.h"
14 
15 static void find_bits(unsigned long mask, u8 *pos, u8 *size)
16 {
17 	u8 first, len;
18 
19 	first = 0;
20 	len = 0;
21 
22 	if (mask) {
23 		while (!(mask & 0x1)) {
24 			mask = mask >> 1;
25 			first++;
26 		}
27 
28 		while (mask & 0x1) {
29 			mask = mask >> 1;
30 			len++;
31 		}
32 	}
33 
34 	*pos = first;
35 	*size = len;
36 }
37 
38 static void
39 setup_pixel_info(struct screen_info *si, u32 pixels_per_scan_line,
40 		 efi_pixel_bitmask_t pixel_info, int pixel_format)
41 {
42 	if (pixel_format == PIXEL_RGB_RESERVED_8BIT_PER_COLOR) {
43 		si->lfb_depth = 32;
44 		si->lfb_linelength = pixels_per_scan_line * 4;
45 		si->red_size = 8;
46 		si->red_pos = 0;
47 		si->green_size = 8;
48 		si->green_pos = 8;
49 		si->blue_size = 8;
50 		si->blue_pos = 16;
51 		si->rsvd_size = 8;
52 		si->rsvd_pos = 24;
53 	} else if (pixel_format == PIXEL_BGR_RESERVED_8BIT_PER_COLOR) {
54 		si->lfb_depth = 32;
55 		si->lfb_linelength = pixels_per_scan_line * 4;
56 		si->red_size = 8;
57 		si->red_pos = 16;
58 		si->green_size = 8;
59 		si->green_pos = 8;
60 		si->blue_size = 8;
61 		si->blue_pos = 0;
62 		si->rsvd_size = 8;
63 		si->rsvd_pos = 24;
64 	} else if (pixel_format == PIXEL_BIT_MASK) {
65 		find_bits(pixel_info.red_mask, &si->red_pos, &si->red_size);
66 		find_bits(pixel_info.green_mask, &si->green_pos,
67 			  &si->green_size);
68 		find_bits(pixel_info.blue_mask, &si->blue_pos, &si->blue_size);
69 		find_bits(pixel_info.reserved_mask, &si->rsvd_pos,
70 			  &si->rsvd_size);
71 		si->lfb_depth = si->red_size + si->green_size +
72 			si->blue_size + si->rsvd_size;
73 		si->lfb_linelength = (pixels_per_scan_line * si->lfb_depth) / 8;
74 	} else {
75 		si->lfb_depth = 4;
76 		si->lfb_linelength = si->lfb_width / 2;
77 		si->red_size = 0;
78 		si->red_pos = 0;
79 		si->green_size = 0;
80 		si->green_pos = 0;
81 		si->blue_size = 0;
82 		si->blue_pos = 0;
83 		si->rsvd_size = 0;
84 		si->rsvd_pos = 0;
85 	}
86 }
87 
88 static efi_status_t setup_gop(struct screen_info *si, efi_guid_t *proto,
89 			      unsigned long size, void **handles)
90 {
91 	efi_graphics_output_protocol_t *gop, *first_gop;
92 	u16 width, height;
93 	u32 pixels_per_scan_line;
94 	u32 ext_lfb_base;
95 	efi_physical_addr_t fb_base;
96 	efi_pixel_bitmask_t pixel_info;
97 	int pixel_format;
98 	efi_status_t status;
99 	efi_handle_t h;
100 	int i;
101 
102 	first_gop = NULL;
103 	gop = NULL;
104 
105 	for_each_efi_handle(h, handles, size, i) {
106 		efi_graphics_output_protocol_mode_t *mode;
107 		efi_graphics_output_mode_info_t *info = NULL;
108 		efi_guid_t conout_proto = EFI_CONSOLE_OUT_DEVICE_GUID;
109 		bool conout_found = false;
110 		void *dummy = NULL;
111 		efi_physical_addr_t current_fb_base;
112 
113 		status = efi_call_early(handle_protocol, h,
114 					proto, (void **)&gop);
115 		if (status != EFI_SUCCESS)
116 			continue;
117 
118 		status = efi_call_early(handle_protocol, h,
119 					&conout_proto, &dummy);
120 		if (status == EFI_SUCCESS)
121 			conout_found = true;
122 
123 		mode = efi_table_attr(gop, mode);
124 		info = efi_table_attr(mode, info);
125 		current_fb_base = efi_table_attr(mode, frame_buffer_base);
126 
127 		if ((!first_gop || conout_found) &&
128 		    info->pixel_format != PIXEL_BLT_ONLY) {
129 			/*
130 			 * Systems that use the UEFI Console Splitter may
131 			 * provide multiple GOP devices, not all of which are
132 			 * backed by real hardware. The workaround is to search
133 			 * for a GOP implementing the ConOut protocol, and if
134 			 * one isn't found, to just fall back to the first GOP.
135 			 */
136 			width = info->horizontal_resolution;
137 			height = info->vertical_resolution;
138 			pixel_format = info->pixel_format;
139 			pixel_info = info->pixel_information;
140 			pixels_per_scan_line = info->pixels_per_scan_line;
141 			fb_base = current_fb_base;
142 
143 			/*
144 			 * Once we've found a GOP supporting ConOut,
145 			 * don't bother looking any further.
146 			 */
147 			first_gop = gop;
148 			if (conout_found)
149 				break;
150 		}
151 	}
152 
153 	/* Did we find any GOPs? */
154 	if (!first_gop)
155 		return EFI_NOT_FOUND;
156 
157 	/* EFI framebuffer */
158 	si->orig_video_isVGA = VIDEO_TYPE_EFI;
159 
160 	si->lfb_width = width;
161 	si->lfb_height = height;
162 	si->lfb_base = fb_base;
163 
164 	ext_lfb_base = (u64)(unsigned long)fb_base >> 32;
165 	if (ext_lfb_base) {
166 		si->capabilities |= VIDEO_CAPABILITY_64BIT_BASE;
167 		si->ext_lfb_base = ext_lfb_base;
168 	}
169 
170 	si->pages = 1;
171 
172 	setup_pixel_info(si, pixels_per_scan_line, pixel_info, pixel_format);
173 
174 	si->lfb_size = si->lfb_linelength * si->lfb_height;
175 
176 	si->capabilities |= VIDEO_CAPABILITY_SKIP_QUIRKS;
177 
178 	return EFI_SUCCESS;
179 }
180 
181 /*
182  * See if we have Graphics Output Protocol
183  */
184 efi_status_t efi_setup_gop(struct screen_info *si, efi_guid_t *proto,
185 			   unsigned long size)
186 {
187 	efi_status_t status;
188 	void **gop_handle = NULL;
189 
190 	status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
191 				size, (void **)&gop_handle);
192 	if (status != EFI_SUCCESS)
193 		return status;
194 
195 	status = efi_call_early(locate_handle,
196 				EFI_LOCATE_BY_PROTOCOL,
197 				proto, NULL, &size, gop_handle);
198 	if (status != EFI_SUCCESS)
199 		goto free_handle;
200 
201 	status = setup_gop(si, proto, size, gop_handle);
202 
203 free_handle:
204 	efi_call_early(free_pool, gop_handle);
205 	return status;
206 }
207