* Re: [GIT PULL] fbdev fix for v7.0-rc3
From: pr-tracker-bot @ 2026-03-07 21:24 UTC (permalink / raw)
To: Helge Deller
Cc: Linus Torvalds, linux-kernel, linux-fbdev, dri-devel,
Uwe Kleine-König
In-Reply-To: <aayOLznDX70UUs6T@carbonx1>
The pull request you sent on Sat, 7 Mar 2026 21:44:31 +0100:
> http://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev.git tags/fbdev-for-7.0-rc3
has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/fb07430e6f98ccff61f6f1a06d01d7f12e29c6d3
Thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/prtracker.html
^ permalink raw reply
* Re: [PATCH] staging: sm750fb: add missing const qualifier to char pointer array
From: kernel test robot @ 2026-03-07 23:05 UTC (permalink / raw)
To: Oskar Ray-Frayssinet, sudipm.mukherjee, teddy.wang, gregkh
Cc: oe-kbuild-all, linux-fbdev, linux-staging, linux-kernel,
Oskar Ray-Frayssinet
In-Reply-To: <20260307131833.1138-1-rayfraytech@gmail.com>
Hi Oskar,
kernel test robot noticed the following build errors:
[auto build test ERROR on staging/staging-testing]
url: https://github.com/intel-lab-lkp/linux/commits/Oskar-Ray-Frayssinet/staging-sm750fb-add-missing-const-qualifier-to-char-pointer-array/20260307-212030
base: staging/staging-testing
patch link: https://lore.kernel.org/r/20260307131833.1138-1-rayfraytech%40gmail.com
patch subject: [PATCH] staging: sm750fb: add missing const qualifier to char pointer array
config: parisc-randconfig-r073-20260308 (https://download.01.org/0day-ci/archive/20260308/202603080719.feszwgV8-lkp@intel.com/config)
compiler: hppa-linux-gcc (GCC) 13.4.0
smatch: v0.5.0-9004-gb810ac53
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260308/202603080719.feszwgV8-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202603080719.feszwgV8-lkp@intel.com/
All errors (new ones prefixed by >>):
drivers/staging/sm750fb/sm750.c: In function 'lynxfb_set_fbinfo':
>> drivers/staging/sm750fb/sm750.c:782:33: error: assignment of read-only location 'g_fbmode[index]'
782 | g_fbmode[index] = g_def_fbmode;
| ^
drivers/staging/sm750fb/sm750.c:784:41: error: assignment of read-only location 'g_fbmode[index]'
784 | g_fbmode[index] = g_fbmode[0];
| ^
drivers/staging/sm750fb/sm750.c: In function 'sm750fb_setup':
>> drivers/staging/sm750fb/sm750.c:893:45: error: assignment of read-only location 'g_fbmode[0]'
893 | g_fbmode[0] = opt;
| ^
drivers/staging/sm750fb/sm750.c:897:45: error: assignment of read-only location 'g_fbmode[1]'
897 | g_fbmode[1] = opt;
| ^
vim +782 drivers/staging/sm750fb/sm750.c
81dee67e215b23 Sudip Mukherjee 2015-03-03 716
81dee67e215b23 Sudip Mukherjee 2015-03-03 717 static int lynxfb_set_fbinfo(struct fb_info *info, int index)
81dee67e215b23 Sudip Mukherjee 2015-03-03 718 {
81dee67e215b23 Sudip Mukherjee 2015-03-03 719 int i;
81dee67e215b23 Sudip Mukherjee 2015-03-03 720 struct lynxfb_par *par;
e359b6a863e19f Mike Rapoport 2015-10-26 721 struct sm750_dev *sm750_dev;
81dee67e215b23 Sudip Mukherjee 2015-03-03 722 struct lynxfb_crtc *crtc;
81dee67e215b23 Sudip Mukherjee 2015-03-03 723 struct lynxfb_output *output;
81dee67e215b23 Sudip Mukherjee 2015-03-03 724 struct fb_var_screeninfo *var;
81dee67e215b23 Sudip Mukherjee 2015-03-03 725 struct fb_fix_screeninfo *fix;
81dee67e215b23 Sudip Mukherjee 2015-03-03 726
81dee67e215b23 Sudip Mukherjee 2015-03-03 727 const struct fb_videomode *pdb[] = {
81dee67e215b23 Sudip Mukherjee 2015-03-03 728 lynx750_ext, NULL, vesa_modes,
81dee67e215b23 Sudip Mukherjee 2015-03-03 729 };
81dee67e215b23 Sudip Mukherjee 2015-03-03 730 int cdb[] = {ARRAY_SIZE(lynx750_ext), 0, VESA_MODEDB_SIZE};
8c475735085a7d Tim Wassink 2025-12-21 731 static const char *fix_id[2] = {
81dee67e215b23 Sudip Mukherjee 2015-03-03 732 "sm750_fb1", "sm750_fb2",
81dee67e215b23 Sudip Mukherjee 2015-03-03 733 };
81dee67e215b23 Sudip Mukherjee 2015-03-03 734
81dee67e215b23 Sudip Mukherjee 2015-03-03 735 int ret, line_length;
81dee67e215b23 Sudip Mukherjee 2015-03-03 736
81dee67e215b23 Sudip Mukherjee 2015-03-03 737 ret = 0;
81dee67e215b23 Sudip Mukherjee 2015-03-03 738 par = (struct lynxfb_par *)info->par;
e359b6a863e19f Mike Rapoport 2015-10-26 739 sm750_dev = par->dev;
81dee67e215b23 Sudip Mukherjee 2015-03-03 740 crtc = &par->crtc;
81dee67e215b23 Sudip Mukherjee 2015-03-03 741 output = &par->output;
81dee67e215b23 Sudip Mukherjee 2015-03-03 742 var = &info->var;
81dee67e215b23 Sudip Mukherjee 2015-03-03 743 fix = &info->fix;
81dee67e215b23 Sudip Mukherjee 2015-03-03 744
81dee67e215b23 Sudip Mukherjee 2015-03-03 745 /* set index */
81dee67e215b23 Sudip Mukherjee 2015-03-03 746 par->index = index;
81dee67e215b23 Sudip Mukherjee 2015-03-03 747 output->channel = &crtc->channel;
81dee67e215b23 Sudip Mukherjee 2015-03-03 748 sm750fb_set_drv(par);
81dee67e215b23 Sudip Mukherjee 2015-03-03 749
d11ac7cbcc266c Sudip Mukherjee 2015-08-07 750 /*
d11ac7cbcc266c Sudip Mukherjee 2015-08-07 751 * set current cursor variable and proc pointer,
d11ac7cbcc266c Sudip Mukherjee 2015-08-07 752 * must be set after crtc member initialized
d11ac7cbcc266c Sudip Mukherjee 2015-08-07 753 */
fdc234d85210d9 Benjamin Philip 2021-07-28 754 crtc->cursor.offset = crtc->o_screen + crtc->vidmem_size - 1024;
e359b6a863e19f Mike Rapoport 2015-10-26 755 crtc->cursor.mmio = sm750_dev->pvReg +
e359b6a863e19f Mike Rapoport 2015-10-26 756 0x800f0 + (int)crtc->channel * 0x140;
81dee67e215b23 Sudip Mukherjee 2015-03-03 757
cd33da26036ea5 Christopher Carbone 2022-08-23 758 crtc->cursor.max_h = 64;
cd33da26036ea5 Christopher Carbone 2022-08-23 759 crtc->cursor.max_w = 64;
39f9137268ee3d Benjamin Philip 2021-07-26 760 crtc->cursor.size = crtc->cursor.max_h * crtc->cursor.max_w * 2 / 8;
e359b6a863e19f Mike Rapoport 2015-10-26 761 crtc->cursor.vstart = sm750_dev->pvMem + crtc->cursor.offset;
81dee67e215b23 Sudip Mukherjee 2015-03-03 762
3de08a2d14ff8c Lorenzo Stoakes 2015-03-20 763 memset_io(crtc->cursor.vstart, 0, crtc->cursor.size);
f7c8a046577e09 Thomas Zimmermann 2023-11-27 764 if (!g_hwcursor)
52d0744d751d8f Arnd Bergmann 2016-11-09 765 sm750_hw_cursor_disable(&crtc->cursor);
81dee67e215b23 Sudip Mukherjee 2015-03-03 766
81dee67e215b23 Sudip Mukherjee 2015-03-03 767 /* set info->fbops, must be set before fb_find_mode */
e359b6a863e19f Mike Rapoport 2015-10-26 768 if (!sm750_dev->accel_off) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 769 /* use 2d acceleration */
f7c8a046577e09 Thomas Zimmermann 2023-11-27 770 if (!g_hwcursor)
f7c8a046577e09 Thomas Zimmermann 2023-11-27 771 info->fbops = &lynxfb_ops_accel;
f7c8a046577e09 Thomas Zimmermann 2023-11-27 772 else
f7c8a046577e09 Thomas Zimmermann 2023-11-27 773 info->fbops = &lynxfb_ops_accel_with_cursor;
f7c8a046577e09 Thomas Zimmermann 2023-11-27 774 } else {
f7c8a046577e09 Thomas Zimmermann 2023-11-27 775 if (!g_hwcursor)
81dee67e215b23 Sudip Mukherjee 2015-03-03 776 info->fbops = &lynxfb_ops;
f7c8a046577e09 Thomas Zimmermann 2023-11-27 777 else
f7c8a046577e09 Thomas Zimmermann 2023-11-27 778 info->fbops = &lynxfb_ops_with_cursor;
f7c8a046577e09 Thomas Zimmermann 2023-11-27 779 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 780
81dee67e215b23 Sudip Mukherjee 2015-03-03 781 if (!g_fbmode[index]) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 @782 g_fbmode[index] = g_def_fbmode;
81dee67e215b23 Sudip Mukherjee 2015-03-03 783 if (index)
81dee67e215b23 Sudip Mukherjee 2015-03-03 784 g_fbmode[index] = g_fbmode[0];
81dee67e215b23 Sudip Mukherjee 2015-03-03 785 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 786
81dee67e215b23 Sudip Mukherjee 2015-03-03 787 for (i = 0; i < 3; i++) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 788 ret = fb_find_mode(var, info, g_fbmode[index],
81dee67e215b23 Sudip Mukherjee 2015-03-03 789 pdb[i], cdb[i], NULL, 8);
81dee67e215b23 Sudip Mukherjee 2015-03-03 790
db7fb3588ab492 Artem Lytkin 2026-02-23 791 if (ret == 1 || ret == 2)
81dee67e215b23 Sudip Mukherjee 2015-03-03 792 break;
81dee67e215b23 Sudip Mukherjee 2015-03-03 793 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 794
81dee67e215b23 Sudip Mukherjee 2015-03-03 795 /* set par */
81dee67e215b23 Sudip Mukherjee 2015-03-03 796 par->info = info;
81dee67e215b23 Sudip Mukherjee 2015-03-03 797
81dee67e215b23 Sudip Mukherjee 2015-03-03 798 /* set info */
e3a3f9f5123683 Mike Rapoport 2015-10-26 799 line_length = ALIGN((var->xres_virtual * var->bits_per_pixel / 8),
e3a3f9f5123683 Mike Rapoport 2015-10-26 800 crtc->line_pad);
81dee67e215b23 Sudip Mukherjee 2015-03-03 801
81dee67e215b23 Sudip Mukherjee 2015-03-03 802 info->pseudo_palette = &par->pseudo_palette[0];
cc59bde1c920ab Benjamin Philip 2021-07-28 803 info->screen_base = crtc->v_screen;
81dee67e215b23 Sudip Mukherjee 2015-03-03 804 info->screen_size = line_length * var->yres_virtual;
81dee67e215b23 Sudip Mukherjee 2015-03-03 805
81dee67e215b23 Sudip Mukherjee 2015-03-03 806 /* set info->fix */
81dee67e215b23 Sudip Mukherjee 2015-03-03 807 fix->type = FB_TYPE_PACKED_PIXELS;
81dee67e215b23 Sudip Mukherjee 2015-03-03 808 fix->type_aux = 0;
81dee67e215b23 Sudip Mukherjee 2015-03-03 809 fix->xpanstep = crtc->xpanstep;
81dee67e215b23 Sudip Mukherjee 2015-03-03 810 fix->ypanstep = crtc->ypanstep;
81dee67e215b23 Sudip Mukherjee 2015-03-03 811 fix->ywrapstep = crtc->ywrapstep;
81dee67e215b23 Sudip Mukherjee 2015-03-03 812 fix->accel = FB_ACCEL_SMI;
81dee67e215b23 Sudip Mukherjee 2015-03-03 813
8c475735085a7d Tim Wassink 2025-12-21 814 strscpy(fix->id, fix_id[index], sizeof(fix->id));
81dee67e215b23 Sudip Mukherjee 2015-03-03 815
fdc234d85210d9 Benjamin Philip 2021-07-28 816 fix->smem_start = crtc->o_screen + sm750_dev->vidmem_start;
d11ac7cbcc266c Sudip Mukherjee 2015-08-07 817 /*
d11ac7cbcc266c Sudip Mukherjee 2015-08-07 818 * according to mmap experiment from user space application,
81dee67e215b23 Sudip Mukherjee 2015-03-03 819 * fix->mmio_len should not larger than virtual size
81dee67e215b23 Sudip Mukherjee 2015-03-03 820 * (xres_virtual x yres_virtual x ByPP)
81dee67e215b23 Sudip Mukherjee 2015-03-03 821 * Below line maybe buggy when user mmap fb dev node and write
81dee67e215b23 Sudip Mukherjee 2015-03-03 822 * data into the bound over virtual size
d11ac7cbcc266c Sudip Mukherjee 2015-08-07 823 */
81dee67e215b23 Sudip Mukherjee 2015-03-03 824 fix->smem_len = crtc->vidmem_size;
81dee67e215b23 Sudip Mukherjee 2015-03-03 825 info->screen_size = fix->smem_len;
81dee67e215b23 Sudip Mukherjee 2015-03-03 826 fix->line_length = line_length;
e359b6a863e19f Mike Rapoport 2015-10-26 827 fix->mmio_start = sm750_dev->vidreg_start;
e359b6a863e19f Mike Rapoport 2015-10-26 828 fix->mmio_len = sm750_dev->vidreg_size;
b610e1193a917f Matej Dujava 2020-04-30 829
b610e1193a917f Matej Dujava 2020-04-30 830 lynxfb_set_visual_mode(info);
81dee67e215b23 Sudip Mukherjee 2015-03-03 831
81dee67e215b23 Sudip Mukherjee 2015-03-03 832 /* set var */
81dee67e215b23 Sudip Mukherjee 2015-03-03 833 var->activate = FB_ACTIVATE_NOW;
81dee67e215b23 Sudip Mukherjee 2015-03-03 834 var->accel_flags = 0;
81dee67e215b23 Sudip Mukherjee 2015-03-03 835 var->vmode = FB_VMODE_NONINTERLACED;
81dee67e215b23 Sudip Mukherjee 2015-03-03 836
61c507cf652da1 Michel von Czettritz 2015-03-26 837 ret = fb_alloc_cmap(&info->cmap, 256, 0);
61c507cf652da1 Michel von Czettritz 2015-03-26 838 if (ret < 0) {
fbab250eb51d6d Artem Lytkin 2026-02-07 839 dev_err(info->device, "Could not allocate memory for cmap.\n");
81dee67e215b23 Sudip Mukherjee 2015-03-03 840 goto exit;
81dee67e215b23 Sudip Mukherjee 2015-03-03 841 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 842
81dee67e215b23 Sudip Mukherjee 2015-03-03 843 exit:
81dee67e215b23 Sudip Mukherjee 2015-03-03 844 lynxfb_ops_check_var(var, info);
81dee67e215b23 Sudip Mukherjee 2015-03-03 845 return ret;
81dee67e215b23 Sudip Mukherjee 2015-03-03 846 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 847
81dee67e215b23 Sudip Mukherjee 2015-03-03 848 /* chip specific g_option configuration routine */
700591a9adc8b1 Mike Rapoport 2015-10-26 849 static void sm750fb_setup(struct sm750_dev *sm750_dev, char *src)
81dee67e215b23 Sudip Mukherjee 2015-03-03 850 {
81dee67e215b23 Sudip Mukherjee 2015-03-03 851 char *opt;
81dee67e215b23 Sudip Mukherjee 2015-03-03 852 int swap;
81dee67e215b23 Sudip Mukherjee 2015-03-03 853
81dee67e215b23 Sudip Mukherjee 2015-03-03 854 swap = 0;
81dee67e215b23 Sudip Mukherjee 2015-03-03 855
cc34db609ff98c Madhumitha Sundar 2026-01-27 856 sm750_dev->init_parm.chip_clk = 0;
cc34db609ff98c Madhumitha Sundar 2026-01-27 857 sm750_dev->init_parm.mem_clk = 0;
cc34db609ff98c Madhumitha Sundar 2026-01-27 858 sm750_dev->init_parm.master_clk = 0;
cc34db609ff98c Madhumitha Sundar 2026-01-27 859 sm750_dev->init_parm.powerMode = 0;
cc34db609ff98c Madhumitha Sundar 2026-01-27 860 sm750_dev->init_parm.setAllEngOff = 0;
cc34db609ff98c Madhumitha Sundar 2026-01-27 861 sm750_dev->init_parm.resetMemory = 1;
81dee67e215b23 Sudip Mukherjee 2015-03-03 862
81dee67e215b23 Sudip Mukherjee 2015-03-03 863 /* defaultly turn g_hwcursor on for both view */
81dee67e215b23 Sudip Mukherjee 2015-03-03 864 g_hwcursor = 3;
81dee67e215b23 Sudip Mukherjee 2015-03-03 865
81dee67e215b23 Sudip Mukherjee 2015-03-03 866 if (!src || !*src) {
c56de0967a658c Elise Lennion 2016-10-31 867 dev_warn(&sm750_dev->pdev->dev, "no specific g_option.\n");
81dee67e215b23 Sudip Mukherjee 2015-03-03 868 goto NO_PARAM;
81dee67e215b23 Sudip Mukherjee 2015-03-03 869 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 870
0fa96e39279988 Sudip Mukherjee 2015-03-10 871 while ((opt = strsep(&src, ":")) != NULL && *opt != 0) {
c56de0967a658c Elise Lennion 2016-10-31 872 dev_info(&sm750_dev->pdev->dev, "opt=%s\n", opt);
c56de0967a658c Elise Lennion 2016-10-31 873 dev_info(&sm750_dev->pdev->dev, "src=%s\n", src);
81dee67e215b23 Sudip Mukherjee 2015-03-03 874
144634a6b42146 Katie Dunne 2017-02-19 875 if (!strncmp(opt, "swap", strlen("swap"))) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 876 swap = 1;
144634a6b42146 Katie Dunne 2017-02-19 877 } else if (!strncmp(opt, "nocrt", strlen("nocrt"))) {
1757d106a9ce8c Mike Rapoport 2015-10-26 878 sm750_dev->nocrt = 1;
144634a6b42146 Katie Dunne 2017-02-19 879 } else if (!strncmp(opt, "36bit", strlen("36bit"))) {
1757d106a9ce8c Mike Rapoport 2015-10-26 880 sm750_dev->pnltype = sm750_doubleTFT;
144634a6b42146 Katie Dunne 2017-02-19 881 } else if (!strncmp(opt, "18bit", strlen("18bit"))) {
1757d106a9ce8c Mike Rapoport 2015-10-26 882 sm750_dev->pnltype = sm750_dualTFT;
144634a6b42146 Katie Dunne 2017-02-19 883 } else if (!strncmp(opt, "24bit", strlen("24bit"))) {
1757d106a9ce8c Mike Rapoport 2015-10-26 884 sm750_dev->pnltype = sm750_24TFT;
144634a6b42146 Katie Dunne 2017-02-19 885 } else if (!strncmp(opt, "nohwc0", strlen("nohwc0"))) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 886 g_hwcursor &= ~0x1;
144634a6b42146 Katie Dunne 2017-02-19 887 } else if (!strncmp(opt, "nohwc1", strlen("nohwc1"))) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 888 g_hwcursor &= ~0x2;
144634a6b42146 Katie Dunne 2017-02-19 889 } else if (!strncmp(opt, "nohwc", strlen("nohwc"))) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 890 g_hwcursor = 0;
144634a6b42146 Katie Dunne 2017-02-19 891 } else {
81dee67e215b23 Sudip Mukherjee 2015-03-03 892 if (!g_fbmode[0]) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 @893 g_fbmode[0] = opt;
cee9ba1c30d051 Abdul Rauf 2017-01-08 894 dev_info(&sm750_dev->pdev->dev,
cee9ba1c30d051 Abdul Rauf 2017-01-08 895 "find fbmode0 : %s\n", g_fbmode[0]);
81dee67e215b23 Sudip Mukherjee 2015-03-03 896 } else if (!g_fbmode[1]) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 897 g_fbmode[1] = opt;
cee9ba1c30d051 Abdul Rauf 2017-01-08 898 dev_info(&sm750_dev->pdev->dev,
cee9ba1c30d051 Abdul Rauf 2017-01-08 899 "find fbmode1 : %s\n", g_fbmode[1]);
81dee67e215b23 Sudip Mukherjee 2015-03-03 900 } else {
c56de0967a658c Elise Lennion 2016-10-31 901 dev_warn(&sm750_dev->pdev->dev, "How many view you wann set?\n");
81dee67e215b23 Sudip Mukherjee 2015-03-03 902 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 903 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 904 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 905
81dee67e215b23 Sudip Mukherjee 2015-03-03 906 NO_PARAM:
e359b6a863e19f Mike Rapoport 2015-10-26 907 if (sm750_dev->revid != SM750LE_REVISION_ID) {
a3f92cc94c6126 Mike Rapoport 2016-01-17 908 if (sm750_dev->fb_count > 1) {
81dee67e215b23 Sudip Mukherjee 2015-03-03 909 if (swap)
1757d106a9ce8c Mike Rapoport 2015-10-26 910 sm750_dev->dataflow = sm750_dual_swap;
81dee67e215b23 Sudip Mukherjee 2015-03-03 911 else
1757d106a9ce8c Mike Rapoport 2015-10-26 912 sm750_dev->dataflow = sm750_dual_normal;
81dee67e215b23 Sudip Mukherjee 2015-03-03 913 } else {
81dee67e215b23 Sudip Mukherjee 2015-03-03 914 if (swap)
1757d106a9ce8c Mike Rapoport 2015-10-26 915 sm750_dev->dataflow = sm750_simul_sec;
81dee67e215b23 Sudip Mukherjee 2015-03-03 916 else
1757d106a9ce8c Mike Rapoport 2015-10-26 917 sm750_dev->dataflow = sm750_simul_pri;
81dee67e215b23 Sudip Mukherjee 2015-03-03 918 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 919 } else {
81dee67e215b23 Sudip Mukherjee 2015-03-03 920 /* SM750LE only have one crt channel */
1757d106a9ce8c Mike Rapoport 2015-10-26 921 sm750_dev->dataflow = sm750_simul_sec;
81dee67e215b23 Sudip Mukherjee 2015-03-03 922 /* sm750le do not have complex attributes */
1757d106a9ce8c Mike Rapoport 2015-10-26 923 sm750_dev->nocrt = 0;
81dee67e215b23 Sudip Mukherjee 2015-03-03 924 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 925 }
81dee67e215b23 Sudip Mukherjee 2015-03-03 926
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply
* Re: [PATCH] staging: sm750fb: add missing const qualifier to char pointer array
From: kernel test robot @ 2026-03-08 1:45 UTC (permalink / raw)
To: Oskar Ray-Frayssinet, sudipm.mukherjee, teddy.wang, gregkh
Cc: llvm, oe-kbuild-all, linux-fbdev, linux-staging, linux-kernel,
Oskar Ray-Frayssinet
In-Reply-To: <20260307131833.1138-1-rayfraytech@gmail.com>
Hi Oskar,
kernel test robot noticed the following build errors:
[auto build test ERROR on staging/staging-testing]
url: https://github.com/intel-lab-lkp/linux/commits/Oskar-Ray-Frayssinet/staging-sm750fb-add-missing-const-qualifier-to-char-pointer-array/20260307-212030
base: staging/staging-testing
patch link: https://lore.kernel.org/r/20260307131833.1138-1-rayfraytech%40gmail.com
patch subject: [PATCH] staging: sm750fb: add missing const qualifier to char pointer array
config: i386-buildonly-randconfig-003-20260308 (https://download.01.org/0day-ci/archive/20260308/202603080944.rMPCAhoj-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260308/202603080944.rMPCAhoj-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202603080944.rMPCAhoj-lkp@intel.com/
All errors (new ones prefixed by >>):
>> drivers/staging/sm750fb/sm750.c:782:19: error: cannot assign to variable 'g_fbmode' with const-qualified type 'const char *const[2]'
782 | g_fbmode[index] = g_def_fbmode;
| ~~~~~~~~~~~~~~~ ^
drivers/staging/sm750fb/sm750.c:36:27: note: variable 'g_fbmode' declared const here
36 | static const char * const g_fbmode[] = {NULL, NULL};
| ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/staging/sm750fb/sm750.c:784:20: error: cannot assign to variable 'g_fbmode' with const-qualified type 'const char *const[2]'
784 | g_fbmode[index] = g_fbmode[0];
| ~~~~~~~~~~~~~~~ ^
drivers/staging/sm750fb/sm750.c:36:27: note: variable 'g_fbmode' declared const here
36 | static const char * const g_fbmode[] = {NULL, NULL};
| ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/staging/sm750fb/sm750.c:893:17: error: cannot assign to variable 'g_fbmode' with const-qualified type 'const char *const[2]'
893 | g_fbmode[0] = opt;
| ~~~~~~~~~~~ ^
drivers/staging/sm750fb/sm750.c:36:27: note: variable 'g_fbmode' declared const here
36 | static const char * const g_fbmode[] = {NULL, NULL};
| ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/staging/sm750fb/sm750.c:897:17: error: cannot assign to variable 'g_fbmode' with const-qualified type 'const char *const[2]'
897 | g_fbmode[1] = opt;
| ~~~~~~~~~~~ ^
drivers/staging/sm750fb/sm750.c:36:27: note: variable 'g_fbmode' declared const here
36 | static const char * const g_fbmode[] = {NULL, NULL};
| ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
4 errors generated.
vim +782 drivers/staging/sm750fb/sm750.c
81dee67e215b23f Sudip Mukherjee 2015-03-03 716
81dee67e215b23f Sudip Mukherjee 2015-03-03 717 static int lynxfb_set_fbinfo(struct fb_info *info, int index)
81dee67e215b23f Sudip Mukherjee 2015-03-03 718 {
81dee67e215b23f Sudip Mukherjee 2015-03-03 719 int i;
81dee67e215b23f Sudip Mukherjee 2015-03-03 720 struct lynxfb_par *par;
e359b6a863e19f2 Mike Rapoport 2015-10-26 721 struct sm750_dev *sm750_dev;
81dee67e215b23f Sudip Mukherjee 2015-03-03 722 struct lynxfb_crtc *crtc;
81dee67e215b23f Sudip Mukherjee 2015-03-03 723 struct lynxfb_output *output;
81dee67e215b23f Sudip Mukherjee 2015-03-03 724 struct fb_var_screeninfo *var;
81dee67e215b23f Sudip Mukherjee 2015-03-03 725 struct fb_fix_screeninfo *fix;
81dee67e215b23f Sudip Mukherjee 2015-03-03 726
81dee67e215b23f Sudip Mukherjee 2015-03-03 727 const struct fb_videomode *pdb[] = {
81dee67e215b23f Sudip Mukherjee 2015-03-03 728 lynx750_ext, NULL, vesa_modes,
81dee67e215b23f Sudip Mukherjee 2015-03-03 729 };
81dee67e215b23f Sudip Mukherjee 2015-03-03 730 int cdb[] = {ARRAY_SIZE(lynx750_ext), 0, VESA_MODEDB_SIZE};
8c475735085a7db Tim Wassink 2025-12-21 731 static const char *fix_id[2] = {
81dee67e215b23f Sudip Mukherjee 2015-03-03 732 "sm750_fb1", "sm750_fb2",
81dee67e215b23f Sudip Mukherjee 2015-03-03 733 };
81dee67e215b23f Sudip Mukherjee 2015-03-03 734
81dee67e215b23f Sudip Mukherjee 2015-03-03 735 int ret, line_length;
81dee67e215b23f Sudip Mukherjee 2015-03-03 736
81dee67e215b23f Sudip Mukherjee 2015-03-03 737 ret = 0;
81dee67e215b23f Sudip Mukherjee 2015-03-03 738 par = (struct lynxfb_par *)info->par;
e359b6a863e19f2 Mike Rapoport 2015-10-26 739 sm750_dev = par->dev;
81dee67e215b23f Sudip Mukherjee 2015-03-03 740 crtc = &par->crtc;
81dee67e215b23f Sudip Mukherjee 2015-03-03 741 output = &par->output;
81dee67e215b23f Sudip Mukherjee 2015-03-03 742 var = &info->var;
81dee67e215b23f Sudip Mukherjee 2015-03-03 743 fix = &info->fix;
81dee67e215b23f Sudip Mukherjee 2015-03-03 744
81dee67e215b23f Sudip Mukherjee 2015-03-03 745 /* set index */
81dee67e215b23f Sudip Mukherjee 2015-03-03 746 par->index = index;
81dee67e215b23f Sudip Mukherjee 2015-03-03 747 output->channel = &crtc->channel;
81dee67e215b23f Sudip Mukherjee 2015-03-03 748 sm750fb_set_drv(par);
81dee67e215b23f Sudip Mukherjee 2015-03-03 749
d11ac7cbcc266c6 Sudip Mukherjee 2015-08-07 750 /*
d11ac7cbcc266c6 Sudip Mukherjee 2015-08-07 751 * set current cursor variable and proc pointer,
d11ac7cbcc266c6 Sudip Mukherjee 2015-08-07 752 * must be set after crtc member initialized
d11ac7cbcc266c6 Sudip Mukherjee 2015-08-07 753 */
fdc234d85210d91 Benjamin Philip 2021-07-28 754 crtc->cursor.offset = crtc->o_screen + crtc->vidmem_size - 1024;
e359b6a863e19f2 Mike Rapoport 2015-10-26 755 crtc->cursor.mmio = sm750_dev->pvReg +
e359b6a863e19f2 Mike Rapoport 2015-10-26 756 0x800f0 + (int)crtc->channel * 0x140;
81dee67e215b23f Sudip Mukherjee 2015-03-03 757
cd33da26036ea54 Christopher Carbone 2022-08-23 758 crtc->cursor.max_h = 64;
cd33da26036ea54 Christopher Carbone 2022-08-23 759 crtc->cursor.max_w = 64;
39f9137268ee3df Benjamin Philip 2021-07-26 760 crtc->cursor.size = crtc->cursor.max_h * crtc->cursor.max_w * 2 / 8;
e359b6a863e19f2 Mike Rapoport 2015-10-26 761 crtc->cursor.vstart = sm750_dev->pvMem + crtc->cursor.offset;
81dee67e215b23f Sudip Mukherjee 2015-03-03 762
3de08a2d14ff8c7 Lorenzo Stoakes 2015-03-20 763 memset_io(crtc->cursor.vstart, 0, crtc->cursor.size);
f7c8a046577e09d Thomas Zimmermann 2023-11-27 764 if (!g_hwcursor)
52d0744d751d8f1 Arnd Bergmann 2016-11-09 765 sm750_hw_cursor_disable(&crtc->cursor);
81dee67e215b23f Sudip Mukherjee 2015-03-03 766
81dee67e215b23f Sudip Mukherjee 2015-03-03 767 /* set info->fbops, must be set before fb_find_mode */
e359b6a863e19f2 Mike Rapoport 2015-10-26 768 if (!sm750_dev->accel_off) {
81dee67e215b23f Sudip Mukherjee 2015-03-03 769 /* use 2d acceleration */
f7c8a046577e09d Thomas Zimmermann 2023-11-27 770 if (!g_hwcursor)
f7c8a046577e09d Thomas Zimmermann 2023-11-27 771 info->fbops = &lynxfb_ops_accel;
f7c8a046577e09d Thomas Zimmermann 2023-11-27 772 else
f7c8a046577e09d Thomas Zimmermann 2023-11-27 773 info->fbops = &lynxfb_ops_accel_with_cursor;
f7c8a046577e09d Thomas Zimmermann 2023-11-27 774 } else {
f7c8a046577e09d Thomas Zimmermann 2023-11-27 775 if (!g_hwcursor)
81dee67e215b23f Sudip Mukherjee 2015-03-03 776 info->fbops = &lynxfb_ops;
f7c8a046577e09d Thomas Zimmermann 2023-11-27 777 else
f7c8a046577e09d Thomas Zimmermann 2023-11-27 778 info->fbops = &lynxfb_ops_with_cursor;
f7c8a046577e09d Thomas Zimmermann 2023-11-27 779 }
81dee67e215b23f Sudip Mukherjee 2015-03-03 780
81dee67e215b23f Sudip Mukherjee 2015-03-03 781 if (!g_fbmode[index]) {
81dee67e215b23f Sudip Mukherjee 2015-03-03 @782 g_fbmode[index] = g_def_fbmode;
81dee67e215b23f Sudip Mukherjee 2015-03-03 783 if (index)
81dee67e215b23f Sudip Mukherjee 2015-03-03 784 g_fbmode[index] = g_fbmode[0];
81dee67e215b23f Sudip Mukherjee 2015-03-03 785 }
81dee67e215b23f Sudip Mukherjee 2015-03-03 786
81dee67e215b23f Sudip Mukherjee 2015-03-03 787 for (i = 0; i < 3; i++) {
81dee67e215b23f Sudip Mukherjee 2015-03-03 788 ret = fb_find_mode(var, info, g_fbmode[index],
81dee67e215b23f Sudip Mukherjee 2015-03-03 789 pdb[i], cdb[i], NULL, 8);
81dee67e215b23f Sudip Mukherjee 2015-03-03 790
db7fb3588ab4920 Artem Lytkin 2026-02-23 791 if (ret == 1 || ret == 2)
81dee67e215b23f Sudip Mukherjee 2015-03-03 792 break;
81dee67e215b23f Sudip Mukherjee 2015-03-03 793 }
81dee67e215b23f Sudip Mukherjee 2015-03-03 794
81dee67e215b23f Sudip Mukherjee 2015-03-03 795 /* set par */
81dee67e215b23f Sudip Mukherjee 2015-03-03 796 par->info = info;
81dee67e215b23f Sudip Mukherjee 2015-03-03 797
81dee67e215b23f Sudip Mukherjee 2015-03-03 798 /* set info */
e3a3f9f5123683b Mike Rapoport 2015-10-26 799 line_length = ALIGN((var->xres_virtual * var->bits_per_pixel / 8),
e3a3f9f5123683b Mike Rapoport 2015-10-26 800 crtc->line_pad);
81dee67e215b23f Sudip Mukherjee 2015-03-03 801
81dee67e215b23f Sudip Mukherjee 2015-03-03 802 info->pseudo_palette = &par->pseudo_palette[0];
cc59bde1c920ab6 Benjamin Philip 2021-07-28 803 info->screen_base = crtc->v_screen;
81dee67e215b23f Sudip Mukherjee 2015-03-03 804 info->screen_size = line_length * var->yres_virtual;
81dee67e215b23f Sudip Mukherjee 2015-03-03 805
81dee67e215b23f Sudip Mukherjee 2015-03-03 806 /* set info->fix */
81dee67e215b23f Sudip Mukherjee 2015-03-03 807 fix->type = FB_TYPE_PACKED_PIXELS;
81dee67e215b23f Sudip Mukherjee 2015-03-03 808 fix->type_aux = 0;
81dee67e215b23f Sudip Mukherjee 2015-03-03 809 fix->xpanstep = crtc->xpanstep;
81dee67e215b23f Sudip Mukherjee 2015-03-03 810 fix->ypanstep = crtc->ypanstep;
81dee67e215b23f Sudip Mukherjee 2015-03-03 811 fix->ywrapstep = crtc->ywrapstep;
81dee67e215b23f Sudip Mukherjee 2015-03-03 812 fix->accel = FB_ACCEL_SMI;
81dee67e215b23f Sudip Mukherjee 2015-03-03 813
8c475735085a7db Tim Wassink 2025-12-21 814 strscpy(fix->id, fix_id[index], sizeof(fix->id));
81dee67e215b23f Sudip Mukherjee 2015-03-03 815
fdc234d85210d91 Benjamin Philip 2021-07-28 816 fix->smem_start = crtc->o_screen + sm750_dev->vidmem_start;
d11ac7cbcc266c6 Sudip Mukherjee 2015-08-07 817 /*
d11ac7cbcc266c6 Sudip Mukherjee 2015-08-07 818 * according to mmap experiment from user space application,
81dee67e215b23f Sudip Mukherjee 2015-03-03 819 * fix->mmio_len should not larger than virtual size
81dee67e215b23f Sudip Mukherjee 2015-03-03 820 * (xres_virtual x yres_virtual x ByPP)
81dee67e215b23f Sudip Mukherjee 2015-03-03 821 * Below line maybe buggy when user mmap fb dev node and write
81dee67e215b23f Sudip Mukherjee 2015-03-03 822 * data into the bound over virtual size
d11ac7cbcc266c6 Sudip Mukherjee 2015-08-07 823 */
81dee67e215b23f Sudip Mukherjee 2015-03-03 824 fix->smem_len = crtc->vidmem_size;
81dee67e215b23f Sudip Mukherjee 2015-03-03 825 info->screen_size = fix->smem_len;
81dee67e215b23f Sudip Mukherjee 2015-03-03 826 fix->line_length = line_length;
e359b6a863e19f2 Mike Rapoport 2015-10-26 827 fix->mmio_start = sm750_dev->vidreg_start;
e359b6a863e19f2 Mike Rapoport 2015-10-26 828 fix->mmio_len = sm750_dev->vidreg_size;
b610e1193a917f4 Matej Dujava 2020-04-30 829
b610e1193a917f4 Matej Dujava 2020-04-30 830 lynxfb_set_visual_mode(info);
81dee67e215b23f Sudip Mukherjee 2015-03-03 831
81dee67e215b23f Sudip Mukherjee 2015-03-03 832 /* set var */
81dee67e215b23f Sudip Mukherjee 2015-03-03 833 var->activate = FB_ACTIVATE_NOW;
81dee67e215b23f Sudip Mukherjee 2015-03-03 834 var->accel_flags = 0;
81dee67e215b23f Sudip Mukherjee 2015-03-03 835 var->vmode = FB_VMODE_NONINTERLACED;
81dee67e215b23f Sudip Mukherjee 2015-03-03 836
61c507cf652da1b Michel von Czettritz 2015-03-26 837 ret = fb_alloc_cmap(&info->cmap, 256, 0);
61c507cf652da1b Michel von Czettritz 2015-03-26 838 if (ret < 0) {
fbab250eb51d6d6 Artem Lytkin 2026-02-07 839 dev_err(info->device, "Could not allocate memory for cmap.\n");
81dee67e215b23f Sudip Mukherjee 2015-03-03 840 goto exit;
81dee67e215b23f Sudip Mukherjee 2015-03-03 841 }
81dee67e215b23f Sudip Mukherjee 2015-03-03 842
81dee67e215b23f Sudip Mukherjee 2015-03-03 843 exit:
81dee67e215b23f Sudip Mukherjee 2015-03-03 844 lynxfb_ops_check_var(var, info);
81dee67e215b23f Sudip Mukherjee 2015-03-03 845 return ret;
81dee67e215b23f Sudip Mukherjee 2015-03-03 846 }
81dee67e215b23f Sudip Mukherjee 2015-03-03 847
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply
* [PATCH v12 0/1] Rust GPU buddy allocator bindings
From: Joel Fernandes @ 2026-03-08 18:04 UTC (permalink / raw)
To: linux-kernel
Cc: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Dave Airlie, Daniel Almeida, Koen Koning,
dri-devel, nouveau, rust-for-linux, Nikola Djukic,
Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, David Airlie,
Simona Vetter, Jonathan Corbet, Alex Deucher,
Christian König, Jani Nikula, Joonas Lahtinen, Rodrigo Vivi,
Tvrtko Ursulin, Huang Rui, Matthew Auld, Matthew Brost,
Lucas De Marchi, Thomas Hellström, Helge Deller, Alex Gaynor,
Boqun Feng, John Hubbard, Alistair Popple, Timur Tabi, Edwin Peer,
Alexandre Courbot, Andrea Righi, Andy Ritger, Zhi Wang,
Balbir Singh, Philipp Stanner, Elle Rhumsaa, alexeyi,
Eliot Courtney, joel, linux-doc, amd-gfx, intel-gfx, intel-xe,
linux-fbdev, Joel Fernandes
This patch adds safe Rust abstractions over the Linux kernel's GPU buddy
allocator for physical memory management. The prerequisite infrastructure
patches (DRM buddy code movement and the uninitialized buddy fix) have been
absorbed into upstream -next, so this is now a standalone patch.
The series along with all dependencies, including clist and nova-core mm
patches, are available at:
git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux.git (tag: nova-mm-current-3-8)
This patch is also here:
https://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux.git/commit/?id=gpu-buddy-bindings-v12
Change log:
Changes from v11 to v12:
- Rebased on linux-next his is now a standalone single patch as dependencies
are absorbed (but not clist is a prequisite)
- Redesigned allocation API (Alexandre Courbot) for better Rust ergonomics.
- Split single long example into 4 self-contained examples (Alexandre Courbot).
- Several safety and invariant comment changes (Danilo).
- MAINTAINERS changes (Arun, Mathew, Danilo, Dave).
- Fixed `#[cfg(CONFIG_GPU_BUDDY)]` to `#[cfg(CONFIG_GPU_BUDDY = "y")]` (Danilo Krummrich).
- Updated `ffi::clist::CListHead` to `interop::list::CListHead`.
Changes from v10 to v11:
- Dropped "rust: ffi: Convert pub use to pub mod and create ffi module" patch;
the ffi module restructuring will go through a different path.
- Dropped "rust: clist: Add support to interface with C linked lists" patch;
the clist module will be submitted separately.
- Dropped "nova-core: Kconfig: Sort select statements alphabetically" cosmetic
patch.
- Patches 1-3 (DRM buddy movement and fix) are included as reference only;
they are already being pulled into upstream via drm-misc-next.
- Removed clist patches as those can go in independently (Alice).
- Moved the Kconfig GPU_BUDDY selection patch to nova-core mm series to enable
it when it is actually used.
- Various nits to comments, etc.
Changes from v9 to v10:
- Absorbed the DRM buddy code movement patches into this series as patches 1-2.
Dave Airlie reworked these into two parts for better git history.
- Added "gpu: Fix uninitialized buddy for built-in drivers" fix by Koen Koning,
using subsys_initcall instead of module_init to fix NULL pointer dereference
when built-in drivers use the buddy allocator before initialization.
- Added "rust: ffi: Convert pub use to pub mod and create ffi module" to prepare
the ffi module for hosting clist as a sub-module.
- Moved clist from rust/kernel/clist.rs to rust/kernel/ffi/.
- Added "nova-core: Kconfig: Sort select statements alphabetically" (Danilo).
Changes from v8 to v9:
- Updated nova-core Kconfig patch: addressed sorting of Kconfig options.
- Added Daniel Almeida's Reviewed-by tag to clist patch.
- Minor refinements to GPU buddy bindings.
Changes from v7 to v8:
- Added nova-core Kconfig patch to select GPU_BUDDY for VRAM allocation.
- Various changes suggested by Danilo Krummrich, Gary Guo, and Daniel Almeida.
- Added Acked-by: Gary Guo for clist patch.
Changes from v6 to v7:
- Major restructuring: split the large 26-patch v6 RFC series. v7 only contains
the Rust infrastructure patches (clist + GPU buddy bindings), extracted from
the full nova-core MM series. The nova-core MM patches follow separately.
- Rebased on linux-next.
Changes from v5 to v6:
- Rebased on drm-rust-kernel/drm-rust-next.
- Expanded from 6 to 26 patches with full nova-core MM infrastructure including
page table walker, VMM, BAR1 user interface, TLB flush, and GpuMm manager.
Changes from v4 to v5:
- Added PRAMIN aperture support with documentation and self-tests.
- Improved buddy allocator bindings (fewer lines of code).
- Based on drm-rust-next instead of linux-next.
Changes from v3 to v4:
- Combined the clist and DRM buddy series into a single coherent series.
- Added DRM buddy allocator movement from drivers/gpu/drm/ up to drivers/gpu/,
renaming API from drm_buddy to gpu_buddy.
- Added Rust bindings for the GPU buddy allocator.
Changes from v2 to v3:
- Squashed 3 clist patches into one due to inter-dependencies.
- Changed Clist to Clist<'a, T> using const generic offset (Alex Courbot).
- Simplified C helpers to only list_add_tail (Alex Courbot, John Hubbard).
- Added init_list_head() Rust function (Alex Courbot).
- Added FusedIterator, PartialEq/Eq impls.
- Added MAINTAINERS entry (Miguel Ojeda).
Changes from v1 (RFC) to v2:
- Dropped DRM buddy allocator patches; series focuses solely on clist module.
- Dropped sample modules, replaced with doctests.
- Added proper lifetime management similar to scatterlist.
- Split clist into 3 separate patches.
Link to v11: https://lore.kernel.org/all/20260224224005.3232841-1-joelagnelf@nvidia.com/
Joel Fernandes (1):
rust: gpu: Add GPU buddy allocator bindings
MAINTAINERS | 6 +-
rust/bindings/bindings_helper.h | 11 +
rust/helpers/gpu.c | 23 ++
rust/helpers/helpers.c | 1 +
rust/kernel/gpu/buddy.rs | 611 ++++++++++++++++++++++++++++++++
rust/kernel/gpu/mod.rs | 5 +
rust/kernel/lib.rs | 2 +
7 files changed, 658 insertions(+), 1 deletion(-)
create mode 100644 rust/helpers/gpu.c
create mode 100644 rust/kernel/gpu/buddy.rs
create mode 100644 rust/kernel/gpu/mod.rs
--
2.34.1
^ permalink raw reply
* [PATCH v12 1/1] rust: gpu: Add GPU buddy allocator bindings
From: Joel Fernandes @ 2026-03-08 18:04 UTC (permalink / raw)
To: linux-kernel
Cc: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Dave Airlie, Daniel Almeida, Koen Koning,
dri-devel, nouveau, rust-for-linux, Nikola Djukic,
Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, David Airlie,
Simona Vetter, Jonathan Corbet, Alex Deucher,
Christian König, Jani Nikula, Joonas Lahtinen, Rodrigo Vivi,
Tvrtko Ursulin, Huang Rui, Matthew Auld, Matthew Brost,
Lucas De Marchi, Thomas Hellström, Helge Deller, Alex Gaynor,
Boqun Feng, John Hubbard, Alistair Popple, Timur Tabi, Edwin Peer,
Alexandre Courbot, Andrea Righi, Andy Ritger, Zhi Wang,
Balbir Singh, Philipp Stanner, Elle Rhumsaa, alexeyi,
Eliot Courtney, joel, linux-doc, amd-gfx, intel-gfx, intel-xe,
linux-fbdev, Joel Fernandes
In-Reply-To: <20260308180407.3988286-1-joelagnelf@nvidia.com>
Add safe Rust abstractions over the Linux kernel's GPU buddy
allocator for physical memory management. The GPU buddy allocator
implements a binary buddy system useful for GPU physical memory
allocation. nova-core will use it for physical memory allocation.
Christian Koenig mentioned he'd like to step down from reviewer role for
GPU buddy so updated accordingly. Arun/Matthew agree on the modified entry.
Cc: Nikola Djukic <ndjukic@nvidia.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
---
MAINTAINERS | 6 +-
rust/bindings/bindings_helper.h | 11 +
rust/helpers/gpu.c | 23 ++
rust/helpers/helpers.c | 1 +
rust/kernel/gpu/buddy.rs | 611 ++++++++++++++++++++++++++++++++
rust/kernel/gpu/mod.rs | 5 +
rust/kernel/lib.rs | 2 +
7 files changed, 658 insertions(+), 1 deletion(-)
create mode 100644 rust/helpers/gpu.c
create mode 100644 rust/kernel/gpu/buddy.rs
create mode 100644 rust/kernel/gpu/mod.rs
diff --git a/MAINTAINERS b/MAINTAINERS
index 4c66f8261ff2..b2600dd05fc2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8513,7 +8513,9 @@ T: git https://gitlab.freedesktop.org/drm/rust/kernel.git
F: drivers/gpu/drm/nova/
F: drivers/gpu/drm/tyr/
F: drivers/gpu/nova-core/
+F: rust/helpers/gpu.c
F: rust/kernel/drm/
+F: rust/kernel/gpu/
DRM DRIVERS FOR ALLWINNER A10
M: Chen-Yu Tsai <wens@kernel.org>
@@ -8926,7 +8928,7 @@ F: include/drm/ttm/
GPU BUDDY ALLOCATOR
M: Matthew Auld <matthew.auld@intel.com>
M: Arun Pravin <arunpravin.paneerselvam@amd.com>
-R: Christian Koenig <christian.koenig@amd.com>
+R: Joel Fernandes <joelagnelf@nvidia.com>
L: dri-devel@lists.freedesktop.org
S: Maintained
T: git https://gitlab.freedesktop.org/drm/misc/kernel.git
@@ -8935,6 +8937,8 @@ F: drivers/gpu/buddy.c
F: drivers/gpu/tests/gpu_buddy_test.c
F: include/linux/gpu_buddy.h
F: include/drm/drm_buddy.h
+F: rust/helpers/gpu.c
+F: rust/kernel/gpu/
DRM AUTOMATED TESTING
M: Helen Koike <helen.fornazier@gmail.com>
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index 083cc44aa952..dbb765a9fdbd 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -29,6 +29,7 @@
#include <linux/hrtimer_types.h>
#include <linux/acpi.h>
+#include <linux/gpu_buddy.h>
#include <drm/drm_device.h>
#include <drm/drm_drv.h>
#include <drm/drm_file.h>
@@ -146,6 +147,16 @@ const vm_flags_t RUST_CONST_HELPER_VM_MIXEDMAP = VM_MIXEDMAP;
const vm_flags_t RUST_CONST_HELPER_VM_HUGEPAGE = VM_HUGEPAGE;
const vm_flags_t RUST_CONST_HELPER_VM_NOHUGEPAGE = VM_NOHUGEPAGE;
+#if IS_ENABLED(CONFIG_GPU_BUDDY)
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_RANGE_ALLOCATION = GPU_BUDDY_RANGE_ALLOCATION;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_TOPDOWN_ALLOCATION = GPU_BUDDY_TOPDOWN_ALLOCATION;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_CONTIGUOUS_ALLOCATION =
+ GPU_BUDDY_CONTIGUOUS_ALLOCATION;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_CLEAR_ALLOCATION = GPU_BUDDY_CLEAR_ALLOCATION;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_CLEARED = GPU_BUDDY_CLEARED;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_TRIM_DISABLE = GPU_BUDDY_TRIM_DISABLE;
+#endif
+
#if IS_ENABLED(CONFIG_ANDROID_BINDER_IPC_RUST)
#include "../../drivers/android/binder/rust_binder.h"
#include "../../drivers/android/binder/rust_binder_events.h"
diff --git a/rust/helpers/gpu.c b/rust/helpers/gpu.c
new file mode 100644
index 000000000000..38b1a4e6bef8
--- /dev/null
+++ b/rust/helpers/gpu.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/gpu_buddy.h>
+
+#ifdef CONFIG_GPU_BUDDY
+
+__rust_helper u64 rust_helper_gpu_buddy_block_offset(const struct gpu_buddy_block *block)
+{
+ return gpu_buddy_block_offset(block);
+}
+
+__rust_helper unsigned int rust_helper_gpu_buddy_block_order(struct gpu_buddy_block *block)
+{
+ return gpu_buddy_block_order(block);
+}
+
+__rust_helper u64 rust_helper_gpu_buddy_block_size(struct gpu_buddy *mm,
+ struct gpu_buddy_block *block)
+{
+ return gpu_buddy_block_size(mm, block);
+}
+
+#endif /* CONFIG_GPU_BUDDY */
diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c
index 724fcb8240ac..a53929ce52a3 100644
--- a/rust/helpers/helpers.c
+++ b/rust/helpers/helpers.c
@@ -32,6 +32,7 @@
#include "err.c"
#include "irq.c"
#include "fs.c"
+#include "gpu.c"
#include "io.c"
#include "jump_label.c"
#include "kunit.c"
diff --git a/rust/kernel/gpu/buddy.rs b/rust/kernel/gpu/buddy.rs
new file mode 100644
index 000000000000..082dc79ab247
--- /dev/null
+++ b/rust/kernel/gpu/buddy.rs
@@ -0,0 +1,611 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! GPU buddy allocator bindings.
+//!
+//! C header: [`include/linux/gpu_buddy.h`](srctree/include/linux/gpu_buddy.h)
+//!
+//! This module provides Rust abstractions over the Linux kernel's GPU buddy
+//! allocator, which implements a binary buddy memory allocator.
+//!
+//! The buddy allocator manages a contiguous address space and allocates blocks
+//! in power-of-two sizes, useful for GPU physical memory management.
+//!
+//! # Examples
+//!
+//! Create a buddy allocator and perform a basic range allocation:
+//!
+//! ```
+//! use kernel::{
+//! gpu::buddy::{GpuBuddy, GpuBuddyAllocMode, GpuBuddyAllocFlags, GpuBuddyParams},
+//! prelude::*,
+//! ptr::Alignment,
+//! sizes::*, //
+//! };
+//!
+//! // Create a 1GB buddy allocator with 4KB minimum chunk size.
+//! let buddy = GpuBuddy::new(GpuBuddyParams {
+//! base_offset: 0,
+//! physical_memory_size: SZ_1G as u64,
+//! chunk_size: SZ_4K,
+//! })?;
+//!
+//! assert_eq!(buddy.size(), SZ_1G as u64);
+//! assert_eq!(buddy.chunk_size(), SZ_4K);
+//! let initial_free = buddy.free_memory();
+//!
+//! // Allocate 16MB, results in a single 16MB block at offset 0.
+//! let allocated = KBox::pin_init(
+//! buddy.alloc_blocks(
+//! GpuBuddyAllocMode::Range { start: 0, end: 0 },
+//! SZ_16M,
+//! Alignment::new::<SZ_16M>(),
+//! GpuBuddyFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//! assert_eq!(buddy.free_memory(), initial_free - SZ_16M as u64);
+//!
+//! let block = allocated.iter().next().expect("expected one block");
+//! assert_eq!(block.offset(), 0);
+//! assert_eq!(block.order(), 12); // 2^12 pages = 16MB
+//! assert_eq!(block.size(), SZ_16M);
+//!
+//! // Dropping the allocation returns the memory to the buddy allocator.
+//! drop(allocated);
+//! assert_eq!(buddy.free_memory(), initial_free);
+//! # Ok::<(), Error>(())
+//! ```
+//!
+//! Top-down allocation allocates from the highest addresses:
+//!
+//! ```
+//! # use kernel::{
+//! # gpu::buddy::{GpuBuddy, GpuBuddyAllocMode, GpuBuddyAllocFlags, GpuBuddyParams},
+//! # prelude::*,
+//! # ptr::Alignment,
+//! # sizes::*, //
+//! # };
+//! # let buddy = GpuBuddy::new(GpuBuddyParams {
+//! # base_offset: 0,
+//! # physical_memory_size: SZ_1G as u64,
+//! # chunk_size: SZ_4K,
+//! # })?;
+//! # let initial_free = buddy.free_memory();
+//! let topdown = KBox::pin_init(
+//! buddy.alloc_blocks(
+//! GpuBuddyAllocMode::TopDown,
+//! SZ_16M,
+//! Alignment::new::<SZ_16M>(),
+//! GpuBuddyFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//! assert_eq!(buddy.free_memory(), initial_free - SZ_16M as u64);
+//!
+//! let block = topdown.iter().next().expect("expected one block");
+//! assert_eq!(block.offset(), (SZ_1G - SZ_16M) as u64);
+//! assert_eq!(block.order(), 12);
+//! assert_eq!(block.size(), SZ_16M);
+//!
+//! // Dropping the allocation returns the memory to the buddy allocator.
+//! drop(topdown);
+//! assert_eq!(buddy.free_memory(), initial_free);
+//! # Ok::<(), Error>(())
+//! ```
+//!
+//! Non-contiguous allocation can fill fragmented memory by returning multiple
+//! blocks:
+//!
+//! ```
+//! # use kernel::{
+//! # gpu::buddy::{
+//! # GpuBuddy, GpuBuddyAllocFlags, GpuBuddyAllocMode, GpuBuddyParams,
+//! # },
+//! # prelude::*,
+//! # ptr::Alignment,
+//! # sizes::*, //
+//! # };
+//! # let buddy = GpuBuddy::new(GpuBuddyParams {
+//! # base_offset: 0,
+//! # physical_memory_size: SZ_1G as u64,
+//! # chunk_size: SZ_4K,
+//! # })?;
+//! # let initial_free = buddy.free_memory();
+//! // Create fragmentation by allocating 4MB blocks at [0,4M) and [8M,12M).
+//! let frag1 = KBox::pin_init(
+//! buddy.alloc_blocks(
+//! GpuBuddyAllocMode::Range { start: 0, end: SZ_4M as u64 },
+//! SZ_4M,
+//! Alignment::new::<SZ_4M>(),
+//! GpuBuddyFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//! assert_eq!(buddy.free_memory(), initial_free - SZ_4M as u64);
+//!
+//! let frag2 = KBox::pin_init(
+//! buddy.alloc_blocks(
+//! GpuBuddyAllocMode::Range {
+//! start: SZ_8M as u64,
+//! end: (SZ_8M + SZ_4M) as u64,
+//! },
+//! SZ_4M,
+//! Alignment::new::<SZ_4M>(),
+//! GpuBuddyFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//! assert_eq!(buddy.free_memory(), initial_free - SZ_8M as u64);
+//!
+//! // Allocate 8MB, this returns 2 blocks from the holes.
+//! let fragmented = KBox::pin_init(
+//! buddy.alloc_blocks(
+//! GpuBuddyAllocMode::Range { start: 0, end: SZ_16M as u64 },
+//! SZ_8M,
+//! Alignment::new::<SZ_4M>(),
+//! GpuBuddyFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//! assert_eq!(buddy.free_memory(), initial_free - SZ_16M as u64);
+//!
+//! let (mut count, mut total) = (0u32, 0usize);
+//! for block in fragmented.iter() {
+//! assert_eq!(block.size(), SZ_4M);
+//! total += block.size();
+//! count += 1;
+//! }
+//! assert_eq!(total, SZ_8M);
+//! assert_eq!(count, 2);
+//! # Ok::<(), Error>(())
+//! ```
+//!
+//! Contiguous allocation fails when only fragmented space is available:
+//!
+//! ```
+//! # use kernel::{
+//! # gpu::buddy::{
+//! # GpuBuddy, GpuBuddyAllocFlag, GpuBuddyAllocMode, GpuBuddyParams,
+//! # },
+//! # prelude::*,
+//! # ptr::Alignment,
+//! # sizes::*, //
+//! # };
+//! // Create a small 16MB buddy allocator with fragmented memory.
+//! let small = GpuBuddy::new(GpuBuddyParams {
+//! base_offset: 0,
+//! physical_memory_size: SZ_16M as u64,
+//! chunk_size: SZ_4K,
+//! })?;
+//!
+//! let _hole1 = KBox::pin_init(
+//! small.alloc_blocks(
+//! GpuBuddyAllocMode::Range { start: 0, end: SZ_4M as u64 },
+//! SZ_4M,
+//! Alignment::new::<SZ_4M>(),
+//! GpuBuddyFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//!
+//! let _hole2 = KBox::pin_init(
+//! small.alloc_blocks(
+//! GpuBuddyAllocMode::Range {
+//! start: SZ_8M as u64,
+//! end: (SZ_8M + SZ_4M) as u64,
+//! },
+//! SZ_4M,
+//! Alignment::new::<SZ_4M>(),
+//! GpuBuddyFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//!
+//! // 8MB contiguous should fail, only two non-contiguous 4MB holes exist.
+//! let result = KBox::pin_init(
+//! small.alloc_blocks(
+//! GpuBuddyAllocMode::Simple,
+//! SZ_8M,
+//! Alignment::new::<SZ_4M>(),
+//! GpuBuddyAllocFlag::Contiguous.into(),
+//! ),
+//! GFP_KERNEL,
+//! );
+//! assert!(result.is_err());
+//! # Ok::<(), Error>(())
+//! ```
+
+use crate::{
+ bindings,
+ clist_create,
+ error::to_result,
+ interop::list::CListHead,
+ new_mutex,
+ prelude::*,
+ ptr::Alignment,
+ sync::{
+ lock::mutex::MutexGuard,
+ Arc,
+ Mutex, //
+ },
+ types::Opaque, //
+};
+
+/// Allocation mode for the GPU buddy allocator.
+///
+/// The mode determines the primary allocation strategy. Modes are mutually
+/// exclusive: an allocation is either simple, range-constrained, or top-down.
+///
+/// Orthogonal modifier flags (e.g., contiguous, clear) are specified separately
+/// via [`GpuBuddyAllocFlags`].
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub enum GpuBuddyAllocMode {
+ /// Simple allocation without constraints.
+ Simple,
+ /// Range-based allocation between `start` and `end` addresses.
+ Range {
+ /// Start of the allocation range.
+ start: u64,
+ /// End of the allocation range.
+ end: u64,
+ },
+ /// Allocate from top of address space downward.
+ TopDown,
+}
+
+impl GpuBuddyAllocMode {
+ // Returns the C flags corresponding to the allocation mode.
+ fn into_flags(self) -> usize {
+ match self {
+ Self::Simple => 0,
+ Self::Range { .. } => bindings::GPU_BUDDY_RANGE_ALLOCATION as usize,
+ Self::TopDown => bindings::GPU_BUDDY_TOPDOWN_ALLOCATION as usize,
+ }
+ }
+
+ // Extracts the range start/end, defaulting to (0, 0) for non-range modes.
+ fn range(self) -> (u64, u64) {
+ match self {
+ Self::Range { start, end } => (start, end),
+ _ => (0, 0),
+ }
+ }
+}
+
+crate::impl_flags!(
+ /// Modifier flags for GPU buddy allocation.
+ ///
+ /// These flags can be combined with any [`GpuBuddyAllocMode`] to control
+ /// additional allocation behavior.
+ #[derive(Clone, Copy, Default, PartialEq, Eq)]
+ pub struct GpuBuddyAllocFlags(u32);
+
+ /// Individual modifier flag for GPU buddy allocation.
+ #[derive(Clone, Copy, PartialEq, Eq)]
+ pub enum GpuBuddyAllocFlag {
+ /// Allocate physically contiguous blocks.
+ Contiguous = bindings::GPU_BUDDY_CONTIGUOUS_ALLOCATION as u32,
+
+ /// Request allocation from cleared (zeroed) memory.
+ Clear = bindings::GPU_BUDDY_CLEAR_ALLOCATION as u32,
+
+ /// Disable trimming of partially used blocks.
+ TrimDisable = bindings::GPU_BUDDY_TRIM_DISABLE as u32,
+ }
+);
+
+/// Parameters for creating a GPU buddy allocator.
+pub struct GpuBuddyParams {
+ /// Base offset (in bytes) where the managed memory region starts.
+ /// Allocations will be offset by this value.
+ pub base_offset: u64,
+ /// Total physical memory size (in bytes) managed by the allocator.
+ pub physical_memory_size: u64,
+ /// Minimum allocation unit / chunk size (in bytes), must be >= 4KB.
+ pub chunk_size: usize,
+}
+
+/// Inner structure holding the actual buddy allocator.
+///
+/// # Synchronization
+///
+/// The C `gpu_buddy` API requires synchronization (see `include/linux/gpu_buddy.h`).
+/// [`GpuBuddyGuard`] ensures that the lock is held for all
+/// allocator and free operations, preventing races between concurrent allocations
+/// and the freeing that occurs when [`AllocatedBlocks`] is dropped.
+///
+/// # Invariants
+///
+/// The inner [`Opaque`] contains an initialized buddy allocator.
+#[pin_data(PinnedDrop)]
+struct GpuBuddyInner {
+ #[pin]
+ inner: Opaque<bindings::gpu_buddy>,
+
+ // TODO: Replace `Mutex<()>` with `Mutex<Opaque<..>>` once `Mutex::new()`
+ // accepts `impl PinInit<T>`.
+ #[pin]
+ lock: Mutex<()>,
+ /// Cached creation parameters (do not change after init).
+ params: GpuBuddyParams,
+}
+
+impl GpuBuddyInner {
+ /// Create a pin-initializer for the buddy allocator.
+ fn new(params: GpuBuddyParams) -> impl PinInit<Self, Error> {
+ let size = params.physical_memory_size;
+ let chunk_size = params.chunk_size;
+
+ // INVARIANT: `gpu_buddy_init` returns 0 on success, at which point the
+ // `gpu_buddy` structure is initialized and ready for use with all
+ // `gpu_buddy_*` APIs. `try_pin_init!` only completes if all fields succeed,
+ // so the invariant holds when construction finishes.
+ try_pin_init!(Self {
+ inner <- Opaque::try_ffi_init(|ptr| {
+ // SAFETY: `ptr` points to valid uninitialized memory from the pin-init
+ // infrastructure. `gpu_buddy_init` will initialize the structure.
+ to_result(unsafe { bindings::gpu_buddy_init(ptr, size, chunk_size as u64) })
+ }),
+ lock <- new_mutex!(()),
+ params,
+ })
+ }
+
+ /// Lock the mutex and return a guard for accessing the allocator.
+ fn lock(&self) -> GpuBuddyGuard<'_> {
+ GpuBuddyGuard {
+ inner: self,
+ _guard: self.lock.lock(),
+ }
+ }
+}
+
+#[pinned_drop]
+impl PinnedDrop for GpuBuddyInner {
+ fn drop(self: Pin<&mut Self>) {
+ let guard = self.lock();
+
+ // SAFETY: Per the type invariant, `inner` contains an initialized
+ // allocator. `guard` provides exclusive access.
+ unsafe {
+ bindings::gpu_buddy_fini(guard.as_raw());
+ }
+ }
+}
+
+// SAFETY: GpuBuddyInner can be sent between threads.
+unsafe impl Send for GpuBuddyInner {}
+
+// SAFETY: `GpuBuddyInner` is `Sync` because `GpuBuddyInner::lock`
+// serializes all access to the C allocator, preventing data races.
+unsafe impl Sync for GpuBuddyInner {}
+
+// Guard that proves the lock is held, enabling access to the allocator.
+// The `_guard` holds the lock for the duration of this guard's lifetime.
+struct GpuBuddyGuard<'a> {
+ inner: &'a GpuBuddyInner,
+ _guard: MutexGuard<'a, ()>,
+}
+
+impl GpuBuddyGuard<'_> {
+ /// Get a raw pointer to the underlying C `gpu_buddy` structure.
+ fn as_raw(&self) -> *mut bindings::gpu_buddy {
+ self.inner.inner.get()
+ }
+}
+
+/// GPU buddy allocator instance.
+///
+/// This structure wraps the C `gpu_buddy` allocator using reference counting.
+/// The allocator is automatically cleaned up when all references are dropped.
+///
+/// Refer to the module-level documentation for usage examples.
+pub struct GpuBuddy(Arc<GpuBuddyInner>);
+
+impl GpuBuddy {
+ /// Create a new buddy allocator.
+ ///
+ /// Creates a buddy allocator that manages a contiguous address space of the given
+ /// size, with the specified minimum allocation unit (chunk_size must be at least 4KB).
+ pub fn new(params: GpuBuddyParams) -> Result<Self> {
+ Ok(Self(Arc::pin_init(GpuBuddyInner::new(params), GFP_KERNEL)?))
+ }
+
+ /// Get the base offset for allocations.
+ pub fn base_offset(&self) -> u64 {
+ self.0.params.base_offset
+ }
+
+ /// Get the chunk size (minimum allocation unit).
+ pub fn chunk_size(&self) -> usize {
+ self.0.params.chunk_size
+ }
+
+ /// Get the total managed size.
+ pub fn size(&self) -> u64 {
+ self.0.params.physical_memory_size
+ }
+
+ /// Get the available (free) memory in bytes.
+ pub fn free_memory(&self) -> u64 {
+ let guard = self.0.lock();
+
+ // SAFETY: Per the type invariant, `inner` contains an initialized allocator.
+ // `guard` provides exclusive access.
+ unsafe { (*guard.as_raw()).avail }
+ }
+
+ /// Allocate blocks from the buddy allocator.
+ ///
+ /// Returns a pin-initializer for [`AllocatedBlocks`].
+ ///
+ /// Takes `&self` instead of `&mut self` because the internal [`Mutex`] provides
+ /// synchronization - no external `&mut` exclusivity needed.
+ pub fn alloc_blocks(
+ &self,
+ mode: GpuBuddyAllocMode,
+ size: usize,
+ min_block_size: Alignment,
+ flags: GpuBuddyAllocFlags,
+ ) -> impl PinInit<AllocatedBlocks, Error> {
+ let buddy_arc = Arc::clone(&self.0);
+ let (start, end) = mode.range();
+ let mode_flags = mode.into_flags();
+ let modifier_flags = u32::from(flags) as usize;
+
+ // Create pin-initializer that initializes list and allocates blocks.
+ try_pin_init!(AllocatedBlocks {
+ buddy: buddy_arc,
+ list <- CListHead::new(),
+ _: {
+ // Lock while allocating to serialize with concurrent frees.
+ let guard = buddy.lock();
+
+ // SAFETY: Per the type invariant, `inner` contains an initialized
+ // allocator. `guard` provides exclusive access.
+ to_result(unsafe {
+ bindings::gpu_buddy_alloc_blocks(
+ guard.as_raw(),
+ start,
+ end,
+ size as u64,
+ min_block_size.as_usize() as u64,
+ list.as_raw(),
+ mode_flags | modifier_flags,
+ )
+ })?
+ }
+ })
+ }
+}
+
+/// Allocated blocks from the buddy allocator with automatic cleanup.
+///
+/// This structure owns a list of allocated blocks and ensures they are
+/// automatically freed when dropped. Use `iter()` to iterate over all
+/// allocated blocks.
+///
+/// # Invariants
+///
+/// - `list` is an initialized, valid list head containing allocated blocks.
+#[pin_data(PinnedDrop)]
+pub struct AllocatedBlocks {
+ #[pin]
+ list: CListHead,
+ buddy: Arc<GpuBuddyInner>,
+}
+
+impl AllocatedBlocks {
+ /// Check if the block list is empty.
+ pub fn is_empty(&self) -> bool {
+ // An empty list head points to itself.
+ !self.list.is_linked()
+ }
+
+ /// Iterate over allocated blocks.
+ ///
+ /// Returns an iterator yielding [`AllocatedBlock`] values. Each [`AllocatedBlock`]
+ /// borrows `self` and is only valid for the duration of that borrow.
+ pub fn iter(&self) -> impl Iterator<Item = AllocatedBlock<'_>> + '_ {
+ // SAFETY:
+ // - Per the type invariant, `list` is an initialized sentinel `list_head`
+ // and is not concurrently modified (we hold a `&self` borrow).
+ // - The list contains `gpu_buddy_block` items linked via
+ // `__bindgen_anon_1.link`.
+ // - `Block` is `#[repr(transparent)]` over `gpu_buddy_block`.
+ let clist = clist_create!(unsafe {
+ self.list.as_raw(),
+ Block,
+ bindings::gpu_buddy_block,
+ __bindgen_anon_1.link
+ });
+
+ clist
+ .iter()
+ .map(|this| AllocatedBlock { this, blocks: self })
+ }
+}
+
+#[pinned_drop]
+impl PinnedDrop for AllocatedBlocks {
+ fn drop(self: Pin<&mut Self>) {
+ let guard = self.buddy.lock();
+
+ // SAFETY:
+ // - list is valid per the type's invariants.
+ // - guard provides exclusive access to the allocator.
+ unsafe {
+ bindings::gpu_buddy_free_list(guard.as_raw(), self.list.as_raw(), 0);
+ }
+ }
+}
+
+/// A GPU buddy block.
+///
+/// Transparent wrapper over C `gpu_buddy_block` structure. This type is returned
+/// as references during iteration over [`AllocatedBlocks`].
+///
+/// # Invariants
+///
+/// The inner [`Opaque`] contains a valid, allocated `gpu_buddy_block`.
+#[repr(transparent)]
+struct Block(Opaque<bindings::gpu_buddy_block>);
+
+impl Block {
+ /// Get a raw pointer to the underlying C block.
+ fn as_raw(&self) -> *mut bindings::gpu_buddy_block {
+ self.0.get()
+ }
+
+ /// Get the block's raw offset in the buddy address space (without base offset).
+ fn offset(&self) -> u64 {
+ // SAFETY: `self.as_raw()` is valid per the type's invariants.
+ unsafe { bindings::gpu_buddy_block_offset(self.as_raw()) }
+ }
+
+ /// Get the block order.
+ fn order(&self) -> u32 {
+ // SAFETY: `self.as_raw()` is valid per the type's invariants.
+ unsafe { bindings::gpu_buddy_block_order(self.as_raw()) }
+ }
+}
+
+// SAFETY: `Block` is a wrapper around `gpu_buddy_block` which can be
+// sent across threads safely.
+unsafe impl Send for Block {}
+
+// SAFETY: `Block` is only accessed through shared references after
+// allocation, and thus safe to access concurrently across threads.
+unsafe impl Sync for Block {}
+
+/// A buddy block paired with its owning [`AllocatedBlocks`] context.
+///
+/// Unlike a raw block, which only knows its offset within the buddy address
+/// space, an [`AllocatedBlock`] also has access to the allocator's `base_offset`
+/// and `chunk_size`, enabling it to compute absolute offsets and byte sizes.
+///
+/// Returned by [`AllocatedBlocks::iter()`].
+pub struct AllocatedBlock<'a> {
+ this: &'a Block,
+ blocks: &'a AllocatedBlocks,
+}
+
+impl AllocatedBlock<'_> {
+ /// Get the block's offset in the address space.
+ ///
+ /// Returns the absolute offset including the allocator's base offset.
+ /// This is the actual address to use for accessing the allocated memory.
+ pub fn offset(&self) -> u64 {
+ self.blocks.buddy.params.base_offset + self.this.offset()
+ }
+
+ /// Get the block order (size = chunk_size << order).
+ pub fn order(&self) -> u32 {
+ self.this.order()
+ }
+
+ /// Get the block's size in bytes.
+ pub fn size(&self) -> usize {
+ self.blocks.buddy.params.chunk_size << self.this.order()
+ }
+}
diff --git a/rust/kernel/gpu/mod.rs b/rust/kernel/gpu/mod.rs
new file mode 100644
index 000000000000..8f25e6367edc
--- /dev/null
+++ b/rust/kernel/gpu/mod.rs
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! GPU subsystem abstractions.
+
+pub mod buddy;
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index bb741f1e0dfd..63e3f656eb6c 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -98,6 +98,8 @@
pub mod firmware;
pub mod fmt;
pub mod fs;
+#[cfg(CONFIG_GPU_BUDDY = "y")]
+pub mod gpu;
#[cfg(CONFIG_I2C = "y")]
pub mod i2c;
pub mod id_pool;
--
2.34.1
^ permalink raw reply related
* [PATCH] staging: sm750fb: fix static const char * warning
From: sluisr @ 2026-03-09 0:28 UTC (permalink / raw)
To: sudipm.mukherjee, teddy.wang
Cc: gregkh, linux-fbdev, linux-staging, linux-kernel, sluisr
This patch fixes a checkpatch.pl warning:
WARNING: static const char * array should probably be static const char * const
by adding the missing const keyword to the g_fbmode array declaration.
Signed-off-by: sluisr <contact@sluisr.com>
---
drivers/staging/sm750fb/sm750.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/staging/sm750fb/sm750.c b/drivers/staging/sm750fb/sm750.c
index dec1f6b88..08d4979c6 100644
--- a/drivers/staging/sm750fb/sm750.c
+++ b/drivers/staging/sm750fb/sm750.c
@@ -33,7 +33,7 @@
static int g_hwcursor = 1;
static int g_noaccel;
static int g_nomtrr;
-static const char *g_fbmode[] = {NULL, NULL};
+static const char * const g_fbmode[] = {NULL, NULL};
static const char *g_def_fbmode = "1024x768-32@60";
static char *g_settings;
static int g_dualview;
--
2.53.0
^ permalink raw reply related
* [PATCH] staging: sm750fb: constify g_fbmode array
From: dipesh chaudhary @ 2026-03-09 9:49 UTC (permalink / raw)
To: sudipm.mukherjee, teddy.wang, gregkh
Cc: linux-fbdev, linux-staging, linux-kernel, dipesh chaudhary
Fix checkpatch warning for static const char array. Make the array of pointers read-only to improve memory safety.
Signed-off-by: dipesh chaudhary <me@dipeshchaudhary.in>
---
Makefile | 6 +++---
drivers/staging/sm750fb/sm750.c | 2 +-
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/Makefile b/Makefile
index df471d4212cc..e944c6e71e81 100644
--- a/Makefile
+++ b/Makefile
@@ -1,8 +1,8 @@
# SPDX-License-Identifier: GPL-2.0
-VERSION = 6
-PATCHLEVEL = 19
+VERSION = 7
+PATCHLEVEL = 0
SUBLEVEL = 0
-EXTRAVERSION =
+EXTRAVERSION = -rc1
NAME = Baby Opossum Posse
# *DOCUMENTATION*
diff --git a/drivers/staging/sm750fb/sm750.c b/drivers/staging/sm750fb/sm750.c
index dec1f6b88a7d..08d4979c6755 100644
--- a/drivers/staging/sm750fb/sm750.c
+++ b/drivers/staging/sm750fb/sm750.c
@@ -33,7 +33,7 @@
static int g_hwcursor = 1;
static int g_noaccel;
static int g_nomtrr;
-static const char *g_fbmode[] = {NULL, NULL};
+static const char * const g_fbmode[] = {NULL, NULL};
static const char *g_def_fbmode = "1024x768-32@60";
static char *g_settings;
static int g_dualview;
--
2.47.3
^ permalink raw reply related
* Re: [PATCH] staging: sm750fb: constify g_fbmode array
From: Greg KH @ 2026-03-09 9:56 UTC (permalink / raw)
To: dipesh chaudhary
Cc: sudipm.mukherjee, teddy.wang, linux-fbdev, linux-staging,
linux-kernel
In-Reply-To: <9e566c42-8ec3-4d06-91be-0489de4e91c0@smtp-relay.sendinblue.com>
On Mon, Mar 09, 2026 at 09:49:57AM +0000, dipesh chaudhary wrote:
>
> Fix checkpatch warning for static const char array. Make the array of pointers read-only to improve memory safety.
>
> Signed-off-by: dipesh chaudhary <me@dipeshchaudhary.in>
> ---
> Makefile | 6 +++---
> drivers/staging/sm750fb/sm750.c | 2 +-
> 2 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index df471d4212cc..e944c6e71e81 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1,8 +1,8 @@
> # SPDX-License-Identifier: GPL-2.0
> -VERSION = 6
> -PATCHLEVEL = 19
> +VERSION = 7
> +PATCHLEVEL = 0
> SUBLEVEL = 0
> -EXTRAVERSION =
> +EXTRAVERSION = -rc1
> NAME = Baby Opossum Posse
>
> # *DOCUMENTATION*
Why have you changed the Makefile?
And did you test-build your change?
thanks,
greg k-h
^ permalink raw reply
* Re: [PATCH] staging: sm750fb: constify g_fbmode array
From: dipesh chaudhary @ 2026-03-09 10:06 UTC (permalink / raw)
To: gregkh
Cc: sudipm.mukherjee, teddy.wang, linux-fbdev, linux-staging,
linux-kernel
Hi Greg,
On Mon, Mar 09, 2026 at 09:49:57AM +0000, dipesh chaudhary wrote:
> --- a/Makefile
> +++ b/Makefile
> @@ -1,8 +1,8 @@
> # SPDX-License-Identifier: GPL-2.0
> -VERSION = 6
> -PATCHLEVEL = 19
> +VERSION = 7
> +PATCHLEVEL = 0
> SUBLEVEL = 0
> -EXTRAVERSION =
> +EXTRAVERSION = -rc1
> Why have you changed the Makefile?
I sincerely apologize for that. This is my very first kernel patch, and I was experimenting with the Makefile earlier on my local machine. I accidentally staged and included it in my commit alongside the driver fix without realizing it.
> And did you test-build your change?
To be completely honest, no. I only ran `checkpatch.pl` to verify the warning was resolved.
I will clean up my Git tree, figure out how to test-build the specific sm750 module locally, and then submit a clean v2 patch. Thank you for your patience with a beginner.
Best regards,
Dipesh Chaudhary
^ permalink raw reply
* Re: [PATCH] staging: sm750fb: constify g_fbmode array
From: dipesh chaudhary @ 2026-03-09 10:13 UTC (permalink / raw)
To: gregkh
Cc: sudipm.mukherjee, teddy.wang, linux-fbdev, linux-staging,
linux-kernel
Hi Greg,
You were absolutely right. I just set up my local build environment and ran `make drivers/staging/sm750fb/sm750.o`, and it immediately threw `error: assignment of read-only location`.
I fell into the classic checkpatch trap. I blindly applied the `const` suggestion without checking the surrounding code, failing to realize the driver dynamically writes to `g_fbmode` during runtime in `sm750fb_setup` and `lynxfb_set_fbinfo`.
Thank you for pushing me to test-build. I will drop this patch entirely, as the checkpatch warning is a false positive here. I have learned a valuable lesson about not trusting static analysis scripts over actually reading the C code and compiling it.
Best regards,
Dipesh Chaudhary
^ permalink raw reply
* [PATCH v12.1 0/1] Rust GPU buddy allocator bindings
From: Joel Fernandes @ 2026-03-09 13:53 UTC (permalink / raw)
To: linux-kernel
Cc: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Dave Airlie, Daniel Almeida, Koen Koning,
dri-devel, nouveau, rust-for-linux, Nikola Djukic,
Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, David Airlie,
Simona Vetter, Jonathan Corbet, Alex Deucher,
Christian König, Jani Nikula, Joonas Lahtinen, Rodrigo Vivi,
Tvrtko Ursulin, Huang Rui, Matthew Auld, Matthew Brost,
Lucas De Marchi, Thomas Hellström, Helge Deller, Alex Gaynor,
Boqun Feng, John Hubbard, Alistair Popple, Timur Tabi, Edwin Peer,
Alexandre Courbot, Andrea Righi, Andy Ritger, Zhi Wang,
Balbir Singh, Philipp Stanner, Elle Rhumsaa, alexeyi,
Eliot Courtney, joel, linux-doc, amd-gfx, intel-gfx, intel-xe,
linux-fbdev, Joel Fernandes
In-Reply-To: <20260308180407.3988286-1-joelagnelf@nvidia.com>
This patch adds safe Rust abstractions over the Linux kernel's GPU buddy
allocator for physical memory management. The prerequisite infrastructure
patches (DRM buddy code movement and the uninitialized buddy fix) have been
absorbed into upstream -next, so this is now a standalone patch.
The git tree with all patches can be found at:
git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux.git (tag: gpu-buddy-bindings-v12.1-20260309)
Change log:
Changes from v12 to v12.1:
- Fixed undeclared type `GpuBuddyFlags` in doc examples: renamed to
`GpuBuddyAllocFlags` in all seven doc test examples (found by kernel
test robot).
Changes from v11 to v12:
- Rebased on linux-next; this is now a standalone single patch as dependencies
are absorbed (but clist is a prerequisite).
- Redesigned allocation API (Alexandre Courbot) for better Rust ergonomics.
- Split single long example into 4 self-contained examples (Alexandre Courbot).
- Several safety and invariant comment changes (Danilo).
- MAINTAINERS changes (Arun, Mathew, Danilo, Dave).
- Fixed `#[cfg(CONFIG_GPU_BUDDY)]` to `#[cfg(CONFIG_GPU_BUDDY = "y")]` (Danilo Krummrich).
- Updated `ffi::clist::CListHead` to `interop::list::CListHead`.
Changes from v10 to v11:
- Dropped "rust: ffi: Convert pub use to pub mod and create ffi module" patch;
the ffi module restructuring will go through a different path.
- Dropped "rust: clist: Add support to interface with C linked lists" patch;
the clist module will be submitted separately.
- Dropped "nova-core: Kconfig: Sort select statements alphabetically" cosmetic
patch.
- Patches 1-3 (DRM buddy movement and fix) are included as reference only;
they are already being pulled into upstream via drm-misc-next.
- Removed clist patches as those can go in independently (Alice).
- Moved the Kconfig GPU_BUDDY selection patch to nova-core mm series to enable
it when it is actually used.
- Various nits to comments, etc.
Changes from v9 to v10:
- Absorbed the DRM buddy code movement patches into this series as patches 1-2.
Dave Airlie reworked these into two parts for better git history.
- Added "gpu: Fix uninitialized buddy for built-in drivers" fix by Koen Koning,
using subsys_initcall instead of module_init to fix NULL pointer dereference
when built-in drivers use the buddy allocator before initialization.
- Added "rust: ffi: Convert pub use to pub mod and create ffi module" to prepare
the ffi module for hosting clist as a sub-module.
- Moved clist from rust/kernel/clist.rs to rust/kernel/ffi/.
- Added "nova-core: Kconfig: Sort select statements alphabetically" (Danilo).
Changes from v8 to v9:
- Updated nova-core Kconfig patch: addressed sorting of Kconfig options.
- Added Daniel Almeida's Reviewed-by tag to clist patch.
- Minor refinements to GPU buddy bindings.
Changes from v7 to v8:
- Added nova-core Kconfig patch to select GPU_BUDDY for VRAM allocation.
- Various changes suggested by Danilo Krummrich, Gary Guo, and Daniel Almeida.
- Added Acked-by: Gary Guo for clist patch.
Changes from v6 to v7:
- Major restructuring: split the large 26-patch v6 RFC series. v7 only contains
the Rust infrastructure patches (clist + GPU buddy bindings), extracted from
the full nova-core MM series. The nova-core MM patches follow separately.
- Rebased on linux-next.
Link to v12: https://lore.kernel.org/all/20260308180407.3988286-1-joelagnelf@nvidia.com/
Link to v11: https://lore.kernel.org/all/20260224224005.3232841-1-joelagnelf@nvidia.com/
Joel Fernandes (1):
rust: gpu: Add GPU buddy allocator bindings
MAINTAINERS | 6 +-
rust/bindings/bindings_helper.h | 11 +
rust/helpers/gpu.c | 23 ++
rust/helpers/helpers.c | 1 +
rust/kernel/gpu/buddy.rs | 611 ++++++++++++++++++++++++++++++++
rust/kernel/gpu/mod.rs | 5 +
rust/kernel/lib.rs | 2 +
7 files changed, 658 insertions(+), 1 deletion(-)
create mode 100644 rust/helpers/gpu.c
create mode 100644 rust/kernel/gpu/buddy.rs
create mode 100644 rust/kernel/gpu/mod.rs
--
2.34.1
^ permalink raw reply
* [PATCH v12.1 1/1] rust: gpu: Add GPU buddy allocator bindings
From: Joel Fernandes @ 2026-03-09 13:53 UTC (permalink / raw)
To: linux-kernel
Cc: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Dave Airlie, Daniel Almeida, Koen Koning,
dri-devel, nouveau, rust-for-linux, Nikola Djukic,
Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, David Airlie,
Simona Vetter, Jonathan Corbet, Alex Deucher,
Christian König, Jani Nikula, Joonas Lahtinen, Rodrigo Vivi,
Tvrtko Ursulin, Huang Rui, Matthew Auld, Matthew Brost,
Lucas De Marchi, Thomas Hellström, Helge Deller, Alex Gaynor,
Boqun Feng, John Hubbard, Alistair Popple, Timur Tabi, Edwin Peer,
Alexandre Courbot, Andrea Righi, Andy Ritger, Zhi Wang,
Balbir Singh, Philipp Stanner, Elle Rhumsaa, alexeyi,
Eliot Courtney, joel, linux-doc, amd-gfx, intel-gfx, intel-xe,
linux-fbdev, Joel Fernandes
In-Reply-To: <20260309135338.3919996-1-joelagnelf@nvidia.com>
Add safe Rust abstractions over the Linux kernel's GPU buddy
allocator for physical memory management. The GPU buddy allocator
implements a binary buddy system useful for GPU physical memory
allocation. nova-core will use it for physical memory allocation.
Christian Koenig mentioned he'd like to step down from reviewer role for
GPU buddy so updated accordingly. Arun/Matthew agree on the modified entry.
Cc: Nikola Djukic <ndjukic@nvidia.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
---
MAINTAINERS | 6 +-
rust/bindings/bindings_helper.h | 11 +
rust/helpers/gpu.c | 23 ++
rust/helpers/helpers.c | 1 +
rust/kernel/gpu/buddy.rs | 611 ++++++++++++++++++++++++++++++++
rust/kernel/gpu/mod.rs | 5 +
rust/kernel/lib.rs | 2 +
7 files changed, 658 insertions(+), 1 deletion(-)
create mode 100644 rust/helpers/gpu.c
create mode 100644 rust/kernel/gpu/buddy.rs
create mode 100644 rust/kernel/gpu/mod.rs
diff --git a/MAINTAINERS b/MAINTAINERS
index 4c66f8261ff2..b2600dd05fc2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8513,7 +8513,9 @@ T: git https://gitlab.freedesktop.org/drm/rust/kernel.git
F: drivers/gpu/drm/nova/
F: drivers/gpu/drm/tyr/
F: drivers/gpu/nova-core/
+F: rust/helpers/gpu.c
F: rust/kernel/drm/
+F: rust/kernel/gpu/
DRM DRIVERS FOR ALLWINNER A10
M: Chen-Yu Tsai <wens@kernel.org>
@@ -8926,7 +8928,7 @@ F: include/drm/ttm/
GPU BUDDY ALLOCATOR
M: Matthew Auld <matthew.auld@intel.com>
M: Arun Pravin <arunpravin.paneerselvam@amd.com>
-R: Christian Koenig <christian.koenig@amd.com>
+R: Joel Fernandes <joelagnelf@nvidia.com>
L: dri-devel@lists.freedesktop.org
S: Maintained
T: git https://gitlab.freedesktop.org/drm/misc/kernel.git
@@ -8935,6 +8937,8 @@ F: drivers/gpu/buddy.c
F: drivers/gpu/tests/gpu_buddy_test.c
F: include/linux/gpu_buddy.h
F: include/drm/drm_buddy.h
+F: rust/helpers/gpu.c
+F: rust/kernel/gpu/
DRM AUTOMATED TESTING
M: Helen Koike <helen.fornazier@gmail.com>
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index 083cc44aa952..dbb765a9fdbd 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -29,6 +29,7 @@
#include <linux/hrtimer_types.h>
#include <linux/acpi.h>
+#include <linux/gpu_buddy.h>
#include <drm/drm_device.h>
#include <drm/drm_drv.h>
#include <drm/drm_file.h>
@@ -146,6 +147,16 @@ const vm_flags_t RUST_CONST_HELPER_VM_MIXEDMAP = VM_MIXEDMAP;
const vm_flags_t RUST_CONST_HELPER_VM_HUGEPAGE = VM_HUGEPAGE;
const vm_flags_t RUST_CONST_HELPER_VM_NOHUGEPAGE = VM_NOHUGEPAGE;
+#if IS_ENABLED(CONFIG_GPU_BUDDY)
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_RANGE_ALLOCATION = GPU_BUDDY_RANGE_ALLOCATION;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_TOPDOWN_ALLOCATION = GPU_BUDDY_TOPDOWN_ALLOCATION;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_CONTIGUOUS_ALLOCATION =
+ GPU_BUDDY_CONTIGUOUS_ALLOCATION;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_CLEAR_ALLOCATION = GPU_BUDDY_CLEAR_ALLOCATION;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_CLEARED = GPU_BUDDY_CLEARED;
+const unsigned long RUST_CONST_HELPER_GPU_BUDDY_TRIM_DISABLE = GPU_BUDDY_TRIM_DISABLE;
+#endif
+
#if IS_ENABLED(CONFIG_ANDROID_BINDER_IPC_RUST)
#include "../../drivers/android/binder/rust_binder.h"
#include "../../drivers/android/binder/rust_binder_events.h"
diff --git a/rust/helpers/gpu.c b/rust/helpers/gpu.c
new file mode 100644
index 000000000000..38b1a4e6bef8
--- /dev/null
+++ b/rust/helpers/gpu.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/gpu_buddy.h>
+
+#ifdef CONFIG_GPU_BUDDY
+
+__rust_helper u64 rust_helper_gpu_buddy_block_offset(const struct gpu_buddy_block *block)
+{
+ return gpu_buddy_block_offset(block);
+}
+
+__rust_helper unsigned int rust_helper_gpu_buddy_block_order(struct gpu_buddy_block *block)
+{
+ return gpu_buddy_block_order(block);
+}
+
+__rust_helper u64 rust_helper_gpu_buddy_block_size(struct gpu_buddy *mm,
+ struct gpu_buddy_block *block)
+{
+ return gpu_buddy_block_size(mm, block);
+}
+
+#endif /* CONFIG_GPU_BUDDY */
diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c
index 724fcb8240ac..a53929ce52a3 100644
--- a/rust/helpers/helpers.c
+++ b/rust/helpers/helpers.c
@@ -32,6 +32,7 @@
#include "err.c"
#include "irq.c"
#include "fs.c"
+#include "gpu.c"
#include "io.c"
#include "jump_label.c"
#include "kunit.c"
diff --git a/rust/kernel/gpu/buddy.rs b/rust/kernel/gpu/buddy.rs
new file mode 100644
index 000000000000..9027c9a7778f
--- /dev/null
+++ b/rust/kernel/gpu/buddy.rs
@@ -0,0 +1,611 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! GPU buddy allocator bindings.
+//!
+//! C header: [`include/linux/gpu_buddy.h`](srctree/include/linux/gpu_buddy.h)
+//!
+//! This module provides Rust abstractions over the Linux kernel's GPU buddy
+//! allocator, which implements a binary buddy memory allocator.
+//!
+//! The buddy allocator manages a contiguous address space and allocates blocks
+//! in power-of-two sizes, useful for GPU physical memory management.
+//!
+//! # Examples
+//!
+//! Create a buddy allocator and perform a basic range allocation:
+//!
+//! ```
+//! use kernel::{
+//! gpu::buddy::{GpuBuddy, GpuBuddyAllocMode, GpuBuddyAllocFlags, GpuBuddyParams},
+//! prelude::*,
+//! ptr::Alignment,
+//! sizes::*, //
+//! };
+//!
+//! // Create a 1GB buddy allocator with 4KB minimum chunk size.
+//! let buddy = GpuBuddy::new(GpuBuddyParams {
+//! base_offset: 0,
+//! physical_memory_size: SZ_1G as u64,
+//! chunk_size: SZ_4K,
+//! })?;
+//!
+//! assert_eq!(buddy.size(), SZ_1G as u64);
+//! assert_eq!(buddy.chunk_size(), SZ_4K);
+//! let initial_free = buddy.free_memory();
+//!
+//! // Allocate 16MB, results in a single 16MB block at offset 0.
+//! let allocated = KBox::pin_init(
+//! buddy.alloc_blocks(
+//! GpuBuddyAllocMode::Range { start: 0, end: 0 },
+//! SZ_16M,
+//! Alignment::new::<SZ_16M>(),
+//! GpuBuddyAllocFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//! assert_eq!(buddy.free_memory(), initial_free - SZ_16M as u64);
+//!
+//! let block = allocated.iter().next().expect("expected one block");
+//! assert_eq!(block.offset(), 0);
+//! assert_eq!(block.order(), 12); // 2^12 pages = 16MB
+//! assert_eq!(block.size(), SZ_16M);
+//!
+//! // Dropping the allocation returns the memory to the buddy allocator.
+//! drop(allocated);
+//! assert_eq!(buddy.free_memory(), initial_free);
+//! # Ok::<(), Error>(())
+//! ```
+//!
+//! Top-down allocation allocates from the highest addresses:
+//!
+//! ```
+//! # use kernel::{
+//! # gpu::buddy::{GpuBuddy, GpuBuddyAllocMode, GpuBuddyAllocFlags, GpuBuddyParams},
+//! # prelude::*,
+//! # ptr::Alignment,
+//! # sizes::*, //
+//! # };
+//! # let buddy = GpuBuddy::new(GpuBuddyParams {
+//! # base_offset: 0,
+//! # physical_memory_size: SZ_1G as u64,
+//! # chunk_size: SZ_4K,
+//! # })?;
+//! # let initial_free = buddy.free_memory();
+//! let topdown = KBox::pin_init(
+//! buddy.alloc_blocks(
+//! GpuBuddyAllocMode::TopDown,
+//! SZ_16M,
+//! Alignment::new::<SZ_16M>(),
+//! GpuBuddyAllocFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//! assert_eq!(buddy.free_memory(), initial_free - SZ_16M as u64);
+//!
+//! let block = topdown.iter().next().expect("expected one block");
+//! assert_eq!(block.offset(), (SZ_1G - SZ_16M) as u64);
+//! assert_eq!(block.order(), 12);
+//! assert_eq!(block.size(), SZ_16M);
+//!
+//! // Dropping the allocation returns the memory to the buddy allocator.
+//! drop(topdown);
+//! assert_eq!(buddy.free_memory(), initial_free);
+//! # Ok::<(), Error>(())
+//! ```
+//!
+//! Non-contiguous allocation can fill fragmented memory by returning multiple
+//! blocks:
+//!
+//! ```
+//! # use kernel::{
+//! # gpu::buddy::{
+//! # GpuBuddy, GpuBuddyAllocFlags, GpuBuddyAllocMode, GpuBuddyParams,
+//! # },
+//! # prelude::*,
+//! # ptr::Alignment,
+//! # sizes::*, //
+//! # };
+//! # let buddy = GpuBuddy::new(GpuBuddyParams {
+//! # base_offset: 0,
+//! # physical_memory_size: SZ_1G as u64,
+//! # chunk_size: SZ_4K,
+//! # })?;
+//! # let initial_free = buddy.free_memory();
+//! // Create fragmentation by allocating 4MB blocks at [0,4M) and [8M,12M).
+//! let frag1 = KBox::pin_init(
+//! buddy.alloc_blocks(
+//! GpuBuddyAllocMode::Range { start: 0, end: SZ_4M as u64 },
+//! SZ_4M,
+//! Alignment::new::<SZ_4M>(),
+//! GpuBuddyAllocFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//! assert_eq!(buddy.free_memory(), initial_free - SZ_4M as u64);
+//!
+//! let frag2 = KBox::pin_init(
+//! buddy.alloc_blocks(
+//! GpuBuddyAllocMode::Range {
+//! start: SZ_8M as u64,
+//! end: (SZ_8M + SZ_4M) as u64,
+//! },
+//! SZ_4M,
+//! Alignment::new::<SZ_4M>(),
+//! GpuBuddyAllocFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//! assert_eq!(buddy.free_memory(), initial_free - SZ_8M as u64);
+//!
+//! // Allocate 8MB, this returns 2 blocks from the holes.
+//! let fragmented = KBox::pin_init(
+//! buddy.alloc_blocks(
+//! GpuBuddyAllocMode::Range { start: 0, end: SZ_16M as u64 },
+//! SZ_8M,
+//! Alignment::new::<SZ_4M>(),
+//! GpuBuddyAllocFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//! assert_eq!(buddy.free_memory(), initial_free - SZ_16M as u64);
+//!
+//! let (mut count, mut total) = (0u32, 0usize);
+//! for block in fragmented.iter() {
+//! assert_eq!(block.size(), SZ_4M);
+//! total += block.size();
+//! count += 1;
+//! }
+//! assert_eq!(total, SZ_8M);
+//! assert_eq!(count, 2);
+//! # Ok::<(), Error>(())
+//! ```
+//!
+//! Contiguous allocation fails when only fragmented space is available:
+//!
+//! ```
+//! # use kernel::{
+//! # gpu::buddy::{
+//! # GpuBuddy, GpuBuddyAllocFlag, GpuBuddyAllocMode, GpuBuddyParams,
+//! # },
+//! # prelude::*,
+//! # ptr::Alignment,
+//! # sizes::*, //
+//! # };
+//! // Create a small 16MB buddy allocator with fragmented memory.
+//! let small = GpuBuddy::new(GpuBuddyParams {
+//! base_offset: 0,
+//! physical_memory_size: SZ_16M as u64,
+//! chunk_size: SZ_4K,
+//! })?;
+//!
+//! let _hole1 = KBox::pin_init(
+//! small.alloc_blocks(
+//! GpuBuddyAllocMode::Range { start: 0, end: SZ_4M as u64 },
+//! SZ_4M,
+//! Alignment::new::<SZ_4M>(),
+//! GpuBuddyAllocFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//!
+//! let _hole2 = KBox::pin_init(
+//! small.alloc_blocks(
+//! GpuBuddyAllocMode::Range {
+//! start: SZ_8M as u64,
+//! end: (SZ_8M + SZ_4M) as u64,
+//! },
+//! SZ_4M,
+//! Alignment::new::<SZ_4M>(),
+//! GpuBuddyAllocFlags::default(),
+//! ),
+//! GFP_KERNEL,
+//! )?;
+//!
+//! // 8MB contiguous should fail, only two non-contiguous 4MB holes exist.
+//! let result = KBox::pin_init(
+//! small.alloc_blocks(
+//! GpuBuddyAllocMode::Simple,
+//! SZ_8M,
+//! Alignment::new::<SZ_4M>(),
+//! GpuBuddyAllocFlag::Contiguous.into(),
+//! ),
+//! GFP_KERNEL,
+//! );
+//! assert!(result.is_err());
+//! # Ok::<(), Error>(())
+//! ```
+
+use crate::{
+ bindings,
+ clist_create,
+ error::to_result,
+ interop::list::CListHead,
+ new_mutex,
+ prelude::*,
+ ptr::Alignment,
+ sync::{
+ lock::mutex::MutexGuard,
+ Arc,
+ Mutex, //
+ },
+ types::Opaque, //
+};
+
+/// Allocation mode for the GPU buddy allocator.
+///
+/// The mode determines the primary allocation strategy. Modes are mutually
+/// exclusive: an allocation is either simple, range-constrained, or top-down.
+///
+/// Orthogonal modifier flags (e.g., contiguous, clear) are specified separately
+/// via [`GpuBuddyAllocFlags`].
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub enum GpuBuddyAllocMode {
+ /// Simple allocation without constraints.
+ Simple,
+ /// Range-based allocation between `start` and `end` addresses.
+ Range {
+ /// Start of the allocation range.
+ start: u64,
+ /// End of the allocation range.
+ end: u64,
+ },
+ /// Allocate from top of address space downward.
+ TopDown,
+}
+
+impl GpuBuddyAllocMode {
+ // Returns the C flags corresponding to the allocation mode.
+ fn into_flags(self) -> usize {
+ match self {
+ Self::Simple => 0,
+ Self::Range { .. } => bindings::GPU_BUDDY_RANGE_ALLOCATION as usize,
+ Self::TopDown => bindings::GPU_BUDDY_TOPDOWN_ALLOCATION as usize,
+ }
+ }
+
+ // Extracts the range start/end, defaulting to (0, 0) for non-range modes.
+ fn range(self) -> (u64, u64) {
+ match self {
+ Self::Range { start, end } => (start, end),
+ _ => (0, 0),
+ }
+ }
+}
+
+crate::impl_flags!(
+ /// Modifier flags for GPU buddy allocation.
+ ///
+ /// These flags can be combined with any [`GpuBuddyAllocMode`] to control
+ /// additional allocation behavior.
+ #[derive(Clone, Copy, Default, PartialEq, Eq)]
+ pub struct GpuBuddyAllocFlags(u32);
+
+ /// Individual modifier flag for GPU buddy allocation.
+ #[derive(Clone, Copy, PartialEq, Eq)]
+ pub enum GpuBuddyAllocFlag {
+ /// Allocate physically contiguous blocks.
+ Contiguous = bindings::GPU_BUDDY_CONTIGUOUS_ALLOCATION as u32,
+
+ /// Request allocation from cleared (zeroed) memory.
+ Clear = bindings::GPU_BUDDY_CLEAR_ALLOCATION as u32,
+
+ /// Disable trimming of partially used blocks.
+ TrimDisable = bindings::GPU_BUDDY_TRIM_DISABLE as u32,
+ }
+);
+
+/// Parameters for creating a GPU buddy allocator.
+pub struct GpuBuddyParams {
+ /// Base offset (in bytes) where the managed memory region starts.
+ /// Allocations will be offset by this value.
+ pub base_offset: u64,
+ /// Total physical memory size (in bytes) managed by the allocator.
+ pub physical_memory_size: u64,
+ /// Minimum allocation unit / chunk size (in bytes), must be >= 4KB.
+ pub chunk_size: usize,
+}
+
+/// Inner structure holding the actual buddy allocator.
+///
+/// # Synchronization
+///
+/// The C `gpu_buddy` API requires synchronization (see `include/linux/gpu_buddy.h`).
+/// [`GpuBuddyGuard`] ensures that the lock is held for all
+/// allocator and free operations, preventing races between concurrent allocations
+/// and the freeing that occurs when [`AllocatedBlocks`] is dropped.
+///
+/// # Invariants
+///
+/// The inner [`Opaque`] contains an initialized buddy allocator.
+#[pin_data(PinnedDrop)]
+struct GpuBuddyInner {
+ #[pin]
+ inner: Opaque<bindings::gpu_buddy>,
+
+ // TODO: Replace `Mutex<()>` with `Mutex<Opaque<..>>` once `Mutex::new()`
+ // accepts `impl PinInit<T>`.
+ #[pin]
+ lock: Mutex<()>,
+ /// Cached creation parameters (do not change after init).
+ params: GpuBuddyParams,
+}
+
+impl GpuBuddyInner {
+ /// Create a pin-initializer for the buddy allocator.
+ fn new(params: GpuBuddyParams) -> impl PinInit<Self, Error> {
+ let size = params.physical_memory_size;
+ let chunk_size = params.chunk_size;
+
+ // INVARIANT: `gpu_buddy_init` returns 0 on success, at which point the
+ // `gpu_buddy` structure is initialized and ready for use with all
+ // `gpu_buddy_*` APIs. `try_pin_init!` only completes if all fields succeed,
+ // so the invariant holds when construction finishes.
+ try_pin_init!(Self {
+ inner <- Opaque::try_ffi_init(|ptr| {
+ // SAFETY: `ptr` points to valid uninitialized memory from the pin-init
+ // infrastructure. `gpu_buddy_init` will initialize the structure.
+ to_result(unsafe { bindings::gpu_buddy_init(ptr, size, chunk_size as u64) })
+ }),
+ lock <- new_mutex!(()),
+ params,
+ })
+ }
+
+ /// Lock the mutex and return a guard for accessing the allocator.
+ fn lock(&self) -> GpuBuddyGuard<'_> {
+ GpuBuddyGuard {
+ inner: self,
+ _guard: self.lock.lock(),
+ }
+ }
+}
+
+#[pinned_drop]
+impl PinnedDrop for GpuBuddyInner {
+ fn drop(self: Pin<&mut Self>) {
+ let guard = self.lock();
+
+ // SAFETY: Per the type invariant, `inner` contains an initialized
+ // allocator. `guard` provides exclusive access.
+ unsafe {
+ bindings::gpu_buddy_fini(guard.as_raw());
+ }
+ }
+}
+
+// SAFETY: GpuBuddyInner can be sent between threads.
+unsafe impl Send for GpuBuddyInner {}
+
+// SAFETY: `GpuBuddyInner` is `Sync` because `GpuBuddyInner::lock`
+// serializes all access to the C allocator, preventing data races.
+unsafe impl Sync for GpuBuddyInner {}
+
+// Guard that proves the lock is held, enabling access to the allocator.
+// The `_guard` holds the lock for the duration of this guard's lifetime.
+struct GpuBuddyGuard<'a> {
+ inner: &'a GpuBuddyInner,
+ _guard: MutexGuard<'a, ()>,
+}
+
+impl GpuBuddyGuard<'_> {
+ /// Get a raw pointer to the underlying C `gpu_buddy` structure.
+ fn as_raw(&self) -> *mut bindings::gpu_buddy {
+ self.inner.inner.get()
+ }
+}
+
+/// GPU buddy allocator instance.
+///
+/// This structure wraps the C `gpu_buddy` allocator using reference counting.
+/// The allocator is automatically cleaned up when all references are dropped.
+///
+/// Refer to the module-level documentation for usage examples.
+pub struct GpuBuddy(Arc<GpuBuddyInner>);
+
+impl GpuBuddy {
+ /// Create a new buddy allocator.
+ ///
+ /// Creates a buddy allocator that manages a contiguous address space of the given
+ /// size, with the specified minimum allocation unit (chunk_size must be at least 4KB).
+ pub fn new(params: GpuBuddyParams) -> Result<Self> {
+ Ok(Self(Arc::pin_init(GpuBuddyInner::new(params), GFP_KERNEL)?))
+ }
+
+ /// Get the base offset for allocations.
+ pub fn base_offset(&self) -> u64 {
+ self.0.params.base_offset
+ }
+
+ /// Get the chunk size (minimum allocation unit).
+ pub fn chunk_size(&self) -> usize {
+ self.0.params.chunk_size
+ }
+
+ /// Get the total managed size.
+ pub fn size(&self) -> u64 {
+ self.0.params.physical_memory_size
+ }
+
+ /// Get the available (free) memory in bytes.
+ pub fn free_memory(&self) -> u64 {
+ let guard = self.0.lock();
+
+ // SAFETY: Per the type invariant, `inner` contains an initialized allocator.
+ // `guard` provides exclusive access.
+ unsafe { (*guard.as_raw()).avail }
+ }
+
+ /// Allocate blocks from the buddy allocator.
+ ///
+ /// Returns a pin-initializer for [`AllocatedBlocks`].
+ ///
+ /// Takes `&self` instead of `&mut self` because the internal [`Mutex`] provides
+ /// synchronization - no external `&mut` exclusivity needed.
+ pub fn alloc_blocks(
+ &self,
+ mode: GpuBuddyAllocMode,
+ size: usize,
+ min_block_size: Alignment,
+ flags: GpuBuddyAllocFlags,
+ ) -> impl PinInit<AllocatedBlocks, Error> {
+ let buddy_arc = Arc::clone(&self.0);
+ let (start, end) = mode.range();
+ let mode_flags = mode.into_flags();
+ let modifier_flags = u32::from(flags) as usize;
+
+ // Create pin-initializer that initializes list and allocates blocks.
+ try_pin_init!(AllocatedBlocks {
+ buddy: buddy_arc,
+ list <- CListHead::new(),
+ _: {
+ // Lock while allocating to serialize with concurrent frees.
+ let guard = buddy.lock();
+
+ // SAFETY: Per the type invariant, `inner` contains an initialized
+ // allocator. `guard` provides exclusive access.
+ to_result(unsafe {
+ bindings::gpu_buddy_alloc_blocks(
+ guard.as_raw(),
+ start,
+ end,
+ size as u64,
+ min_block_size.as_usize() as u64,
+ list.as_raw(),
+ mode_flags | modifier_flags,
+ )
+ })?
+ }
+ })
+ }
+}
+
+/// Allocated blocks from the buddy allocator with automatic cleanup.
+///
+/// This structure owns a list of allocated blocks and ensures they are
+/// automatically freed when dropped. Use `iter()` to iterate over all
+/// allocated blocks.
+///
+/// # Invariants
+///
+/// - `list` is an initialized, valid list head containing allocated blocks.
+#[pin_data(PinnedDrop)]
+pub struct AllocatedBlocks {
+ #[pin]
+ list: CListHead,
+ buddy: Arc<GpuBuddyInner>,
+}
+
+impl AllocatedBlocks {
+ /// Check if the block list is empty.
+ pub fn is_empty(&self) -> bool {
+ // An empty list head points to itself.
+ !self.list.is_linked()
+ }
+
+ /// Iterate over allocated blocks.
+ ///
+ /// Returns an iterator yielding [`AllocatedBlock`] values. Each [`AllocatedBlock`]
+ /// borrows `self` and is only valid for the duration of that borrow.
+ pub fn iter(&self) -> impl Iterator<Item = AllocatedBlock<'_>> + '_ {
+ // SAFETY:
+ // - Per the type invariant, `list` is an initialized sentinel `list_head`
+ // and is not concurrently modified (we hold a `&self` borrow).
+ // - The list contains `gpu_buddy_block` items linked via
+ // `__bindgen_anon_1.link`.
+ // - `Block` is `#[repr(transparent)]` over `gpu_buddy_block`.
+ let clist = clist_create!(unsafe {
+ self.list.as_raw(),
+ Block,
+ bindings::gpu_buddy_block,
+ __bindgen_anon_1.link
+ });
+
+ clist
+ .iter()
+ .map(|this| AllocatedBlock { this, blocks: self })
+ }
+}
+
+#[pinned_drop]
+impl PinnedDrop for AllocatedBlocks {
+ fn drop(self: Pin<&mut Self>) {
+ let guard = self.buddy.lock();
+
+ // SAFETY:
+ // - list is valid per the type's invariants.
+ // - guard provides exclusive access to the allocator.
+ unsafe {
+ bindings::gpu_buddy_free_list(guard.as_raw(), self.list.as_raw(), 0);
+ }
+ }
+}
+
+/// A GPU buddy block.
+///
+/// Transparent wrapper over C `gpu_buddy_block` structure. This type is returned
+/// as references during iteration over [`AllocatedBlocks`].
+///
+/// # Invariants
+///
+/// The inner [`Opaque`] contains a valid, allocated `gpu_buddy_block`.
+#[repr(transparent)]
+struct Block(Opaque<bindings::gpu_buddy_block>);
+
+impl Block {
+ /// Get a raw pointer to the underlying C block.
+ fn as_raw(&self) -> *mut bindings::gpu_buddy_block {
+ self.0.get()
+ }
+
+ /// Get the block's raw offset in the buddy address space (without base offset).
+ fn offset(&self) -> u64 {
+ // SAFETY: `self.as_raw()` is valid per the type's invariants.
+ unsafe { bindings::gpu_buddy_block_offset(self.as_raw()) }
+ }
+
+ /// Get the block order.
+ fn order(&self) -> u32 {
+ // SAFETY: `self.as_raw()` is valid per the type's invariants.
+ unsafe { bindings::gpu_buddy_block_order(self.as_raw()) }
+ }
+}
+
+// SAFETY: `Block` is a wrapper around `gpu_buddy_block` which can be
+// sent across threads safely.
+unsafe impl Send for Block {}
+
+// SAFETY: `Block` is only accessed through shared references after
+// allocation, and thus safe to access concurrently across threads.
+unsafe impl Sync for Block {}
+
+/// A buddy block paired with its owning [`AllocatedBlocks`] context.
+///
+/// Unlike a raw block, which only knows its offset within the buddy address
+/// space, an [`AllocatedBlock`] also has access to the allocator's `base_offset`
+/// and `chunk_size`, enabling it to compute absolute offsets and byte sizes.
+///
+/// Returned by [`AllocatedBlocks::iter()`].
+pub struct AllocatedBlock<'a> {
+ this: &'a Block,
+ blocks: &'a AllocatedBlocks,
+}
+
+impl AllocatedBlock<'_> {
+ /// Get the block's offset in the address space.
+ ///
+ /// Returns the absolute offset including the allocator's base offset.
+ /// This is the actual address to use for accessing the allocated memory.
+ pub fn offset(&self) -> u64 {
+ self.blocks.buddy.params.base_offset + self.this.offset()
+ }
+
+ /// Get the block order (size = chunk_size << order).
+ pub fn order(&self) -> u32 {
+ self.this.order()
+ }
+
+ /// Get the block's size in bytes.
+ pub fn size(&self) -> usize {
+ self.blocks.buddy.params.chunk_size << self.this.order()
+ }
+}
diff --git a/rust/kernel/gpu/mod.rs b/rust/kernel/gpu/mod.rs
new file mode 100644
index 000000000000..8f25e6367edc
--- /dev/null
+++ b/rust/kernel/gpu/mod.rs
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! GPU subsystem abstractions.
+
+pub mod buddy;
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index bb741f1e0dfd..63e3f656eb6c 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -98,6 +98,8 @@
pub mod firmware;
pub mod fmt;
pub mod fs;
+#[cfg(CONFIG_GPU_BUDDY = "y")]
+pub mod gpu;
#[cfg(CONFIG_I2C = "y")]
pub mod i2c;
pub mod id_pool;
--
2.34.1
^ permalink raw reply related
* [PATCH v3 00/13] vc,fbcon,fonts: Proper handling of font data
From: Thomas Zimmermann @ 2026-03-09 14:14 UTC (permalink / raw)
To: gregkh, deller, sam
Cc: linux-fbdev, dri-devel, linux-kernel, Thomas Zimmermann
Provide helpers for handling console font data. Update consoles and VT.
VT's vc_state stores font data as a plain byte array of glphys. Fbcon,
newport_con and the kernel's internal fonts store the glyph data as an
array of plain bytes plus a hidden header for reference counting, check
sums and buffer sizes. The reference counting only works for user-space
fonts but not for internal fonts. Font-data handling is duplicated in
several places. Most of the font handling is open-coded and mixed up with
VT's plain glyph arrays.
To address these issues, add proper handling of font data to all involved
components: struct vc_font for font state in VC; a font data type for the
consoles. Then implement interfaces for handling font data one by one.
Patch 1 prepares the fbdev interface.
Patches 2 to 4 prepare VT's font handling.
Patches 5 to 13 refactor fbcon and newport_con to use clean interfaces for
their fonts.
Fbcon has long been a source of problems and bug reports. [1] With its
confusing implementation, it is hard to find the cause of these bugs.
Cleaning up the fbcon code will hopefully help with resolving bug reports
in the future.
The series has been tested with fbcon under DRM's bochs driver by changing
fonts at runtime using the setfont utility. [2] The changes to newport_con
have only been tested to compile.
v3:
- fix module font linking (Nathan, Arnd)
- fix typos (Helge)
- clarify return value of font_data_put()
v2:
- keep declaring the internal fonts in the public header file (Helge)
- rebase and clean up
[1] https://lore.kernel.org/all/6992c84c.a70a0220.2c38d7.00e8.GAE@google.com/
[2] https://www.man7.org/linux/man-pages/man8/setfont.8.html
Thomas Zimmermann (13):
fbdev: Declare src parameter of fb_pad_ helpers as constant
vt: Remove trailing whitespaces
vt: Store font in struct vc_font
vt: Calculate font-buffer size with vc_font_size()
lib/fonts: Remove trailing whitespaces
lib/fonts: Remove FNTCHARCNT()
lib/fonts: Store font data as font_data_t; update consoles
lib/fonts: Read font size with font_data_size()
lib/fonts: Manage font-data lifetime with font_data_get/_put()
lib/fonts: Compare font data for equality with font_data_is_equal()
lib/fonts: Create font_data_t from struct console_font with
font_data_import()
lib/fonts: Store font data for user space with font_data_export()
lib/fonts: Remove internal symbols and macros from public header file
drivers/video/console/newport_con.c | 61 +++-----
drivers/video/fbdev/core/bitblit.c | 11 +-
drivers/video/fbdev/core/fbcon.c | 194 +++++++----------------
drivers/video/fbdev/core/fbcon.h | 8 +-
drivers/video/fbdev/core/fbmem.c | 6 +-
include/linux/console_struct.h | 59 ++++++-
include/linux/fb.h | 10 +-
include/linux/font.h | 115 +++++++++-----
lib/fonts/font.h | 38 +++++
lib/fonts/font_10x18.c | 2 +-
lib/fonts/font_6x10.c | 3 +-
lib/fonts/font_6x11.c | 2 +-
lib/fonts/font_6x8.c | 3 +-
lib/fonts/font_7x14.c | 2 +-
lib/fonts/font_8x16.c | 3 +-
lib/fonts/font_8x8.c | 2 +-
lib/fonts/font_acorn_8x8.c | 4 +-
lib/fonts/font_mini_4x6.c | 10 +-
lib/fonts/font_pearl_8x8.c | 2 +-
lib/fonts/font_sun12x22.c | 3 +-
lib/fonts/font_sun8x16.c | 3 +-
lib/fonts/font_ter10x18.c | 4 +-
lib/fonts/font_ter16x32.c | 4 +-
lib/fonts/fonts.c | 232 +++++++++++++++++++++++++++-
24 files changed, 514 insertions(+), 267 deletions(-)
create mode 100644 lib/fonts/font.h
base-commit: 3594e3a9ce7d4ad237f43ff907e9744446108603
prerequisite-patch-id: c67e5d886a47b7d0266d81100837557fda34cb24
prerequisite-patch-id: a5a973e527c88a5b47053d7a72aefe0b550197cb
prerequisite-patch-id: 719d09751d38f5da743beed6266585ee063e1e29
prerequisite-patch-id: 5030de433a01c2e99056cadb676a8e2ba35f055a
prerequisite-patch-id: f7831e8fe81681bbe7fcd7b8455753f5ab4ada2d
--
2.53.0
^ permalink raw reply
* [PATCH v3 04/13] vt: Calculate font-buffer size with vc_font_size()
From: Thomas Zimmermann @ 2026-03-09 14:14 UTC (permalink / raw)
To: gregkh, deller, sam
Cc: linux-fbdev, dri-devel, linux-kernel, Thomas Zimmermann
In-Reply-To: <20260309141723.137364-1-tzimmermann@suse.de>
In fbcon, fbcon_resize() computes the size of the font buffer from the
values stored in vc_font. Move these calculations to the dedicated helpers
vc_font_pitch() and vc_font_size().
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/video/fbdev/core/fbcon.c | 9 ++-------
include/linux/console_struct.h | 28 ++++++++++++++++++++++++++++
2 files changed, 30 insertions(+), 7 deletions(-)
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 247bb90c08d3..103e91c8d874 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -2037,7 +2037,6 @@ static void updatescrollmode(struct fbcon_display *p,
}
#define PITCH(w) (((w) + 7) >> 3)
-#define CALC_FONTSZ(h, p, c) ((h) * (p) * (c)) /* size = height * pitch * charcount */
static int fbcon_resize(struct vc_data *vc, unsigned int width,
unsigned int height, bool from_user)
@@ -2049,8 +2048,7 @@ static int fbcon_resize(struct vc_data *vc, unsigned int width,
int x_diff, y_diff, virt_w, virt_h, virt_fw, virt_fh;
if (p->userfont && FNTSIZE(vc->vc_font.data)) {
- int size;
- int pitch = PITCH(vc->vc_font.width);
+ unsigned int size = vc_font_size(&vc->vc_font);
/*
* If user font, ensure that a possible change to user font
@@ -2059,10 +2057,7 @@ static int fbcon_resize(struct vc_data *vc, unsigned int width,
* charcount can change and cannot be used to determine the
* font data allocated size.
*/
- if (pitch <= 0)
- return -EINVAL;
- size = CALC_FONTSZ(vc->vc_font.height, pitch, vc->vc_font.charcount);
- if (size > FNTSIZE(vc->vc_font.data))
+ if (!size || size > FNTSIZE(vc->vc_font.data))
return -EINVAL;
}
diff --git a/include/linux/console_struct.h b/include/linux/console_struct.h
index ea0cdf4278a3..771cba16cb54 100644
--- a/include/linux/console_struct.h
+++ b/include/linux/console_struct.h
@@ -83,6 +83,34 @@ struct vc_font {
const unsigned char *data;
};
+/**
+ * vc_font_pitch - Calculates the number of bytes between two adjacent scanlines
+ * @font: The VC font
+ *
+ * Returns:
+ * The number of bytes between two adjacent scanlines in the font data
+ */
+static inline unsigned int vc_font_pitch(const struct vc_font *font)
+{
+ return DIV_ROUND_UP(font->width, 8);
+}
+
+/**
+ * vc_font_size - Calculates the size of the font data in bytes
+ * @font: The VC font
+ *
+ * vc_font_size() calculates the number of bytes of font data in the
+ * font specified by @font. The function calculates the size from the
+ * font parameters.
+ *
+ * Returns:
+ * The size of the font data in bytes.
+ */
+static inline unsigned int vc_font_size(const struct vc_font *font)
+{
+ return font->height * vc_font_pitch(font) * font->charcount;
+}
+
/*
* Example: vc_data of a console that was scrolled 3 lines down.
*
--
2.53.0
^ permalink raw reply related
* [PATCH v3 01/13] fbdev: Declare src parameter of fb_pad_ helpers as constant
From: Thomas Zimmermann @ 2026-03-09 14:14 UTC (permalink / raw)
To: gregkh, deller, sam
Cc: linux-fbdev, dri-devel, linux-kernel, Thomas Zimmermann
In-Reply-To: <20260309141723.137364-1-tzimmermann@suse.de>
Fbdev's padding helpers do not modify the source buffer. Declare the
parameter as 'const'.
Fbcon's font-rendering code calls these helpers with the font data.
Declaring src as const will allow for making the font data constant
as well.
While at it, also remove the extern qualifier from the function
declarations in the header file.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/video/fbdev/core/fbmem.c | 6 +++---
include/linux/fb.h | 10 +++++-----
2 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index cf199038f069..30f2b59c47bf 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -91,14 +91,14 @@ EXPORT_SYMBOL(fb_get_color_depth);
/*
* Data padding functions.
*/
-void fb_pad_aligned_buffer(u8 *dst, u32 d_pitch, u8 *src, u32 s_pitch, u32 height)
+void fb_pad_aligned_buffer(u8 *dst, u32 d_pitch, const u8 *src, u32 s_pitch, u32 height)
{
__fb_pad_aligned_buffer(dst, d_pitch, src, s_pitch, height);
}
EXPORT_SYMBOL(fb_pad_aligned_buffer);
-void fb_pad_unaligned_buffer(u8 *dst, u32 d_pitch, u8 *src, u32 idx, u32 height,
- u32 shift_high, u32 shift_low, u32 mod)
+void fb_pad_unaligned_buffer(u8 *dst, u32 d_pitch, const u8 *src, u32 idx, u32 height,
+ u32 shift_high, u32 shift_low, u32 mod)
{
u8 mask = (u8) (0xff << shift_high), tmp;
int i, j;
diff --git a/include/linux/fb.h b/include/linux/fb.h
index 6d4a58084fd5..324b0fd5f617 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -605,9 +605,9 @@ extern int register_framebuffer(struct fb_info *fb_info);
extern void unregister_framebuffer(struct fb_info *fb_info);
extern int devm_register_framebuffer(struct device *dev, struct fb_info *fb_info);
extern char* fb_get_buffer_offset(struct fb_info *info, struct fb_pixmap *buf, u32 size);
-extern void fb_pad_unaligned_buffer(u8 *dst, u32 d_pitch, u8 *src, u32 idx,
- u32 height, u32 shift_high, u32 shift_low, u32 mod);
-extern void fb_pad_aligned_buffer(u8 *dst, u32 d_pitch, u8 *src, u32 s_pitch, u32 height);
+void fb_pad_unaligned_buffer(u8 *dst, u32 d_pitch, const u8 *src, u32 idx, u32 height,
+ u32 shift_high, u32 shift_low, u32 mod);
+void fb_pad_aligned_buffer(u8 *dst, u32 d_pitch, const u8 *src, u32 s_pitch, u32 height);
extern void fb_set_suspend(struct fb_info *info, int state);
extern int fb_get_color_depth(struct fb_var_screeninfo *var,
struct fb_fix_screeninfo *fix);
@@ -633,8 +633,8 @@ static inline struct device *dev_of_fbinfo(const struct fb_info *info)
#endif
}
-static inline void __fb_pad_aligned_buffer(u8 *dst, u32 d_pitch,
- u8 *src, u32 s_pitch, u32 height)
+static inline void __fb_pad_aligned_buffer(u8 *dst, u32 d_pitch, const u8 *src, u32 s_pitch,
+ u32 height)
{
u32 i, j;
--
2.53.0
^ permalink raw reply related
* [PATCH v3 06/13] lib/fonts: Remove FNTCHARCNT()
From: Thomas Zimmermann @ 2026-03-09 14:14 UTC (permalink / raw)
To: gregkh, deller, sam
Cc: linux-fbdev, dri-devel, linux-kernel, Thomas Zimmermann
In-Reply-To: <20260309141723.137364-1-tzimmermann@suse.de>
The character count in the font data is unused. The internal fonts also
do not set it. Remove FNTCHARCNT().
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/video/console/newport_con.c | 1 -
include/linux/font.h | 1 -
2 files changed, 2 deletions(-)
diff --git a/drivers/video/console/newport_con.c b/drivers/video/console/newport_con.c
index b178678566e7..e2922caa8685 100644
--- a/drivers/video/console/newport_con.c
+++ b/drivers/video/console/newport_con.c
@@ -516,7 +516,6 @@ static int newport_set_font(int unit, const struct console_font *op,
new_data += FONT_EXTRA_WORDS * sizeof(int);
FNTSIZE(new_data) = size;
- FNTCHARCNT(new_data) = op->charcount;
REFCOUNT(new_data) = 0; /* usage counter */
FNTSUM(new_data) = 0;
diff --git a/include/linux/font.h b/include/linux/font.h
index fd8625cd76b2..d929c5fa32ca 100644
--- a/include/linux/font.h
+++ b/include/linux/font.h
@@ -68,7 +68,6 @@ extern const struct font_desc *get_default_font(int xres, int yres,
/* Extra word getters */
#define REFCOUNT(fd) (((int *)(fd))[-1])
#define FNTSIZE(fd) (((int *)(fd))[-2])
-#define FNTCHARCNT(fd) (((int *)(fd))[-3])
#define FNTSUM(fd) (((int *)(fd))[-4])
#define FONT_EXTRA_WORDS 4
--
2.53.0
^ permalink raw reply related
* [PATCH v3 02/13] vt: Remove trailing whitespaces
From: Thomas Zimmermann @ 2026-03-09 14:14 UTC (permalink / raw)
To: gregkh, deller, sam
Cc: linux-fbdev, dri-devel, linux-kernel, Thomas Zimmermann
In-Reply-To: <20260309141723.137364-1-tzimmermann@suse.de>
Fix coding style. No functional changes.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
include/linux/console_struct.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/console_struct.h b/include/linux/console_struct.h
index 13b35637bd5a..ebdb9750d348 100644
--- a/include/linux/console_struct.h
+++ b/include/linux/console_struct.h
@@ -120,7 +120,7 @@ struct vc_data {
unsigned short vc_complement_mask; /* [#] Xor mask for mouse pointer */
unsigned short vc_s_complement_mask; /* Saved mouse pointer mask */
unsigned long vc_pos; /* Cursor address */
- /* fonts */
+ /* fonts */
unsigned short vc_hi_font_mask; /* [#] Attribute set for upper 256 chars of font or 0 if not supported */
struct console_font vc_font; /* Current VC font set */
unsigned short vc_video_erase_char; /* Background erase character */
--
2.53.0
^ permalink raw reply related
* [PATCH v3 07/13] lib/fonts: Store font data as font_data_t; update consoles
From: Thomas Zimmermann @ 2026-03-09 14:14 UTC (permalink / raw)
To: gregkh, deller, sam
Cc: linux-fbdev, dri-devel, linux-kernel, Thomas Zimmermann
In-Reply-To: <20260309141723.137364-1-tzimmermann@suse.de>
Store font data as pointer to font_data_t instead of unsigned char.
Update consoles.
Pointers to font data refer to the raw data. There is a hidden header
before the data that contains additional state. Document the existing
layout and semantics of font_data_t.
The data field in struct vc_font can be used by any console. Therefore
it still points to plain data without the additional header. Fbcon sets
its value from struct fbcon_display.fontdata. Hence, update the size
test in fbcon_resize() to use struct fbcon_display.fontdata instead of
struct vc_font.data.
v3:
- fix typos (Helge)
v2:
- 'Font lookup' -> 'Font description' in <linux/font.h>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/video/console/newport_con.c | 17 ++++++-----
drivers/video/fbdev/core/fbcon.c | 44 ++++++++++++++++-----------
drivers/video/fbdev/core/fbcon.h | 3 +-
include/linux/font.h | 47 ++++++++++++++++++++++++++++-
4 files changed, 84 insertions(+), 27 deletions(-)
diff --git a/drivers/video/console/newport_con.c b/drivers/video/console/newport_con.c
index e2922caa8685..9b9ed1940404 100644
--- a/drivers/video/console/newport_con.c
+++ b/drivers/video/console/newport_con.c
@@ -33,9 +33,9 @@
#define NEWPORT_LEN 0x10000
-#define FONT_DATA ((unsigned char *)font_vga_8x16.data)
+#define FONT_DATA font_vga_8x16.data
-static unsigned char *font_data[MAX_NR_CONSOLES];
+static font_data_t *font_data[MAX_NR_CONSOLES];
static struct newport_regs *npregs;
static unsigned long newport_addr;
@@ -370,9 +370,9 @@ static void newport_clear(struct vc_data *vc, unsigned int sy, unsigned int sx,
static void newport_putc(struct vc_data *vc, u16 charattr, unsigned int ypos,
unsigned int xpos)
{
- unsigned char *p;
+ const unsigned char *p;
- p = &font_data[vc->vc_num][(charattr & 0xff) << 4];
+ p = &font_data_buf(font_data[vc->vc_num])[(charattr & 0xff) << 4];
charattr = (charattr >> 8) & 0xff;
xpos <<= 3;
ypos <<= 4;
@@ -400,7 +400,7 @@ static void newport_putcs(struct vc_data *vc, const u16 *s,
unsigned int count, unsigned int ypos,
unsigned int xpos)
{
- unsigned char *p;
+ const unsigned char *p;
unsigned int i;
u16 charattr;
@@ -424,7 +424,7 @@ static void newport_putcs(struct vc_data *vc, const u16 *s,
NPORT_DMODE0_L32);
for (i = 0; i < count; i++, xpos += 8) {
- p = &font_data[vc->vc_num][(scr_readw(s++) & 0xff) << 4];
+ p = &font_data_buf(font_data[vc->vc_num])[(scr_readw(s++) & 0xff) << 4];
newport_wait(npregs);
@@ -503,7 +503,8 @@ static int newport_set_font(int unit, const struct console_font *op,
int h = op->height;
int size = h * op->charcount;
int i;
- unsigned char *new_data, *data = op->data, *p;
+ font_data_t *new_data;
+ unsigned char *data = op->data, *p;
/* ladis: when I grow up, there will be a day... and more sizes will
* be supported ;-) */
@@ -519,7 +520,7 @@ static int newport_set_font(int unit, const struct console_font *op,
REFCOUNT(new_data) = 0; /* usage counter */
FNTSUM(new_data) = 0;
- p = new_data;
+ p = (unsigned char *)font_data_buf(new_data);
for (i = 0; i < op->charcount; i++) {
memcpy(p, data, h);
data += 32;
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 103e91c8d874..8d7840b9ebad 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -1019,8 +1019,10 @@ static const char *fbcon_startup(void)
info->pixmap.blit_y);
vc->vc_font.width = font->width;
vc->vc_font.height = font->height;
- vc->vc_font.data = (void *)(p->fontdata = font->data);
+ vc->vc_font.data = font_data_buf(font->data);
vc->vc_font.charcount = font->charcount;
+
+ p->fontdata = font->data;
}
cols = FBCON_SWAP(par->rotate, info->var.xres, info->var.yres);
@@ -1078,11 +1080,12 @@ static void fbcon_init(struct vc_data *vc, bool init)
if (t->fontdata) {
struct vc_data *fvc = vc_cons[fg_console].d;
- vc->vc_font.data = (void *)(p->fontdata =
- fvc->vc_font.data);
+ vc->vc_font.data = fvc->vc_font.data;
vc->vc_font.width = fvc->vc_font.width;
vc->vc_font.height = fvc->vc_font.height;
vc->vc_font.charcount = fvc->vc_font.charcount;
+
+ p->fontdata = t->fontdata;
p->userfont = t->userfont;
if (p->userfont)
@@ -1097,8 +1100,10 @@ static void fbcon_init(struct vc_data *vc, bool init)
info->pixmap.blit_y);
vc->vc_font.width = font->width;
vc->vc_font.height = font->height;
- vc->vc_font.data = (void *)(p->fontdata = font->data);
+ vc->vc_font.data = font_data_buf(font->data);
vc->vc_font.charcount = font->charcount;
+
+ p->fontdata = font->data;
}
}
@@ -1409,11 +1414,12 @@ static void fbcon_set_disp(struct fb_info *info, struct fb_var_screeninfo *var,
svc = *default_mode;
t = &fb_display[svc->vc_num];
- if (!vc->vc_font.data) {
- vc->vc_font.data = (void *)(p->fontdata = t->fontdata);
+ if (!p->fontdata) {
+ vc->vc_font.data = font_data_buf(t->fontdata);
vc->vc_font.width = (*default_mode)->vc_font.width;
vc->vc_font.height = (*default_mode)->vc_font.height;
vc->vc_font.charcount = (*default_mode)->vc_font.charcount;
+ p->fontdata = t->fontdata;
p->userfont = t->userfont;
if (p->userfont)
REFCOUNT(p->fontdata)++;
@@ -2047,7 +2053,7 @@ static int fbcon_resize(struct vc_data *vc, unsigned int width,
struct fb_var_screeninfo var = info->var;
int x_diff, y_diff, virt_w, virt_h, virt_fw, virt_fh;
- if (p->userfont && FNTSIZE(vc->vc_font.data)) {
+ if (p->userfont && FNTSIZE(p->fontdata)) {
unsigned int size = vc_font_size(&vc->vc_font);
/*
@@ -2057,7 +2063,7 @@ static int fbcon_resize(struct vc_data *vc, unsigned int width,
* charcount can change and cannot be used to determine the
* font data allocated size.
*/
- if (!size || size > FNTSIZE(vc->vc_font.data))
+ if (!size || size > FNTSIZE(p->fontdata))
return -EINVAL;
}
@@ -2281,7 +2287,8 @@ static bool fbcon_blank(struct vc_data *vc, enum vesa_blank_mode blank,
static int fbcon_get_font(struct vc_data *vc, struct console_font *font, unsigned int vpitch)
{
- const u8 *fontdata = vc->vc_font.data;
+ struct fbcon_display *p = &fb_display[vc->vc_num];
+ font_data_t *fontdata = p->fontdata;
u8 *data = font->data;
int i, j;
@@ -2406,16 +2413,18 @@ static void set_vc_hi_font(struct vc_data *vc, bool set)
}
static int fbcon_do_set_font(struct vc_data *vc, int w, int h, int charcount,
- const u8 * data, int userfont)
+ font_data_t *data, int userfont)
{
struct fb_info *info = fbcon_info_from_console(vc->vc_num);
struct fbcon_par *par = info->fbcon_par;
struct fbcon_display *p = &fb_display[vc->vc_num];
int resize, ret, old_userfont, old_width, old_height, old_charcount;
+ font_data_t *old_fontdata = p->fontdata;
const u8 *old_data = vc->vc_font.data;
resize = (w != vc->vc_font.width) || (h != vc->vc_font.height);
- vc->vc_font.data = (void *)(p->fontdata = data);
+ p->fontdata = data;
+ vc->vc_font.data = font_data_buf(p->fontdata);
old_userfont = p->userfont;
if ((p->userfont = userfont))
REFCOUNT(data)++;
@@ -2448,12 +2457,12 @@ static int fbcon_do_set_font(struct vc_data *vc, int w, int h, int charcount,
update_screen(vc);
}
- if (old_userfont && (--REFCOUNT(old_data) == 0))
- kfree(old_data - FONT_EXTRA_WORDS * sizeof(int));
+ if (old_userfont && (--REFCOUNT(old_fontdata) == 0))
+ kfree(old_fontdata - FONT_EXTRA_WORDS * sizeof(int));
return 0;
err_out:
- p->fontdata = old_data;
+ p->fontdata = old_fontdata;
vc->vc_font.data = old_data;
if (userfont) {
@@ -2483,7 +2492,8 @@ static int fbcon_set_font(struct vc_data *vc, const struct console_font *font,
int h = font->height;
int size, alloc_size;
int i, csum;
- u8 *new_data, *data = font->data;
+ font_data_t *new_data;
+ u8 *data = font->data;
int pitch = PITCH(font->width);
/* Is there a reason why fbconsole couldn't handle any charcount >256?
@@ -2522,13 +2532,13 @@ static int fbcon_set_font(struct vc_data *vc, const struct console_font *font,
if (!new_data)
return -ENOMEM;
- memset(new_data, 0, FONT_EXTRA_WORDS * sizeof(int));
+ memset((u8 *)new_data, 0, FONT_EXTRA_WORDS * sizeof(int));
new_data += FONT_EXTRA_WORDS * sizeof(int);
FNTSIZE(new_data) = size;
REFCOUNT(new_data) = 0; /* usage counter */
for (i=0; i< charcount; i++) {
- memcpy(new_data + i*h*pitch, data + i*vpitch*pitch, h*pitch);
+ memcpy((u8 *)new_data + i * h * pitch, data + i * vpitch * pitch, h * pitch);
}
/* Since linux has a nice crc32 function use it for counting font
diff --git a/drivers/video/fbdev/core/fbcon.h b/drivers/video/fbdev/core/fbcon.h
index 3f4386a40237..d26ee7860cf5 100644
--- a/drivers/video/fbdev/core/fbcon.h
+++ b/drivers/video/fbdev/core/fbcon.h
@@ -11,6 +11,7 @@
#ifndef _VIDEO_FBCON_H
#define _VIDEO_FBCON_H
+#include <linux/font.h>
#include <linux/types.h>
#include <linux/vt_buffer.h>
#include <linux/vt_kern.h>
@@ -25,7 +26,7 @@
struct fbcon_display {
/* Filled in by the low-level console driver */
- const u_char *fontdata;
+ font_data_t *fontdata;
int userfont; /* != 0 if fontdata kmalloc()ed */
#ifdef CONFIG_FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION
u_short scrollmode; /* Scroll Method, use fb_scrollmode() */
diff --git a/include/linux/font.h b/include/linux/font.h
index d929c5fa32ca..746a0996a018 100644
--- a/include/linux/font.h
+++ b/include/linux/font.h
@@ -13,12 +13,57 @@
#include <linux/types.h>
+/*
+ * font_data_t and helpers
+ */
+
+/**
+ * font_data_t - Raw font data
+ *
+ * Values of type font_data_t store a pointer to raw font data. The format
+ * is monochrome. Each bit sets a pixel of a stored glyph. Font data does
+ * not store geometry information for the individual glyphs. Users of the
+ * font have to store glyph size, pitch and character count separately.
+ *
+ * Font data in font_data_t is not equivalent to raw u8. Each pointer stores
+ * an additional hidden header before the font data. The layout is
+ *
+ * +------+-----------------------------+
+ * | -16 | CRC32 Checksum (optional) |
+ * | -12 | <Unused> |
+ * | -8 | Number of data bytes |
+ * | -4 | Reference count |
+ * +------+-----------------------------+
+ * | 0 | Data buffer |
+ * | ... | |
+ * +------+-----------------------------+
+ *
+ * Use helpers to access font_data_t. Use font_data_buf() to get the stored data.
+ */
+typedef const unsigned char font_data_t;
+
+/**
+ * font_data_buf() - Returns the font data as raw bytes
+ * @fd: The font data
+ *
+ * Returns:
+ * The raw font data. The provided buffer is read-only.
+ */
+static inline const unsigned char *font_data_buf(font_data_t *fd)
+{
+ return (const unsigned char *)fd;
+}
+
+/*
+ * Font description
+ */
+
struct font_desc {
int idx;
const char *name;
unsigned int width, height;
unsigned int charcount;
- const void *data;
+ font_data_t *data;
int pref;
};
--
2.53.0
^ permalink raw reply related
* [PATCH v3 03/13] vt: Store font in struct vc_font
From: Thomas Zimmermann @ 2026-03-09 14:14 UTC (permalink / raw)
To: gregkh, deller, sam
Cc: linux-fbdev, dri-devel, linux-kernel, Thomas Zimmermann
In-Reply-To: <20260309141723.137364-1-tzimmermann@suse.de>
Replace struct console_font with struct vc_font for the type of the
vc_font field of struct vc_data. Struct console_font is UAPI, which
prevents further changes. Hence a new data type is required.
Struct console_font has a documented vertical pitch of 32 bytes. This
is not the case after the font data has been loaded into the kernel.
Changing the type of vc_font addresses this inconsistency.
The font data is now declared as constant, as it might come from the
kernel's read-only section. There's some fallout throughout the console
code where non-const variables refer to it. Fix them. A later update
will declare the font data to a dedicated data type.
v3:
- fix typos
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/video/fbdev/core/bitblit.c | 11 +++++------
drivers/video/fbdev/core/fbcon.c | 4 ++--
drivers/video/fbdev/core/fbcon.h | 4 ++--
include/linux/console_struct.h | 29 +++++++++++++++++++++++++++--
4 files changed, 36 insertions(+), 12 deletions(-)
diff --git a/drivers/video/fbdev/core/bitblit.c b/drivers/video/fbdev/core/bitblit.c
index 085ffb44c51a..7478accea8ec 100644
--- a/drivers/video/fbdev/core/bitblit.c
+++ b/drivers/video/fbdev/core/bitblit.c
@@ -22,8 +22,7 @@
/*
* Accelerated handlers.
*/
-static void update_attr(u8 *dst, u8 *src, int attribute,
- struct vc_data *vc)
+static void update_attr(u8 *dst, const u8 *src, int attribute, struct vc_data *vc)
{
int i, offset = (vc->vc_font.height < 10) ? 1 : 2;
int width = DIV_ROUND_UP(vc->vc_font.width, 8);
@@ -81,7 +80,7 @@ static inline void bit_putcs_aligned(struct vc_data *vc, struct fb_info *info,
u16 charmask = vc->vc_hi_font_mask ? 0x1ff : 0xff;
unsigned int charcnt = vc->vc_font.charcount;
u32 idx = vc->vc_font.width >> 3;
- u8 *src;
+ const u8 *src;
while (cnt--) {
u16 ch = scr_readw(s++) & charmask;
@@ -120,7 +119,7 @@ static inline void bit_putcs_unaligned(struct vc_data *vc,
u32 shift_low = 0, mod = vc->vc_font.width % 8;
u32 shift_high = 8;
u32 idx = vc->vc_font.width >> 3;
- u8 *src;
+ const u8 *src;
while (cnt--) {
u16 ch = scr_readw(s++) & charmask;
@@ -267,7 +266,7 @@ static void bit_cursor(struct vc_data *vc, struct fb_info *info, bool enable,
int y = real_y(par->p, vc->state.y);
int attribute, use_sw = vc->vc_cursor_type & CUR_SW;
int err = 1;
- char *src;
+ const u8 *src;
cursor.set = 0;
@@ -278,7 +277,7 @@ static void bit_cursor(struct vc_data *vc, struct fb_info *info, bool enable,
attribute = get_attribute(info, c);
src = vc->vc_font.data + ((c & charmask) * (w * vc->vc_font.height));
- if (par->cursor_state.image.data != src ||
+ if (par->cursor_state.image.data != (const char *)src ||
par->cursor_reset) {
par->cursor_state.image.data = src;
cursor.set |= FB_CUR_SETIMAGE;
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 666261ae59d8..247bb90c08d3 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -2286,7 +2286,7 @@ static bool fbcon_blank(struct vc_data *vc, enum vesa_blank_mode blank,
static int fbcon_get_font(struct vc_data *vc, struct console_font *font, unsigned int vpitch)
{
- u8 *fontdata = vc->vc_font.data;
+ const u8 *fontdata = vc->vc_font.data;
u8 *data = font->data;
int i, j;
@@ -2417,7 +2417,7 @@ static int fbcon_do_set_font(struct vc_data *vc, int w, int h, int charcount,
struct fbcon_par *par = info->fbcon_par;
struct fbcon_display *p = &fb_display[vc->vc_num];
int resize, ret, old_userfont, old_width, old_height, old_charcount;
- u8 *old_data = vc->vc_font.data;
+ const u8 *old_data = vc->vc_font.data;
resize = (w != vc->vc_font.width) || (h != vc->vc_font.height);
vc->vc_font.data = (void *)(p->fontdata = data);
diff --git a/drivers/video/fbdev/core/fbcon.h b/drivers/video/fbdev/core/fbcon.h
index fca14e9b729b..3f4386a40237 100644
--- a/drivers/video/fbdev/core/fbcon.h
+++ b/drivers/video/fbdev/core/fbcon.h
@@ -82,8 +82,8 @@ struct fbcon_par {
int rotate;
int cur_rotate;
char *cursor_data;
- u8 *fontbuffer;
- u8 *fontdata;
+ u8 *fontbuffer;
+ const u8 *fontdata;
u8 *cursor_src;
u32 cursor_size;
u32 fd_size;
diff --git a/include/linux/console_struct.h b/include/linux/console_struct.h
index ebdb9750d348..ea0cdf4278a3 100644
--- a/include/linux/console_struct.h
+++ b/include/linux/console_struct.h
@@ -13,8 +13,9 @@
#ifndef _LINUX_CONSOLE_STRUCT_H
#define _LINUX_CONSOLE_STRUCT_H
-#include <linux/wait.h>
+#include <linux/math.h>
#include <linux/vt.h>
+#include <linux/wait.h>
#include <linux/workqueue.h>
struct uni_pagedict;
@@ -58,6 +59,30 @@ struct vc_state {
bool reverse;
};
+/**
+ * struct vc_font - Describes a font
+ * @width: The width of a single glyph in bits
+ * @height: The height of a single glyph in scanlines
+ * @charcount: The number of glyphs in the font
+ * @data: The raw font data
+ *
+ * Font data is organized as an array of glyphs. Each glyph is a bitmap with
+ * set bits indicating the foreground color. Unset bits indicate background
+ * color. The fields @width and @height store a single glyph's number of
+ * horizontal bits and vertical scanlines. If width is not a multiple of 8,
+ * there are trailing bits to fill up the byte. These bits should not be drawn.
+ *
+ * The field @data points to the first glyph's first byte. The value @charcount
+ * gives the number of glyphs in the font. There are no empty scanlines between
+ * two adjacent glyphs.
+ */
+struct vc_font {
+ unsigned int width;
+ unsigned int height;
+ unsigned int charcount;
+ const unsigned char *data;
+};
+
/*
* Example: vc_data of a console that was scrolled 3 lines down.
*
@@ -122,7 +147,7 @@ struct vc_data {
unsigned long vc_pos; /* Cursor address */
/* fonts */
unsigned short vc_hi_font_mask; /* [#] Attribute set for upper 256 chars of font or 0 if not supported */
- struct console_font vc_font; /* Current VC font set */
+ struct vc_font vc_font; /* Current VC font set */
unsigned short vc_video_erase_char; /* Background erase character */
/* VT terminal data */
unsigned int vc_state; /* Escape sequence parser state */
--
2.53.0
^ permalink raw reply related
* [PATCH v3 09/13] lib/fonts: Manage font-data lifetime with font_data_get/_put()
From: Thomas Zimmermann @ 2026-03-09 14:14 UTC (permalink / raw)
To: gregkh, deller, sam
Cc: linux-fbdev, dri-devel, linux-kernel, Thomas Zimmermann
In-Reply-To: <20260309141723.137364-1-tzimmermann@suse.de>
Add font_data_get() and font_data_put(). Update consoles to use them
over REFCOUNT() and plain kfree().
Newly allocated font data starts with a reference count of 1. Loading
the font puts the previously loaded font. If the reference count reaches
zero, font_data_put() frees the font data.
The kernel stores a refcount of zero for internal font data. Invoking
font_data_get() and font_data_put() tests this internally and returns
success without further operation. From the caller's perspective,
getting and putting works the same for all font data.
Fbcon used the userfont flag distinguish between internal fonts and
fonts loaded by user space. Only the latter where refcounted. With the
new helper's automatic handling of internal font data, remove the
userfont flag from fbcon.
Newport_con uses a default font, FONT_DATA, until user space loads
custom font data. Remove all special cases for FONT_DATA, as the get
and put calls' read-only handling also covers this case.
v3:
- fix module linker error wrt font symbols (Nathan, Arnd)
- fix typos
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/video/console/newport_con.c | 23 +++------
drivers/video/fbdev/core/fbcon.c | 65 +++++++++++-------------
drivers/video/fbdev/core/fbcon.h | 1 -
include/linux/font.h | 2 +
lib/fonts/fonts.c | 77 ++++++++++++++++++++++++++++-
5 files changed, 115 insertions(+), 53 deletions(-)
diff --git a/drivers/video/console/newport_con.c b/drivers/video/console/newport_con.c
index 1198c6bc2777..43a1a4f41057 100644
--- a/drivers/video/console/newport_con.c
+++ b/drivers/video/console/newport_con.c
@@ -517,7 +517,7 @@ static int newport_set_font(int unit, const struct console_font *op,
new_data += FONT_EXTRA_WORDS * sizeof(int);
FNTSIZE(new_data) = size;
- REFCOUNT(new_data) = 0; /* usage counter */
+ REFCOUNT(new_data) = 1; /* usage counter */
FNTSUM(new_data) = 0;
p = (unsigned char *)font_data_buf(new_data);
@@ -532,21 +532,17 @@ static int newport_set_font(int unit, const struct console_font *op,
if (font_data[i] != FONT_DATA
&& font_data_size(font_data[i]) == size
&& !memcmp(font_data[i], new_data, size)) {
- kfree(new_data - FONT_EXTRA_WORDS * sizeof(int));
+ font_data_put(new_data);
/* current font is the same as the new one */
if (i == unit)
return 0;
new_data = font_data[i];
+ font_data_get(new_data);
break;
}
}
- /* old font is user font */
- if (font_data[unit] != FONT_DATA) {
- if (--REFCOUNT(font_data[unit]) == 0)
- kfree(font_data[unit] -
- FONT_EXTRA_WORDS * sizeof(int));
- }
- REFCOUNT(new_data)++;
+
+ font_data_put(font_data[unit]);
font_data[unit] = new_data;
return 0;
@@ -554,12 +550,9 @@ static int newport_set_font(int unit, const struct console_font *op,
static int newport_set_def_font(int unit, struct console_font *op)
{
- if (font_data[unit] != FONT_DATA) {
- if (--REFCOUNT(font_data[unit]) == 0)
- kfree(font_data[unit] -
- FONT_EXTRA_WORDS * sizeof(int));
- font_data[unit] = FONT_DATA;
- }
+ font_data_put(font_data[unit]);
+ font_data[unit] = FONT_DATA;
+ font_data_get(font_data[unit]);
return 0;
}
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index fa8f3e4196de..ac59480c98cb 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -1023,6 +1023,7 @@ static const char *fbcon_startup(void)
vc->vc_font.charcount = font->charcount;
p->fontdata = font->data;
+ font_data_get(p->fontdata);
}
cols = FBCON_SWAP(par->rotate, info->var.xres, info->var.yres);
@@ -1086,10 +1087,7 @@ static void fbcon_init(struct vc_data *vc, bool init)
vc->vc_font.charcount = fvc->vc_font.charcount;
p->fontdata = t->fontdata;
- p->userfont = t->userfont;
-
- if (p->userfont)
- REFCOUNT(p->fontdata)++;
+ font_data_get(p->fontdata);
} else {
const struct font_desc *font = NULL;
@@ -1104,6 +1102,7 @@ static void fbcon_init(struct vc_data *vc, bool init)
vc->vc_font.charcount = font->charcount;
p->fontdata = font->data;
+ font_data_get(p->fontdata);
}
}
@@ -1194,10 +1193,10 @@ static void fbcon_init(struct vc_data *vc, bool init)
static void fbcon_free_font(struct fbcon_display *p)
{
- if (p->userfont && p->fontdata && (--REFCOUNT(p->fontdata) == 0))
- kfree(p->fontdata - FONT_EXTRA_WORDS * sizeof(int));
- p->fontdata = NULL;
- p->userfont = 0;
+ if (p->fontdata) {
+ font_data_put(p->fontdata);
+ p->fontdata = NULL;
+ }
}
static void set_vc_hi_font(struct vc_data *vc, bool set);
@@ -1420,9 +1419,7 @@ static void fbcon_set_disp(struct fb_info *info, struct fb_var_screeninfo *var,
vc->vc_font.height = (*default_mode)->vc_font.height;
vc->vc_font.charcount = (*default_mode)->vc_font.charcount;
p->fontdata = t->fontdata;
- p->userfont = t->userfont;
- if (p->userfont)
- REFCOUNT(p->fontdata)++;
+ font_data_get(p->fontdata);
}
var->activate = FB_ACTIVATE_NOW;
@@ -2053,7 +2050,7 @@ static int fbcon_resize(struct vc_data *vc, unsigned int width,
struct fb_var_screeninfo var = info->var;
int x_diff, y_diff, virt_w, virt_h, virt_fw, virt_fh;
- if (p->userfont && font_data_size(p->fontdata)) {
+ if (font_data_size(p->fontdata)) {
unsigned int size = vc_font_size(&vc->vc_font);
/*
@@ -2413,21 +2410,20 @@ static void set_vc_hi_font(struct vc_data *vc, bool set)
}
static int fbcon_do_set_font(struct vc_data *vc, int w, int h, int charcount,
- font_data_t *data, int userfont)
+ font_data_t *data)
{
struct fb_info *info = fbcon_info_from_console(vc->vc_num);
struct fbcon_par *par = info->fbcon_par;
struct fbcon_display *p = &fb_display[vc->vc_num];
- int resize, ret, old_userfont, old_width, old_height, old_charcount;
+ int resize, ret, old_width, old_height, old_charcount;
font_data_t *old_fontdata = p->fontdata;
const u8 *old_data = vc->vc_font.data;
+ font_data_get(data);
+
resize = (w != vc->vc_font.width) || (h != vc->vc_font.height);
p->fontdata = data;
vc->vc_font.data = font_data_buf(p->fontdata);
- old_userfont = p->userfont;
- if ((p->userfont = userfont))
- REFCOUNT(data)++;
old_width = vc->vc_font.width;
old_height = vc->vc_font.height;
@@ -2457,24 +2453,20 @@ static int fbcon_do_set_font(struct vc_data *vc, int w, int h, int charcount,
update_screen(vc);
}
- if (old_userfont && (--REFCOUNT(old_fontdata) == 0))
- kfree(old_fontdata - FONT_EXTRA_WORDS * sizeof(int));
+ if (old_fontdata)
+ font_data_put(old_fontdata);
+
return 0;
err_out:
p->fontdata = old_fontdata;
vc->vc_font.data = old_data;
-
- if (userfont) {
- p->userfont = old_userfont;
- if (--REFCOUNT(data) == 0)
- kfree(data - FONT_EXTRA_WORDS * sizeof(int));
- }
-
vc->vc_font.width = old_width;
vc->vc_font.height = old_height;
vc->vc_font.charcount = old_charcount;
+ font_data_put(data);
+
return ret;
}
@@ -2491,9 +2483,9 @@ static int fbcon_set_font(struct vc_data *vc, const struct console_font *font,
int w = font->width;
int h = font->height;
int size, alloc_size;
- int i, csum;
+ int i, csum, ret;
font_data_t *new_data;
- u8 *data = font->data;
+ const u8 *data = font->data;
int pitch = PITCH(font->width);
/* Is there a reason why fbconsole couldn't handle any charcount >256?
@@ -2536,7 +2528,7 @@ static int fbcon_set_font(struct vc_data *vc, const struct console_font *font,
new_data += FONT_EXTRA_WORDS * sizeof(int);
FNTSIZE(new_data) = size;
- REFCOUNT(new_data) = 0; /* usage counter */
+ REFCOUNT(new_data) = 1; /* usage counter */
for (i=0; i< charcount; i++) {
memcpy((u8 *)new_data + i * h * pitch, data + i * vpitch * pitch, h * pitch);
}
@@ -2550,18 +2542,21 @@ static int fbcon_set_font(struct vc_data *vc, const struct console_font *font,
for (i = first_fb_vc; i <= last_fb_vc; i++) {
struct vc_data *tmp = vc_cons[i].d;
- if (fb_display[i].userfont &&
- fb_display[i].fontdata &&
+ if (fb_display[i].fontdata &&
FNTSUM(fb_display[i].fontdata) == csum &&
font_data_size(fb_display[i].fontdata) == size &&
tmp->vc_font.width == w &&
!memcmp(fb_display[i].fontdata, new_data, size)) {
- kfree(new_data - FONT_EXTRA_WORDS * sizeof(int));
- new_data = (u8 *)fb_display[i].fontdata;
+ font_data_get(fb_display[i].fontdata);
+ font_data_put(new_data);
+ new_data = fb_display[i].fontdata;
break;
}
}
- return fbcon_do_set_font(vc, font->width, font->height, charcount, new_data, 1);
+ ret = fbcon_do_set_font(vc, font->width, font->height, charcount, new_data);
+ font_data_put(new_data);
+
+ return ret;
}
static int fbcon_set_def_font(struct vc_data *vc, struct console_font *font,
@@ -2578,7 +2573,7 @@ static int fbcon_set_def_font(struct vc_data *vc, struct console_font *font,
font->width = f->width;
font->height = f->height;
- return fbcon_do_set_font(vc, f->width, f->height, f->charcount, f->data, 0);
+ return fbcon_do_set_font(vc, f->width, f->height, f->charcount, f->data);
}
static u16 palette_red[16];
diff --git a/drivers/video/fbdev/core/fbcon.h b/drivers/video/fbdev/core/fbcon.h
index d26ee7860cf5..1e3c1ef84762 100644
--- a/drivers/video/fbdev/core/fbcon.h
+++ b/drivers/video/fbdev/core/fbcon.h
@@ -27,7 +27,6 @@
struct fbcon_display {
/* Filled in by the low-level console driver */
font_data_t *fontdata;
- int userfont; /* != 0 if fontdata kmalloc()ed */
#ifdef CONFIG_FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION
u_short scrollmode; /* Scroll Method, use fb_scrollmode() */
#endif
diff --git a/include/linux/font.h b/include/linux/font.h
index 5b8557813c5c..dd319d0f0201 100644
--- a/include/linux/font.h
+++ b/include/linux/font.h
@@ -54,6 +54,8 @@ static inline const unsigned char *font_data_buf(font_data_t *fd)
return (const unsigned char *)fd;
}
+void font_data_get(font_data_t *fd);
+bool font_data_put(font_data_t *fd);
unsigned int font_data_size(font_data_t *fd);
/*
diff --git a/lib/fonts/fonts.c b/lib/fonts/fonts.c
index 8c9a6762061c..d25efd8d6c31 100644
--- a/lib/fonts/fonts.c
+++ b/lib/fonts/fonts.c
@@ -12,18 +12,91 @@
* for more details.
*/
+#include <linux/container_of.h>
+#include <linux/font.h>
#include <linux/module.h>
-#include <linux/types.h>
+#include <linux/slab.h>
#include <linux/string.h>
+#include <linux/types.h>
+
#if defined(__mc68000__)
#include <asm/setup.h>
#endif
-#include <linux/font.h>
/*
* Helpers for font_data_t
*/
+static struct font_data *to_font_data_struct(font_data_t *fd)
+{
+ return container_of(fd, struct font_data, data[0]);
+}
+
+static bool font_data_is_internal(font_data_t *fd)
+{
+ return !REFCOUNT(fd); /* internal fonts have no reference counting */
+}
+
+static void font_data_free(font_data_t *fd)
+{
+ kfree(to_font_data_struct(fd));
+}
+
+/**
+ * font_data_get - Acquires a reference on font data
+ * @fd: Font data
+ *
+ * Font data from user space is reference counted. The helper
+ * font_data_get() increases the reference counter by one. Invoke
+ * font_data_put() to release the reference.
+ *
+ * Internal font data is located in read-only memory. In this case
+ * the helper returns success without modifying the counter field.
+ * It is still required to call font_data_put() on internal font data.
+ */
+void font_data_get(font_data_t *fd)
+{
+ if (font_data_is_internal(fd))
+ return; /* never ref static data */
+
+ if (WARN_ON(!REFCOUNT(fd)))
+ return; /* should never be 0 */
+ ++REFCOUNT(fd);
+}
+EXPORT_SYMBOL_GPL(font_data_get);
+
+/**
+ * font_data_put - Release a reference on font data
+ * @fd: Font data
+ *
+ * Font data from user space is reference counted. The helper
+ * font_data_put() decreases the reference counter by one. If this was
+ * the final reference, it frees the allocated memory.
+ *
+ * Internal font data is located in read-only memory. In this case
+ * the helper returns success without modifying the counter field.
+ *
+ * Returns:
+ * True if the font data's memory buffer has been freed, false otherwise.
+ */
+bool font_data_put(font_data_t *fd)
+{
+ unsigned int count;
+
+ if (font_data_is_internal(fd))
+ return false; /* never unref static data */
+
+ if (WARN_ON(!REFCOUNT(fd)))
+ return false; /* should never be 0 */
+
+ count = --REFCOUNT(fd);
+ if (!count)
+ font_data_free(fd);
+
+ return !count;
+}
+EXPORT_SYMBOL_GPL(font_data_put);
+
/**
* font_data_size - Return size of the font data in bytes
* @fd: Font data
--
2.53.0
^ permalink raw reply related
* [PATCH v3 05/13] lib/fonts: Remove trailing whitespaces
From: Thomas Zimmermann @ 2026-03-09 14:14 UTC (permalink / raw)
To: gregkh, deller, sam
Cc: linux-fbdev, dri-devel, linux-kernel, Thomas Zimmermann
In-Reply-To: <20260309141723.137364-1-tzimmermann@suse.de>
Fix coding style. No functional changes.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
lib/fonts/font_acorn_8x8.c | 2 +-
lib/fonts/font_mini_4x6.c | 8 ++++----
2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/lib/fonts/font_acorn_8x8.c b/lib/fonts/font_acorn_8x8.c
index 18755c33d249..af5fa72aa8b7 100644
--- a/lib/fonts/font_acorn_8x8.c
+++ b/lib/fonts/font_acorn_8x8.c
@@ -68,7 +68,7 @@ static const struct font_data acorndata_8x8 = {
/* 3A */ 0x00, 0x00, 0x18, 0x18, 0x00, 0x18, 0x18, 0x00, /* : */
/* 3B */ 0x00, 0x00, 0x18, 0x18, 0x00, 0x18, 0x18, 0x30, /* ; */
/* 3C */ 0x0C, 0x18, 0x30, 0x60, 0x30, 0x18, 0x0C, 0x00, /* < */
-/* 3D */ 0x00, 0x00, 0x7E, 0x00, 0x7E, 0x00, 0x00, 0x00, /* = */
+/* 3D */ 0x00, 0x00, 0x7E, 0x00, 0x7E, 0x00, 0x00, 0x00, /* = */
/* 3E */ 0x30, 0x18, 0x0C, 0x06, 0x0C, 0x18, 0x30, 0x00, /* > */
/* 3F */ 0x3C, 0x66, 0x0C, 0x18, 0x18, 0x00, 0x18, 0x00, /* ? */
/* 40 */ 0x3C, 0x66, 0x6E, 0x6A, 0x6E, 0x60, 0x3C, 0x00, /* @ */
diff --git a/lib/fonts/font_mini_4x6.c b/lib/fonts/font_mini_4x6.c
index 8d39fd447952..cc21dc70cfd1 100644
--- a/lib/fonts/font_mini_4x6.c
+++ b/lib/fonts/font_mini_4x6.c
@@ -18,15 +18,15 @@
s{((0x)?[0-9a-fA-F]+)(.*\[([\*\ ]{4})\])}{
($num,$pat,$bits) = ($1,$3,$4);
-
+
$bits =~ s/([^\s0])|(.)/ defined($1) + 0 /ge;
-
+
$num = ord(pack("B8", $bits));
$num |= $num >> 4;
$num = sprintf("0x%.2x", $num);
-
+
#print "$num,$pat,$bits\n";
-
+
$num . $pat;
}ge;
--
2.53.0
^ permalink raw reply related
* [PATCH v3 11/13] lib/fonts: Create font_data_t from struct console_font with font_data_import()
From: Thomas Zimmermann @ 2026-03-09 14:14 UTC (permalink / raw)
To: gregkh, deller, sam
Cc: linux-fbdev, dri-devel, linux-kernel, Thomas Zimmermann
In-Reply-To: <20260309141723.137364-1-tzimmermann@suse.de>
Add font_data_import() and update consoles to use it.
The implementation of font_data_import() is based on code from fbcon,
which supports overflow checks and crc32 checksums. Fbcon uses the crc32
checksum.
Newport_con now implements the same overflow checks as fbcon. As before,
this console does not support checksums, which are optional. Newport_con
can now also handle input font data with a vertical pitch other than 32
bytes. (The vertical pitch is the offset between two glyphs in the font
data.)
As an internal change, remove the const qualifier from the data field
if struct font_data. This allows font_data_import() to write the data
without type casting. For all users of the font data via font_data_t,
the stored data is still read only.
v3:
- fix typos
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/video/console/newport_con.c | 22 ++--------
drivers/video/fbdev/core/fbcon.c | 38 ++----------------
include/linux/font.h | 6 ++-
lib/fonts/fonts.c | 62 +++++++++++++++++++++++++++++
4 files changed, 75 insertions(+), 53 deletions(-)
diff --git a/drivers/video/console/newport_con.c b/drivers/video/console/newport_con.c
index 1bc3cb1ea116..ecbbe2e4e2a6 100644
--- a/drivers/video/console/newport_con.c
+++ b/drivers/video/console/newport_con.c
@@ -501,31 +501,17 @@ static int newport_set_font(int unit, const struct console_font *op,
{
int w = op->width;
int h = op->height;
- int size = h * op->charcount;
int i;
font_data_t *new_data;
- unsigned char *data = op->data, *p;
/* ladis: when I grow up, there will be a day... and more sizes will
* be supported ;-) */
- if ((w != 8) || (h != 16) || (vpitch != 32)
- || (op->charcount != 256 && op->charcount != 512))
+ if (w != 8 || h != 16 || (op->charcount != 256 && op->charcount != 512))
return -EINVAL;
- if (!(new_data = kmalloc(FONT_EXTRA_WORDS * sizeof(int) + size,
- GFP_USER))) return -ENOMEM;
-
- new_data += FONT_EXTRA_WORDS * sizeof(int);
- FNTSIZE(new_data) = size;
- REFCOUNT(new_data) = 1; /* usage counter */
- FNTSUM(new_data) = 0;
-
- p = (unsigned char *)font_data_buf(new_data);
- for (i = 0; i < op->charcount; i++) {
- memcpy(p, data, h);
- data += 32;
- p += h;
- }
+ new_data = font_data_import(op, vpitch, NULL);
+ if (IS_ERR(new_data))
+ return PTR_ERR(new_data);
/* check if font is already used by other console */
for (i = 0; i < MAX_NR_CONSOLES; i++) {
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 00255ac92e42..53677c09a0ec 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -2039,8 +2039,6 @@ static void updatescrollmode(struct fbcon_display *p,
updatescrollmode_accel(p, info, vc);
}
-#define PITCH(w) (((w) + 7) >> 3)
-
static int fbcon_resize(struct vc_data *vc, unsigned int width,
unsigned int height, bool from_user)
{
@@ -2424,7 +2422,6 @@ static int fbcon_do_set_font(struct vc_data *vc, int w, int h, int charcount,
resize = (w != vc->vc_font.width) || (h != vc->vc_font.height);
p->fontdata = data;
vc->vc_font.data = font_data_buf(p->fontdata);
-
old_width = vc->vc_font.width;
old_height = vc->vc_font.height;
old_charcount = vc->vc_font.charcount;
@@ -2482,11 +2479,8 @@ static int fbcon_set_font(struct vc_data *vc, const struct console_font *font,
unsigned charcount = font->charcount;
int w = font->width;
int h = font->height;
- int size, alloc_size;
- int i, csum, ret;
+ int i, ret;
font_data_t *new_data;
- const u8 *data = font->data;
- int pitch = PITCH(font->width);
/* Is there a reason why fbconsole couldn't handle any charcount >256?
* If not this check should be changed to charcount < 256 */
@@ -2510,34 +2504,10 @@ static int fbcon_set_font(struct vc_data *vc, const struct console_font *font,
if (fbcon_invalid_charcount(info, charcount))
return -EINVAL;
- /* Check for integer overflow in font size calculation */
- if (check_mul_overflow(h, pitch, &size) ||
- check_mul_overflow(size, charcount, &size))
- return -EINVAL;
-
- /* Check for overflow in allocation size calculation */
- if (check_add_overflow(FONT_EXTRA_WORDS * sizeof(int), size, &alloc_size))
- return -EINVAL;
-
- new_data = kmalloc(alloc_size, GFP_USER);
-
- if (!new_data)
- return -ENOMEM;
-
- memset((u8 *)new_data, 0, FONT_EXTRA_WORDS * sizeof(int));
-
- new_data += FONT_EXTRA_WORDS * sizeof(int);
- FNTSIZE(new_data) = size;
- REFCOUNT(new_data) = 1; /* usage counter */
- for (i=0; i< charcount; i++) {
- memcpy((u8 *)new_data + i * h * pitch, data + i * vpitch * pitch, h * pitch);
- }
-
- /* Since linux has a nice crc32 function use it for counting font
- * checksums. */
- csum = crc32(0, new_data, size);
+ new_data = font_data_import(font, vpitch, crc32);
+ if (IS_ERR(new_data))
+ return PTR_ERR(new_data);
- FNTSUM(new_data) = csum;
/* Check if the same font is on some other console already */
for (i = first_fb_vc; i <= last_fb_vc; i++) {
if (fb_display[i].fontdata &&
diff --git a/include/linux/font.h b/include/linux/font.h
index 58bf3c64cabb..3eb4818402c5 100644
--- a/include/linux/font.h
+++ b/include/linux/font.h
@@ -13,6 +13,8 @@
#include <linux/types.h>
+struct console_font;
+
/*
* font_data_t and helpers
*/
@@ -54,6 +56,8 @@ static inline const unsigned char *font_data_buf(font_data_t *fd)
return (const unsigned char *)fd;
}
+font_data_t *font_data_import(const struct console_font *font, unsigned int vpitch,
+ u32 (*calc_csum)(u32, const void *, size_t));
void font_data_get(font_data_t *fd);
bool font_data_put(font_data_t *fd);
unsigned int font_data_size(font_data_t *fd);
@@ -124,7 +128,7 @@ extern const struct font_desc *get_default_font(int xres, int yres,
struct font_data {
unsigned int extra[FONT_EXTRA_WORDS];
- const unsigned char data[];
+ unsigned char data[];
} __packed;
#endif /* _VIDEO_FONT_H */
diff --git a/lib/fonts/fonts.c b/lib/fonts/fonts.c
index 3fb76d185647..16e75c3d2a0f 100644
--- a/lib/fonts/fonts.c
+++ b/lib/fonts/fonts.c
@@ -14,7 +14,9 @@
#include <linux/container_of.h>
#include <linux/font.h>
+#include <linux/kd.h>
#include <linux/module.h>
+#include <linux/overflow.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/types.h>
@@ -23,6 +25,8 @@
#include <asm/setup.h>
#endif
+#define console_font_pitch(font) DIV_ROUND_UP((font)->width, 8)
+
/*
* Helpers for font_data_t
*/
@@ -42,6 +46,64 @@ static void font_data_free(font_data_t *fd)
kfree(to_font_data_struct(fd));
}
+/**
+ * font_data_import - Allocates and initializes font data from user space
+ * @font: A font from user space
+ * @vpitch: The size of a single glyph in @font in bytes
+ * @calc_csum: An optional helper to calculate a chechsum
+ *
+ * Font data from user space must be translated to the kernel's format. The
+ * font's glyph geometry and data is provided in @font. The parameter @vpitch
+ * gives the number of bytes per glyph, including trailing bytes.
+ *
+ * The parameter @calc_csum is optional. Fbcon passes crc32() to calculate the
+ * font data's checksum.
+ *
+ * Returns:
+ * Newly initialized font data on success, or a pointer-encoded errno value otherwise.
+ */
+font_data_t *font_data_import(const struct console_font *font, unsigned int vpitch,
+ u32 (*calc_csum)(u32, const void *, size_t))
+{
+ unsigned int pitch = console_font_pitch(font);
+ unsigned int h = font->height;
+ unsigned int charcount = font->charcount;
+ const unsigned char *data = font->data;
+ u32 csum = 0;
+ struct font_data *font_data;
+ int size, alloc_size;
+ unsigned int i;
+ font_data_t *fd;
+
+ /* Check for integer overflow in font-size calculation */
+ if (check_mul_overflow(h, pitch, &size) ||
+ check_mul_overflow(size, charcount, &size))
+ return ERR_PTR(-EINVAL);
+
+ /* Check for overflow in allocation size calculation */
+ if (check_add_overflow(sizeof(*font_data), size, &alloc_size))
+ return ERR_PTR(-EINVAL);
+
+ font_data = kmalloc(alloc_size, GFP_USER);
+ if (!font_data)
+ return ERR_PTR(-ENOMEM);
+ memset(font_data->extra, 0, sizeof(font_data->extra));
+
+ for (i = 0; i < charcount; ++i)
+ memcpy(font_data->data + i * h * pitch, data + i * vpitch * pitch, h * pitch);
+
+ if (calc_csum)
+ csum = calc_csum(0, font_data->data, size);
+
+ fd = font_data->data;
+ REFCOUNT(fd) = 1; /* start with reference acquired */
+ FNTSIZE(fd) = size;
+ FNTSUM(fd) = csum;
+
+ return fd;
+}
+EXPORT_SYMBOL_GPL(font_data_import);
+
/**
* font_data_get - Acquires a reference on font data
* @fd: Font data
--
2.53.0
^ permalink raw reply related
* [PATCH v3 08/13] lib/fonts: Read font size with font_data_size()
From: Thomas Zimmermann @ 2026-03-09 14:14 UTC (permalink / raw)
To: gregkh, deller, sam
Cc: linux-fbdev, dri-devel, linux-kernel, Thomas Zimmermann
In-Reply-To: <20260309141723.137364-1-tzimmermann@suse.de>
Add font_data_size() and update consoles to use it.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/video/console/newport_con.c | 2 +-
drivers/video/fbdev/core/fbcon.c | 14 +++++++-------
include/linux/font.h | 2 ++
lib/fonts/fonts.c | 21 +++++++++++++++++++++
4 files changed, 31 insertions(+), 8 deletions(-)
diff --git a/drivers/video/console/newport_con.c b/drivers/video/console/newport_con.c
index 9b9ed1940404..1198c6bc2777 100644
--- a/drivers/video/console/newport_con.c
+++ b/drivers/video/console/newport_con.c
@@ -530,7 +530,7 @@ static int newport_set_font(int unit, const struct console_font *op,
/* check if font is already used by other console */
for (i = 0; i < MAX_NR_CONSOLES; i++) {
if (font_data[i] != FONT_DATA
- && FNTSIZE(font_data[i]) == size
+ && font_data_size(font_data[i]) == size
&& !memcmp(font_data[i], new_data, size)) {
kfree(new_data - FONT_EXTRA_WORDS * sizeof(int));
/* current font is the same as the new one */
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 8d7840b9ebad..fa8f3e4196de 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -2053,7 +2053,7 @@ static int fbcon_resize(struct vc_data *vc, unsigned int width,
struct fb_var_screeninfo var = info->var;
int x_diff, y_diff, virt_w, virt_h, virt_fw, virt_fh;
- if (p->userfont && FNTSIZE(p->fontdata)) {
+ if (p->userfont && font_data_size(p->fontdata)) {
unsigned int size = vc_font_size(&vc->vc_font);
/*
@@ -2063,7 +2063,7 @@ static int fbcon_resize(struct vc_data *vc, unsigned int width,
* charcount can change and cannot be used to determine the
* font data allocated size.
*/
- if (!size || size > FNTSIZE(p->fontdata))
+ if (!size || size > font_data_size(p->fontdata))
return -EINVAL;
}
@@ -2302,7 +2302,7 @@ static int fbcon_get_font(struct vc_data *vc, struct console_font *font, unsigne
if (font->width <= 8) {
j = vc->vc_font.height;
- if (font->charcount * j > FNTSIZE(fontdata))
+ if (font->charcount * j > font_data_size(fontdata))
return -EINVAL;
for (i = 0; i < font->charcount; i++) {
@@ -2313,7 +2313,7 @@ static int fbcon_get_font(struct vc_data *vc, struct console_font *font, unsigne
}
} else if (font->width <= 16) {
j = vc->vc_font.height * 2;
- if (font->charcount * j > FNTSIZE(fontdata))
+ if (font->charcount * j > font_data_size(fontdata))
return -EINVAL;
for (i = 0; i < font->charcount; i++) {
@@ -2323,7 +2323,7 @@ static int fbcon_get_font(struct vc_data *vc, struct console_font *font, unsigne
fontdata += j;
}
} else if (font->width <= 24) {
- if (font->charcount * (vc->vc_font.height * sizeof(u32)) > FNTSIZE(fontdata))
+ if (font->charcount * (vc->vc_font.height * sizeof(u32)) > font_data_size(fontdata))
return -EINVAL;
for (i = 0; i < font->charcount; i++) {
@@ -2338,7 +2338,7 @@ static int fbcon_get_font(struct vc_data *vc, struct console_font *font, unsigne
}
} else {
j = vc->vc_font.height * 4;
- if (font->charcount * j > FNTSIZE(fontdata))
+ if (font->charcount * j > font_data_size(fontdata))
return -EINVAL;
for (i = 0; i < font->charcount; i++) {
@@ -2553,7 +2553,7 @@ static int fbcon_set_font(struct vc_data *vc, const struct console_font *font,
if (fb_display[i].userfont &&
fb_display[i].fontdata &&
FNTSUM(fb_display[i].fontdata) == csum &&
- FNTSIZE(fb_display[i].fontdata) == size &&
+ font_data_size(fb_display[i].fontdata) == size &&
tmp->vc_font.width == w &&
!memcmp(fb_display[i].fontdata, new_data, size)) {
kfree(new_data - FONT_EXTRA_WORDS * sizeof(int));
diff --git a/include/linux/font.h b/include/linux/font.h
index 746a0996a018..5b8557813c5c 100644
--- a/include/linux/font.h
+++ b/include/linux/font.h
@@ -54,6 +54,8 @@ static inline const unsigned char *font_data_buf(font_data_t *fd)
return (const unsigned char *)fd;
}
+unsigned int font_data_size(font_data_t *fd);
+
/*
* Font description
*/
diff --git a/lib/fonts/fonts.c b/lib/fonts/fonts.c
index a7f118b30171..8c9a6762061c 100644
--- a/lib/fonts/fonts.c
+++ b/lib/fonts/fonts.c
@@ -20,6 +20,27 @@
#endif
#include <linux/font.h>
+/*
+ * Helpers for font_data_t
+ */
+
+/**
+ * font_data_size - Return size of the font data in bytes
+ * @fd: Font data
+ *
+ * Returns:
+ * The number of bytes in the given font data.
+ */
+unsigned int font_data_size(font_data_t *fd)
+{
+ return FNTSIZE(fd);
+}
+EXPORT_SYMBOL_GPL(font_data_size);
+
+/*
+ * Font lookup
+ */
+
static const struct font_desc *fonts[] = {
#ifdef CONFIG_FONT_8x8
&font_vga_8x8,
--
2.53.0
^ permalink raw reply related
* [PATCH v3 13/13] lib/fonts: Remove internal symbols and macros from public header file
From: Thomas Zimmermann @ 2026-03-09 14:14 UTC (permalink / raw)
To: gregkh, deller, sam
Cc: linux-fbdev, dri-devel, linux-kernel, Thomas Zimmermann
In-Reply-To: <20260309141723.137364-1-tzimmermann@suse.de>
Define access macros for font_data_t in fonts.c. Define struct font_data
and declare most of the font symbols in the internal header font.h, where
they can only be seen by the font code.
Also move font indices into internal font.h. They appear to be unused
though. There is m86k assembly code that operates on the idx field, so
leave them in place for now.
List all built-in fonts in a separate section in the public header file.
v2:
- do not add config guards around font symbols (Helge)
- keep declaration of built-in fonts in public header
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
include/linux/font.h | 57 ++++++++++++--------------------------
lib/fonts/font.h | 38 +++++++++++++++++++++++++
lib/fonts/font_10x18.c | 2 +-
lib/fonts/font_6x10.c | 3 +-
lib/fonts/font_6x11.c | 2 +-
lib/fonts/font_6x8.c | 3 +-
lib/fonts/font_7x14.c | 2 +-
lib/fonts/font_8x16.c | 3 +-
lib/fonts/font_8x8.c | 2 +-
lib/fonts/font_acorn_8x8.c | 2 +-
lib/fonts/font_mini_4x6.c | 2 +-
lib/fonts/font_pearl_8x8.c | 2 +-
lib/fonts/font_sun12x22.c | 3 +-
lib/fonts/font_sun8x16.c | 3 +-
lib/fonts/font_ter10x18.c | 4 ++-
lib/fonts/font_ter16x32.c | 4 ++-
lib/fonts/fonts.c | 8 +++++-
17 files changed, 85 insertions(+), 55 deletions(-)
create mode 100644 lib/fonts/font.h
diff --git a/include/linux/font.h b/include/linux/font.h
index d80db66a5c17..5401f07dd6ce 100644
--- a/include/linux/font.h
+++ b/include/linux/font.h
@@ -77,36 +77,6 @@ struct font_desc {
int pref;
};
-#define VGA8x8_IDX 0
-#define VGA8x16_IDX 1
-#define PEARL8x8_IDX 2
-#define VGA6x11_IDX 3
-#define FONT7x14_IDX 4
-#define FONT10x18_IDX 5
-#define SUN8x16_IDX 6
-#define SUN12x22_IDX 7
-#define ACORN8x8_IDX 8
-#define MINI4x6_IDX 9
-#define FONT6x10_IDX 10
-#define TER16x32_IDX 11
-#define FONT6x8_IDX 12
-#define TER10x18_IDX 13
-
-extern const struct font_desc font_vga_8x8,
- font_vga_8x16,
- font_pearl_8x8,
- font_vga_6x11,
- font_7x14,
- font_10x18,
- font_sun_8x16,
- font_sun_12x22,
- font_acorn_8x8,
- font_mini_4x6,
- font_6x10,
- font_ter_16x32,
- font_6x8,
- font_ter_10x18;
-
/* Find a font with a specific name */
extern const struct font_desc *find_font(const char *name);
@@ -120,16 +90,23 @@ extern const struct font_desc *get_default_font(int xres, int yres,
/* Max. length for the name of a predefined font */
#define MAX_FONT_NAME 32
-/* Extra word getters */
-#define REFCOUNT(fd) (((int *)(fd))[-1])
-#define FNTSIZE(fd) (((int *)(fd))[-2])
-#define FNTSUM(fd) (((int *)(fd))[-4])
-
-#define FONT_EXTRA_WORDS 4
+/*
+ * Built-in fonts
+ */
-struct font_data {
- unsigned int extra[FONT_EXTRA_WORDS];
- unsigned char data[];
-} __packed;
+extern const struct font_desc font_10x18;
+extern const struct font_desc font_6x10;
+extern const struct font_desc font_6x8;
+extern const struct font_desc font_7x14;
+extern const struct font_desc font_acorn_8x8;
+extern const struct font_desc font_mini_4x6;
+extern const struct font_desc font_pearl_8x8;
+extern const struct font_desc font_sun_12x22;
+extern const struct font_desc font_sun_8x16;
+extern const struct font_desc font_ter_10x18;
+extern const struct font_desc font_ter_16x32;
+extern const struct font_desc font_vga_6x11;
+extern const struct font_desc font_vga_8x16;
+extern const struct font_desc font_vga_8x8;
#endif /* _VIDEO_FONT_H */
diff --git a/lib/fonts/font.h b/lib/fonts/font.h
new file mode 100644
index 000000000000..4f1adf0b6b54
--- /dev/null
+++ b/lib/fonts/font.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _LIB_FONTS_FONT_H
+#define _LIB_FONTS_FONT_H
+
+#include <linux/font.h>
+
+/*
+ * Font data
+ */
+
+#define FONT_EXTRA_WORDS 4
+
+struct font_data {
+ unsigned int extra[FONT_EXTRA_WORDS];
+ unsigned char data[];
+} __packed;
+
+/*
+ * Built-in fonts
+ */
+
+#define VGA8x8_IDX 0
+#define VGA8x16_IDX 1
+#define PEARL8x8_IDX 2
+#define VGA6x11_IDX 3
+#define FONT7x14_IDX 4
+#define FONT10x18_IDX 5
+#define SUN8x16_IDX 6
+#define SUN12x22_IDX 7
+#define ACORN8x8_IDX 8
+#define MINI4x6_IDX 9
+#define FONT6x10_IDX 10
+#define TER16x32_IDX 11
+#define FONT6x8_IDX 12
+#define TER10x18_IDX 13
+
+#endif
diff --git a/lib/fonts/font_10x18.c b/lib/fonts/font_10x18.c
index 5d940db626e7..10edebc4bb74 100644
--- a/lib/fonts/font_10x18.c
+++ b/lib/fonts/font_10x18.c
@@ -4,7 +4,7 @@
* by Jurriaan Kalkman 06-2005 *
********************************/
-#include <linux/font.h>
+#include "font.h"
#define FONTDATAMAX 9216
diff --git a/lib/fonts/font_6x10.c b/lib/fonts/font_6x10.c
index e65df019e0d2..660d3a371b30 100644
--- a/lib/fonts/font_6x10.c
+++ b/lib/fonts/font_6x10.c
@@ -1,5 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
-#include <linux/font.h>
+
+#include "font.h"
#define FONTDATAMAX 2560
diff --git a/lib/fonts/font_6x11.c b/lib/fonts/font_6x11.c
index bd76b3f6b635..671487ccc172 100644
--- a/lib/fonts/font_6x11.c
+++ b/lib/fonts/font_6x11.c
@@ -5,7 +5,7 @@
/* */
/**********************************************/
-#include <linux/font.h>
+#include "font.h"
#define FONTDATAMAX (11*256)
diff --git a/lib/fonts/font_6x8.c b/lib/fonts/font_6x8.c
index 06ace7792521..5811ee07f4d8 100644
--- a/lib/fonts/font_6x8.c
+++ b/lib/fonts/font_6x8.c
@@ -1,5 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
-#include <linux/font.h>
+
+#include "font.h"
#define FONTDATAMAX 2048
diff --git a/lib/fonts/font_7x14.c b/lib/fonts/font_7x14.c
index a2f561c9fa04..0c7475d643c8 100644
--- a/lib/fonts/font_7x14.c
+++ b/lib/fonts/font_7x14.c
@@ -4,7 +4,7 @@
/* by Jurriaan Kalkman 05-2005 */
/**************************************/
-#include <linux/font.h>
+#include "font.h"
#define FONTDATAMAX 3584
diff --git a/lib/fonts/font_8x16.c b/lib/fonts/font_8x16.c
index 06ae14088514..523e95c75569 100644
--- a/lib/fonts/font_8x16.c
+++ b/lib/fonts/font_8x16.c
@@ -5,9 +5,10 @@
/* */
/**********************************************/
-#include <linux/font.h>
#include <linux/module.h>
+#include "font.h"
+
#define FONTDATAMAX 4096
static const struct font_data fontdata_8x16 = {
diff --git a/lib/fonts/font_8x8.c b/lib/fonts/font_8x8.c
index 69570b8c31af..e5b697fc9675 100644
--- a/lib/fonts/font_8x8.c
+++ b/lib/fonts/font_8x8.c
@@ -5,7 +5,7 @@
/* */
/**********************************************/
-#include <linux/font.h>
+#include "font.h"
#define FONTDATAMAX 2048
diff --git a/lib/fonts/font_acorn_8x8.c b/lib/fonts/font_acorn_8x8.c
index af5fa72aa8b7..36c51016769d 100644
--- a/lib/fonts/font_acorn_8x8.c
+++ b/lib/fonts/font_acorn_8x8.c
@@ -1,7 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
/* Acorn-like font definition, with PC graphics characters */
-#include <linux/font.h>
+#include "font.h"
#define FONTDATAMAX 2048
diff --git a/lib/fonts/font_mini_4x6.c b/lib/fonts/font_mini_4x6.c
index cc21dc70cfd1..dc919c160dde 100644
--- a/lib/fonts/font_mini_4x6.c
+++ b/lib/fonts/font_mini_4x6.c
@@ -39,7 +39,7 @@ __END__;
MSBit to LSBit = left to right.
*/
-#include <linux/font.h>
+#include "font.h"
#define FONTDATAMAX 1536
diff --git a/lib/fonts/font_pearl_8x8.c b/lib/fonts/font_pearl_8x8.c
index ae98ca17982e..2438b374acea 100644
--- a/lib/fonts/font_pearl_8x8.c
+++ b/lib/fonts/font_pearl_8x8.c
@@ -10,7 +10,7 @@
/* */
/**********************************************/
-#include <linux/font.h>
+#include "font.h"
#define FONTDATAMAX 2048
diff --git a/lib/fonts/font_sun12x22.c b/lib/fonts/font_sun12x22.c
index 91daf5ab8b6b..2afbc144bea8 100644
--- a/lib/fonts/font_sun12x22.c
+++ b/lib/fonts/font_sun12x22.c
@@ -1,5 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
-#include <linux/font.h>
+
+#include "font.h"
#define FONTDATAMAX 11264
diff --git a/lib/fonts/font_sun8x16.c b/lib/fonts/font_sun8x16.c
index 81bb4eeae04e..2b7b2d8e548a 100644
--- a/lib/fonts/font_sun8x16.c
+++ b/lib/fonts/font_sun8x16.c
@@ -1,5 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
-#include <linux/font.h>
+
+#include "font.h"
#define FONTDATAMAX 4096
diff --git a/lib/fonts/font_ter10x18.c b/lib/fonts/font_ter10x18.c
index 80356e9d56c7..3f30b4a211ab 100644
--- a/lib/fonts/font_ter10x18.c
+++ b/lib/fonts/font_ter10x18.c
@@ -1,7 +1,9 @@
// SPDX-License-Identifier: GPL-2.0
-#include <linux/font.h>
+
#include <linux/module.h>
+#include "font.h"
+
#define FONTDATAMAX 9216
static const struct font_data fontdata_ter10x18 = {
diff --git a/lib/fonts/font_ter16x32.c b/lib/fonts/font_ter16x32.c
index 5baedc573dd6..93616cffe642 100644
--- a/lib/fonts/font_ter16x32.c
+++ b/lib/fonts/font_ter16x32.c
@@ -1,7 +1,9 @@
// SPDX-License-Identifier: GPL-2.0
-#include <linux/font.h>
+
#include <linux/module.h>
+#include "font.h"
+
#define FONTDATAMAX 16384
static const struct font_data fontdata_ter16x32 = {
diff --git a/lib/fonts/fonts.c b/lib/fonts/fonts.c
index a861b375e35d..5938f542906b 100644
--- a/lib/fonts/fonts.c
+++ b/lib/fonts/fonts.c
@@ -13,7 +13,6 @@
*/
#include <linux/container_of.h>
-#include <linux/font.h>
#include <linux/kd.h>
#include <linux/module.h>
#include <linux/overflow.h>
@@ -25,12 +24,19 @@
#include <asm/setup.h>
#endif
+#include "font.h"
+
#define console_font_pitch(font) DIV_ROUND_UP((font)->width, 8)
/*
* Helpers for font_data_t
*/
+/* Extra word getters */
+#define REFCOUNT(fd) (((int *)(fd))[-1])
+#define FNTSIZE(fd) (((int *)(fd))[-2])
+#define FNTSUM(fd) (((int *)(fd))[-4])
+
static struct font_data *to_font_data_struct(font_data_t *fd)
{
return container_of(fd, struct font_data, data[0]);
--
2.53.0
^ permalink raw reply related
* [PATCH v3 10/13] lib/fonts: Compare font data for equality with font_data_is_equal()
From: Thomas Zimmermann @ 2026-03-09 14:14 UTC (permalink / raw)
To: gregkh, deller, sam
Cc: linux-fbdev, dri-devel, linux-kernel, Thomas Zimmermann
In-Reply-To: <20260309141723.137364-1-tzimmermann@suse.de>
Add font_data_is_equal() and update consoles to use it.
Font data is equal if it has the same size and contains the same values
on all bytes. Only fbcon uses a crc32 checksum. If set in both operands
the checksums have to be equal.
The new helper also guarantees to not compare internal fonts against
fonts from user space. Internal fonts cannot be ref-counted, so making
them equal to user-space fonts with the same byte sequence results in
undefined behavior.
The test only compares data buffers. Their interpretation is up each
console. Therefore remove a width test in fbcon_set_font().
v3:
- rebase onto font_data_{get,put}()
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/video/console/newport_con.c | 4 +---
drivers/video/fbdev/core/fbcon.c | 7 +------
include/linux/font.h | 1 +
lib/fonts/fonts.c | 26 ++++++++++++++++++++++++++
4 files changed, 29 insertions(+), 9 deletions(-)
diff --git a/drivers/video/console/newport_con.c b/drivers/video/console/newport_con.c
index 43a1a4f41057..1bc3cb1ea116 100644
--- a/drivers/video/console/newport_con.c
+++ b/drivers/video/console/newport_con.c
@@ -529,9 +529,7 @@ static int newport_set_font(int unit, const struct console_font *op,
/* check if font is already used by other console */
for (i = 0; i < MAX_NR_CONSOLES; i++) {
- if (font_data[i] != FONT_DATA
- && font_data_size(font_data[i]) == size
- && !memcmp(font_data[i], new_data, size)) {
+ if (font_data_is_equal(font_data[i], new_data)) {
font_data_put(new_data);
/* current font is the same as the new one */
if (i == unit)
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index ac59480c98cb..00255ac92e42 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -2540,13 +2540,8 @@ static int fbcon_set_font(struct vc_data *vc, const struct console_font *font,
FNTSUM(new_data) = csum;
/* Check if the same font is on some other console already */
for (i = first_fb_vc; i <= last_fb_vc; i++) {
- struct vc_data *tmp = vc_cons[i].d;
-
if (fb_display[i].fontdata &&
- FNTSUM(fb_display[i].fontdata) == csum &&
- font_data_size(fb_display[i].fontdata) == size &&
- tmp->vc_font.width == w &&
- !memcmp(fb_display[i].fontdata, new_data, size)) {
+ font_data_is_equal(fb_display[i].fontdata, new_data)) {
font_data_get(fb_display[i].fontdata);
font_data_put(new_data);
new_data = fb_display[i].fontdata;
diff --git a/include/linux/font.h b/include/linux/font.h
index dd319d0f0201..58bf3c64cabb 100644
--- a/include/linux/font.h
+++ b/include/linux/font.h
@@ -57,6 +57,7 @@ static inline const unsigned char *font_data_buf(font_data_t *fd)
void font_data_get(font_data_t *fd);
bool font_data_put(font_data_t *fd);
unsigned int font_data_size(font_data_t *fd);
+bool font_data_is_equal(font_data_t *lhs, font_data_t *rhs);
/*
* Font description
diff --git a/lib/fonts/fonts.c b/lib/fonts/fonts.c
index d25efd8d6c31..3fb76d185647 100644
--- a/lib/fonts/fonts.c
+++ b/lib/fonts/fonts.c
@@ -110,6 +110,32 @@ unsigned int font_data_size(font_data_t *fd)
}
EXPORT_SYMBOL_GPL(font_data_size);
+/**
+ * font_data_is_equal - Compares font data for equality
+ * @lhs: Left-hand side font data
+ * @rhs: Right-hand-size font data
+ *
+ * Font data is equal if is constain the same sequence of values. The
+ * helper also use the checksum, if both arguments contain it. Font data
+ * coming from different origins, internal or from user space, is never
+ * equal. Allowing this would break reference counting.
+ *
+ * Returns:
+ * True if the given font data is equal, false otherwise.
+ */
+bool font_data_is_equal(font_data_t *lhs, font_data_t *rhs)
+{
+ if (font_data_is_internal(lhs) != font_data_is_internal(rhs))
+ return false;
+ if (font_data_size(lhs) != font_data_size(rhs))
+ return false;
+ if (FNTSUM(lhs) && FNTSUM(rhs) && FNTSUM(lhs) != FNTSUM(rhs))
+ return false;
+
+ return !memcmp(lhs, rhs, FNTSIZE(lhs));
+}
+EXPORT_SYMBOL_GPL(font_data_is_equal);
+
/*
* Font lookup
*/
--
2.53.0
^ permalink raw reply related
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