From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- drivers/video/fbdev/sstfb.c | 1543 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1543 insertions(+) create mode 100644 drivers/video/fbdev/sstfb.c (limited to 'drivers/video/fbdev/sstfb.c') diff --git a/drivers/video/fbdev/sstfb.c b/drivers/video/fbdev/sstfb.c new file mode 100644 index 000000000..2ea947f57 --- /dev/null +++ b/drivers/video/fbdev/sstfb.c @@ -0,0 +1,1543 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/drivers/video/sstfb.c -- voodoo graphics frame buffer + * + * Copyright (c) 2000-2002 Ghozlane Toumi + * + * Created 15 Jan 2000 by Ghozlane Toumi + * + * Contributions (and many thanks) : + * + * 03/2001 James Simmons + * 04/2001 Paul Mundt + * 05/2001 Urs Ganse + * (initial work on voodoo2 port, interlace) + * 09/2002 Helge Deller + * (enable driver on big-endian machines (hppa), ioctl fixes) + * 12/2002 Helge Deller + * (port driver to new frambuffer infrastructure) + * 01/2003 Helge Deller + * (initial work on fb hardware acceleration for voodoo2) + * 08/2006 Alan Cox + * Remove never finished and bogus 24/32bit support + * Clean up macro abuse + * Minor tidying for format. + * 12/2006 Helge Deller + * add /sys/class/graphics/fbX/vgapass sysfs-interface + * add module option "mode_option" to set initial screen mode + * use fbdev default videomode database + * remove debug functions from ioctl + */ + +/* + * The voodoo1 has the following memory mapped address space: + * 0x000000 - 0x3fffff : registers (4MB) + * 0x400000 - 0x7fffff : linear frame buffer (4MB) + * 0x800000 - 0xffffff : texture memory (8MB) + */ + +/* + * misc notes, TODOs, toASKs, and deep thoughts + +-TODO: at one time or another test that the mode is acceptable by the monitor +-ASK: Can I choose different ordering for the color bitfields (rgba argb ...) + which one should i use ? is there any preferred one ? It seems ARGB is + the one ... +-TODO: in set_var check the validity of timings (hsync vsync)... +-TODO: check and recheck the use of sst_wait_idle : we don't flush the fifo via + a nop command. so it's ok as long as the commands we pass don't go + through the fifo. warning: issuing a nop command seems to need pci_fifo +-FIXME: in case of failure in the init sequence, be sure we return to a safe + state. +- FIXME: Use accelerator for 2D scroll +-FIXME: 4MB boards have banked memory (FbiInit2 bits 1 & 20) + */ + +/* + * debug info + * SST_DEBUG : enable debugging + * SST_DEBUG_REG : debug registers + * 0 : no debug + * 1 : dac calls, [un]set_bits, FbiInit + * 2 : insane debug level (log every register read/write) + * SST_DEBUG_FUNC : functions + * 0 : no debug + * 1 : function call / debug ioctl + * 2 : variables + * 3 : flood . you don't want to do that. trust me. + * SST_DEBUG_VAR : debug display/var structs + * 0 : no debug + * 1 : dumps display, fb_var + * + * sstfb specific ioctls: + * toggle vga (0x46db) : toggle vga_pass_through + */ + +#undef SST_DEBUG + + +/* + * Includes + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include