From a9e3760b0838299649c0d57cca44daaf40ba3c33 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 14 Sep 2026 22:12:34 -1000 Subject: sched_ext: Maintain an online cid mask in the scheduler arena Schedulers on the default cid mapping treat [0, nr_online_cids) as the online set and restart on hotplug. Schedulers that install their own mapping with scx_bpf_cid_override() have no way to learn which cids are online: the count no longer identifies members and the CPU-form cpumask is unusable from cid programs. This is an obvious hole in the cid API. Add scx_bpf_online_cmask(), a kernel-maintained cmask in the scheduler's arena, allocated alongside the per-CPU scratch masks and populated after the cid mapping is finalized and before ops.init(), for child schedulers too. The pointer stays valid through ops.exit() with no reference to take. It is the arena offset as a void pointer, the same form struct_ops arena arguments arrive in. The verifier types the void return as a scalar for the program's arena cast. The mask follows the SCX hotplug notifications: seeded from cpu_active_mask and updated before ops.cid_online/offline() runs, so it lags cpu_online_mask only inside a hotplug transition. Updates walk the scheduler list under the lock that also serializes unlinking. Reads are live, not atomic snapshots. Root initialization excludes hotplug. v2: Reworded the getter kerneldoc (Andrea Righi). Signed-off-by: Tejun Heo Reviewed-by: Andrea Righi --- 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