kernel/linux.git/drivers/nubus/proc.c, branch linux-6.12.y

nubus: Don't list slot resources by default

2023-05-22T11:51:56+00:00

Some Nubus card ROMs contain many slot resources. A single Radius video card produced well over a thousand entries under /proc/bus/nubus/. Populating /proc/bus/nubus/ on a slow machine with several such cards installed takes long enough that the user may think that the system is wedged. All those procfs entries also consume significant RAM though they are not normally needed (except by developers). Omit these resources from /proc/bus/nubus/ by default and add a kernel parameter to enable them when needed. On the test machine, this saved 300 kB and 10 seconds. Cc: Brad Boyer Reviewed-by: Brad Boyer Tested-by: Stan Johnson Signed-off-by: Finn Thain Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/71ed7fb234a5f7381a50253b0d841a656d53e64c.1684200125.git.fthain@linux-m68k.org Signed-off-by: Geert Uytterhoeven

nubus: Remove proc entries before adding them

2023-05-22T11:51:48+00:00

The config ROMs on some Nubus cards contain mistakes such as resource duplication. This results in a warning from proc_register(): NuBus: Scanning NuBus slots. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1 at fs/proc/generic.c:376 proc_register+0xbc/0xda proc_dir_entry '24/5' already registered Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 6.1.0-5-m68k #1 Debian 6.1.12-1 Stack from 00829d18: 00829d18 00451507 00451507 00000000 00000009 0038c57c 00451507 00386bae 00442945 0045f062 00000178 00868580 00868f50 00386c42 0045f062 00000178 00166fc8 00000009 00000000 00829d78 008685e4 0037f9ec 00000025 00248808 0045f0df 00829d94 00166fc8 0045f062 00000178 00000009 0045f0df 008689e4 008685e4 fafe3a20 00868980 00829df3 00829e32 00000024 00829dc0 00167332 00868980 00868580 00829e40 00248d36 00829df3 00008124 00868980 00248b0c Call Trace: [<0038c57c>] dump_stack+0xc/0x10 [<00386bae>] __warn+0x70/0xbc [<00386c42>] warn_slowpath_fmt+0x48/0x66 [<00166fc8>] proc_register+0xbc/0xda [<0037f9ec>] memcmp+0x0/0x56 [<00248808>] nubus_get_rsrc_str+0x0/0x5e [<00166fc8>] proc_register+0xbc/0xda [<00167332>] proc_create_single_data+0x40/0x48 [<00248d36>] nubus_proc_add_rsrc_mem+0x68/0xa4 [<00008124>] amiga_mksound+0xb8/0xc8 [<00248b0c>] nubus_proc_rsrc_show+0x0/0xa4 [<00386180>] memset+0x0/0x94 [<0024864a>] nubus_readdir+0x0/0x66 [<00560f35>] nubus_get_vendorinfo.isra.0+0x87/0x10e [<00560fb4>] nubus_get_vendorinfo.isra.0+0x106/0x10e [<00248d72>] nubus_proc_add_rsrc+0x0/0x8e [<001f6f50>] __dynamic_pr_debug+0x0/0x96 [<0038741e>] _printk+0x0/0x18 [<0016fafe>] kernfs_link_sibling+0x9a/0xaa [<00561cb0>] nubus_init+0x660/0x79c [<0037f7c6>] strcpy+0x0/0x1c [<0003f58c>] parse_args+0x0/0x308 [<00002104>] do_one_initcall+0x0/0x184 [<00561650>] nubus_init+0x0/0x79c [<00010000>] frc1_dst+0xe/0x14 [<00002172>] do_one_initcall+0x6e/0x184 [<0037f7c6>] strcpy+0x0/0x1c [<0003f58c>] parse_args+0x0/0x308 [<00002104>] do_one_initcall+0x0/0x184 [<0054b25c>] kernel_init_freeable+0x192/0x19c [<00561650>] nubus_init+0x0/0x79c [<0038c6c4>] kernel_init+0x0/0xec [<0038c6d8>] kernel_init+0x14/0xec [<0038c6c4>] kernel_init+0x0/0xec [<0000297c>] ret_from_kernel_thread+0xc/0x14 ---[ end trace 0000000000000000 ]--- This particular card (a Radius video card) contains a duplicated resource hence the /proc/bus/nubus/a/1/24/5 entry got registered twice. (A date resource has ID 5, the vendor info directory has ID 24) The solution for this is to remove a potentially pre-existing entry before adding the procfs entry for the resource. Reported-and-tested-by: Stan Johnson Signed-off-by: Finn Thain Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/dd1b560bbe426b351cdbb3bbf89414753c3d0117.1679446472.git.fthain@linux-m68k.org Signed-off-by: Geert Uytterhoeven

nubus: Partially revert proc_create_single_data() conversion

2023-05-22T11:51:47+00:00

The conversion to proc_create_single_data() introduced a regression whereby reading a file in /proc/bus/nubus results in a seg fault: # grep -r . /proc/bus/nubus/e/ Data read fault at 0x00000020 in Super Data (pc=0x1074c2) BAD KERNEL BUSERR Oops: 00000000 Modules linked in: PC: [<001074c2>] PDE_DATA+0xc/0x16 SR: 2010 SP: 38284958 a2: 01152370 d0: 00000001 d1: 01013000 d2: 01002790 d3: 00000000 d4: 00000001 d5: 0008ce2e a0: 00000000 a1: 00222a40 Process grep (pid: 45, task=142f8727) Frame format=B ssw=074d isc=2008 isb=4e5e daddr=00000020 dobuf=01199e70 baddr=001074c8 dibuf=ffffffff ver=f Stack from 01199e48: 01199e70 00222a58 01002790 00000000 011a3000 01199eb0 015000c0 00000000 00000000 01199ec0 01199ec0 000d551a 011a3000 00000001 00000000 00018000 d003f000 00000003 00000001 0002800d 01052840 01199fa8 c01f8000 00000000 00000029 0b532b80 00000000 00000000 00000029 0b532b80 01199ee4 00103640 011198c0 d003f000 00018000 01199fa8 00000000 011198c0 00000000 01199f4c 000b3344 011198c0 d003f000 00018000 01199fa8 00000000 00018000 011198c0 Call Trace: [<00222a58>] nubus_proc_rsrc_show+0x18/0xa0 [<000d551a>] seq_read+0xc4/0x510 [<00018000>] fp_fcos+0x2/0x82 [<0002800d>] __sys_setreuid+0x115/0x1c6 [<00103640>] proc_reg_read+0x5c/0xb0 [<00018000>] fp_fcos+0x2/0x82 [<000b3344>] __vfs_read+0x2c/0x13c [<00018000>] fp_fcos+0x2/0x82 [<00018000>] fp_fcos+0x2/0x82 [<000b8aa2>] sys_statx+0x60/0x7e [<000b34b6>] vfs_read+0x62/0x12a [<00018000>] fp_fcos+0x2/0x82 [<00018000>] fp_fcos+0x2/0x82 [<000b39c2>] ksys_read+0x48/0xbe [<00018000>] fp_fcos+0x2/0x82 [<000b3a4e>] sys_read+0x16/0x1a [<00018000>] fp_fcos+0x2/0x82 [<00002b84>] syscall+0x8/0xc [<00018000>] fp_fcos+0x2/0x82 [<0000c016>] not_ext+0xa/0x18 Code: 4e5e 4e75 4e56 0000 206e 0008 2068 ffe8 <2068> 0020 2008 4e5e 4e75 4e56 0000 2f0b 206e 0008 2068 0004 2668 0020 206b ffe8 Disabling lock debugging due to kernel taint Segmentation fault The proc_create_single_data() conversion does not work because single_open(file, nubus_proc_rsrc_show, PDE_DATA(inode)) is not equivalent to the original code. Fixes: 3f3942aca6da ("proc: introduce proc_create_single{,_data}") Cc: Christoph Hellwig Cc: stable@vger.kernel.org # 5.6+ Signed-off-by: Finn Thain Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/d4e2a586e793cc8d9442595684ab8a077c0fe726.1678783919.git.fthain@linux-m68k.org Signed-off-by: Geert Uytterhoeven

proc: remove PDE_DATA() completely

2022-01-22T06:33:37+00:00

Remove PDE_DATA() completely and replace it with pde_data(). [akpm@linux-foundation.org: fix naming clash in drivers/nubus/proc.c] [akpm@linux-foundation.org: now fix it properly] Link: https://lkml.kernel.org/r/20211124081956.87711-2-songmuchun@bytedance.com Signed-off-by: Muchun Song Acked-by: Christian Brauner Cc: Alexey Dobriyan Cc: Alexey Gladkov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

proc: introduce proc_create_single{,_data}

2018-05-16T05:23:35+00:00

Variants of proc_create{,_data} that directly take a seq_file show callback and drastically reduces the boilerplate code in the callers. All trivial callers converted over. Signed-off-by: Christoph Hellwig

nubus: Add support for the driver model

2018-01-16T15:47:29+00:00

This patch brings basic support for the Linux Driver Model to the NuBus subsystem. For flexibility, the matching of boards with drivers is left up to the drivers. This is also the approach taken by NetBSD. A board may have many functions, and drivers may have to consider many functional resources and board resources in order to match a device. This implementation does not bind drivers to resources (nor does it bind many drivers to the same board). Apple's NuBus declaration ROM design is flexible enough to allow that, but I don't see a need to support it as we don't use the "slot zero" resources (in the main logic board ROM). Eliminate the global nubus_boards linked list by rewriting the procfs board iterator around bus_for_each_dev(). Hence the nubus device refcount can be used to determine the lifespan of board objects. Cc: Greg Kroah-Hartman Reviewed-by: Greg Kroah-Hartman Tested-by: Stan Johnson Signed-off-by: Finn Thain Signed-off-by: Geert Uytterhoeven

nubus: Adopt standard linked list implementation

2018-01-16T15:47:29+00:00

This increases code re-use and improves readability. Cc: "David S. Miller" Cc: Bartlomiej Zolnierkiewicz Acked-by: Bartlomiej Zolnierkiewicz Tested-by: Stan Johnson Signed-off-by: Finn Thain Signed-off-by: Geert Uytterhoeven

nubus: Rename struct nubus_dev

2018-01-16T15:47:29+00:00

It is misleading to call a functional resource a "device". In adopting the Linux Driver Model, the struct device will be embedded in struct nubus_board. That will compound the terminlogy problem because drivers will bind with boards, not with functional resources. Avoid this by renaming struct nubus_dev as struct nubus_rsrc. "Functional resource" is the vendor's terminology so this helps avoid confusion. Cc: "David S. Miller" Cc: Bartlomiej Zolnierkiewicz Acked-by: Bartlomiej Zolnierkiewicz Tested-by: Stan Johnson Signed-off-by: Finn Thain Signed-off-by: Geert Uytterhoeven

nubus: Rework /proc/bus/nubus/s/ implementation

2018-01-16T15:47:29+00:00

The /proc/bus/nubus/s/ directory tree for any slot s is missing a lot of information. The struct file_operations methods have long been left unimplemented (hence the familiar compile-time warning, "Need to set some I/O handlers here"). Slot resources have a complex structure which varies depending on board function. The logic for interpreting these ROM data structures is found in nubus.c. Let's not duplicate that logic in proc.c. Create the /proc/bus/nubus/s/ inodes while scanning slot s. During descent through slot resource subdirectories, call the new nubus_proc_add_foo() functions to create the procfs inodes. Also add a new function, nubus_seq_write_rsrc_mem(), to write the contents of a particular slot resource to a given seq_file. This is used by the procfs file_operations methods, to finally give userspace access to slot ROM information, such as the available video modes. Tested-by: Stan Johnson Signed-off-by: Finn Thain Signed-off-by: Geert Uytterhoeven

nubus: Remove redundant code

2018-01-16T15:47:29+00:00

Eliminate unused values from struct nubus_dev to save wasted memory (a Radius PrecisionColor 24X card has about 95 functional resources and up to six such cards may be fitted). Also remove redundant static variable initialization, an unreachable !MACH_IS_MAC conditional, the unused nubus_find_device() function, the bogus get_nubus_list() prototype and the pointless card_present temporary variable. Tested-by: Stan Johnson Signed-off-by: Finn Thain Signed-off-by: Geert Uytterhoeven