kernel/linux.git/arch/mips/dec, branch v7.0.12

serial: zs: Convert to use a platform device

2026-06-09T10:32:48+00:00

commit 7cac59d08a73cb866ec51a483a6f3fe0f531947c upstream. Prevent a crash from happening as the first serial port is initialised: Console: switching to mono frame buffer device 160x64 fb0: PMAG-AA frame buffer device at tc0 DECstation Z85C30 serial driver version 0.10 CPU 0 Unable to handle kernel paging request at virtual address 0000002c, epc == 803ab00c, ra == 803aafe0 Oops[#1]: CPU: 0 PID: 1 Comm: swapper Not tainted 6.4.0-rc3-00031-g84a9582fd203-dirty #57 $ 0 : 00000000 10012c00 803aaeb0 00000000 $ 4 : 80e12f60 80e12f50 80e12f58 81000030 $ 8 : 00000000 805ff37c 00000000 33433538 $12 : 65732030 00000006 80c2915d 6c616972 $16 : 80e12f00 807b7630 00000000 00000000 $20 : 00000004 00000348 000001a0 807623b8 $24 : 00000018 00000000 $28 : 80c24000 80c25d60 8078b148 803aafe0 Hi : 00000000 Lo : 00000000 epc : 803ab00c serial_base_ctrl_add+0x78/0xf4 ra : 803aafe0 serial_base_ctrl_add+0x4c/0xf4 Status: 10012c03 KERNEL EXL IE Cause : 00000008 (ExcCode 02) BadVA : 0000002c PrId : 00000440 (R4400SC) Modules linked in: Process swapper (pid: 1, threadinfo=(ptrval), task=(ptrval), tls=00000000) Stack : 80760000 00000cc0 00400044 00400040 803aa02c 80d61ab8 00000000 807b7630 80760000 807623b8 807b7628 803aa644 80386998 00000000 80e17780 80220f68 80e17780 80d61ab8 80c17d80 80e17780 80e17780 8063c798 80e17780 80383fa0 00000010 80e17780 00000000 80386998 807a0000 00000000 00400040 8038f848 807623b8 80d61ab8 00000004 80e17780 00000000 803a68e4 80c25e2c 803bb884 ... Call Trace: [<803ab00c>] serial_base_ctrl_add+0x78/0xf4 [<803aa644>] serial_core_register_port+0x174/0x69c [<8077e9ac>] zs_init+0xc8/0xfc [<800404d4>] do_one_initcall+0x40/0x2ac [<8076cecc>] kernel_init_freeable+0x1e4/0x270 [<80605bec>] kernel_init+0x20/0x108 [<800431e8>] ret_from_kernel_thread+0x14/0x1c Code: 2442aeb0 ae120024 ae0200d0 <8c67002c> 50e00001 8c670000 3c06806e 3c05806e afb30010 ---[ end trace 0000000000000000 ]--- (report at the offending commit) -- where a pointer is dereferenced that has been derived from a null pointer to the port's parent device. Since no device is available with legacy probing and it's not anymore a preferable way to discover devices anyway, switch the driver to using a platform device and use it as the port's parent device. Update resource handling accordingly and only request the actual span of addresses used within the slot, which will have had its resource already requested by generic platform device code. Use platform_driver_probe() not just because SCC devices are fixed with solder on board and not straightforward to remove, but foremost because the associated TTY's major device number is the same as used by the dz driver and the first driver to claim it will prevent the other one from using it. Either one DZ device or some SCC devices will be present in a given system but never both at a time, and therefore we want the major device number to be claimed by the first driver to actually successfully bind to its device and platform_driver_probe() is a way to fulfil that. An unfortunate consequence of the switch to a platform device is we now hand the console over from the bootconsole much later in the bootstrap. The firmware console handler appears good enough though to work so late and in particular with interrupts enabled. Since there is one way only remaining to reach zs_reset() now, remove the port initialisation marker as no longer needed and go through the channel reset unconditionally. Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") Signed-off-by: Maciej W. Rozycki Cc: stable@vger.kernel.org # needs to use .remove_new for <= 6.10 Link: https://patch.msgid.link/alpine.DEB.2.21.2605062328480.46195@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

serial: dz: Convert to use a platform device

2026-06-09T10:32:48+00:00

commit 5d7a49d60b8fda66da60e240fd7315232fa1754f upstream. Prevent a crash from happening as the first serial port is initialised: Console: switching to colour frame buffer device 160x64 tgafb: SFB+ detected, rev=0x02 fb0: Digital ZLX-E1 frame buffer device at 0x1e000000 DECstation DZ serial driver version 1.04 CPU 0 Unable to handle kernel paging request at virtual address 000000bc, epc == 8048b3a4, ra == 80470a78 Oops[#1]: CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.19.0-dirty #35 NONE $ 0 : 00000000 1000ac00 00000004 804707ac $ 4 : 00000000 80e20850 80e20858 81000030 $ 8 : 00000000 8072c81c 00000008 fefefeff $12 : 6c616972 00000006 80c5917f 69726420 $16 : 80e20800 00000000 808f8968 80e20800 $20 : 00000000 807f5a90 808b0094 808d3bc8 $24 : 00000018 80479030 $28 : 80c2e000 80c2fd70 00000069 80470a78 Hi : 00000004 Lo : 00000000 epc : 8048b3a4 __dev_fwnode+0x0/0xc ra : 80470a78 serial_base_ctrl_add+0xa0/0x168 Status: 1000ac04 IEp Cause : 30000008 (ExcCode 02) BadVA : 000000bc PrId : 00000220 (R3000) Modules linked in: Process swapper/0 (pid: 1, threadinfo=(ptrval), task=(ptrval), tls=00000000) Stack : 00400044 00400040 8046f4cc 00000000 808a6148 808a0000 808f8968 8086983c 808e0000 8046fc84 1000ac01 00000028 80e20700 802ba3f8 80e20700 80d34a94 80c1b900 80e20700 80e20700 80e20700 80e20700 80444650 00000000 00000000 00000000 807f5a90 808b0094 80447080 00400040 808e0000 80d34a94 808a6148 80d34a94 00000004 80e20700 00000000 8076974c 80469810 80c2fe3c 1000ac01 ... Call Trace: [<8048b3a4>] __dev_fwnode+0x0/0xc [<80470a78>] serial_base_ctrl_add+0xa0/0x168 [<8046fc84>] serial_core_register_port+0x1c8/0x974 [<808c6af0>] dz_init+0x74/0xc8 [<800470e0>] do_one_initcall+0x44/0x2d4 [<808b111c>] kernel_init_freeable+0x258/0x308 [<8072e434>] kernel_init+0x20/0x114 [<80049cd0>] ret_from_kernel_thread+0x14/0x1c Code: 27bd0018 03e00008 2402ffea <8c8200bc> 03e00008 00000000 27bdffc0 afbe0038 afb30024 ---[ end trace 0000000000000000 ]--- -- where a pointer is dereferenced that has been derived from a null pointer to the port's parent device. Since no device is available with legacy probing and it's not anymore a preferable way to discover devices anyway, switch the driver to using a platform device and use it as the port's parent device. Update resource handling accordingly and only request the actual span of addresses used within the slot, which will have had its resource already requested by generic platform device code. Use platform_driver_probe() not just because the DZ device is fixed with solder on board and not straightforward to remove, but foremost because the associated TTY's major device number is the same as used by the zs driver and the first driver to claim it will prevent the other one from using it. Either one DZ device or some SCC devices will be present in a given system but never both at a time, and therefore we want the major device number to be claimed by the first driver to actually successfully bind to its device and platform_driver_probe() is a way to fulfil that. An unfortunate consequence of the switch to a platform device is we now hand the console over from the bootconsole much later in the bootstrap. The firmware console handler appears good enough though to work so late and in particular with interrupts enabled. Conversely only starting the console port so late lets the reset code fully utilise our delay handlers, so switch from udelay() to fsleep() for transmitter draining so as to avoid busy-waiting for an excessive amount of time. Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") Signed-off-by: Maciej W. Rozycki Cc: stable@vger.kernel.org # needs to use .remove_new for <= 6.10 Link: https://patch.msgid.link/alpine.DEB.2.21.2605062326540.46195@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman

MIPS: dec: Declare which_prom() as static

2025-02-27T09:40:45+00:00

Declare which_prom() as static to suppress gcc compiler warning that 'missing-prototypes'. This function is not intended to be called from other parts. Fix follow error with gcc-14 when -Werror: arch/mips/dec/prom/init.c:45:13: error: no previous prototype for ‘which_prom’ [-Werror=missing-prototypes] 45 | void __init which_prom(s32 magic, s32 *prom_vec) | ^~~~~~~~~~ cc1: all warnings being treated as errors make[6]: *** [scripts/Makefile.build:207: arch/mips/dec/prom/init.o] Error 1 make[5]: *** [scripts/Makefile.build:465: arch/mips/dec/prom] Error 2 make[5]: *** Waiting for unfinished jobs.... Signed-off-by: WangYuli Signed-off-by: Thomas Bogendoerfer

genirq: Convert kstat_irqs to a struct

2024-04-12T15:08:05+00:00

The irq_desc::kstat_irqs member is a per-CPU variable of type int, which is only capable of counting. A snapshot mechanism for interrupt statistics will be added soon, which requires an additional variable to store the snapshot. To facilitate expansion, convert kstat_irqs here to a struct containing only the count. Originally-by: Thomas Gleixner Signed-off-by: Bitao Hu Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20240411074134.30922-2-yaoma@linux.alibaba.com

MIPS: fix typos in comments

2022-05-04T20:22:59+00:00

Various spelling mistakes in comments. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall Signed-off-by: Thomas Bogendoerfer

DEC: Limit PMAX memory probing to R3k systems

2022-03-07T12:10:44+00:00

Recent tightening of the opcode table in binutils so as to consistently disallow the assembly or disassembly of CP0 instructions not supported by the processor architecture chosen has caused a regression like below: arch/mips/dec/prom/locore.S: Assembler messages: arch/mips/dec/prom/locore.S:29: Error: opcode not supported on this processor: r4600 (mips3) `rfe' in a piece of code used to probe for memory with PMAX DECstation models, which have non-REX firmware. Those computers always have an R2000 CPU and consequently the exception handler used in memory probing uses the RFE instruction, which those processors use. While adding 64-bit support this code was correctly excluded for 64-bit configurations, however it should have also been excluded for irrelevant 32-bit configurations. Do this now then, and only enable PMAX memory probing for R3k systems. Reported-by: Jan-Benedict Glaw Reported-by: Sudip Mukherjee Signed-off-by: Maciej W. Rozycki Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org # v2.6.12+ Signed-off-by: Thomas Bogendoerfer

mips: DEC: honor CONFIG_MIPS_FP_SUPPORT=n

2022-03-07T12:10:09+00:00

Include the DECstation interrupt handler in opting out of FPU support. Fixes a linker error: mips-linux-ld: arch/mips/dec/int-handler.o: in function `fpu': (.text+0x148): undefined reference to `handle_fpe_int' Fixes: 183b40f992c8 ("MIPS: Allow FP support to be disabled") Signed-off-by: Randy Dunlap Reported-by: kernel test robot Cc: Paul Burton Cc: Thomas Bogendoerfer Cc: Maciej W. Rozycki Cc: linux-mips@vger.kernel.org Acked-by: Maciej W. Rozycki Signed-off-by: Thomas Bogendoerfer

mips: dec: provide the correctly capitalized config CPU_R4X00 in init error message

2021-12-16T14:47:37+00:00

The config for MIPS R4000-series processors is named CPU_R4X00 with upper-case X, not CPU_R4x00 as the error message suggests. Hence, ./scripts/checkkconfigsymbols.py reports this invalid reference: CPU_R4x00 Referencing files: arch/mips/dec/prom/init.c When human users encounter this error message, they probably just deal with this minor discrepancy; so, the spelling never was a big deal here. Still, the script ./scripts/checkkconfigsymbols.py has been quite useful to identify a number of bugs with Kconfig symbols and deserves to be executed and checked regularly. So, repair the error message to reduce the reports made the script and simplify to use this script, as new issues are easier to spot when the list of reports is shorter. Signed-off-by: Lukas Bulwahn Signed-off-by: Thomas Bogendoerfer

MIPS: Allow modules to set board_be_handler

2021-11-09T15:07:26+00:00

After making the brcmstb_gisb driver modular with 707a4cdf86e5 ("bus: brcmstb_gisb: Allow building as module") Guenter reported that mips allmodconfig failed to link because board_be_handler was referenced. Thomas indicated that if we were to continue making the brcmstb_gisb driver modular for MIPS we would need to introduce a function that allows setting the board_be_handler and export that function towards modules. This is what is being done here: board_be_handler is made static and is now settable with a mips_set_be_handler() function which is exported. Reported-by: Guenter Roeck Suggested-by: Thomas Bogendoerfer Fixes: 707a4cdf86e5 ("bus: brcmstb_gisb: Allow building as module") Signed-off-by: Florian Fainelli Tested-by: Guenter Roeck Signed-off-by: Thomas Bogendoerfer

MIPS: DEC: Restore bootmem reservation for firmware working memory area

2020-10-14T21:57:57+00:00

Fix a crash on DEC platforms starting with: VFS: Mounted root (nfs filesystem) on device 0:11. Freeing unused PROM memory: 124k freed BUG: Bad page state in process swapper pfn:00001 page:(ptrval) refcount:0 mapcount:-128 mapping:00000000 index:0x1 pfn:0x1 flags: 0x0() raw: 00000000 00000100 00000122 00000000 00000001 00000000 ffffff7f 00000000 page dumped because: nonzero mapcount Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 5.9.0-00858-g865c50e1d279 #1 Stack : 8065dc48 0000000b 8065d2b8 9bc27dcc 80645bfc 9bc259a4 806a1b97 80703124 80710000 8064a900 00000001 80099574 806b116c 1000ec00 9bc27d88 806a6f30 00000000 00000000 80645bfc 00000000 31232039 80706ba4 2e392e35 8039f348 2d383538 00000070 0000000a 35363867 00000000 806c2830 80710000 806b0000 80710000 8064a900 00000001 81000000 00000000 00000000 8035af2c 80700000 ... Call Trace: [<8004bc5c>] show_stack+0x34/0x104 [<8015675c>] bad_page+0xfc/0x128 [<80157714>] free_pcppages_bulk+0x1f4/0x5dc [<801591cc>] free_unref_page+0xc0/0x130 [<8015cb04>] free_reserved_area+0x144/0x1d8 [<805abd78>] kernel_init+0x20/0x100 [<80046070>] ret_from_kernel_thread+0x14/0x1c Disabling lock debugging due to kernel taint caused by an attempt to free bootmem space that as from commit b93ddc4f9156 ("mips: Reserve memory for the kernel image resources") has not been anymore reserved due to the removal of generic MIPS arch code that used to reserve all the memory from the beginning of RAM up to the kernel load address. This memory does need to be reserved on DEC platforms however as it is used by REX firmware as working area, as per the TURBOchannel firmware specification[1]: Table 2-2 REX Memory Regions ------------------------------------------------------------------------- Starting Ending Region Address Address Use ------------------------------------------------------------------------- 0 0xa0000000 0xa000ffff Restart block, exception vectors, REX stack and bss 1 0xa0010000 0xa0017fff Keyboard or tty drivers 2 0xa0018000 0xa001f3ff 1) CRT driver 3 0xa0020000 0xa002ffff boot, cnfg, init and t objects 4 0xa0020000 0xa002ffff 64KB scratch space ------------------------------------------------------------------------- 1) Note that the last 3 Kbytes of region 2 are reserved for backward compatibility with previous system software. ------------------------------------------------------------------------- (this table uses KSEG2 unmapped virtual addresses, which in the MIPS architecture are offset from physical addresses by a fixed value of 0xa0000000 and therefore the regions referred do correspond to the beginning of the physical address space) and we call into the firmware on several occasions throughout the bootstrap process. It is believed that pre-REX firmware used with non-TURBOchannel DEC platforms has the same requirements, as hinted by note #1 cited. Recreate the discarded reservation then, in DEC platform code, removing the crash. References: [1] "TURBOchannel Firmware Specification", On-line version, EK-TCAAD-FS-004, Digital Equipment Corporation, January 1993, Chapter 2 "System Module Firmware", p. 2-5 Signed-off-by: Maciej W. Rozycki Fixes: b93ddc4f9156 ("mips: Reserve memory for the kernel image resources") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Thomas Bogendoerfer