kernel/linux.git/arch/mips/include, branch v6.12.97

MIPS: DEC: Ensure 32-bit stack location for o32 prom_printf()

2026-07-24T14:11:32+00:00

commit 5ff79e8bdc75db51e30298a75939e2308e7658e0 upstream. In 64-bit configurations calling any firmware entry points from a kernel thread other than the initial one will result in a situation where the stack has been placed in the XKPHYS 64-bit memory segment. Consequently the stack pointer is no longer a 32-bit value and when the 32-bit firmware code called uses 32-bit ALU operations to manipulate the stack pointer, the calculated result is incorrect (in fact in the 64-bit MIPS ISA almost all 32-bit ALU operations will produce an unpredictable result when executed on 64-bit data) and control goes astray. This may happen when no final console driver has been enabled in the configuration and consequently the initial console continues being used late into bootstrap, or with an upcoming change that will switch the zs driver to use a platform device, which in turn will make the console handover happen only after other kernel threads have already been started, and the kernel will hang at: pid_max: default: 32768 minimum: 301 or somewhat later, but always before: cblist_init_generic: Setting adjustable number of callback queues. has been printed. It seems that only the prom_printf() entry point is affected. Of all the other entry points wired only rex_slot_address() and rex_gettcinfo() are called from a kernel thread other than the initial one, specifically kernel_init(), and they are leaf functions that do no business with the stack, having worked with no issue ever since 64-bit support was added for the platform back in 2002. To address this issue then, arrange for the stack to be switched in the o32 wrapper as required for prom_printf() only, by supplying call_o32() with a pointer to a chunk of initdata space, which is placed in the CKSEG0 32-bit compatibility segment, observing that prom_printf() is only called from console output handler and therefore with the console lock held, implying no need for this code to be reentrant. Other firmware entry points may be called with interrupts enabled and no lock held, and may therefore require that call_o32() be reentrant. They trigger no issue at this point and "if it ain't broke, don't fix it," so just leave them alone. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Maciej W. Rozycki Cc: stable@vger.kernel.org # v2.6.12+ Signed-off-by: Thomas Bogendoerfer Signed-off-by: Greg Kroah-Hartman

ring-buffer: Flush and stop persistent ring buffer on panic

2026-06-09T10:26:03+00:00

[ Upstream commit a494d3c8d5392bcdff83c2a593df0c160ff9f322 ] On real hardware, panic and machine reboot may not flush hardware cache to memory. This means the persistent ring buffer, which relies on a coherent state of memory, may not have its events written to the buffer and they may be lost. Moreover, there may be inconsistency with the counters which are used for validation of the integrity of the persistent ring buffer which may cause all data to be discarded. To avoid this issue, stop recording of the ring buffer on panic and flush the cache of the ring buffer's memory. Fixes: e645535a954a ("tracing: Add option to use memmapped memory for trace boot instance") Cc: stable@vger.kernel.org Cc: Will Deacon Cc: Mathieu Desnoyers Cc: Ian Rogers Link: https://patch.msgid.link/177751969602.2136606.12031934362587643488.stgit@mhiramat.tok.corp.google.com Signed-off-by: Masami Hiramatsu (Google) Acked-by: Catalin Marinas Acked-by: Geert Uytterhoeven Signed-off-by: Steven Rostedt Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

MIPS: Always record SEGBITS in cpu_data.vmbits

2026-04-18T08:41:55+00:00

commit 8374c2cb83b95b3c92f129fd56527225c20a058c upstream. With a 32-bit kernel running on 64-bit MIPS hardware the hardcoded value of `cpu_vmbits' only records the size of compatibility useg and does not reflect the size of native xuseg or the complete range of values allowed in the VPN2 field of TLB entries. An upcoming change will need the actual VPN2 value range permitted even in 32-bit kernel configurations, so always include the `vmbits' member in `struct cpuinfo_mips' and probe for SEGBITS when running on 64-bit hardware and resorting to the currently hardcoded value of 31 on 32-bit processors. No functional change for users of `cpu_vmbits'. Signed-off-by: Maciej W. Rozycki Signed-off-by: Thomas Bogendoerfer Signed-off-by: Sasha Levin

MIPS: Loongson: Make cpumask_of_node() robust against NUMA_NO_NODE

2026-03-04T12:21:26+00:00

[ Upstream commit d55d3fe2d1470ac5b6e93efe7998b728013c9fc8 ] The arch definition of cpumask_of_node() cannot handle NUMA_NO_NODE - which is a valid index - so add a check for this. Signed-off-by: John Garry Reviewed-by: Huacai Chen Signed-off-by: Thomas Bogendoerfer Signed-off-by: Sasha Levin

MIPS: vpe-mt: add missing prototypes for vpe_{alloc,start,stop,free}

2025-08-20T16:30:42+00:00

[ Upstream commit 844615dd0f2d95c018ec66b943e08af22b62aff3 ] These functions are exported but their prototypes are not defined. This patch adds the missing function prototypes to fix the following compilation warnings: arch/mips/kernel/vpe-mt.c:180:7: error: no previous prototype for 'vpe_alloc' [-Werror=missing-prototypes] 180 | void *vpe_alloc(void) | ^~~~~~~~~ arch/mips/kernel/vpe-mt.c:198:5: error: no previous prototype for 'vpe_start' [-Werror=missing-prototypes] 198 | int vpe_start(void *vpe, unsigned long start) | ^~~~~~~~~ arch/mips/kernel/vpe-mt.c:208:5: error: no previous prototype for 'vpe_stop' [-Werror=missing-prototypes] 208 | int vpe_stop(void *vpe) | ^~~~~~~~ arch/mips/kernel/vpe-mt.c:229:5: error: no previous prototype for 'vpe_free' [-Werror=missing-prototypes] 229 | int vpe_free(void *vpe) | ^~~~~~~~ Signed-off-by: Shiji Yang Signed-off-by: Thomas Bogendoerfer Signed-off-by: Sasha Levin

MIPS: Use arch specific syscall name match function

2025-05-29T09:02:40+00:00

[ Upstream commit 756276ce78d5624dc814f9d99f7d16c8fd51076e ] On MIPS system, most of the syscall function name begin with prefix sys_. Some syscalls are special such as clone/fork, function name of these begin with __sys_. Since scratch registers need be saved in stack when these system calls happens. With ftrace system call method, system call functions are declared with SYSCALL_DEFINEx, metadata of the system call symbol name begins with sys_. Here mips specific function arch_syscall_match_sym_name is used to compare function name between sys_call_table[] and metadata of syscall symbol. Signed-off-by: Bibo Mao Signed-off-by: Thomas Bogendoerfer Signed-off-by: Sasha Levin

MIPS: Fix MAX_REG_OFFSET

2025-05-18T06:24:56+00:00

[ Upstream commit c44572e0cc13c9afff83fd333135a0aa9b27ba26 ] Fix MAX_REG_OFFSET to point to the last register in 'pt_regs' and not to the marker itself, which could allow regs_get_register() to return an invalid offset. Fixes: 40e084a506eb ("MIPS: Add uprobes support.") Suggested-by: Maciej W. Rozycki Signed-off-by: Thorsten Blum Signed-off-by: Thomas Bogendoerfer Signed-off-by: Sasha Levin

MIPS: cm: Fix warning if MIPS_CM is disabled

2025-05-02T05:59:32+00:00

commit b73c3ccdca95c237750c981054997c71d33e09d7 upstream. Commit e27fbe16af5c ("MIPS: cm: Detect CM quirks from device tree") introduced arch/mips/include/asm/mips-cm.h:119:13: error: ‘mips_cm_update_property’ defined but not used [-Werror=unused-function] Fix this by making empty function implementation inline Fixes: e27fbe16af5c ("MIPS: cm: Detect CM quirks from device tree") Signed-off-by: Thomas Bogendoerfer Signed-off-by: Greg Kroah-Hartman

MIPS: cm: Detect CM quirks from device tree

2025-05-02T05:59:14+00:00

[ Upstream commit e27fbe16af5cfc40639de4ced67d1a866a1953e9 ] Some information that should be retrieved at runtime for the Coherence Manager can be either absent or wrong. This patch allows checking if some of this information is available from the device tree and updates the internal variable accordingly. For now, only the compatible string associated with the broken HCI is being retrieved. Signed-off-by: Gregory CLEMENT Signed-off-by: Thomas Bogendoerfer Signed-off-by: Sasha Levin

MIPS: ds1287: Match ds1287_set_base_clock() function types

2025-04-25T08:48:07+00:00

commit a759109b234385b74d2f5f4c86b5f59b3201ec12 upstream. Synchronize the declaration of ds1287_set_base_clock() between cevt-ds1287.c and ds1287.h. Fix follow error with gcc-14 when -Werror: arch/mips/kernel/cevt-ds1287.c:21:5: error: conflicting types for ‘ds1287_set_base_clock’; have ‘int(unsigned int)’ 21 | int ds1287_set_base_clock(unsigned int hz) | ^~~~~~~~~~~~~~~~~~~~~ In file included from arch/mips/kernel/cevt-ds1287.c:13: ./arch/mips/include/asm/ds1287.h:11:13: note: previous declaration of ‘ds1287_set_base_clock’ with type ‘void(unsigned int)’ 11 | extern void ds1287_set_base_clock(unsigned int clock); | ^~~~~~~~~~~~~~~~~~~~~ make[7]: *** [scripts/Makefile.build:207: arch/mips/kernel/cevt-ds1287.o] Error 1 make[6]: *** [scripts/Makefile.build:465: arch/mips/kernel] Error 2 make[6]: *** Waiting for unfinished jobs.... Signed-off-by: WangYuli Signed-off-by: Thomas Bogendoerfer Signed-off-by: Greg Kroah-Hartman