kernel/linux.git/arch/mips/include/uapi, branch linux-5.9.y

MIPS: Retire kvm paravirt

2020-07-24T08:53:23+00:00

paravirt machine was introduced for Cavium's partial virtualization technology, however, it's host side support and QEMU support never landed in upstream. As Cavium was acquired by Marvel and they have no intention to maintain their MIPS product line, also paravirt is unlikely to be utilized by community users, it's time to retire it if nobody steps in to maintain it. Signed-off-by: Jiaxun Yang Signed-off-by: Thomas Bogendoerfer

KVM: MIPS: Add CPUCFG emulation for Loongson-3

2020-06-04T17:51:33+00:00

Loongson-3 overrides lwc2 instructions to implement CPUCFG and CSR read/write functions. These instructions all cause guest exit so CSR doesn't benifit KVM guest (and there are always legacy methods to provide the same functions as CSR). So, we only emulate CPUCFG and let it return a reduced feature list (which means the virtual CPU doesn't have any other advanced features, including CSR) in KVM. Reviewed-by: Aleksandar Markovic Signed-off-by: Huacai Chen Co-developed-by: Jiaxun Yang Message-Id: <1590220602-3547-12-git-send-email-chenhc@lemote.com> Signed-off-by: Paolo Bonzini

MIPS: Expose Loongson CPUCFG availability via HWCAP

2020-05-31T08:53:56+00:00

The point is to allow userspace to probe for CPUCFG without possibly triggering invalid instructions. In addition to that, future Loongson feature bits could all be stuffed into CPUCFG bit fields (or "leaves" in x86-speak) if Loongson does not make mistakes, so ELF HWCAP bits are conserved. Userspace can determine native CPUCFG availability by checking the LCSRP (Loongson CSR Present) bit in CPUCFG output after seeing CPUCFG bit in HWCAP. Native CPUCFG always sets the LCSRP bit, as CPUCFG is part of the Loongson CSR ASE, while the emulation intentionally leaves this bit clear. The other existing Loongson-specific HWCAP bits are, to my best knowledge, unused, as (1) they are fairly recent additions, (2) Loongson never back-ported the patch into their kernel fork, and (3) Loongson's existing installed base rarely upgrade, if ever; However, they are still considered userspace ABI, hence unfortunately unremovable. But hopefully at least we could stop adding new Loongson HWCAP bits in the future. Cc: Paul Burton Cc: Jiaxun Yang Cc: Huacai Chen Signed-off-by: WANG Xuerui Reviewed-by: Huacai Chen Signed-off-by: Thomas Bogendoerfer

MIPS: Loongson-3: Add some unaligned instructions emulation

2020-04-24T16:18:38+00:00

1, Add unaligned gslq, gssq, gslqc1, gssqc1 emulation; 2, Add unaligned gsl{h, w, d}x, gss{h, w, d}x emulation; 3, Add unaligned gslwxc1, gsswxc1, gsldxc1, gssdxc1 emulation. Signed-off-by: Huacai Chen Signed-off-by: Pei Huang Reviewed-by: Jiaxun Yang Signed-off-by: Thomas Bogendoerfer

arch: sembuf.h: make uapi asm/sembuf.h self-contained

2019-12-05T03:44:14+00:00

Userspace cannot compile due to some missing type definitions. For example, building it for x86 fails as follows: CC usr/include/asm/sembuf.h.s In file included from :32:0: usr/include/asm/sembuf.h:17:20: error: field `sem_perm' has incomplete type struct ipc64_perm sem_perm; /* permissions .. see ipc.h */ ^~~~~~~~ usr/include/asm/sembuf.h:24:2: error: unknown type name `__kernel_time_t' __kernel_time_t sem_otime; /* last semop time */ ^~~~~~~~~~~~~~~ usr/include/asm/sembuf.h:25:2: error: unknown type name `__kernel_ulong_t' __kernel_ulong_t __unused1; ^~~~~~~~~~~~~~~~ usr/include/asm/sembuf.h:26:2: error: unknown type name `__kernel_time_t' __kernel_time_t sem_ctime; /* last change time */ ^~~~~~~~~~~~~~~ usr/include/asm/sembuf.h:27:2: error: unknown type name `__kernel_ulong_t' __kernel_ulong_t __unused2; ^~~~~~~~~~~~~~~~ usr/include/asm/sembuf.h:29:2: error: unknown type name `__kernel_ulong_t' __kernel_ulong_t sem_nsems; /* no. of semaphores in array */ ^~~~~~~~~~~~~~~~ usr/include/asm/sembuf.h:30:2: error: unknown type name `__kernel_ulong_t' __kernel_ulong_t __unused3; ^~~~~~~~~~~~~~~~ usr/include/asm/sembuf.h:31:2: error: unknown type name `__kernel_ulong_t' __kernel_ulong_t __unused4; ^~~~~~~~~~~~~~~~ It is just a matter of missing include directive. Include to make it self-contained, and add it to the compile-test coverage. Link: http://lkml.kernel.org/r/20191030063855.9989-3-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada Cc: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

arch: msgbuf.h: make uapi asm/msgbuf.h self-contained

2019-12-05T03:44:14+00:00

Userspace cannot compile due to some missing type definitions. For example, building it for x86 fails as follows: CC usr/include/asm/msgbuf.h.s In file included from usr/include/asm/msgbuf.h:6:0, from :32: usr/include/asm-generic/msgbuf.h:25:20: error: field `msg_perm' has incomplete type struct ipc64_perm msg_perm; ^~~~~~~~ usr/include/asm-generic/msgbuf.h:27:2: error: unknown type name `__kernel_time_t' __kernel_time_t msg_stime; /* last msgsnd time */ ^~~~~~~~~~~~~~~ usr/include/asm-generic/msgbuf.h:28:2: error: unknown type name `__kernel_time_t' __kernel_time_t msg_rtime; /* last msgrcv time */ ^~~~~~~~~~~~~~~ usr/include/asm-generic/msgbuf.h:29:2: error: unknown type name `__kernel_time_t' __kernel_time_t msg_ctime; /* last change time */ ^~~~~~~~~~~~~~~ usr/include/asm-generic/msgbuf.h:41:2: error: unknown type name `__kernel_pid_t' __kernel_pid_t msg_lspid; /* pid of last msgsnd */ ^~~~~~~~~~~~~~ usr/include/asm-generic/msgbuf.h:42:2: error: unknown type name `__kernel_pid_t' __kernel_pid_t msg_lrpid; /* last receive pid */ ^~~~~~~~~~~~~~ It is just a matter of missing include directive. Include to make it self-contained, and add it to the compile-test coverage. Link: http://lkml.kernel.org/r/20191030063855.9989-2-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada Cc: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

y2038: stat: avoid 'time_t' in 'struct stat'

2019-11-15T13:38:28+00:00

The time_t definition may differ between user space and kernel space, so replace time_t with an unambiguous 'long' for the mips and sparc. The same structures also contain 'off_t', which has the same problem, so replace that as well on those two architectures and powerpc. Signed-off-by: Arnd Bergmann

y2038: ipc: remove __kernel_time_t reference from headers

2019-11-15T13:38:28+00:00

There are two structures based on time_t that conflict between libc and kernel: timeval and timespec. Both are now renamed to __kernel_old_timeval and __kernel_old_timespec. For time_t, the old typedef is still __kernel_time_t. There is nothing wrong with that name, but it would be nice to not use that going forward as this type is used almost only in deprecated interfaces because of the y2038 overflow. In the IPC headers (msgbuf.h, sembuf.h, shmbuf.h), __kernel_time_t is only used for the 64-bit variants, which are not deprecated. Change these to a plain 'long', which is the same type as __kernel_time_t on all 64-bit architectures anyway, to reduce the number of users of the old type. Signed-off-by: Arnd Bergmann

MIPS: elf_hwcap: Export userspace ASEs

2019-10-10T18:57:36+00:00

A Golang developer reported MIPS hwcap isn't reflecting instructions that the processor actually supported so programs can't apply optimized code at runtime. Thus we export the ASEs that can be used in userspace programs. Reported-by: Meng Zhuo Signed-off-by: Jiaxun Yang Cc: linux-mips@vger.kernel.org Cc: Paul Burton Cc: # 4.14+ Signed-off-by: Paul Burton

mm: introduce MADV_PAGEOUT

2019-09-26T00:51:41+00:00

When a process expects no accesses to a certain memory range for a long time, it could hint kernel that the pages can be reclaimed instantly but data should be preserved for future use. This could reduce workingset eviction so it ends up increasing performance. This patch introduces the new MADV_PAGEOUT hint to madvise(2) syscall. MADV_PAGEOUT can be used by a process to mark a memory range as not expected to be used for a long time so that kernel reclaims *any LRU* pages instantly. The hint can help kernel in deciding which pages to evict proactively. A note: It doesn't apply SWAP_CLUSTER_MAX LRU page isolation limit intentionally because it's automatically bounded by PMD size. If PMD size(e.g., 256) makes some trouble, we could fix it later by limit it to SWAP_CLUSTER_MAX[1]. - man-page material MADV_PAGEOUT (since Linux x.x) Do not expect access in the near future so pages in the specified regions could be reclaimed instantly regardless of memory pressure. Thus, access in the range after successful operation could cause major page fault but never lose the up-to-date contents unlike MADV_DONTNEED. Pages belonging to a shared mapping are only processed if a write access is allowed for the calling process. MADV_PAGEOUT cannot be applied to locked pages, Huge TLB pages, or VM_PFNMAP pages. [1] https://lore.kernel.org/lkml/20190710194719.GS29695@dhcp22.suse.cz/ [minchan@kernel.org: clear PG_active on MADV_PAGEOUT] Link: http://lkml.kernel.org/r/20190802200643.GA181880@google.com [akpm@linux-foundation.org: resolve conflicts with hmm.git] Link: http://lkml.kernel.org/r/20190726023435.214162-5-minchan@kernel.org Signed-off-by: Minchan Kim Reported-by: kbuild test robot Acked-by: Michal Hocko Cc: James E.J. Bottomley Cc: Richard Henderson Cc: Ralf Baechle Cc: Chris Zankel Cc: Daniel Colascione Cc: Dave Hansen Cc: Hillf Danton Cc: Joel Fernandes (Google) Cc: Johannes Weiner Cc: Kirill A. Shutemov Cc: Oleksandr Natalenko Cc: Shakeel Butt Cc: Sonny Rao Cc: Suren Baghdasaryan Cc: Tim Murray Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds