linux/arch/mips/kernel/unaligned.c, branch v4.5

MIPS: Declare mips_debugfs_dir in a header

2015-10-26T08:49:42Z

We have many extern declarations of mips_debugfs_dir through arch/mips/ in various C files. Unify them by declaring mips_debugfs_dir in a header, including it in each affected C file & removing the duplicate declarations. Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Cc: Steven J. Hill Cc: Alexander Sverdlin Cc: Masahiro Yamada Cc: Leonid Yegoshin Cc: Maciej W. Rozycki Cc: linux-kernel@vger.kernel.org Cc: Joe Perches Cc: Jaedon Shin Cc: James Hogan Cc: David Daney Cc: Zubair Lutfullah Kakakhel Cc: Markos Chandras Cc: James Cowgill Patchwork: https://patchwork.linux-mips.org/patch/11181/ Signed-off-by: Ralf Baechle

MIPS: unaligned: Move from deprecated __initcall to arch_initcall.

2015-09-03T10:07:49Z

Signed-off-by: Ralf Baechle

MIPS: MSA unaligned memory access support

2015-09-03T10:07:40Z

The MSA architecture specification allows for hardware to not implement unaligned vector memory accesses in some or all cases. A typical example of this is the I6400 core which does not implement unaligned vector memory access when the memory crosses a page boundary. The architecture also requires that such memory accesses complete successfully as far as userland is concerned, so the kernel is required to emulate them. This patch implements support for emulating unaligned MSA ld & st instructions by copying between the user memory & the tasks FP context in struct thread_struct, updating hardware registers from there as appropriate in order to avoid saving & restoring the entire vector context for each unaligned memory access. Tested both using an I6400 CPU and with a QEMU build hacked to produce AdEL exceptions for unaligned vector memory accesses. [paul.burton@imgtec.com: - Remove #ifdef's - Move msa_op into enum major_op rather than #define - Replace msa_{to,from}_wd with {read,write}_msa_wr_{b,h,w,l} and the format-agnostic wrappers, removing the custom endian mangling for big endian systems. - Restructure the msa_op case in emulate_load_store_insn to share more code between the load & store cases. - Avoid the need for a temporary union fpureg on the stack by simply reusing the already suitably aligned context in struct thread_struct. - Use sizeof(*fpr) rather than hardcoding 16 as the size for user memory checks & copies. - Stop recalculating the address of the unaligned vector memory access and rely upon the value read from BadVAddr as we do for other unaligned memory access instructions. - Drop the now unused val8 & val16 fields in union fpureg. - Rewrite commit message. - General formatting cleanups.] Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Cc: Leonid Yegoshin Cc: Huacai Chen Cc: Maciej W. Rozycki Cc: linux-kernel@vger.kernel.org Cc: Jie Chen Cc: Markos Chandras Patchwork: https://patchwork.linux-mips.org/patch/10573/ Signed-off-by: Ralf Baechle

MIPS: unaligned: Fix build error on big endian R6 kernels

2015-08-03T07:25:05Z

Commit eeb538950367 ("MIPS: unaligned: Prevent EVA instructions on kernel unaligned accesses") renamed the Load* and Store* defines in unaligned.c to _Load* and _Store* as part of its fix. One define was missed out which causes big endian R6 kernels to fail to build. arch/mips/kernel/unaligned.c:880:35: error: implicit declaration of function '_StoreDW' #define StoreDW(addr, value, res) _StoreDW(addr, value, res) ^ Signed-off-by: James Cowgill Fixes: eeb538950367 ("MIPS: unaligned: Prevent EVA instructions on kernel unaligned accesses") Cc: Markos Chandras Cc: # 4.0+ Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10575/ Signed-off-by: Ralf Baechle

Merge branch '4.0-fixes' into mips-for-linux-next

2015-04-13T14:03:32Z

MIPS: unaligned: Fix regular load/store instruction emulation for EVA

2015-04-10T13:41:45Z

When emulating a regular lh/lw/lhu/sh/sw we need to use the appropriate instruction if we are in EVA mode. This is necessary for userspace applications which trigger alignment exceptions. In such case, the userspace load/store instruction needs to be emulated with the correct eva/non-eva instruction by the kernel emulator. Signed-off-by: Markos Chandras Fixes: c1771216ab48 ("MIPS: kernel: unaligned: Handle unaligned accesses for EVA") Cc: # v3.15+ Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9503/ Signed-off-by: Ralf Baechle

MIPS: unaligned: Surround load/store macros in do {} while statements

2015-04-10T13:41:44Z

It's best to surround such complex macros with do {} while statements so they can appear as independent logical blocks when used within other control blocks. Signed-off-by: Markos Chandras Cc: # v3.15+ Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9502/ Signed-off-by: Ralf Baechle

MIPS: unaligned: Prevent EVA instructions on kernel unaligned accesses

2015-04-10T13:41:44Z

Commit c1771216ab48 ("MIPS: kernel: unaligned: Handle unaligned accesses for EVA") allowed unaligned accesses to be emulated for EVA. However, when emulating regular load/store unaligned accesses, we need to use the appropriate "address space" instructions for that. Previously, an unaligned load/store instruction in kernel space would have used the corresponding EVA instructions to emulate it which led to segmentation faults because of the address translation that happens with EVA instructions. This is now fixed by using the EVA instruction only when emulating EVA unaligned accesses. Signed-off-by: Markos Chandras Fixes: c1771216ab48 ("MIPS: kernel: unaligned: Handle unaligned accesses for EVA") Cc: # v3.15+ Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9501/ Signed-off-by: Ralf Baechle

MIPS: Fix double inclusion of headers in misalignment emulator.

2015-04-07T23:10:49Z

Introduced in 34c2f668d0f6b2ca1c076d8170d6cd4f2235a9d4 (MIPS: microMIPS: Add unaligned access support.) Signed-off-by: Ralf Baechle

MIPS: Set `si_code' for SIGFPE signals sent from emulation too

2015-04-07T23:10:19Z

Rework `process_fpemu_return' and move IEEE 754 exception interpretation there, from `do_fpe'. Record the cause bits set in FCSR before they are cleared and pass them through to `process_fpemu_return' so as to set `si_code' correctly too for SIGFPE signals sent from emulation rather than those issued by hardware with the FPE processor exception only. For simplicity `mipsr2_decoder' assumes `*fcr31' has been preinitialised and only sets it to anything if an FPU instruction has been emulated, which in turn is the only case SIGFPE can be issued for here. Signed-off-by: Maciej W. Rozycki Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9705/ Signed-off-by: Ralf Baechle