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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-06 14:54:03 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-06 14:54:03 -0700 |
| commit | 00f178e15095fbcf04db00486378a6fa416a125e (patch) | |
| tree | a66dd51d66f2737abac8a14eae2ce8a78828aa2c /arch/xtensa/kernel/process.c | |
| parent | 0b707e572a1955b892dfcb32e7b573fab78767d9 (diff) | |
| parent | bd47cdb78997f83bd170c389ef59de9eec65976a (diff) | |
| download | linux-00f178e15095fbcf04db00486378a6fa416a125e.tar.gz linux-00f178e15095fbcf04db00486378a6fa416a125e.tar.bz2 linux-00f178e15095fbcf04db00486378a6fa416a125e.zip | |
Merge tag 'xtensa-20211105' of git://github.com/jcmvbkbc/linux-xtensa
Pull xtensa updates from Max Filippov:
- add support for xtensa cores without windowed registers option
* tag 'xtensa-20211105' of git://github.com/jcmvbkbc/linux-xtensa:
xtensa: move section symbols to asm/sections.h
xtensa: remove unused variable wmask
xtensa: only build windowed register support code when needed
xtensa: use register window specific opcodes only when present
xtensa: implement call0 ABI support in assembly
xtensa: definitions for call0 ABI
xtensa: don't use a12 in __xtensa_copy_user in call0 ABI
xtensa: don't use a12 in strncpy_user
xtensa: use a14 instead of a15 in inline assembly
xtensa: move _SimulateUserKernelVectorException out of WindowVectors
Diffstat (limited to 'arch/xtensa/kernel/process.c')
| -rw-r--r-- | arch/xtensa/kernel/process.c | 27 |
1 files changed, 24 insertions, 3 deletions
diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c index 47f933fed870..bd80df890b1e 100644 --- a/arch/xtensa/kernel/process.c +++ b/arch/xtensa/kernel/process.c @@ -211,11 +211,18 @@ int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn, struct thread_info *ti; #endif +#if defined(__XTENSA_WINDOWED_ABI__) /* Create a call4 dummy-frame: a0 = 0, a1 = childregs. */ SPILL_SLOT(childregs, 1) = (unsigned long)childregs; SPILL_SLOT(childregs, 0) = 0; p->thread.sp = (unsigned long)childregs; +#elif defined(__XTENSA_CALL0_ABI__) + /* Reserve 16 bytes for the _switch_to stack frame. */ + p->thread.sp = (unsigned long)childregs - 16; +#else +#error Unsupported Xtensa ABI +#endif if (!(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { struct pt_regs *regs = current_pt_regs(); @@ -272,11 +279,25 @@ int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn, p->thread.ra = MAKE_RA_FOR_CALL( (unsigned long)ret_from_kernel_thread, 1); - /* pass parameters to ret_from_kernel_thread: - * a2 = thread_fn, a3 = thread_fn arg + /* pass parameters to ret_from_kernel_thread: */ +#if defined(__XTENSA_WINDOWED_ABI__) + /* + * a2 = thread_fn, a3 = thread_fn arg. + * Window underflow will load registers from the + * spill slots on the stack on return from _switch_to. */ - SPILL_SLOT(childregs, 3) = thread_fn_arg; SPILL_SLOT(childregs, 2) = usp_thread_fn; + SPILL_SLOT(childregs, 3) = thread_fn_arg; +#elif defined(__XTENSA_CALL0_ABI__) + /* + * a12 = thread_fn, a13 = thread_fn arg. + * _switch_to epilogue will load registers from the stack. + */ + ((unsigned long *)p->thread.sp)[0] = usp_thread_fn; + ((unsigned long *)p->thread.sp)[1] = thread_fn_arg; +#else +#error Unsupported Xtensa ABI +#endif /* Childregs are only used when we're going to userspace * in which case start_thread will set them up. |