git: 7588c7024ed9 - stable/14 - arm64: Add the SVE registers to the signal frame
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Date: Mon, 21 Oct 2024 15:05:11 UTC
The branch stable/14 has been updated by andrew: URL: https://cgit.FreeBSD.org/src/commit/?id=7588c7024ed9b3d9845529edd56e46b675430a02 commit 7588c7024ed9b3d9845529edd56e46b675430a02 Author: Andrew Turner <andrew@FreeBSD.org> AuthorDate: 2024-09-27 13:37:03 +0000 Commit: Andrew Turner <andrew@FreeBSD.org> CommitDate: 2024-10-21 15:03:26 +0000 arm64: Add the SVE registers to the signal frame Use the new extended register support in the arm64 signal frame to handle the SVE registers. As these registers alias the VFP registers we use the floating point register values to restore the lower bits of the SVE registers. This is to support software that doesn't understand SVE to continue working. Sponsored by: Arm Ltd Differential Revision: https://reviews.freebsd.org/D43307 (cherry picked from commit e45132e978030f0aa964d975a9fbad5614f260bd) --- sys/arm64/arm64/exec_machdep.c | 88 +++++++++++++++++++++++++++++++++++++++++- sys/arm64/include/ucontext.h | 8 ++++ 2 files changed, 94 insertions(+), 2 deletions(-) diff --git a/sys/arm64/arm64/exec_machdep.c b/sys/arm64/arm64/exec_machdep.c index 31191ec21602..67760850c56a 100644 --- a/sys/arm64/arm64/exec_machdep.c +++ b/sys/arm64/arm64/exec_machdep.c @@ -464,9 +464,10 @@ set_mcontext(struct thread *td, mcontext_t *mcp) #define PSR_13_MASK 0xfffffffful struct arm64_reg_context ctx; struct trapframe *tf = td->td_frame; + struct pcb *pcb; uint64_t spsr; vm_offset_t addr; - int error; + int error, seen_types; bool done; spsr = mcp->mc_gpregs.gp_spsr; @@ -512,7 +513,11 @@ set_mcontext(struct thread *td, mcontext_t *mcp) /* Read any register contexts we find */ if (mcp->mc_ptr != 0) { addr = mcp->mc_ptr; + pcb = td->td_pcb; + +#define CTX_TYPE_FLAG_SVE (1 << 0) + seen_types = 0; done = false; do { if (!__is_aligned(addr, @@ -524,6 +529,38 @@ set_mcontext(struct thread *td, mcontext_t *mcp) return (error); switch (ctx.ctx_id) { +#ifdef VFP + case ARM64_CTX_SVE: { + struct sve_context sve_ctx; + size_t buf_size; + + if ((seen_types & CTX_TYPE_FLAG_SVE) != 0) + return (EINVAL); + seen_types |= CTX_TYPE_FLAG_SVE; + + if (pcb->pcb_svesaved == NULL) + return (EINVAL); + + /* XXX: Check pcb_svesaved is valid */ + + buf_size = sve_buf_size(td); + /* Check the size is valid */ + if (ctx.ctx_size != + (sizeof(sve_ctx) + buf_size)) + return (EINVAL); + + memset(pcb->pcb_svesaved, 0, + sve_max_buf_size()); + + /* Copy the SVE registers from userspace */ + if (copyin((void *)(addr + sizeof(sve_ctx)), + pcb->pcb_svesaved, buf_size) != 0) + return (EINVAL); + + pcb->pcb_fpflags |= PCB_FP_SVEVALID; + break; + } +#endif case ARM64_CTX_END: done = true; break; @@ -533,6 +570,8 @@ set_mcontext(struct thread *td, mcontext_t *mcp) addr += ctx.ctx_size; } while (!done); + +#undef CTX_TYPE_FLAG_SVE } return (0); @@ -593,7 +632,7 @@ set_fpcontext(struct thread *td, mcontext_t *mcp) sizeof(mcp->mc_fpregs.fp_q)); curpcb->pcb_fpustate.vfp_fpcr = mcp->mc_fpregs.fp_cr; curpcb->pcb_fpustate.vfp_fpsr = mcp->mc_fpregs.fp_sr; - curpcb->pcb_fpflags = mcp->mc_fpregs.fp_flags & PCB_FP_USERMASK; + curpcb->pcb_fpflags = mcp->mc_fpregs.fp_flags & PCB_FP_STARTED; } #endif } @@ -613,6 +652,13 @@ sys_sigreturn(struct thread *td, struct sigreturn_args *uap) if (error != 0) return (error); + /* + * Sync the VFP and SVE registers. To be backwards compatible we + * use the VFP registers to restore the lower bits of the SVE + * register it aliases. + */ + vfp_to_sve_sync(td); + /* Restore signal mask. */ kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0); @@ -638,9 +684,47 @@ sendsig_ctx_end(struct thread *td, vm_offset_t *addrp) return (true); } +static bool +sendsig_ctx_sve(struct thread *td, vm_offset_t *addrp) +{ + struct sve_context ctx; + struct pcb *pcb; + size_t buf_size; + vm_offset_t ctx_addr; + + pcb = td->td_pcb; + /* Do nothing if sve hasn't started */ + if (pcb->pcb_svesaved == NULL) + return (true); + + MPASS(pcb->pcb_svesaved != NULL); + + buf_size = sve_buf_size(td); + + /* Address for the full context */ + *addrp -= sizeof(ctx) + buf_size; + ctx_addr = *addrp; + + memset(&ctx, 0, sizeof(ctx)); + ctx.sve_ctx.ctx_id = ARM64_CTX_SVE; + ctx.sve_ctx.ctx_size = sizeof(ctx) + buf_size; + ctx.sve_vector_len = pcb->pcb_sve_len; + ctx.sve_flags = 0; + + /* Copy out the header and data */ + if (copyout(&ctx, (void *)ctx_addr, sizeof(ctx)) != 0) + return (false); + if (copyout(pcb->pcb_svesaved, (void *)(ctx_addr + sizeof(ctx)), + buf_size) != 0) + return (false); + + return (true); +} + typedef bool(*ctx_func)(struct thread *, vm_offset_t *); static const ctx_func ctx_funcs[] = { sendsig_ctx_end, /* Must be first to end the linked list */ + sendsig_ctx_sve, NULL, }; diff --git a/sys/arm64/include/ucontext.h b/sys/arm64/include/ucontext.h index dedbd061ec6b..a4f0ee243b3a 100644 --- a/sys/arm64/include/ucontext.h +++ b/sys/arm64/include/ucontext.h @@ -62,6 +62,14 @@ struct arm64_reg_context { }; #define ARM64_CTX_END 0xa5a5a5a5 +#define ARM64_CTX_SVE 0x00657673 + +struct sve_context { + struct arm64_reg_context sve_ctx; + __uint16_t sve_vector_len; + __uint16_t sve_flags; + __uint16_t sve_reserved[2]; +}; struct __mcontext { struct gpregs mc_gpregs;