Add support for reading and writing registers for Aarch64 SVE.
We need to support the cases where the kernel only gives us a
fpsimd structure. This occurs when there is no active SVE state
in the kernel (for example, after starting a new process).
Added checks to make sure the vector length has not changed whilst
the process is running.
gdb/
* aarch64-linux-nat.c (fetch_sveregs_from_thread): New function.
(store_sveregs_to_thread): Likewise.
(aarch64_linux_fetch_inferior_registers): Check for SVE.
(aarch64_linux_store_inferior_registers): Likewise.
* nat/aarch64-sve-linux-ptrace.c (aarch64_sve_get_sveregs): New
function.
(aarch64_sve_regs_copy_to_regcache): Likewise.
(aarch64_sve_regs_copy_from_regcache): Likewise.
* nat/aarch64-sve-linux-ptrace.h (aarch64_sve_get_sveregs): New
declaration.
(aarch64_sve_regs_copy_to_regcache): Likewise.
(aarch64_sve_regs_copy_from_regcache): Likewise.
(sve_context): Structure from Linux headers.
(SVE_SIG_ZREGS_SIZE): Define from Linux headers.
(SVE_SIG_ZREG_SIZE): Likewise.
(SVE_SIG_PREG_SIZE): Likewise.
(SVE_SIG_FFR_SIZE): Likewise.
(SVE_SIG_REGS_OFFSET): Likewise.
(SVE_SIG_ZREGS_OFFSET): Likewise.
(SVE_SIG_ZREG_OFFSET): Likewise.
(SVE_SIG_ZREGS_SIZE): Likewise.
(SVE_SIG_PREGS_OFFSET): Likewise.
(SVE_SIG_PREG_OFFSET): Likewise.
(SVE_SIG_PREGS_SIZE): Likewise.
(SVE_SIG_FFR_OFFSET): Likewise.
(SVE_SIG_REGS_SIZE): Likewise.
(SVE_SIG_CONTEXT_SIZE): Likewise.
(SVE_PT_REGS_MASK): Likewise.
(SVE_PT_REGS_FPSIMD): Likewise.
(SVE_PT_REGS_SVE): Likewise.
(SVE_PT_VL_INHERIT): Likewise.
(SVE_PT_VL_ONEXEC): Likewise.
(SVE_PT_REGS_OFFSET): Likewise.
(SVE_PT_FPSIMD_OFFSET): Likewise.
(SVE_PT_FPSIMD_SIZE): Likewise.
(SVE_PT_SVE_ZREG_SIZE): Likewise.
(SVE_PT_SVE_PREG_SIZE): Likewise.
(SVE_PT_SVE_FFR_SIZE): Likewise.
(SVE_PT_SVE_FPSR_SIZE): Likewise.
(SVE_PT_SVE_FPCR_SIZE): Likewise.
(__SVE_SIG_TO_PT): Likewise.
(SVE_PT_SVE_OFFSET): Likewise.
(SVE_PT_SVE_ZREGS_OFFSET): Likewise.
(SVE_PT_SVE_ZREG_OFFSET): Likewise.
(SVE_PT_SVE_ZREGS_SIZE): Likewise.
(SVE_PT_SVE_PREGS_OFFSET): Likewise.
(SVE_PT_SVE_PREG_OFFSET): Likewise.
(SVE_PT_SVE_PREGS_SIZE): Likewise.
(SVE_PT_SVE_FFR_OFFSET): Likewise.
(SVE_PT_SVE_FPSR_OFFSET): Likewise.
(SVE_PT_SVE_FPCR_OFFSET): Likewise.
(SVE_PT_SVE_SIZE): Likewise.
(SVE_PT_SIZE): Likewise.
(HAS_SVE_STATE): New define.
gdbserver/
* Makefile.in: Add aarch64-sve-linux-ptrace.c.
Previously VQ was of type long. Using uint64_t ensures it always matches the
same type as the VG register.
Note that in the Linux kernel, VQ is 16bits. We cast it up to 64bits
immediately after reading to ensure we always use the same type throughout
the code.
gdb/
* aarch64-tdep.c (aarch64_read_description): Use uint64_t for VQ.
* aarch64-tdep.h (aarch64_read_description): Likewise.
* arch/aarch64.c (aarch64_create_target_description): Likewise.
* arch/aarch64.h (aarch64_create_target_description): Likewise.
* features/aarch64-sve.c (create_feature_aarch64_sve): Likewise.
* nat/aarch64-sve-linux-ptrace.c(aarch64_sve_get_vq): Likewise.
* nat/aarch64-sve-linux-ptrace.h (aarch64_sve_get_vq): Likewise.
Returns 0 for systems without SVE support.
Note the defines taken from Linux kernel headers
in aarch64-sve-linux-ptrace.h.
gdb/
* Makefile.in: Add new header.
* gdb/arch/aarch64.h (sve_vg_from_vl): New macro.
(sve_vl_from_vg): Likewise.
(sve_vq_from_vl): Likewise.
(sve_vl_from_vq): Likewise.
(sve_vq_from_vg): Likewise.
(sve_vg_from_vq): Likewise.
* configure.nat: Add new c file.
* nat/aarch64-sve-linux-ptrace.c: New file.
* nat/aarch64-sve-linux-ptrace.h: New file.
gdbserver/
* configure.srv: Add new c/h file.
Alan Hayward