freebsd-dev/sys/i386
John Baldwin 1a62e9bc00 Add <machine/tls.h> header to hold MD constants and helpers for TLS.
The header exports the following:

- Definition of struct tcb.
- Helpers to get/set the tcb for the current thread.
- TLS_TCB_SIZE (size of TCB)
- TLS_TCB_ALIGN (alignment of TCB)
- TLS_VARIANT_I or TLS_VARIANT_II
- TLS_DTV_OFFSET (bias of pointers in dtv[])
- TLS_TP_OFFSET (bias of "thread pointer" relative to TCB)

Note that TLS_TP_OFFSET does not account for if the unbiased thread
pointer points to the start of the TCB (arm and x86) or the end of the
TCB (MIPS, PowerPC, and RISC-V).

Note also that for amd64, the struct tcb does not include the unused
tcb_spare field included in the current structure in libthr.  libthr
does not use this field, and the existing calls in libc and rtld that
allocate a TCB for amd64 assume it is the size of 3 Elf_Addr's (and
thus do not allocate room for tcb_spare).

A <sys/_tls_variant_i.h> header is used by architectures using
Variant I TLS which uses a common struct tcb.

Reviewed by:	kib (older version of x86/tls.h), jrtc27
Sponsored by:	The University of Cambridge, Google Inc.
Differential Revision:	https://reviews.freebsd.org/D33351
2021-12-09 13:17:13 -08:00
..
acpica x86: duplicate acpi_wakeup.c per i386 and amd64 2021-09-14 00:23:14 +03:00
bios
conf x86 GENERIC/MINIMAL: group sc(4) devices together 2021-11-28 14:38:41 -05:00
i386 x86: remove unused T_USER flag 2021-12-05 11:12:40 -04:00
include Add <machine/tls.h> header to hold MD constants and helpers for TLS. 2021-12-09 13:17:13 -08:00
linux Regen 2021-12-09 02:49:10 +02:00
pci
Makefile