freebsd-skq/sys/riscv/include/asm.h
mhorne 13a454c463 Fix global pointer relaxations in the RISC-V kernel
The gp register is intended to used by the linker as another means of
performing relaxations, and should point to the small data section (.sdata).

Currently gp is being used as the pcpu pointer within the kernel, but the more
appropriate choice for this is the tp register, which is unused.

Swap existing usage of gp with tp within the kernel, and set up gp properly
at boot with the value of __global_pointer$ for all harts.

Additionally, remove some cases of accessing tp from the PCB, as it is not
part of the per-thread state. The user's tp and gp should be tracked only
through the trapframe.

Reviewed by:	markj, jhb
Approved by:	markj (mentor)
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D19893
2019-06-09 15:43:38 +00:00

75 lines
2.6 KiB
C

/*-
* Copyright (c) 2015-2018 Ruslan Bukin <br@bsdpad.com>
* All rights reserved.
*
* Portions of this software were developed by SRI International and the
* University of Cambridge Computer Laboratory under DARPA/AFRL contract
* FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme.
*
* Portions of this software were developed by the University of Cambridge
* Computer Laboratory as part of the CTSRD Project, with support from the
* UK Higher Education Innovation Fund (HEIF).
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _MACHINE_ASM_H_
#define _MACHINE_ASM_H_
#undef __FBSDID
#if !defined(lint) && !defined(STRIP_FBSDID)
#define __FBSDID(s) .ident s
#else
#define __FBSDID(s) /* nothing */
#endif /* not lint and not STRIP_FBSDID */
#define _C_LABEL(x) x
#define ENTRY(sym) \
.text; .globl sym; .type sym,@function; .align 4; sym:
#define END(sym) .size sym, . - sym
#define EENTRY(sym) \
.globl sym; sym:
#define EEND(sym)
#define WEAK_REFERENCE(sym, alias) \
.weak alias; \
.set alias,sym
#define SET_FAULT_HANDLER(handler, tmp) \
ld tmp, PC_CURTHREAD(tp); \
ld tmp, TD_PCB(tmp); /* Load the pcb */ \
sd handler, PCB_ONFAULT(tmp) /* Set the handler */
#define ENTER_USER_ACCESS(tmp) \
li tmp, SSTATUS_SUM; \
csrs sstatus, tmp
#define EXIT_USER_ACCESS(tmp) \
li tmp, SSTATUS_SUM; \
csrc sstatus, tmp
#endif /* _MACHINE_ASM_H_ */