On 9. Feb 2012, at 22:17 , Oleksandr Tymoshenko wrote:
> Author: gonzo
> Date: Thu Feb 9 22:17:13 2012
> New Revision: 231312
> URL: http://svn.freebsd.org/changeset/base/231312
>
> Log:
> - Emulate RDHWR instruction for TLS support
>
> Reading register $29 with RDHWR is becoming the de-facto standard to
> implement TLS. According to linux-mips wiki, MIPS Technologies has
> reserved hardware register $29 for ABI use. Furthermore current GCC
> makes the following assumptions:
> - RDHWR is natively available or otherwise emulated by the kernel
> - Register $29 holds the TLS pointer
>
> Submitted by: Robert Millan <r...@debian.org>
mips XLPN32 kernel failed, check _.mips.XLPN32 for details
mips XLRN32 kernel failed, check _.mips.XLRN32 for details
/scratch/tmp/bz/head.svn/sys/mips/mips/trap.c: In function 'trap':
/scratch/tmp/bz/head.svn/sys/mips/mips/trap.c:768: warning: cast to pointer
from integer of different size [-Wint-to-pointer-cast]
/scratch/tmp/bz/head.svn/sys/mips/mips/trap.c:776: warning: cast from pointer
to integer of different size [-Wpointer-to-int-cast]
>
> Modified:
> head/sys/mips/include/mips_opcode.h
> head/sys/mips/mips/trap.c
>
> Modified: head/sys/mips/include/mips_opcode.h
> ==============================================================================
> --- head/sys/mips/include/mips_opcode.h Thu Feb 9 22:13:20 2012
> (r231311)
> +++ head/sys/mips/include/mips_opcode.h Thu Feb 9 22:17:13 2012
> (r231312)
> @@ -176,6 +176,11 @@ typedef union {
> #define OP_LDL 032
> #define OP_LDR 033
>
> +#define OP_SPECIAL2 034
> +#define OP_JALX 035
> +
> +#define OP_SPECIAL3 037
> +
> #define OP_LB 040
> #define OP_LH 041
> #define OP_LWL 042
> @@ -389,6 +394,11 @@ typedef union {
> #define OP_R_BGEZALL OP_BGEZALL
>
> /*
> + * Values for the 'func' field when 'op' == OP_SPECIAL3.
> + */
> +#define OP_RDHWR 073
> +
> +/*
> * Values for the 'rs' field when 'op' == OP_COPz.
> */
> #define OP_MF 000
>
> Modified: head/sys/mips/mips/trap.c
> ==============================================================================
> --- head/sys/mips/mips/trap.c Thu Feb 9 22:13:20 2012 (r231311)
> +++ head/sys/mips/mips/trap.c Thu Feb 9 22:17:13 2012 (r231312)
> @@ -414,6 +414,7 @@ trap(struct trapframe *trapframe)
> intptr_t addr = 0;
> register_t pc;
> int cop;
> + register_t *frame_regs;
>
> trapdebug_enter(trapframe, 0);
>
> @@ -762,9 +763,29 @@ dofault:
> }
>
> case T_RES_INST + T_USER:
> - log_illegal_instruction("RES_INST", trapframe);
> - i = SIGILL;
> - addr = trapframe->pc;
> + {
> + InstFmt inst;
> + inst = *(InstFmt *)trapframe->pc;
> + switch (inst.RType.op) {
> + case OP_SPECIAL3:
> + switch (inst.RType.func) {
> + case OP_RDHWR:
> + /* Register 29 used for TLS */
> + if (inst.RType.rd == 29) {
> + frame_regs = &(trapframe->zero);
> + frame_regs[inst.RType.rt] =
> (register_t)td->td_md.md_tls;
> + trapframe->pc += sizeof(int);
> + goto out;
> + }
> + break;
> + }
> + break;
> + }
> +
> + log_illegal_instruction("RES_INST", trapframe);
> + i = SIGILL;
> + addr = trapframe->pc;
> + }
> break;
> case T_C2E:
> case T_C2E + T_USER:
--
Bjoern A. Zeeb You have to have visions!
It does not matter how good you are. It matters what good you do!
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