[mips] add support for using the MIPS user register for TLS data.

This work, originally from Stacey Son, uses the MIPS UserReg for
reading the TLS data, and will fall back to the normal syscall path
when it isn't supported.

This code dynamically patches cpu_switch() to bypass the UserReg
instruction so to avoid generating a machine exception.

Thanks to sson for the original work, and to Dan Nelson for
bringing it to date and testing it on MIPS32 with me.

Tested:

* mips64 (sson)
* mips74k (dnelson_1901@yahoo.com) - AR9344 SoC, UserReg support
* mips24k (adrian) - AR9331 SoC, no UserReg support

Obtained from:	sson, dnelson_1901@yahoo.com
This commit is contained in:
Adrian Chadd 2016-08-07 01:29:55 +00:00
parent e13c1ef1e7
commit b812fe4d6b
10 changed files with 289 additions and 12 deletions

View File

@ -61,6 +61,7 @@ _tcb_set(struct tcb *tcb)
/*
* Get the current tcb.
*/
#ifdef TLS_USE_SYSARCH
static __inline struct tcb *
_tcb_get(void)
{
@ -70,6 +71,55 @@ _tcb_get(void)
return tcb;
}
#else /* ! TLS_USE_SYSARCH */
# if defined(__mips_n64)
static __inline struct tcb *
_tcb_get(void)
{
uint64_t _rv;
__asm__ __volatile__ (
".set\tpush\n\t"
".set\tmips64r2\n\t"
"rdhwr\t%0, $29\n\t"
".set\tpop"
: "=v" (_rv));
/*
* XXXSS See 'git show c6be4f4d2d1b71c04de5d3bbb6933ce2dbcdb317'
*
* Remove the offset since this really a request to get the TLS
* pointer via sysarch() (in theory). Of course, this may go away
* once the TLS code is rewritten.
*/
return (struct tcb *)(_rv - TLS_TP_OFFSET - TLS_TCB_SIZE);
}
# else /* mips 32 */
static __inline struct tcb *
_tcb_get(void)
{
uint32_t _rv;
__asm__ __volatile__ (
".set\tpush\n\t"
".set\tmips32r2\n\t"
"rdhwr\t%0, $29\n\t"
".set\tpop"
: "=v" (_rv));
/*
* XXXSS See 'git show c6be4f4d2d1b71c04de5d3bbb6933ce2dbcdb317'
*
* Remove the offset since this really a request to get the TLS
* pointer via sysarch() (in theory). Of course, this may go away
* once the TLS code is rewritten.
*/
return (struct tcb *)(_rv - TLS_TP_OFFSET - TLS_TCB_SIZE);
}
# endif /* ! __mips_n64 */
#endif /* ! TLS_USE_SYSARCH */
extern struct pthread *_thr_initial;
static __inline struct pthread *

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@ -634,13 +634,67 @@ allocate_initial_tls(Obj_Entry *objs)
sysarch(MIPS_SET_TLS, tls);
}
#ifdef __mips_n64
void *
_mips_get_tls(void)
{
uint64_t _rv;
__asm__ __volatile__ (
".set\tpush\n\t"
".set\tmips64r2\n\t"
"rdhwr\t%0, $29\n\t"
".set\tpop"
: "=v" (_rv));
/*
* XXXSS See 'git show c6be4f4d2d1b71c04de5d3bbb6933ce2dbcdb317'
*
* Remove the offset since this really a request to get the TLS
* pointer via sysarch() (in theory). Of course, this may go away
* once the TLS code is rewritten.
*/
_rv = _rv - TLS_TP_OFFSET - TLS_TCB_SIZE;
return (void *)_rv;
}
#else /* mips 32 */
void *
_mips_get_tls(void)
{
uint32_t _rv;
__asm__ __volatile__ (
".set\tpush\n\t"
".set\tmips32r2\n\t"
"rdhwr\t%0, $29\n\t"
".set\tpop"
: "=v" (_rv));
/*
* XXXSS See 'git show c6be4f4d2d1b71c04de5d3bbb6933ce2dbcdb317'
*
* Remove the offset since this really a request to get the TLS
* pointer via sysarch() (in theory). Of course, this may go away
* once the TLS code is rewritten.
*/
_rv = _rv - TLS_TP_OFFSET - TLS_TCB_SIZE;
return (void *)_rv;
}
#endif /* ! __mips_n64 */
void *
__tls_get_addr(tls_index* ti)
{
Elf_Addr** tls;
char *p;
#ifdef TLS_USE_SYSARCH
sysarch(MIPS_GET_TLS, &tls);
#else
tls = _mips_get_tls();
#endif
p = tls_get_addr_common(tls, ti->ti_module, ti->ti_offset + TLS_DTP_OFFSET);

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@ -159,6 +159,7 @@ mips_wr_ ## n(uint64_t a0) \
MIPS_RW64_COP0(excpc, MIPS_COP_0_EXC_PC);
MIPS_RW64_COP0(entryhi, MIPS_COP_0_TLB_HI);
MIPS_RW64_COP0(pagemask, MIPS_COP_0_TLB_PG_MASK);
MIPS_RW64_COP0_SEL(userlocal, MIPS_COP_0_USERLOCAL, 2);
#ifdef CPU_CNMIPS
MIPS_RW64_COP0_SEL(cvmcount, MIPS_COP_0_COUNT, 6);
MIPS_RW64_COP0_SEL(cvmctl, MIPS_COP_0_COUNT, 7);
@ -265,6 +266,7 @@ MIPS_RW32_COP0_SEL(cmgcrbase, 15, 3);
#if !defined(__mips_n64)
MIPS_RW32_COP0(entryhi, MIPS_COP_0_TLB_HI);
MIPS_RW32_COP0(pagemask, MIPS_COP_0_TLB_PG_MASK);
MIPS_RW32_COP0_SEL(userlocal, MIPS_COP_0_USERLOCAL, 2);
#endif
#ifdef CPU_NLM
MIPS_RW32_COP0_SEL(pagegrain, MIPS_COP_0_TLB_PG_MASK, 1);
@ -289,6 +291,7 @@ MIPS_RW32_COP0_SEL(perfcnt0, MIPS_COP_0_PERFCNT, 0);
MIPS_RW32_COP0_SEL(perfcnt1, MIPS_COP_0_PERFCNT, 1);
MIPS_RW32_COP0_SEL(perfcnt2, MIPS_COP_0_PERFCNT, 2);
MIPS_RW32_COP0_SEL(perfcnt3, MIPS_COP_0_PERFCNT, 3);
MIPS_RW32_COP0(hwrena, MIPS_COP_0_HWRENA);
#undef MIPS_RW32_COP0
#undef MIPS_RW32_COP0_SEL

View File

@ -58,6 +58,7 @@ struct mips_cpuinfo {
u_int16_t tlb_nentries;
u_int8_t icache_virtual;
boolean_t cache_coherent_dma;
boolean_t userlocal_reg;
struct {
u_int32_t ic_size;
u_int8_t ic_linesize;

View File

@ -454,9 +454,10 @@
* 2 MIPS_COP_0_TLB_LO0 .636 r4k TLB entry low.
* 3 MIPS_COP_0_TLB_LO1 .636 r4k TLB entry low, extended.
* 4 MIPS_COP_0_TLB_CONTEXT 3636 TLB Context.
* 4/2 MIPS_COP_0_USERLOCAL ..36 UserLocal.
* 5 MIPS_COP_0_TLB_PG_MASK .333 TLB Page Mask register.
* 6 MIPS_COP_0_TLB_WIRED .333 Wired TLB number.
* 7 MIPS_COP_0_INFO ..33 Info registers
* 7 MIPS_COP_0_HWRENA ..33 rdHWR Enable.
* 8 MIPS_COP_0_BAD_VADDR 3636 Bad virtual address.
* 9 MIPS_COP_0_COUNT .333 Count register.
* 10 MIPS_COP_0_TLB_HI 3636 TLB entry high.
@ -534,7 +535,8 @@
#define MIPS_COP_0_ERROR_PC _(30)
/* MIPS32/64 */
#define MIPS_COP_0_INFO _(7)
#define MIPS_COP_0_USERLOCAL _(4) /* sel 2 is userlevel register */
#define MIPS_COP_0_HWRENA _(7)
#define MIPS_COP_0_DEBUG _(23)
#define MIPS_COP_0_DEPC _(24)
#define MIPS_COP_0_PERFCNT _(25)
@ -548,11 +550,21 @@
#define MIPS_MMU_BAT 0x02 /* Standard BAT */
#define MIPS_MMU_FIXED 0x03 /* Standard fixed mapping */
#define MIPS_CONFIG0_MT_MASK 0x00000380 /* bits 9..7 MMU Type */
#define MIPS_CONFIG0_MT_SHIFT 7
#define MIPS_CONFIG0_BE 0x00008000 /* data is big-endian */
#define MIPS_CONFIG0_VI 0x00000008 /* instruction cache is virtual */
/*
* Config Register Fields
* (See "MIPS Architecture for Programmers Volume III", MD00091, Table 9.39)
*/
#define MIPS_CONFIG0_M 0x80000000 /* Flag: Config1 is present. */
#define MIPS_CONFIG0_MT_MASK 0x00000380 /* bits 9..7 MMU Type */
#define MIPS_CONFIG0_MT_SHIFT 7
#define MIPS_CONFIG0_BE 0x00008000 /* data is big-endian */
#define MIPS_CONFIG0_VI 0x00000008 /* inst cache is virtual */
/*
* Config1 Register Fields
* (See "MIPS Architecture for Programmers Volume III", MD00091, Table 9-1)
*/
#define MIPS_CONFIG1_M 0x80000000 /* Flag: Config2 is present. */
#define MIPS_CONFIG1_TLBSZ_MASK 0x7E000000 /* bits 30..25 # tlb entries minus one */
#define MIPS_CONFIG1_TLBSZ_SHIFT 25
@ -586,6 +598,19 @@
#define MIPS_CONFIG3_CMGCR_MASK (1 << 29) /* Coherence manager present */
/*
* Config2 Register Fields
* (See "MIPS Architecture for Programmers Volume III", MD00091, Table 9.40)
*/
#define MIPS_CONFIG2_M 0x80000000 /* Flag: Config3 is present. */
/*
* Config3 Register Fields
* (See "MIPS Architecture for Programmers Volume III", MD00091, Table 9.41)
*/
#define MIPS_CONFIG3_M 0x80000000 /* Flag: Config4 is present */
#define MIPS_CONFIG3_ULR 0x00002000 /* UserLocal reg implemented */
#define MIPS_CONFIG4_MMUSIZEEXT 0x000000FF /* bits 7.. 0 MMU Size Extension */
#define MIPS_CONFIG4_MMUEXTDEF 0x0000C000 /* bits 15.14 MMU Extension Definition */
#define MIPS_CONFIG4_MMUEXTDEF_MMUSIZEEXT 0x00004000 /* This values denotes CONFIG4 bits */
@ -667,4 +692,15 @@
#define MIPS_CMGCRB_BASE 11
#define MIPS_CMGCRF_BASE (~((1 << MIPS_CMGCRB_BASE) - 1))
/*
* Bits defined for for the HWREna (CP0 register 7, select 0).
*/
#define MIPS_HWRENA_CPUNUM (1<<0) /* CPU number program is running on */
#define MIPS_HWRENA_SYNCI_STEP (1<<1) /* Address step sized used with SYNCI */
#define MIPS_HWRENA_CC (1<<2) /* Hi Res cycle counter */
#define MIPS_HWRENA_CCRES (1<<3) /* Cycle counter resolution */
#define MIPS_HWRENA_UL (1<<29) /* UserLocal Register */
#define MIPS_HWRENA_IMPL30 (1<<30) /* Implementation-dependent 30 */
#define MIPS_HWRENA_IMPL31 (1<<31) /* Implementation-dependent 31 */
#endif /* _MIPS_CPUREGS_H_ */

View File

@ -30,6 +30,7 @@ __FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/proc.h>
#include <sys/stdint.h>
#include <sys/bus.h>
@ -49,6 +50,9 @@ __FBSDID("$FreeBSD$");
#include <machine/pte.h>
#include <machine/tlb.h>
#include <machine/hwfunc.h>
#include <machine/mips_opcode.h>
#include <machine/regnum.h>
#include <machine/tls.h>
#if defined(CPU_CNMIPS)
#include <contrib/octeon-sdk/cvmx.h>
@ -59,6 +63,63 @@ static void cpu_identify(void);
struct mips_cpuinfo cpuinfo;
#define _ENCODE_INSN(a,b,c,d,e) \
((uint32_t)(((a) << 26)|((b) << 21)|((c) << 16)|((d) << 11)|(e)))
#if defined(__mips_n64)
# define _LOAD_T0_MDTLS_A1 \
_ENCODE_INSN(OP_LD, A1, T0, 0, offsetof(struct thread, td_md.md_tls))
# if defined(COMPAT_FREEBSD32)
# define _ADDIU_V0_T0_TLS_OFFSET \
_ENCODE_INSN(OP_DADDIU, T0, V0, 0, (TLS_TP_OFFSET + TLS_TCB_SIZE32))
# else
# define _ADDIU_V0_T0_TLS_OFFSET \
_ENCODE_INSN(OP_DADDIU, T0, V0, 0, (TLS_TP_OFFSET + TLS_TCB_SIZE))
# endif /* ! COMPAT_FREEBSD32 */
# define _MTC0_V0_USERLOCAL \
_ENCODE_INSN(OP_COP0, OP_DMT, V0, 4, 2)
#else /* mips 32 */
# define _LOAD_T0_MDTLS_A1 \
_ENCODE_INSN(OP_LW, A1, T0, 0, offsetof(struct thread, td_md.md_tls))
# define _ADDIU_V0_T0_TLS_OFFSET \
_ENCODE_INSN(OP_ADDIU, T0, V0, 0, (TLS_TP_OFFSET + TLS_TCB_SIZE))
# define _MTC0_V0_USERLOCAL \
_ENCODE_INSN(OP_COP0, OP_MT, V0, 4, 2)
#endif /* ! __mips_n64 */
#define _JR_RA _ENCODE_INSN(OP_SPECIAL, RA, 0, 0, OP_JR)
#define _NOP 0
/*
* Patch cpu_switch() by removing the UserLocal register code at the end.
* For MIPS hardware that don't support UserLocal Register Implementation
* we remove the instructions that update this register which may cause a
* reserved instruction exception in the kernel.
*/
static void
remove_userlocal_code(uint32_t *cpu_switch_code)
{
uint32_t *instructp;
for (instructp = cpu_switch_code;; instructp++) {
if (instructp[0] == _JR_RA)
panic("%s: Unable to patch cpu_switch().", __func__);
if (instructp[0] == _LOAD_T0_MDTLS_A1 &&
instructp[1] == _ADDIU_V0_T0_TLS_OFFSET &&
instructp[2] == _MTC0_V0_USERLOCAL) {
instructp[0] = _JR_RA;
instructp[1] = _NOP;
break;
}
}
}
/*
* Attempt to identify the MIPS CPU as much as possible.
*
@ -73,9 +134,8 @@ mips_get_identity(struct mips_cpuinfo *cpuinfo)
u_int32_t prid;
u_int32_t cfg0;
u_int32_t cfg1;
#ifndef CPU_CNMIPS
u_int32_t cfg2;
#endif
u_int32_t cfg3;
#if defined(CPU_CNMIPS)
u_int32_t cfg4;
#endif
@ -96,13 +156,36 @@ mips_get_identity(struct mips_cpuinfo *cpuinfo)
((cfg0 & MIPS_CONFIG0_MT_MASK) >> MIPS_CONFIG0_MT_SHIFT);
cpuinfo->icache_virtual = cfg0 & MIPS_CONFIG0_VI;
/* If config register selection 1 does not exist, exit. */
if (!(cfg0 & MIPS_CONFIG_CM))
/* If config register selection 1 does not exist, return. */
if (!(cfg0 & MIPS_CONFIG0_M))
return;
/* Learn TLB size and L1 cache geometry. */
cfg1 = mips_rd_config1();
/* Get the Config2 and Config3 registers as well. */
if (cfg1 & MIPS_CONFIG1_M) {
cfg2 = mips_rd_config2();
if (cfg2 & MIPS_CONFIG2_M)
cfg3 = mips_rd_config3();
}
/* Check to see if UserLocal register is implemented. */
if (cfg3 & MIPS_CONFIG3_ULR) {
/* UserLocal register is implemented, enable it. */
cpuinfo->userlocal_reg = true;
tmp = mips_rd_hwrena();
mips_wr_hwrena(tmp | MIPS_HWRENA_UL);
} else {
/*
* UserLocal register is not implemented. Patch
* cpu_switch() and remove unsupported code.
*/
cpuinfo->userlocal_reg = false;
remove_userlocal_code((uint32_t *)cpu_switch);
}
#if defined(CPU_NLM)
/* Account for Extended TLB entries in XLP */
tmp = mips_rd_config6();
@ -387,7 +470,7 @@ cpu_identify(void)
/* Print Config3 if it contains any useful info */
if (cfg3 & ~(0x80000000))
printf(" Config3=0x%b\n", cfg3, "\20\2SmartMIPS\1TraceLogic");
printf(" Config3=0x%b\n", cfg3, "\20\14ULRI\2SmartMIPS\1TraceLogic");
}
static struct rman cpu_hardirq_rman;

View File

@ -57,6 +57,7 @@ __FBSDID("$FreeBSD$");
#include <machine/pcb.h>
#include <machine/sigframe.h>
#include <machine/proc.h>
#include <machine/tls.h>
#ifdef CPU_CNMIPS
#include <machine/octeon_cop2.h>
@ -72,6 +73,13 @@ ASSYM(TD_KSTACK, offsetof(struct thread, td_kstack));
ASSYM(TD_FLAGS, offsetof(struct thread, td_flags));
ASSYM(TD_LOCK, offsetof(struct thread, td_lock));
ASSYM(TD_MDFLAGS, offsetof(struct thread, td_md.md_flags));
ASSYM(TD_MDTLS, offsetof(struct thread, td_md.md_tls));
#if defined(__mips_n64) && defined(COMPAT_FREEBSD32)
ASSYM(TLS_TCB_OFFSET, (TLS_TP_OFFSET + TLS_TCB_SIZE32));
#else
ASSYM(TLS_TCB_OFFSET, (TLS_TP_OFFSET + TLS_TCB_SIZE));
#endif
ASSYM(U_PCB_REGS, offsetof(struct pcb, pcb_regs.zero));
ASSYM(U_PCB_CONTEXT, offsetof(struct pcb, pcb_context));

View File

@ -358,6 +358,7 @@ sw2:
* Restore registers and return.
*/
move a0, s0
move a1, s7
RESTORE_U_PCB_CONTEXT(gp, PCB_REG_GP, a0)
RESTORE_U_PCB_CONTEXT(v0, PCB_REG_SR, a0) # restore kernel context
RESTORE_U_PCB_CONTEXT(ra, PCB_REG_RA, a0)
@ -377,6 +378,15 @@ sw2:
or v0, v0, t0
mtc0 v0, MIPS_COP_0_STATUS
ITLBNOPFIX
/*
* Set the new thread's TLS pointer.
*
* Note that this code is removed if the CPU doesn't support ULRI by
* remove_userlocal_code() in cpu.c.
*/
PTR_L t0, TD_MDTLS(a1) # Get TLS pointer
PTR_ADDIU v0, t0, TLS_TCB_OFFSET # Add TLS/TCB offset
MTC0 v0, MIPS_COP_0_USERLOCAL, 2 # write it to ULR for rdhwr
j ra
nop

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@ -39,7 +39,11 @@ __FBSDID("$FreeBSD$");
#include <sys/syscall.h>
#include <sys/sysent.h>
#include <machine/cpufunc.h>
#include <machine/cpuinfo.h>
#include <machine/sysarch.h>
#include <machine/cpuregs.h>
#include <machine/tls.h>
#ifndef _SYS_SYSPROTO_H_
struct sysarch_args {
@ -57,6 +61,22 @@ sysarch(struct thread *td, struct sysarch_args *uap)
switch (uap->op) {
case MIPS_SET_TLS:
td->td_md.md_tls = uap->parms;
/*
* If there is an user local register implementation (ULRI)
* update it as well. Add the TLS and TCB offsets so the
* value in this register is adjusted like in the case of the
* rdhwr trap() instruction handler.
*/
if (cpuinfo.userlocal_reg == true) {
#if defined(__mips_n64) && defined(COMPAT_FREEBSD32)
mips_wr_userlocal((unsigned long)(uap->parms +
TLS_TP_OFFSET + TLS_TCB_SIZE32));
#else
mips_wr_userlocal((unsigned long)(uap->parms +
TLS_TP_OFFSET + TLS_TCB_SIZE));
#endif
}
return (0);
case MIPS_GET_TLS:
tlsbase = td->td_md.md_tls;

View File

@ -60,8 +60,11 @@ __FBSDID("$FreeBSD$");
#include <machine/cache.h>
#include <machine/clock.h>
#include <machine/cpu.h>
#include <machine/cpufunc.h>
#include <machine/cpuinfo.h>
#include <machine/md_var.h>
#include <machine/pcb.h>
#include <machine/tls.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
@ -492,6 +495,15 @@ cpu_set_user_tls(struct thread *td, void *tls_base)
{
td->td_md.md_tls = (char*)tls_base;
if (td == curthread && cpuinfo.userlocal_reg == true) {
#if defined(__mips_n64) && defined(COMPAT_FREEBSD32)
mips_wr_userlocal((unsigned long)tls_base + TLS_TP_OFFSET +
TLS_TCB_SIZE32);
#else
mips_wr_userlocal((unsigned long)tls_base + TLS_TP_OFFSET +
TLS_TCB_SIZE);
#endif
}
return (0);
}