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MIPS: microMIPS: Floating point support.

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Add logic needed to do floating point emulation in microMIPS mode.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Steven J. Hill <Steven. Hill@imgtec.com>
This commit is contained in:
Leonid Yegoshin 2013-03-25 12:09:02 -05:00 committed by Ralf Baechle
parent cf6d905828
commit 102cedc32a
7 changed files with 900 additions and 107 deletions
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6
arch/mips/include/asm/fpu_emulator.h
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@ -54,6 +54,12 @@ do { \
extern int mips_dsemul(struct pt_regs *regs, mips_instruction ir,
unsigned long cpc);
extern int do_dsemulret(struct pt_regs *xcp);
extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
struct mips_fpu_struct *ctx, int has_fpu,
void *__user *fault_addr);
int process_fpemu_return(int sig, void __user *fault_addr);
int mm_isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
unsigned long *contpc);
/*
* Instruction inserted following the badinst to further tag the sequence

9
arch/mips/include/asm/inst.h
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@ -73,4 +73,13 @@
typedef unsigned int mips_instruction;
/* microMIPS instruction decode structure. Do NOT export!!! */
struct mm_decoded_insn {
mips_instruction insn;
mips_instruction next_insn;
int pc_inc;
int next_pc_inc;
int micro_mips_mode;
};
#endif /* _ASM_INST_H */

5
arch/mips/include/uapi/asm/inst.h
View File

@ -423,6 +423,11 @@ enum mm_16d_minor_op {
mm_addiusp_func,
};
/*
* (microMIPS & MIPS16e) NOP instruction.
*/
#define MM_NOP16 0x0c00
/*
* Damn ... bitfields depend from byteorder :-(
*/

2
arch/mips/kernel/traps.c
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@ -675,7 +675,7 @@ asmlinkage void do_ov(struct pt_regs *regs)
force_sig_info(SIGFPE, &info, current);
}
static int process_fpemu_return(int sig, void __user *fault_addr)
int process_fpemu_return(int sig, void __user *fault_addr)
{
if (sig == SIGSEGV || sig == SIGBUS) {
struct siginfo si = {0};

22
arch/mips/kernel/unaligned.c
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@ -83,6 +83,8 @@
#include <asm/branch.h>
#include <asm/byteorder.h>
#include <asm/cop2.h>
#include <asm/fpu.h>
#include <asm/fpu_emulator.h>
#include <asm/inst.h>
#include <asm/uaccess.h>
@ -108,6 +110,7 @@ static void emulate_load_store_insn(struct pt_regs *regs,
union mips_instruction insn;
unsigned long value;
unsigned int res;
void __user *fault_addr = NULL;
perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
@ -447,10 +450,21 @@ static void emulate_load_store_insn(struct pt_regs *regs,
case ldc1_op:
case swc1_op:
case sdc1_op:
/*
* I herewith declare: this does not happen. So send SIGBUS.
*/
goto sigbus;
die_if_kernel("Unaligned FP access in kernel code", regs);
BUG_ON(!used_math());
BUG_ON(!is_fpu_owner());
lose_fpu(1); /* Save FPU state for the emulator. */
res = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
&fault_addr);
own_fpu(1); /* Restore FPU state. */
/* Signal if something went wrong. */
process_fpemu_return(res, fault_addr);
if (res == 0)
break;
return;
/*
* COP2 is available to implementor for application specific use.

933
arch/mips/math-emu/cp1emu.c
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File diff suppressed because it is too large Load Diff

30
arch/mips/math-emu/dsemul.c
View File

@ -55,7 +55,9 @@ int mips_dsemul(struct pt_regs *regs, mips_instruction ir, unsigned long cpc)
struct emuframe __user *fr;
int err;
if (ir == 0) { /* a nop is easy */
if ((get_isa16_mode(regs->cp0_epc) && ((ir >> 16) == MM_NOP16)) ||
(ir == 0)) {
/* NOP is easy */
regs->cp0_epc = cpc;
regs->cp0_cause &= ~CAUSEF_BD;
return 0;
@ -91,8 +93,16 @@ int mips_dsemul(struct pt_regs *regs, mips_instruction ir, unsigned long cpc)
if (unlikely(!access_ok(VERIFY_WRITE, fr, sizeof(struct emuframe))))
return SIGBUS;
err = __put_user(ir, &fr->emul);
err |= __put_user((mips_instruction)BREAK_MATH, &fr->badinst);
if (get_isa16_mode(regs->cp0_epc)) {
err = __put_user(ir >> 16, (u16 __user *)(&fr->emul));
err |= __put_user(ir & 0xffff, (u16 __user *)((long)(&fr->emul) + 2));
err |= __put_user(BREAK_MATH >> 16, (u16 __user *)(&fr->badinst));
err |= __put_user(BREAK_MATH & 0xffff, (u16 __user *)((long)(&fr->badinst) + 2));
} else {
err = __put_user(ir, &fr->emul);
err |= __put_user((mips_instruction)BREAK_MATH, &fr->badinst);
}
err |= __put_user((mips_instruction)BD_COOKIE, &fr->cookie);
err |= __put_user(cpc, &fr->epc);
@ -101,7 +111,8 @@ int mips_dsemul(struct pt_regs *regs, mips_instruction ir, unsigned long cpc)
return SIGBUS;
}
regs->cp0_epc = (unsigned long) &fr->emul;
regs->cp0_epc = ((unsigned long) &fr->emul) |
get_isa16_mode(regs->cp0_epc);
flush_cache_sigtramp((unsigned long)&fr->badinst);
@ -114,9 +125,10 @@ int do_dsemulret(struct pt_regs *xcp)
unsigned long epc;
u32 insn, cookie;
int err = 0;
u16 instr[2];
fr = (struct emuframe __user *)
(xcp->cp0_epc - sizeof(mips_instruction));
(msk_isa16_mode(xcp->cp0_epc) - sizeof(mips_instruction));
/*
* If we can't even access the area, something is very wrong, but we'll
@ -131,7 +143,13 @@ int do_dsemulret(struct pt_regs *xcp)
* - Is the instruction pointed to by the EPC an BREAK_MATH?
* - Is the following memory word the BD_COOKIE?
*/
err = __get_user(insn, &fr->badinst);
if (get_isa16_mode(xcp->cp0_epc)) {
err = __get_user(instr[0], (u16 __user *)(&fr->badinst));
err |= __get_user(instr[1], (u16 __user *)((long)(&fr->badinst) + 2));
insn = (instr[0] << 16) | instr[1];
} else {
err = __get_user(insn, &fr->badinst);
}
err |= __get_user(cookie, &fr->cookie);
if (unlikely(err || (insn != BREAK_MATH) || (cookie != BD_COOKIE))) {