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MIPS: math-emu: Set FIR feature flags for full emulation

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Implement FIR feature flags in the FPU emulator according to features
supported and architecture level requirements.  The W, L and F64 bits
have only been added at level #2 even though the features they refer to
were also included with the MIPS64r1 ISA and the W fixed-point format
also with the MIPS32r1 ISA.

This is only relevant for the full emulation mode and the emulated CFC1
instruction as well as ptrace(2) accesses.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9707/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Maciej W. Rozycki 2015-04-03 23:27:26 +01:00 • committed by Ralf Baechle
commit f684362689
2 changed files with 25 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

25
arch/mips/kernel/cpu-probe.c
View file

@ -20,6 +20,7 @@
#include <asm/bugs.h> #include <asm/bugs.h>
#include <asm/cpu.h> #include <asm/cpu.h>
#include <asm/cpu-features.h>
#include <asm/cpu-type.h> #include <asm/cpu-type.h>
#include <asm/fpu.h> #include <asm/fpu.h>
#include <asm/mipsregs.h> #include <asm/mipsregs.h>
@ -31,11 +32,30 @@
#include <asm/spram.h> #include <asm/spram.h>
#include <asm/uaccess.h> #include <asm/uaccess.h>
/*
* Set the FIR feature flags for the FPU emulator.
*/
static void cpu_set_nofpu_id(struct cpuinfo_mips *c)
{
u32 value;
value = 0;
if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6))
value |= MIPS_FPIR_D | MIPS_FPIR_S;
if (c->isa_level & (MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6))
value |= MIPS_FPIR_F64 | MIPS_FPIR_L | MIPS_FPIR_W;
c->fpu_id = value;
}
static int mips_fpu_disabled; static int mips_fpu_disabled;
static int __init fpu_disable(char *s) static int __init fpu_disable(char *s)
{ {
cpu_data[0].options &= ~MIPS_CPU_FPU; boot_cpu_data.options &= ~MIPS_CPU_FPU;
cpu_set_nofpu_id(&boot_cpu_data);
mips_fpu_disabled = 1; mips_fpu_disabled = 1;
return 1; return 1;
@ -1382,7 +1402,8 @@ void cpu_probe(void)
if (c->fpu_id & MIPS_FPIR_FREP) if (c->fpu_id & MIPS_FPIR_FREP)
c->options |= MIPS_CPU_FRE; c->options |= MIPS_CPU_FRE;
} }
} } else
cpu_set_nofpu_id(c);
if (cpu_has_mips_r2_r6) { if (cpu_has_mips_r2_r6) {
c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1; c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;

3
arch/mips/math-emu/cp1emu.c
View file

@ -45,6 +45,7 @@
#include <asm/signal.h> #include <asm/signal.h>
#include <asm/uaccess.h> #include <asm/uaccess.h>
#include <asm/cpu-info.h>
#include <asm/processor.h> #include <asm/processor.h>
#include <asm/fpu_emulator.h> #include <asm/fpu_emulator.h>
#include <asm/fpu.h> #include <asm/fpu.h>
@ -853,7 +854,7 @@ static inline void cop1_cfc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
(void *)xcp->cp0_epc, (void *)xcp->cp0_epc,
MIPSInst_RT(ir), value); MIPSInst_RT(ir), value);
} else if (MIPSInst_RD(ir) == FPCREG_RID) } else if (MIPSInst_RD(ir) == FPCREG_RID)
value = 0; value = current_cpu_data.fpu_id;
else else
value = 0; value = 0;
if (MIPSInst_RT(ir)) if (MIPSInst_RT(ir))