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-rw-r--r--arch/mips/kernel/cpu-probe.c53
-rw-r--r--arch/mips/kernel/ptrace.c10
-rw-r--r--arch/mips/kernel/r2300_switch.S7
-rw-r--r--arch/mips/kernel/r4k_switch.S7
4 files changed, 65 insertions, 12 deletions
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index ca9b9c62c6ea..2911ad5977d7 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -33,6 +33,35 @@
#include <asm/uaccess.h>
/*
+ * Determine the FCSR mask for FPU hardware.
+ */
+static inline void cpu_set_fpu_fcsr_mask(struct cpuinfo_mips *c)
+{
+ unsigned long sr, mask, fcsr, fcsr0, fcsr1;
+
+ mask = FPU_CSR_ALL_X | FPU_CSR_ALL_E | FPU_CSR_ALL_S | FPU_CSR_RM;
+
+ sr = read_c0_status();
+ __enable_fpu(FPU_AS_IS);
+
+ fcsr = read_32bit_cp1_register(CP1_STATUS);
+
+ fcsr0 = fcsr & mask;
+ write_32bit_cp1_register(CP1_STATUS, fcsr0);
+ fcsr0 = read_32bit_cp1_register(CP1_STATUS);
+
+ fcsr1 = fcsr | ~mask;
+ write_32bit_cp1_register(CP1_STATUS, fcsr1);
+ fcsr1 = read_32bit_cp1_register(CP1_STATUS);
+
+ write_32bit_cp1_register(CP1_STATUS, fcsr);
+
+ write_c0_status(sr);
+
+ c->fpu_msk31 = ~(fcsr0 ^ fcsr1) & ~mask;
+}
+
+/*
* Set the FIR feature flags for the FPU emulator.
*/
static void cpu_set_nofpu_id(struct cpuinfo_mips *c)
@@ -50,11 +79,15 @@ static void cpu_set_nofpu_id(struct cpuinfo_mips *c)
c->fpu_id = value;
}
+/* Determined FPU emulator mask to use for the boot CPU with "nofpu". */
+static unsigned int mips_nofpu_msk31;
+
static int mips_fpu_disabled;
static int __init fpu_disable(char *s)
{
boot_cpu_data.options &= ~MIPS_CPU_FPU;
+ boot_cpu_data.fpu_msk31 = mips_nofpu_msk31;
cpu_set_nofpu_id(&boot_cpu_data);
mips_fpu_disabled = 1;
@@ -597,6 +630,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
case PRID_IMP_R2000:
c->cputype = CPU_R2000;
__cpu_name[cpu] = "R2000";
+ c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
MIPS_CPU_NOFPUEX;
if (__cpu_has_fpu())
@@ -616,6 +650,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
c->cputype = CPU_R3000;
__cpu_name[cpu] = "R3000";
}
+ c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
MIPS_CPU_NOFPUEX;
if (__cpu_has_fpu())
@@ -664,6 +699,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
}
set_isa(c, MIPS_CPU_ISA_III);
+ c->fpu_msk31 |= FPU_CSR_CONDX;
c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_WATCH | MIPS_CPU_VCE |
MIPS_CPU_LLSC;
@@ -671,6 +707,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
break;
case PRID_IMP_VR41XX:
set_isa(c, MIPS_CPU_ISA_III);
+ c->fpu_msk31 |= FPU_CSR_CONDX;
c->options = R4K_OPTS;
c->tlbsize = 32;
switch (c->processor_id & 0xf0) {
@@ -712,6 +749,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
c->cputype = CPU_R4300;
__cpu_name[cpu] = "R4300";
set_isa(c, MIPS_CPU_ISA_III);
+ c->fpu_msk31 |= FPU_CSR_CONDX;
c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_LLSC;
c->tlbsize = 32;
@@ -720,6 +758,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
c->cputype = CPU_R4600;
__cpu_name[cpu] = "R4600";
set_isa(c, MIPS_CPU_ISA_III);
+ c->fpu_msk31 |= FPU_CSR_CONDX;
c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_LLSC;
c->tlbsize = 48;
@@ -735,11 +774,13 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
c->cputype = CPU_R4650;
__cpu_name[cpu] = "R4650";
set_isa(c, MIPS_CPU_ISA_III);
+ c->fpu_msk31 |= FPU_CSR_CONDX;
c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
c->tlbsize = 48;
break;
#endif
case PRID_IMP_TX39:
+ c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
@@ -765,6 +806,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
c->cputype = CPU_R4700;
__cpu_name[cpu] = "R4700";
set_isa(c, MIPS_CPU_ISA_III);
+ c->fpu_msk31 |= FPU_CSR_CONDX;
c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_LLSC;
c->tlbsize = 48;
@@ -773,6 +815,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
c->cputype = CPU_TX49XX;
__cpu_name[cpu] = "R49XX";
set_isa(c, MIPS_CPU_ISA_III);
+ c->fpu_msk31 |= FPU_CSR_CONDX;
c->options = R4K_OPTS | MIPS_CPU_LLSC;
if (!(c->processor_id & 0x08))
c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
@@ -814,6 +857,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
c->cputype = CPU_R6000;
__cpu_name[cpu] = "R6000";
set_isa(c, MIPS_CPU_ISA_II);
+ c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
MIPS_CPU_LLSC;
c->tlbsize = 32;
@@ -822,6 +866,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
c->cputype = CPU_R6000A;
__cpu_name[cpu] = "R6000A";
set_isa(c, MIPS_CPU_ISA_II);
+ c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
MIPS_CPU_LLSC;
c->tlbsize = 32;
@@ -893,12 +938,14 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
__cpu_name[cpu] = "ICT Loongson-2";
set_elf_platform(cpu, "loongson2e");
set_isa(c, MIPS_CPU_ISA_III);
+ c->fpu_msk31 |= FPU_CSR_CONDX;
break;
case PRID_REV_LOONGSON2F:
c->cputype = CPU_LOONGSON2;
__cpu_name[cpu] = "ICT Loongson-2";
set_elf_platform(cpu, "loongson2f");
set_isa(c, MIPS_CPU_ISA_III);
+ c->fpu_msk31 |= FPU_CSR_CONDX;
break;
case PRID_REV_LOONGSON3A:
c->cputype = CPU_LOONGSON3;
@@ -1335,6 +1382,9 @@ void cpu_probe(void)
c->cputype = CPU_UNKNOWN;
c->writecombine = _CACHE_UNCACHED;
+ c->fpu_csr31 = FPU_CSR_RN;
+ c->fpu_msk31 = FPU_CSR_RSVD | FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
+
c->processor_id = read_c0_prid();
switch (c->processor_id & PRID_COMP_MASK) {
case PRID_COMP_LEGACY:
@@ -1393,6 +1443,7 @@ void cpu_probe(void)
if (c->options & MIPS_CPU_FPU) {
c->fpu_id = cpu_get_fpu_id();
+ mips_nofpu_msk31 = c->fpu_msk31;
if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
@@ -1402,6 +1453,8 @@ void cpu_probe(void)
if (c->fpu_id & MIPS_FPIR_FREP)
c->options |= MIPS_CPU_FRE;
}
+
+ cpu_set_fpu_fcsr_mask(c);
} else
cpu_set_nofpu_id(c);
diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
index 510452812594..6d1e3f8005f7 100644
--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -32,6 +32,7 @@
#include <asm/byteorder.h>
#include <asm/cpu.h>
+#include <asm/cpu-info.h>
#include <asm/dsp.h>
#include <asm/fpu.h>
#include <asm/mipsregs.h>
@@ -137,6 +138,9 @@ int ptrace_setfpregs(struct task_struct *child, __u32 __user *data)
{
union fpureg *fregs;
u64 fpr_val;
+ u32 fcr31;
+ u32 value;
+ u32 mask;
int i;
if (!access_ok(VERIFY_READ, data, 33 * 8))
@@ -149,8 +153,10 @@ int ptrace_setfpregs(struct task_struct *child, __u32 __user *data)
set_fpr64(&fregs[i], 0, fpr_val);
}
- __get_user(child->thread.fpu.fcr31, data + 64);
- child->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
+ __get_user(value, data + 64);
+ fcr31 = child->thread.fpu.fcr31;
+ mask = current_cpu_data.fpu_msk31;
+ child->thread.fpu.fcr31 = (value & ~mask) | (fcr31 & mask);
/* FIR may not be written. */
diff --git a/arch/mips/kernel/r2300_switch.S b/arch/mips/kernel/r2300_switch.S
index 435ea652f5fa..5087a4b72e6b 100644
--- a/arch/mips/kernel/r2300_switch.S
+++ b/arch/mips/kernel/r2300_switch.S
@@ -115,11 +115,9 @@ LEAF(_restore_fp)
* the property that no matter whether considered as single or as double
* precision represents signaling NANS.
*
- * We initialize fcr31 to rounding to nearest, no exceptions.
+ * The value to initialize fcr31 to comes in $a0.
*/
-#define FPU_DEFAULT 0x00000000
-
.set push
SET_HARDFLOAT
@@ -129,8 +127,7 @@ LEAF(_init_fpu)
or t0, t1
mtc0 t0, CP0_STATUS
- li t1, FPU_DEFAULT
- ctc1 t1, fcr31
+ ctc1 a0, fcr31
li t0, -1
diff --git a/arch/mips/kernel/r4k_switch.S b/arch/mips/kernel/r4k_switch.S
index 3b1a36f13a7d..04cbbde3521b 100644
--- a/arch/mips/kernel/r4k_switch.S
+++ b/arch/mips/kernel/r4k_switch.S
@@ -165,11 +165,9 @@ LEAF(_init_msa_upper)
* the property that no matter whether considered as single or as double
* precision represents signaling NANS.
*
- * We initialize fcr31 to rounding to nearest, no exceptions.
+ * The value to initialize fcr31 to comes in $a0.
*/
-#define FPU_DEFAULT 0x00000000
-
.set push
SET_HARDFLOAT
@@ -180,8 +178,7 @@ LEAF(_init_fpu)
mtc0 t0, CP0_STATUS
enable_fpu_hazard
- li t1, FPU_DEFAULT
- ctc1 t1, fcr31
+ ctc1 a0, fcr31
li t1, -1 # SNaN
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-07-06 09:03:48 +0200