summaryrefslogtreecommitdiff
path: root/arch/mips/kernel/cpu-probe.c
diff options
context:
space:
mode:
authorMarc Zyngier <maz@kernel.org>2020-11-13 00:20:43 +0300
committerMarc Zyngier <maz@kernel.org>2020-11-13 00:20:43 +0300
commit4f6b838c378a52ea3ae0b15f12ca8a20849072fa (patch)
treefbd8c2346320f97eda221b9150d787f9006e8b35 /arch/mips/kernel/cpu-probe.c
parentc512298eed0360923d0cbc4a1f30bc0509af0d50 (diff)
parent3650b228f83adda7e5ee532e2b90429c03f7b9ec (diff)
downloadlinux-4f6b838c378a52ea3ae0b15f12ca8a20849072fa.tar.xz
Merge tag 'v5.10-rc1' into kvmarm-master/next
Linux 5.10-rc1 Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'arch/mips/kernel/cpu-probe.c')
-rw-r--r--arch/mips/kernel/cpu-probe.c344
1 files changed, 12 insertions, 332 deletions
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index e2955f1f6316..e6853697a056 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -28,336 +28,14 @@
#include <asm/spram.h>
#include <linux/uaccess.h>
+#include "fpu-probe.h"
+
#include <asm/mach-loongson64/cpucfg-emul.h>
/* Hardware capabilities */
unsigned int elf_hwcap __read_mostly;
EXPORT_SYMBOL_GPL(elf_hwcap);
-#ifdef CONFIG_MIPS_FP_SUPPORT
-
-/*
- * Get the FPU Implementation/Revision.
- */
-static inline unsigned long cpu_get_fpu_id(void)
-{
- unsigned long tmp, fpu_id;
-
- tmp = read_c0_status();
- __enable_fpu(FPU_AS_IS);
- fpu_id = read_32bit_cp1_register(CP1_REVISION);
- write_c0_status(tmp);
- return fpu_id;
-}
-
-/*
- * Check if the CPU has an external FPU.
- */
-static inline int __cpu_has_fpu(void)
-{
- return (cpu_get_fpu_id() & FPIR_IMP_MASK) != FPIR_IMP_NONE;
-}
-
-/*
- * 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;
-
- fcsr = c->fpu_csr31;
- 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);
-
- 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;
-}
-
-/*
- * Determine the IEEE 754 NaN encodings and ABS.fmt/NEG.fmt execution modes
- * supported by FPU hardware.
- */
-static void cpu_set_fpu_2008(struct cpuinfo_mips *c)
-{
- if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
- MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
- MIPS_CPU_ISA_M32R5 | MIPS_CPU_ISA_M64R5 |
- MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6)) {
- unsigned long sr, fir, fcsr, fcsr0, fcsr1;
-
- sr = read_c0_status();
- __enable_fpu(FPU_AS_IS);
-
- fir = read_32bit_cp1_register(CP1_REVISION);
- if (fir & MIPS_FPIR_HAS2008) {
- fcsr = read_32bit_cp1_register(CP1_STATUS);
-
- /*
- * MAC2008 toolchain never landed in real world, so we're only
- * testing wether it can be disabled and don't try to enabled
- * it.
- */
- fcsr0 = fcsr & ~(FPU_CSR_ABS2008 | FPU_CSR_NAN2008 | FPU_CSR_MAC2008);
- write_32bit_cp1_register(CP1_STATUS, fcsr0);
- fcsr0 = read_32bit_cp1_register(CP1_STATUS);
-
- fcsr1 = fcsr | FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
- write_32bit_cp1_register(CP1_STATUS, fcsr1);
- fcsr1 = read_32bit_cp1_register(CP1_STATUS);
-
- write_32bit_cp1_register(CP1_STATUS, fcsr);
-
- if (c->isa_level & (MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2)) {
- /*
- * The bit for MAC2008 might be reused by R6 in future,
- * so we only test for R2-R5.
- */
- if (fcsr0 & FPU_CSR_MAC2008)
- c->options |= MIPS_CPU_MAC_2008_ONLY;
- }
-
- if (!(fcsr0 & FPU_CSR_NAN2008))
- c->options |= MIPS_CPU_NAN_LEGACY;
- if (fcsr1 & FPU_CSR_NAN2008)
- c->options |= MIPS_CPU_NAN_2008;
-
- if ((fcsr0 ^ fcsr1) & FPU_CSR_ABS2008)
- c->fpu_msk31 &= ~FPU_CSR_ABS2008;
- else
- c->fpu_csr31 |= fcsr & FPU_CSR_ABS2008;
-
- if ((fcsr0 ^ fcsr1) & FPU_CSR_NAN2008)
- c->fpu_msk31 &= ~FPU_CSR_NAN2008;
- else
- c->fpu_csr31 |= fcsr & FPU_CSR_NAN2008;
- } else {
- c->options |= MIPS_CPU_NAN_LEGACY;
- }
-
- write_c0_status(sr);
- } else {
- c->options |= MIPS_CPU_NAN_LEGACY;
- }
-}
-
-/*
- * IEEE 754 conformance mode to use. Affects the NaN encoding and the
- * ABS.fmt/NEG.fmt execution mode.
- */
-static enum { STRICT, LEGACY, STD2008, RELAXED } ieee754 = STRICT;
-
-/*
- * Set the IEEE 754 NaN encodings and the ABS.fmt/NEG.fmt execution modes
- * to support by the FPU emulator according to the IEEE 754 conformance
- * mode selected. Note that "relaxed" straps the emulator so that it
- * allows 2008-NaN binaries even for legacy processors.
- */
-static void cpu_set_nofpu_2008(struct cpuinfo_mips *c)
-{
- c->options &= ~(MIPS_CPU_NAN_2008 | MIPS_CPU_NAN_LEGACY);
- c->fpu_csr31 &= ~(FPU_CSR_ABS2008 | FPU_CSR_NAN2008);
- c->fpu_msk31 &= ~(FPU_CSR_ABS2008 | FPU_CSR_NAN2008);
-
- switch (ieee754) {
- case STRICT:
- if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 |
- MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 |
- MIPS_CPU_ISA_M32R5 | MIPS_CPU_ISA_M64R5 |
- MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6)) {
- c->options |= MIPS_CPU_NAN_2008 | MIPS_CPU_NAN_LEGACY;
- } else {
- c->options |= MIPS_CPU_NAN_LEGACY;
- c->fpu_msk31 |= FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
- }
- break;
- case LEGACY:
- c->options |= MIPS_CPU_NAN_LEGACY;
- c->fpu_msk31 |= FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
- break;
- case STD2008:
- c->options |= MIPS_CPU_NAN_2008;
- c->fpu_csr31 |= FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
- c->fpu_msk31 |= FPU_CSR_ABS2008 | FPU_CSR_NAN2008;
- break;
- case RELAXED:
- c->options |= MIPS_CPU_NAN_2008 | MIPS_CPU_NAN_LEGACY;
- break;
- }
-}
-
-/*
- * Override the IEEE 754 NaN encoding and ABS.fmt/NEG.fmt execution mode
- * according to the "ieee754=" parameter.
- */
-static void cpu_set_nan_2008(struct cpuinfo_mips *c)
-{
- switch (ieee754) {
- case STRICT:
- mips_use_nan_legacy = !!cpu_has_nan_legacy;
- mips_use_nan_2008 = !!cpu_has_nan_2008;
- break;
- case LEGACY:
- mips_use_nan_legacy = !!cpu_has_nan_legacy;
- mips_use_nan_2008 = !cpu_has_nan_legacy;
- break;
- case STD2008:
- mips_use_nan_legacy = !cpu_has_nan_2008;
- mips_use_nan_2008 = !!cpu_has_nan_2008;
- break;
- case RELAXED:
- mips_use_nan_legacy = true;
- mips_use_nan_2008 = true;
- break;
- }
-}
-
-/*
- * IEEE 754 NaN encoding and ABS.fmt/NEG.fmt execution mode override
- * settings:
- *
- * strict: accept binaries that request a NaN encoding supported by the FPU
- * legacy: only accept legacy-NaN binaries
- * 2008: only accept 2008-NaN binaries
- * relaxed: accept any binaries regardless of whether supported by the FPU
- */
-static int __init ieee754_setup(char *s)
-{
- if (!s)
- return -1;
- else if (!strcmp(s, "strict"))
- ieee754 = STRICT;
- else if (!strcmp(s, "legacy"))
- ieee754 = LEGACY;
- else if (!strcmp(s, "2008"))
- ieee754 = STD2008;
- else if (!strcmp(s, "relaxed"))
- ieee754 = RELAXED;
- else
- return -1;
-
- if (!(boot_cpu_data.options & MIPS_CPU_FPU))
- cpu_set_nofpu_2008(&boot_cpu_data);
- cpu_set_nan_2008(&boot_cpu_data);
-
- return 0;
-}
-
-early_param("ieee754", ieee754_setup);
-
-/*
- * 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_M32R5 | MIPS_CPU_ISA_M64R5 |
- 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_M32R5 | MIPS_CPU_ISA_M64R5 |
- MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6))
- value |= MIPS_FPIR_F64 | MIPS_FPIR_L | MIPS_FPIR_W;
- if (c->options & MIPS_CPU_NAN_2008)
- value |= MIPS_FPIR_HAS2008;
- c->fpu_id = value;
-}
-
-/* Determined FPU emulator mask to use for the boot CPU with "nofpu". */
-static unsigned int mips_nofpu_msk31;
-
-/*
- * Set options for FPU hardware.
- */
-static void cpu_set_fpu_opts(struct cpuinfo_mips *c)
-{
- 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 |
- MIPS_CPU_ISA_M32R5 | MIPS_CPU_ISA_M64R5 |
- MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6)) {
- if (c->fpu_id & MIPS_FPIR_3D)
- c->ases |= MIPS_ASE_MIPS3D;
- if (c->fpu_id & MIPS_FPIR_UFRP)
- c->options |= MIPS_CPU_UFR;
- if (c->fpu_id & MIPS_FPIR_FREP)
- c->options |= MIPS_CPU_FRE;
- }
-
- cpu_set_fpu_fcsr_mask(c);
- cpu_set_fpu_2008(c);
- cpu_set_nan_2008(c);
-}
-
-/*
- * Set options for the FPU emulator.
- */
-static void cpu_set_nofpu_opts(struct cpuinfo_mips *c)
-{
- c->options &= ~MIPS_CPU_FPU;
- c->fpu_msk31 = mips_nofpu_msk31;
-
- cpu_set_nofpu_2008(c);
- cpu_set_nan_2008(c);
- cpu_set_nofpu_id(c);
-}
-
-static int mips_fpu_disabled;
-
-static int __init fpu_disable(char *s)
-{
- cpu_set_nofpu_opts(&boot_cpu_data);
- mips_fpu_disabled = 1;
-
- return 1;
-}
-
-__setup("nofpu", fpu_disable);
-
-#else /* !CONFIG_MIPS_FP_SUPPORT */
-
-#define mips_fpu_disabled 1
-
-static inline unsigned long cpu_get_fpu_id(void)
-{
- return FPIR_IMP_NONE;
-}
-
-static inline int __cpu_has_fpu(void)
-{
- return 0;
-}
-
-static void cpu_set_fpu_opts(struct cpuinfo_mips *c)
-{
- /* no-op */
-}
-
-static void cpu_set_nofpu_opts(struct cpuinfo_mips *c)
-{
- /* no-op */
-}
-
-#endif /* CONFIG_MIPS_FP_SUPPORT */
-
static inline unsigned long cpu_get_msa_id(void)
{
unsigned long status, msa_id;
@@ -1600,8 +1278,9 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
- MIPS_CPU_LLSC | MIPS_CPU_BP_GHIST;
+ MIPS_CPU_LLSC;
c->tlbsize = 64;
+ write_c0_r10k_diag(read_c0_r10k_diag() | R10K_DIAG_E_GHIST);
break;
case PRID_IMP_R14000:
if (((c->processor_id >> 4) & 0x0f) > 2) {
@@ -1615,8 +1294,9 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
- MIPS_CPU_LLSC | MIPS_CPU_BP_GHIST;
+ MIPS_CPU_LLSC;
c->tlbsize = 64;
+ write_c0_r10k_diag(read_c0_r10k_diag() | R10K_DIAG_E_GHIST);
break;
case PRID_IMP_LOONGSON_64C: /* Loongson-2/3 */
switch (c->processor_id & PRID_REV_MASK) {
@@ -2123,7 +1803,10 @@ static inline void cpu_probe_ingenic(struct cpuinfo_mips *c, unsigned int cpu)
/* XBurst does not implement the CP0 counter. */
c->options &= ~MIPS_CPU_COUNTER;
- BUG_ON(!__builtin_constant_p(cpu_has_counter) || cpu_has_counter);
+ BUG_ON(__builtin_constant_p(cpu_has_counter) && cpu_has_counter);
+
+ /* XBurst has virtually tagged icache */
+ c->icache.flags |= MIPS_CACHE_VTAG;
switch (c->processor_id & PRID_IMP_MASK) {
@@ -2169,8 +1852,9 @@ static inline void cpu_probe_ingenic(struct cpuinfo_mips *c, unsigned int cpu)
/* XBurst®1 with MXU2.0 SIMD ISA */
case PRID_IMP_XBURST_REV2:
+ /* Ingenic uses the WA bit to achieve write-combine memory writes */
+ c->writecombine = _CACHE_CACHABLE_WA;
c->cputype = CPU_XBURST;
- c->writecombine = _CACHE_UNCACHED_ACCELERATED;
__cpu_name[cpu] = "Ingenic XBurst";
break;
@@ -2372,10 +2056,6 @@ void cpu_probe(void)
else
cpu_set_nofpu_opts(c);
- if (cpu_has_bp_ghist)
- write_c0_r10k_diag(read_c0_r10k_diag() |
- R10K_DIAG_E_GHIST);
-
if (cpu_has_mips_r2_r6) {
c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
/* R2 has Performance Counter Interrupt indicator */