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Commit 6ad816e7 authored by James Hogan's avatar James Hogan Committed by Ralf Baechle
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MIPS: Add probing & defs for VZ & guest features



Add a few new cpu-features.h definitions for VZ sub-features, namely the
existence of the CP0_GuestCtl0Ext, CP0_GuestCtl1, and CP0_GuestCtl2
registers, and support for GuestID to dialias TLB entries belonging to
different guests.

Also add certain features present in the guest, with the naming scheme
cpu_guest_has_*. These are added separately to the main options bitfield
since they generally parallel similar features in the root context. A
few of these (FPU, MSA, watchpoints, perf counters, CP0_[X]ContextConfig
registers, MAAR registers, and probably others in future) can be
dynamically configured in the guest context, for which the
cpu_guest_has_dyn_* macros are added.

[ralf@linux-mips.org: Resolve merge conflict.]

Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13231/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 7eb91118
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+98 −0
Original line number Diff line number Diff line
@@ -120,6 +120,21 @@
#ifndef kernel_uses_llsc
#define kernel_uses_llsc	cpu_has_llsc
#endif
#ifndef cpu_has_guestctl0ext
#define cpu_has_guestctl0ext	(cpu_data[0].options & MIPS_CPU_GUESTCTL0EXT)
#endif
#ifndef cpu_has_guestctl1
#define cpu_has_guestctl1	(cpu_data[0].options & MIPS_CPU_GUESTCTL1)
#endif
#ifndef cpu_has_guestctl2
#define cpu_has_guestctl2	(cpu_data[0].options & MIPS_CPU_GUESTCTL2)
#endif
#ifndef cpu_has_guestid
#define cpu_has_guestid		(cpu_data[0].options & MIPS_CPU_GUESTID)
#endif
#ifndef cpu_has_drg
#define cpu_has_drg		(cpu_data[0].options & MIPS_CPU_DRG)
#endif
#ifndef cpu_has_mips16
#define cpu_has_mips16		(cpu_data[0].ases & MIPS_ASE_MIPS16)
#endif
@@ -458,4 +473,87 @@
# define cpu_has_perf		(cpu_data[0].options & MIPS_CPU_PERF)
#endif

/*
 * Guest capabilities
 */
#ifndef cpu_guest_has_conf1
#define cpu_guest_has_conf1	(cpu_data[0].guest.conf & (1 << 1))
#endif
#ifndef cpu_guest_has_conf2
#define cpu_guest_has_conf2	(cpu_data[0].guest.conf & (1 << 2))
#endif
#ifndef cpu_guest_has_conf3
#define cpu_guest_has_conf3	(cpu_data[0].guest.conf & (1 << 3))
#endif
#ifndef cpu_guest_has_conf4
#define cpu_guest_has_conf4	(cpu_data[0].guest.conf & (1 << 4))
#endif
#ifndef cpu_guest_has_conf5
#define cpu_guest_has_conf5	(cpu_data[0].guest.conf & (1 << 5))
#endif
#ifndef cpu_guest_has_conf6
#define cpu_guest_has_conf6	(cpu_data[0].guest.conf & (1 << 6))
#endif
#ifndef cpu_guest_has_conf7
#define cpu_guest_has_conf7	(cpu_data[0].guest.conf & (1 << 7))
#endif
#ifndef cpu_guest_has_fpu
#define cpu_guest_has_fpu	(cpu_data[0].guest.options & MIPS_CPU_FPU)
#endif
#ifndef cpu_guest_has_watch
#define cpu_guest_has_watch	(cpu_data[0].guest.options & MIPS_CPU_WATCH)
#endif
#ifndef cpu_guest_has_contextconfig
#define cpu_guest_has_contextconfig (cpu_data[0].guest.options & MIPS_CPU_CTXTC)
#endif
#ifndef cpu_guest_has_segments
#define cpu_guest_has_segments	(cpu_data[0].guest.options & MIPS_CPU_SEGMENTS)
#endif
#ifndef cpu_guest_has_badinstr
#define cpu_guest_has_badinstr	(cpu_data[0].guest.options & MIPS_CPU_BADINSTR)
#endif
#ifndef cpu_guest_has_badinstrp
#define cpu_guest_has_badinstrp	(cpu_data[0].guest.options & MIPS_CPU_BADINSTRP)
#endif
#ifndef cpu_guest_has_htw
#define cpu_guest_has_htw	(cpu_data[0].guest.options & MIPS_CPU_HTW)
#endif
#ifndef cpu_guest_has_msa
#define cpu_guest_has_msa	(cpu_data[0].guest.ases & MIPS_ASE_MSA)
#endif
#ifndef cpu_guest_has_kscr
#define cpu_guest_has_kscr(n)	(cpu_data[0].guest.kscratch_mask & (1u << (n)))
#endif
#ifndef cpu_guest_has_rw_llb
#define cpu_guest_has_rw_llb	(cpu_has_mips_r6 || (cpu_data[0].guest.options & MIPS_CPU_RW_LLB))
#endif
#ifndef cpu_guest_has_perf
#define cpu_guest_has_perf	(cpu_data[0].guest.options & MIPS_CPU_PERF)
#endif
#ifndef cpu_guest_has_maar
#define cpu_guest_has_maar	(cpu_data[0].guest.options & MIPS_CPU_MAAR)
#endif

/*
 * Guest dynamic capabilities
 */
#ifndef cpu_guest_has_dyn_fpu
#define cpu_guest_has_dyn_fpu	(cpu_data[0].guest.options_dyn & MIPS_CPU_FPU)
#endif
#ifndef cpu_guest_has_dyn_watch
#define cpu_guest_has_dyn_watch	(cpu_data[0].guest.options_dyn & MIPS_CPU_WATCH)
#endif
#ifndef cpu_guest_has_dyn_contextconfig
#define cpu_guest_has_dyn_contextconfig (cpu_data[0].guest.options_dyn & MIPS_CPU_CTXTC)
#endif
#ifndef cpu_guest_has_dyn_perf
#define cpu_guest_has_dyn_perf	(cpu_data[0].guest.options_dyn & MIPS_CPU_PERF)
#endif
#ifndef cpu_guest_has_dyn_msa
#define cpu_guest_has_dyn_msa	(cpu_data[0].guest.ases_dyn & MIPS_ASE_MSA)
#endif
#ifndef cpu_guest_has_dyn_maar
#define cpu_guest_has_dyn_maar	(cpu_data[0].guest.options_dyn & MIPS_CPU_MAAR)
#endif

#endif /* __ASM_CPU_FEATURES_H */
+14 −0
Original line number Diff line number Diff line
@@ -28,6 +28,15 @@ struct cache_desc {
	unsigned char flags;	/* Flags describing cache properties */
};

struct guest_info {
	unsigned long		ases;
	unsigned long		ases_dyn;
	unsigned long long	options;
	unsigned long long	options_dyn;
	u8			conf;
	u8			kscratch_mask;
};

/*
 * Flag definitions
 */
@@ -95,6 +104,11 @@ struct cpuinfo_mips {
	 * htw_start/htw_stop calls
	 */
	unsigned int		htw_seq;

	/* VZ & Guest features */
	struct guest_info	guest;
	unsigned int		gtoffset_mask;
	unsigned int		guestid_mask;
} __attribute__((aligned(SMP_CACHE_BYTES)));

extern struct cpuinfo_mips cpu_data[];
+5 −0
Original line number Diff line number Diff line
@@ -409,6 +409,11 @@ enum cpu_type_enum {
#define MIPS_CPU_BADINSTRP	MBIT_ULL(45)	/* CPU has BadInstrP register */
#define MIPS_CPU_CTXTC		MBIT_ULL(46)	/* CPU has [X]ConfigContext registers */
#define MIPS_CPU_PERF		MBIT_ULL(47)	/* CPU has MIPS performance counters */
#define MIPS_CPU_GUESTCTL0EXT	MBIT_ULL(48)	/* CPU has VZ GuestCtl0Ext register */
#define MIPS_CPU_GUESTCTL1	MBIT_ULL(49)	/* CPU has VZ GuestCtl1 register */
#define MIPS_CPU_GUESTCTL2	MBIT_ULL(50)	/* CPU has VZ GuestCtl2 register */
#define MIPS_CPU_GUESTID	MBIT_ULL(51)	/* CPU uses VZ ASE GuestID feature */
#define MIPS_CPU_DRG		MBIT_ULL(52)	/* CPU has VZ Direct Root to Guest (DRG) */

/*
 * CPU ASE encodings
+232 −0
Original line number Diff line number Diff line
@@ -915,6 +915,235 @@ static void decode_configs(struct cpuinfo_mips *c)
#endif
}

/*
 * Probe for certain guest capabilities by writing config bits and reading back.
 * Finally write back the original value.
 */
#define probe_gc0_config(name, maxconf, bits)				\
do {									\
	unsigned int tmp;						\
	tmp = read_gc0_##name();					\
	write_gc0_##name(tmp | (bits));					\
	back_to_back_c0_hazard();					\
	maxconf = read_gc0_##name();					\
	write_gc0_##name(tmp);						\
} while (0)

/*
 * Probe for dynamic guest capabilities by changing certain config bits and
 * reading back to see if they change. Finally write back the original value.
 */
#define probe_gc0_config_dyn(name, maxconf, dynconf, bits)		\
do {									\
	maxconf = read_gc0_##name();					\
	write_gc0_##name(maxconf ^ (bits));				\
	back_to_back_c0_hazard();					\
	dynconf = maxconf ^ read_gc0_##name();				\
	write_gc0_##name(maxconf);					\
	maxconf |= dynconf;						\
} while (0)

static inline unsigned int decode_guest_config0(struct cpuinfo_mips *c)
{
	unsigned int config0;

	probe_gc0_config(config, config0, MIPS_CONF_M);

	if (config0 & MIPS_CONF_M)
		c->guest.conf |= BIT(1);
	return config0 & MIPS_CONF_M;
}

static inline unsigned int decode_guest_config1(struct cpuinfo_mips *c)
{
	unsigned int config1, config1_dyn;

	probe_gc0_config_dyn(config1, config1, config1_dyn,
			     MIPS_CONF_M | MIPS_CONF1_PC | MIPS_CONF1_WR |
			     MIPS_CONF1_FP);

	if (config1 & MIPS_CONF1_FP)
		c->guest.options |= MIPS_CPU_FPU;
	if (config1_dyn & MIPS_CONF1_FP)
		c->guest.options_dyn |= MIPS_CPU_FPU;

	if (config1 & MIPS_CONF1_WR)
		c->guest.options |= MIPS_CPU_WATCH;
	if (config1_dyn & MIPS_CONF1_WR)
		c->guest.options_dyn |= MIPS_CPU_WATCH;

	if (config1 & MIPS_CONF1_PC)
		c->guest.options |= MIPS_CPU_PERF;
	if (config1_dyn & MIPS_CONF1_PC)
		c->guest.options_dyn |= MIPS_CPU_PERF;

	if (config1 & MIPS_CONF_M)
		c->guest.conf |= BIT(2);
	return config1 & MIPS_CONF_M;
}

static inline unsigned int decode_guest_config2(struct cpuinfo_mips *c)
{
	unsigned int config2;

	probe_gc0_config(config2, config2, MIPS_CONF_M);

	if (config2 & MIPS_CONF_M)
		c->guest.conf |= BIT(3);
	return config2 & MIPS_CONF_M;
}

static inline unsigned int decode_guest_config3(struct cpuinfo_mips *c)
{
	unsigned int config3, config3_dyn;

	probe_gc0_config_dyn(config3, config3, config3_dyn,
			     MIPS_CONF_M | MIPS_CONF3_MSA | MIPS_CONF3_CTXTC);

	if (config3 & MIPS_CONF3_CTXTC)
		c->guest.options |= MIPS_CPU_CTXTC;
	if (config3_dyn & MIPS_CONF3_CTXTC)
		c->guest.options_dyn |= MIPS_CPU_CTXTC;

	if (config3 & MIPS_CONF3_PW)
		c->guest.options |= MIPS_CPU_HTW;

	if (config3 & MIPS_CONF3_SC)
		c->guest.options |= MIPS_CPU_SEGMENTS;

	if (config3 & MIPS_CONF3_BI)
		c->guest.options |= MIPS_CPU_BADINSTR;
	if (config3 & MIPS_CONF3_BP)
		c->guest.options |= MIPS_CPU_BADINSTRP;

	if (config3 & MIPS_CONF3_MSA)
		c->guest.ases |= MIPS_ASE_MSA;
	if (config3_dyn & MIPS_CONF3_MSA)
		c->guest.ases_dyn |= MIPS_ASE_MSA;

	if (config3 & MIPS_CONF_M)
		c->guest.conf |= BIT(4);
	return config3 & MIPS_CONF_M;
}

static inline unsigned int decode_guest_config4(struct cpuinfo_mips *c)
{
	unsigned int config4;

	probe_gc0_config(config4, config4,
			 MIPS_CONF_M | MIPS_CONF4_KSCREXIST);

	c->guest.kscratch_mask = (config4 & MIPS_CONF4_KSCREXIST)
				>> MIPS_CONF4_KSCREXIST_SHIFT;

	if (config4 & MIPS_CONF_M)
		c->guest.conf |= BIT(5);
	return config4 & MIPS_CONF_M;
}

static inline unsigned int decode_guest_config5(struct cpuinfo_mips *c)
{
	unsigned int config5, config5_dyn;

	probe_gc0_config_dyn(config5, config5, config5_dyn,
			 MIPS_CONF_M | MIPS_CONF5_MRP);

	if (config5 & MIPS_CONF5_MRP)
		c->guest.options |= MIPS_CPU_MAAR;
	if (config5_dyn & MIPS_CONF5_MRP)
		c->guest.options_dyn |= MIPS_CPU_MAAR;

	if (config5 & MIPS_CONF5_LLB)
		c->guest.options |= MIPS_CPU_RW_LLB;

	if (config5 & MIPS_CONF_M)
		c->guest.conf |= BIT(6);
	return config5 & MIPS_CONF_M;
}

static inline void decode_guest_configs(struct cpuinfo_mips *c)
{
	unsigned int ok;

	ok = decode_guest_config0(c);
	if (ok)
		ok = decode_guest_config1(c);
	if (ok)
		ok = decode_guest_config2(c);
	if (ok)
		ok = decode_guest_config3(c);
	if (ok)
		ok = decode_guest_config4(c);
	if (ok)
		decode_guest_config5(c);
}

static inline void cpu_probe_guestctl0(struct cpuinfo_mips *c)
{
	unsigned int guestctl0, temp;

	guestctl0 = read_c0_guestctl0();

	if (guestctl0 & MIPS_GCTL0_G0E)
		c->options |= MIPS_CPU_GUESTCTL0EXT;
	if (guestctl0 & MIPS_GCTL0_G1)
		c->options |= MIPS_CPU_GUESTCTL1;
	if (guestctl0 & MIPS_GCTL0_G2)
		c->options |= MIPS_CPU_GUESTCTL2;
	if (!(guestctl0 & MIPS_GCTL0_RAD)) {
		c->options |= MIPS_CPU_GUESTID;

		/*
		 * Probe for Direct Root to Guest (DRG). Set GuestCtl1.RID = 0
		 * first, otherwise all data accesses will be fully virtualised
		 * as if they were performed by guest mode.
		 */
		write_c0_guestctl1(0);
		tlbw_use_hazard();

		write_c0_guestctl0(guestctl0 | MIPS_GCTL0_DRG);
		back_to_back_c0_hazard();
		temp = read_c0_guestctl0();

		if (temp & MIPS_GCTL0_DRG) {
			write_c0_guestctl0(guestctl0);
			c->options |= MIPS_CPU_DRG;
		}
	}
}

static inline void cpu_probe_guestctl1(struct cpuinfo_mips *c)
{
	if (cpu_has_guestid) {
		/* determine the number of bits of GuestID available */
		write_c0_guestctl1(MIPS_GCTL1_ID);
		back_to_back_c0_hazard();
		c->guestid_mask = (read_c0_guestctl1() & MIPS_GCTL1_ID)
						>> MIPS_GCTL1_ID_SHIFT;
		write_c0_guestctl1(0);
	}
}

static inline void cpu_probe_gtoffset(struct cpuinfo_mips *c)
{
	/* determine the number of bits of GTOffset available */
	write_c0_gtoffset(0xffffffff);
	back_to_back_c0_hazard();
	c->gtoffset_mask = read_c0_gtoffset();
	write_c0_gtoffset(0);
}

static inline void cpu_probe_vz(struct cpuinfo_mips *c)
{
	cpu_probe_guestctl0(c);
	if (cpu_has_guestctl1)
		cpu_probe_guestctl1(c);

	cpu_probe_gtoffset(c);

	decode_guest_configs(c);
}

#define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
		| MIPS_CPU_COUNTER)

@@ -1817,6 +2046,9 @@ void cpu_probe(void)
		elf_hwcap |= HWCAP_MIPS_MSA;
	}

	if (cpu_has_vz)
		cpu_probe_vz(c);

	cpu_probe_vmbits(c);

#ifdef CONFIG_64BIT