Re: [kvm-unit-tests PATCH v5 09/11] arm/arm64: add initial gicv3 support

["Alex Bennée" <alex.bennee@linaro.org>]

Andrew Jones <drjones@redhat.com> writes:

> Signed-off-by: Andrew Jones <drjones@redhat.com>
>
> ---
> v5: use modern register names [Andre]
> v4:
>  - only take defines from kernel we need now [Andre]
>  - simplify enable by not caring if we reinit the distributor [drew]
> v2:
>  - configure irqs as NS GRP1
> ---
>  lib/arm/asm/arch_gicv3.h   | 42 +++++++++++++++++++++
>  lib/arm/asm/gic-v3.h       | 94 ++++++++++++++++++++++++++++++++++++++++++++++
>  lib/arm/asm/gic.h          |  6 ++-
>  lib/arm/gic.c              | 65 ++++++++++++++++++++++++++++++++
>  lib/arm64/asm/arch_gicv3.h | 44 ++++++++++++++++++++++
>  lib/arm64/asm/gic-v3.h     |  1 +
>  lib/arm64/asm/sysreg.h     | 44 ++++++++++++++++++++++
>  7 files changed, 294 insertions(+), 2 deletions(-)
>  create mode 100644 lib/arm/asm/arch_gicv3.h
>  create mode 100644 lib/arm/asm/gic-v3.h
>  create mode 100644 lib/arm64/asm/arch_gicv3.h
>  create mode 100644 lib/arm64/asm/gic-v3.h
>  create mode 100644 lib/arm64/asm/sysreg.h
>
> diff --git a/lib/arm/asm/arch_gicv3.h b/lib/arm/asm/arch_gicv3.h
> new file mode 100644
> index 000000000000..81a1e5f6c29c
> --- /dev/null
> +++ b/lib/arm/asm/arch_gicv3.h
> @@ -0,0 +1,42 @@
> +/*
> + * All ripped off from arch/arm/include/asm/arch_gicv3.h
> + *
> + * Copyright (C) 2016, Red Hat Inc, Andrew Jones <drjones@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU LGPL, version 2.
> + */
> +#ifndef _ASMARM_ARCH_GICV3_H_
> +#define _ASMARM_ARCH_GICV3_H_
> +
> +#ifndef __ASSEMBLY__
> +#include <libcflat.h>
> +#include <asm/barrier.h>
> +#include <asm/io.h>
> +
> +#define __stringify xstr
> +
> +#define __ACCESS_CP15(CRn, Op1, CRm, Op2)	p15, Op1, %0, CRn, CRm, Op2
> +
> +#define ICC_PMR				__ACCESS_CP15(c4, 0, c6, 0)
> +#define ICC_IGRPEN1			__ACCESS_CP15(c12, 0, c12, 7)
> +
> +static inline void gicv3_write_pmr(u32 val)
> +{
> +	asm volatile("mcr " __stringify(ICC_PMR) : : "r" (val));
> +}
> +
> +static inline void gicv3_write_grpen1(u32 val)
> +{
> +	asm volatile("mcr " __stringify(ICC_IGRPEN1) : : "r" (val));
> +	isb();
> +}
> +
> +static inline u64 gicv3_read_typer(const volatile void __iomem *addr)
> +{
> +	u64 val = readl(addr);
> +	val |= (u64)readl(addr + 4) << 32;

I'd be tempted to wrap the cast in additional parentheses for clarity:

  val |= ((u64)readl(addr + 4)) << 32;

> +	return val;
> +}
> +
> +#endif /* !__ASSEMBLY__ */
> +#endif /* _ASMARM_ARCH_GICV3_H_ */
> diff --git a/lib/arm/asm/gic-v3.h b/lib/arm/asm/gic-v3.h
> new file mode 100644
> index 000000000000..e0f303d82508
> --- /dev/null
> +++ b/lib/arm/asm/gic-v3.h
> @@ -0,0 +1,94 @@
> +/*
> + * All GIC* defines are lifted from include/linux/irqchip/arm-gic-v3.h
> + *
> + * Copyright (C) 2016, Red Hat Inc, Andrew Jones <drjones@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU LGPL, version 2.
> + */
> +#ifndef _ASMARM_GIC_V3_H_
> +#define _ASMARM_GIC_V3_H_
> +
> +#ifndef _ASMARM_GIC_H_
> +#error Do not directly include <asm/gic-v3.h>. Include <asm/gic.h>
> +#endif
> +
> +#define GICD_CTLR_RWP			(1U << 31)
> +#define GICD_CTLR_ARE_NS		(1U << 4)
> +#define GICD_CTLR_ENABLE_G1A		(1U << 1)
> +#define GICD_CTLR_ENABLE_G1		(1U << 0)

I got confused when looking at the data sheet until I noticed Secure and
Non-secure worlds have subtly different bit positions. It might be worth
making that clear in a comment.

> +
> +/* Re-Distributor registers, offsets from RD_base */
> +#define GICR_TYPER			0x0008
> +
> +#define GICR_TYPER_LAST			(1U << 4)
> +
> +/* Re-Distributor registers, offsets from SGI_base */
> +#define GICR_IGROUPR0			GICD_IGROUPR
> +#define GICR_ISENABLER0			GICD_ISENABLER
> +#define GICR_IPRIORITYR0		GICD_IPRIORITYR
> +
> +#include <asm/arch_gicv3.h>
> +
> +#ifndef __ASSEMBLY__
> +#include <asm/setup.h>
> +#include <asm/smp.h>
> +#include <asm/processor.h>
> +#include <asm/io.h>
> +
> +struct gicv3_data {
> +	void *dist_base;
> +	void *redist_base[NR_CPUS];
> +	unsigned int irq_nr;
> +};
> +extern struct gicv3_data gicv3_data;
> +
> +#define gicv3_dist_base()		(gicv3_data.dist_base)
> +#define gicv3_redist_base()		(gicv3_data.redist_base[smp_processor_id()])
> +#define gicv3_sgi_base()		(gicv3_data.redist_base[smp_processor_id()] + SZ_64K)
> +
> +extern int gicv3_init(void);
> +extern void gicv3_enable_defaults(void);
> +extern void gicv3_set_redist_base(void);
> +
> +static inline void gicv3_do_wait_for_rwp(void *base)
> +{
> +	int count = 100000;	/* 1s */
> +
> +	while (readl(base + GICD_CTLR) & GICD_CTLR_RWP) {
> +		if (!--count) {
> +			printf("GICv3: RWP timeout!\n");
> +			abort();
> +		}
> +		cpu_relax();
> +		udelay(10);
> +	};
> +}
> +
> +static inline void gicv3_dist_wait_for_rwp(void)
> +{
> +	gicv3_do_wait_for_rwp(gicv3_dist_base());
> +}
> +
> +static inline void gicv3_redist_wait_for_rwp(void)
> +{
> +	gicv3_do_wait_for_rwp(gicv3_redist_base());
> +}
> +
> +static inline u32 mpidr_compress(u64 mpidr)
> +{
> +	u64 compressed = mpidr & MPIDR_HWID_BITMASK;
> +
> +	compressed = (((compressed >> 32) & 0xff) << 24) | compressed;
> +	return compressed;
> +}
> +
> +static inline u64 mpidr_uncompress(u32 compressed)
> +{
> +	u64 mpidr = ((u64)compressed >> 24) << 32;
> +
> +	mpidr |= compressed & MPIDR_HWID_BITMASK;
> +	return mpidr;
> +}
> +
> +#endif /* !__ASSEMBLY__ */
> +#endif /* _ASMARM_GIC_V3_H_ */
> diff --git a/lib/arm/asm/gic.h b/lib/arm/asm/gic.h
> index a16645708c35..981518620d18 100644
> --- a/lib/arm/asm/gic.h
> +++ b/lib/arm/asm/gic.h
> @@ -6,10 +6,9 @@
>  #ifndef _ASMARM_GIC_H_
>  #define _ASMARM_GIC_H_
>
> -#include <asm/gic-v2.h>
> -
>  #define GICD_CTLR			0x0000
>  #define GICD_TYPER			0x0004
> +#define GICD_IGROUPR			0x0080
>  #define GICD_ISENABLER			0x0100
>  #define GICD_IPRIORITYR			0x0400
>  #define GICD_SGIR			0x0f00
> @@ -26,6 +25,9 @@
>  #define GICC_INT_PRI_THRESHOLD		0xf0
>  #define GICC_INT_SPURIOUS		0x3ff
>
> +#include <asm/gic-v2.h>
> +#include <asm/gic-v3.h>
> +
>  #ifndef __ASSEMBLY__
>
>  /*
> diff --git a/lib/arm/gic.c b/lib/arm/gic.c
> index d655105e058b..d929d3f0fa05 100644
> --- a/lib/arm/gic.c
> +++ b/lib/arm/gic.c
> @@ -8,9 +8,11 @@
>  #include <asm/io.h>
>
>  struct gicv2_data gicv2_data;
> +struct gicv3_data gicv3_data;
>
>  /*
>   * Documentation/devicetree/bindings/interrupt-controller/arm,gic.txt
> + * Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
>   */
>  static bool
>  gic_get_dt_bases(const char *compatible, void **base1, void **base2)
> @@ -48,10 +50,18 @@ int gicv2_init(void)
>  			&gicv2_data.dist_base, &gicv2_data.cpu_base);
>  }
>
> +int gicv3_init(void)
> +{
> +	return gic_get_dt_bases("arm,gic-v3", &gicv3_data.dist_base,
> +			&gicv3_data.redist_base[0]);
> +}
> +
>  int gic_init(void)
>  {
>  	if (gicv2_init())
>  		return 2;
> +	else if (gicv3_init())
> +		return 3;
>  	return 0;
>  }
>
> @@ -74,3 +84,58 @@ void gicv2_enable_defaults(void)
>  	writel(GICC_INT_PRI_THRESHOLD, cpu_base + GICC_PMR);
>  	writel(GICC_ENABLE, cpu_base + GICC_CTLR);
>  }
> +
> +void gicv3_set_redist_base(void)
> +{
> +	u32 aff = mpidr_compress(get_mpidr());
> +	void *ptr = gicv3_data.redist_base[0];
> +	u64 typer;
> +
> +	do {
> +		typer = gicv3_read_typer(ptr + GICR_TYPER);
> +		if ((typer >> 32) == aff) {
> +			gicv3_redist_base() = ptr;
> +			return;
> +		}
> +		ptr += SZ_64K * 2; /* skip RD_base and SGI_base */
> +	} while (!(typer & GICR_TYPER_LAST));
> +	assert(0);

Maybe:

  /* should never reach here */
  assert(false);

> +}
> +
> +void gicv3_enable_defaults(void)
> +{
> +	void *dist = gicv3_dist_base();
> +	void *sgi_base;
> +	unsigned int i;
> +
> +	gicv3_data.irq_nr = GICD_TYPER_IRQS(readl(dist + GICD_TYPER));
> +	if (gicv3_data.irq_nr > 1020)
> +		gicv3_data.irq_nr = 1020;
> +
> +	writel(0, dist + GICD_CTLR);
> +	gicv3_dist_wait_for_rwp();
> +
> +	writel(GICD_CTLR_ARE_NS | GICD_CTLR_ENABLE_G1A | GICD_CTLR_ENABLE_G1,
> +	       dist + GICD_CTLR);
> +	gicv3_dist_wait_for_rwp();
> +
> +	for (i = 0; i < gicv3_data.irq_nr; i += 4)
> +		writel(~0, dist + GICD_IGROUPR + i);
> +	gicv3_dist_wait_for_rwp();
> +
> +	if (!gicv3_redist_base())
> +		gicv3_set_redist_base();
> +	sgi_base = gicv3_sgi_base();
> +
> +	writel(~0, sgi_base + GICR_IGROUPR0);
> +
> +	for (i = 0; i < 16; i += 4)
> +		writel(GICD_INT_DEF_PRI_X4, sgi_base + GICR_IPRIORITYR0 + i);
> +
> +	writel(GICD_INT_EN_SET_SGI, sgi_base + GICR_ISENABLER0);
> +
> +	gicv3_redist_wait_for_rwp();
> +
> +	gicv3_write_pmr(GICC_INT_PRI_THRESHOLD);
> +	gicv3_write_grpen1(1);
> +}
> diff --git a/lib/arm64/asm/arch_gicv3.h b/lib/arm64/asm/arch_gicv3.h
> new file mode 100644
> index 000000000000..6d353567f56a
> --- /dev/null
> +++ b/lib/arm64/asm/arch_gicv3.h
> @@ -0,0 +1,44 @@
> +/*
> + * All ripped off from arch/arm64/include/asm/arch_gicv3.h
> + *
> + * Copyright (C) 2016, Red Hat Inc, Andrew Jones <drjones@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU LGPL, version 2.
> + */
> +#ifndef _ASMARM64_ARCH_GICV3_H_
> +#define _ASMARM64_ARCH_GICV3_H_
> +
> +#include <asm/sysreg.h>
> +
> +#define ICC_PMR_EL1			sys_reg(3, 0, 4, 6, 0)
> +#define ICC_GRPEN1_EL1			sys_reg(3, 0, 12, 12, 7)
> +
> +#ifndef __ASSEMBLY__
> +
> +#include <libcflat.h>
> +#include <asm/barrier.h>
> +
> +#define __stringify xstr
> +
> +/*
> + * Low-level accessors
> + *
> + * These system registers are 32 bits, but we make sure that the compiler
> + * sets the GP register's most significant bits to 0 with an explicit cast.
> + */
> +
> +static inline void gicv3_write_pmr(u32 val)
> +{
> +	asm volatile("msr_s " __stringify(ICC_PMR_EL1) ", %0" : : "r" ((u64)val));
> +}
> +
> +static inline void gicv3_write_grpen1(u32 val)
> +{
> +	asm volatile("msr_s " __stringify(ICC_GRPEN1_EL1) ", %0" : : "r" ((u64)val));
> +	isb();
> +}
> +
> +#define gicv3_read_typer(c)		readq(c)
> +
> +#endif /* __ASSEMBLY__ */
> +#endif /* _ASMARM64_ARCH_GICV3_H_ */
> diff --git a/lib/arm64/asm/gic-v3.h b/lib/arm64/asm/gic-v3.h
> new file mode 100644
> index 000000000000..8ee5d4d9c181
> --- /dev/null
> +++ b/lib/arm64/asm/gic-v3.h
> @@ -0,0 +1 @@
> +#include "../../arm/asm/gic-v3.h"
> diff --git a/lib/arm64/asm/sysreg.h b/lib/arm64/asm/sysreg.h
> new file mode 100644
> index 000000000000..544a46cb8cc5
> --- /dev/null
> +++ b/lib/arm64/asm/sysreg.h
> @@ -0,0 +1,44 @@
> +/*
> + * Ripped off from arch/arm64/include/asm/sysreg.h
> + *
> + * Copyright (C) 2016, Red Hat Inc, Andrew Jones <drjones@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU LGPL, version 2.
> + */
> +#ifndef _ASMARM64_SYSREG_H_
> +#define _ASMARM64_SYSREG_H_
> +
> +#define sys_reg(op0, op1, crn, crm, op2) \
> +	((((op0)&3)<<19)|((op1)<<16)|((crn)<<12)|((crm)<<8)|((op2)<<5))
> +
> +#ifdef __ASSEMBLY__
> +	.irp	num,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30
> +	.equ	.L__reg_num_x\num, \num
> +	.endr
> +	.equ	.L__reg_num_xzr, 31
> +
> +	.macro	mrs_s, rt, sreg
> +	.inst	0xd5200000|(\sreg)|(.L__reg_num_\rt)
> +	.endm
> +
> +	.macro	msr_s, sreg, rt
> +	.inst	0xd5000000|(\sreg)|(.L__reg_num_\rt)
> +	.endm
> +#else
> +asm(
> +"	.irp	num,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30\n"
> +"	.equ	.L__reg_num_x\\num, \\num\n"
> +"	.endr\n"
> +"	.equ	.L__reg_num_xzr, 31\n"
> +"\n"
> +"	.macro	mrs_s, rt, sreg\n"
> +"	.inst	0xd5200000|(\\sreg)|(.L__reg_num_\\rt)\n"
> +"	.endm\n"
> +"\n"
> +"	.macro	msr_s, sreg, rt\n"
> +"	.inst	0xd5000000|(\\sreg)|(.L__reg_num_\\rt)\n"
> +"	.endm\n"
> +);
> +#endif
> +
> +#endif /* _ASMARM64_SYSREG_H_ */

Otherwise:

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

--
Alex Bennée