Re: [kvm-unit-tests PATCH v5 06/11] arm/arm64: add initial gicv2 support

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

Andrew Jones <drjones@redhat.com> writes:

> Add some gicv2 support. This just adds init and enable
> functions, allowing unit tests to start messing with it.
>
> Signed-off-by: Andrew Jones <drjones@redhat.com>
>
> ---
> v5: share/use only the modern register names [Andre]
> v4:
>  - only take defines from kernel we need now [Andre]
>  - moved defines to asm/gic.h so they'll be shared with v3 [drew]
>  - simplify enable by not caring if we reinit the distributor [drew]
>  - init all GICD_INT_DEF_PRI_X4 registers [Eric]
> ---
>  arm/Makefile.common    |  1 +
>  lib/arm/asm/gic-v2.h   | 34 ++++++++++++++++++++++
>  lib/arm/asm/gic.h      | 37 ++++++++++++++++++++++++
>  lib/arm/gic.c          | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  lib/arm64/asm/gic-v2.h |  1 +
>  lib/arm64/asm/gic.h    |  1 +
>  6 files changed, 150 insertions(+)
>  create mode 100644 lib/arm/asm/gic-v2.h
>  create mode 100644 lib/arm/asm/gic.h
>  create mode 100644 lib/arm/gic.c
>  create mode 100644 lib/arm64/asm/gic-v2.h
>  create mode 100644 lib/arm64/asm/gic.h
>
> diff --git a/arm/Makefile.common b/arm/Makefile.common
> index ccb554d9251a..41239c37e092 100644
> --- a/arm/Makefile.common
> +++ b/arm/Makefile.common
> @@ -42,6 +42,7 @@ cflatobjs += lib/arm/mmu.o
>  cflatobjs += lib/arm/bitops.o
>  cflatobjs += lib/arm/psci.o
>  cflatobjs += lib/arm/smp.o
> +cflatobjs += lib/arm/gic.o
>
>  libeabi = lib/arm/libeabi.a
>  eabiobjs = lib/arm/eabi_compat.o
> diff --git a/lib/arm/asm/gic-v2.h b/lib/arm/asm/gic-v2.h
> new file mode 100644
> index 000000000000..c2d5fecd4886
> --- /dev/null
> +++ b/lib/arm/asm/gic-v2.h
> @@ -0,0 +1,34 @@
> +/*
> + * All GIC* defines are lifted from include/linux/irqchip/arm-gic.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_V2_H_
> +#define _ASMARM_GIC_V2_H_
> +
> +#ifndef _ASMARM_GIC_H_
> +#error Do not directly include <asm/gic-v2.h>. Include <asm/gic.h>
> +#endif
> +
> +#define GICD_ENABLE			0x1
> +#define GICC_ENABLE			0x1
> +
> +#ifndef __ASSEMBLY__
> +
> +struct gicv2_data {
> +	void *dist_base;
> +	void *cpu_base;
> +	unsigned int irq_nr;
> +};
> +extern struct gicv2_data gicv2_data;
> +
> +#define gicv2_dist_base()		(gicv2_data.dist_base)
> +#define gicv2_cpu_base()		(gicv2_data.cpu_base)
> +
> +extern int gicv2_init(void);
> +extern void gicv2_enable_defaults(void);
> +
> +#endif /* !__ASSEMBLY__ */
> +#endif /* _ASMARM_GIC_V2_H_ */
> diff --git a/lib/arm/asm/gic.h b/lib/arm/asm/gic.h
> new file mode 100644
> index 000000000000..d44e47bcf404
> --- /dev/null
> +++ b/lib/arm/asm/gic.h
> @@ -0,0 +1,37 @@
> +/*
> + * 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_H_
> +#define _ASMARM_GIC_H_
> +
> +#include <asm/gic-v2.h>
> +
> +#define GICD_CTLR			0x0000
> +#define GICD_TYPER			0x0004
> +#define GICD_ISENABLER			0x0100
> +#define GICD_IPRIORITYR			0x0400

Maybe GICD_ISENABLER_BASE and GICD_IPRIORITYR_BASE as they are the start
of a series of registers? Also what happened to the formatting?

> +
> +#define GICD_TYPER_IRQS(typer)		((((typer) & 0x1f) + 1)
> * 32)
> +#define GICD_INT_EN_SET_SGI		0x0000ffff
> +#define GICD_INT_DEF_PRI_X4		0xa0a0a0a0

This doesn't seem to be used and I'm not sure what GICD_TYPER_IRQS it is
trying to achieve.

A comment above and here to make it clear we are talking about offsets
in the distributor and cpu register maps would aid confusion.

> +
> +#define GICC_CTLR			0x0000
> +#define GICC_PMR			0x0004
> +
> +#define GICC_INT_PRI_THRESHOLD		0xf0
> +
> +#ifndef __ASSEMBLY__
> +
> +/*
> + * gic_init will try to find all known gics, and then
> + * initialize the gic data for the one found.
> + * returns
> + *  0   : no gic was found
> + *  > 0 : the gic version of the gic found
> + */
> +extern int gic_init(void);

If we are going to make the library API agnostic I guess returning NULL
or an ops structure would be best here?

> +
> +#endif /* !__ASSEMBLY__ */
> +#endif /* _ASMARM_GIC_H_ */
> diff --git a/lib/arm/gic.c b/lib/arm/gic.c
> new file mode 100644
> index 000000000000..d655105e058b
> --- /dev/null
> +++ b/lib/arm/gic.c
> @@ -0,0 +1,76 @@
> +/*
> + * Copyright (C) 2016, Red Hat Inc, Andrew Jones <drjones@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU LGPL, version 2.
> + */
> +#include <devicetree.h>
> +#include <asm/gic.h>
> +#include <asm/io.h>
> +
> +struct gicv2_data gicv2_data;
> +
> +/*
> + * Documentation/devicetree/bindings/interrupt-controller/arm,gic.txt
> + */
> +static bool
> +gic_get_dt_bases(const char *compatible, void **base1, void **base2)
> +{
> +	struct dt_pbus_reg reg;
> +	struct dt_device gic;
> +	struct dt_bus bus;
> +	int node, ret;
> +
> +	dt_bus_init_defaults(&bus);
> +	dt_device_init(&gic, &bus, NULL);
> +
> +	node = dt_device_find_compatible(&gic, compatible);
> +	assert(node >= 0 || node == -FDT_ERR_NOTFOUND);
> +
> +	if (node == -FDT_ERR_NOTFOUND)
> +		return false;
> +
> +	dt_device_bind_node(&gic, node);
> +
> +	ret = dt_pbus_translate(&gic, 0, &reg);
> +	assert(ret == 0);
> +	*base1 = ioremap(reg.addr, reg.size);
> +
> +	ret = dt_pbus_translate(&gic, 1, &reg);
> +	assert(ret == 0);
> +	*base2 = ioremap(reg.addr, reg.size);
> +
> +	return true;
> +}
> +
> +int gicv2_init(void)
> +{
> +	return gic_get_dt_bases("arm,cortex-a15-gic",
> +			&gicv2_data.dist_base, &gicv2_data.cpu_base);
> +}
> +
> +int gic_init(void)
> +{
> +	if (gicv2_init())
> +		return 2;
> +	return 0;
> +}
> +
> +void gicv2_enable_defaults(void)
> +{
> +	void *dist = gicv2_dist_base();
> +	void *cpu_base = gicv2_cpu_base();
> +	unsigned int i;
> +
> +	gicv2_data.irq_nr = GICD_TYPER_IRQS(readl(dist + GICD_TYPER));
> +	if (gicv2_data.irq_nr > 1020)
> +		gicv2_data.irq_nr = 1020;
> +
> +	for (i = 0; i < gicv2_data.irq_nr; i += 4)
> +		writel(GICD_INT_DEF_PRI_X4, dist + GICD_IPRIORITYR + i);
> +
> +	writel(GICD_INT_EN_SET_SGI, dist + GICD_ISENABLER + 0);
> +	writel(GICD_ENABLE, dist + GICD_CTLR);
> +
> +	writel(GICC_INT_PRI_THRESHOLD, cpu_base + GICC_PMR);
> +	writel(GICC_ENABLE, cpu_base + GICC_CTLR);
> +}
> diff --git a/lib/arm64/asm/gic-v2.h b/lib/arm64/asm/gic-v2.h
> new file mode 100644
> index 000000000000..52226624a209
> --- /dev/null
> +++ b/lib/arm64/asm/gic-v2.h
> @@ -0,0 +1 @@
> +#include "../../arm/asm/gic-v2.h"
> diff --git a/lib/arm64/asm/gic.h b/lib/arm64/asm/gic.h
> new file mode 100644
> index 000000000000..e5eb302a31b4
> --- /dev/null
> +++ b/lib/arm64/asm/gic.h
> @@ -0,0 +1 @@
> +#include "../../arm/asm/gic.h"


--
Alex Bennée
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