diff mbox series

[kvm-unit-tests,v2,05/16] arm/arm64: ITS: Introspection tests

Message ID 20200110145412.14937-6-eric.auger@redhat.com
State New
Headers show
Series arm/arm64: Add ITS tests | expand

Commit Message

Eric Auger Jan. 10, 2020, 2:54 p.m. UTC 
Detect the presence of an ITS as part of the GICv3 init
routine, initialize its base address and read few registers
the IIDR, the TYPER to store its dimensioning parameters.

This is our first ITS test, belonging to a new "its" group.

Signed-off-by: Eric Auger <eric.auger@redhat.com>

---

v1 -> v2:
- clean GITS_TYPER macros and unused fields in typer struct
- remove memory attribute related macros
---
 arm/Makefile.common        |  1 +
 arm/gic.c                  | 34 ++++++++++++++++
 arm/unittests.cfg          |  6 +++
 lib/arm/asm/gic-v3-its.h   | 81 ++++++++++++++++++++++++++++++++++++++
 lib/arm/asm/gic.h          |  1 +
 lib/arm/gic-v3-its.c       | 39 ++++++++++++++++++
 lib/arm/gic.c              | 31 ++++++++++++---
 lib/arm64/asm/gic-v3-its.h |  1 +
 8 files changed, 189 insertions(+), 5 deletions(-)
 create mode 100644 lib/arm/asm/gic-v3-its.h
 create mode 100644 lib/arm/gic-v3-its.c
 create mode 100644 lib/arm64/asm/gic-v3-its.h

Comments

Andrew Jones Jan. 13, 2020, 5:11 p.m. UTC | #1 
On Fri, Jan 10, 2020 at 03:54:01PM +0100, Eric Auger wrote:
> Detect the presence of an ITS as part of the GICv3 init
> routine, initialize its base address and read few registers
> the IIDR, the TYPER to store its dimensioning parameters.
> 
> This is our first ITS test, belonging to a new "its" group.
> 
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> 
> ---
> 
> v1 -> v2:
> - clean GITS_TYPER macros and unused fields in typer struct
> - remove memory attribute related macros
> ---
>  arm/Makefile.common        |  1 +
>  arm/gic.c                  | 34 ++++++++++++++++
>  arm/unittests.cfg          |  6 +++
>  lib/arm/asm/gic-v3-its.h   | 81 ++++++++++++++++++++++++++++++++++++++
>  lib/arm/asm/gic.h          |  1 +
>  lib/arm/gic-v3-its.c       | 39 ++++++++++++++++++
>  lib/arm/gic.c              | 31 ++++++++++++---
>  lib/arm64/asm/gic-v3-its.h |  1 +
>  8 files changed, 189 insertions(+), 5 deletions(-)
>  create mode 100644 lib/arm/asm/gic-v3-its.h
>  create mode 100644 lib/arm/gic-v3-its.c
>  create mode 100644 lib/arm64/asm/gic-v3-its.h
> 
> diff --git a/arm/Makefile.common b/arm/Makefile.common
> index b8988f2..1aae5a3 100644
> --- a/arm/Makefile.common
> +++ b/arm/Makefile.common
> @@ -52,6 +52,7 @@ cflatobjs += lib/arm/psci.o
>  cflatobjs += lib/arm/smp.o
>  cflatobjs += lib/arm/delay.o
>  cflatobjs += lib/arm/gic.o lib/arm/gic-v2.o lib/arm/gic-v3.o
> +cflatobjs += lib/arm/gic-v3-its.o
>  
>  OBJDIRS += lib/arm
>  
> diff --git a/arm/gic.c b/arm/gic.c
> index ba43ae5..adeb981 100644
> --- a/arm/gic.c
> +++ b/arm/gic.c
> @@ -506,6 +506,36 @@ static void gic_test_mmio(void)
>  		test_targets(nr_irqs);
>  }
>  
> +static void test_its_introspection(void)
> +{
> +	struct its_typer *typer = &its_data.typer;
> +
> +	if (!gicv3_its_base()) {
> +		report_skip("No ITS, skip ...");
> +		return;
> +	}
> +
> +	/* IIDR */
> +	report(test_readonly_32(gicv3_its_base() + GITS_IIDR, false),
> +	       "GITS_IIDR is read-only"),
> +
> +	/* TYPER */
> +	report(test_readonly_32(gicv3_its_base() + GITS_TYPER, false),
> +	       "GITS_TYPER is read-only");
> +
> +	report(typer->phys_lpi, "ITS supports physical LPIs");
> +	report_info("vLPI support: %s", typer->virt_lpi ? "yes" : "no");
> +	report_info("ITT entry size = 0x%x", typer->ite_size);
> +	report_info("Bit Count: EventID=%d DeviceId=%d CollId=%d",
> +		    typer->eventid_bits, typer->deviceid_bits,
> +		    typer->collid_bits);
> +	report(typer->eventid_bits && typer->deviceid_bits &&
> +	       typer->collid_bits, "ID spaces");
> +	report(!typer->hw_collections, "collections only in ext memory");
> +	report_info("Target address format %s",
> +			typer->pta ? "Redist basse address" : "PE #");
> +}
> +
>  int main(int argc, char **argv)
>  {
>  	if (!gic_init()) {
> @@ -537,6 +567,10 @@ int main(int argc, char **argv)
>  		report_prefix_push(argv[1]);
>  		gic_test_mmio();
>  		report_prefix_pop();
> +	} else if (strcmp(argv[1], "its-introspection") == 0) {
> +		report_prefix_push(argv[1]);
> +		test_its_introspection();
> +		report_prefix_pop();
>  	} else {
>  		report_abort("Unknown subtest '%s'", argv[1]);
>  	}
> diff --git a/arm/unittests.cfg b/arm/unittests.cfg
> index daeb5a0..bd20460 100644
> --- a/arm/unittests.cfg
> +++ b/arm/unittests.cfg
> @@ -122,6 +122,12 @@ smp = $MAX_SMP
>  extra_params = -machine gic-version=3 -append 'active'
>  groups = gic
>  
> +[its-introspection]
> +file = gic.flat
> +smp = $MAX_SMP
> +extra_params = -machine gic-version=3 -append 'its-introspection'
> +groups = its
> +
>  # Test PSCI emulation
>  [psci]
>  file = psci.flat
> diff --git a/lib/arm/asm/gic-v3-its.h b/lib/arm/asm/gic-v3-its.h
> new file mode 100644
> index 0000000..8816d57
> --- /dev/null
> +++ b/lib/arm/asm/gic-v3-its.h
> @@ -0,0 +1,81 @@
> +/*
> + * All ITS* defines are lifted from include/linux/irqchip/arm-gic-v3.h
> + *
> + * Copyright (C) 2016, Red Hat Inc, Andrew Jones <drjones@redhat.com>

I don't recall writing this file. Well, I guess it was four years ago, so
I probably just forgot :-)

> + *
> + * This work is licensed under the terms of the GNU LGPL, version 2.
> + */
> +#ifndef _ASMARM_GIC_V3_ITS_H_
> +#define _ASMARM_GIC_V3_ITS_H_
> +
> +#ifndef __ASSEMBLY__
> +
> +#define GITS_CTLR			0x0000
> +#define GITS_IIDR			0x0004
> +#define GITS_TYPER			0x0008
> +#define GITS_CBASER			0x0080
> +#define GITS_CWRITER			0x0088
> +#define GITS_CREADR			0x0090
> +#define GITS_BASER			0x0100
> +
> +#define GITS_TYPER_PLPIS                BIT(0)
> +#define GITS_TYPER_VLPIS		BIT(1)
> +#define GITS_TYPER_ITT_ENTRY_SIZE	GENMASK_ULL(7, 4)
> +#define GITS_TYPER_ITT_ENTRY_SIZE_SHIFT	4
> +#define GITS_TYPER_IDBITS		GENMASK_ULL(8, 12)
> +#define GITS_TYPER_IDBITS_SHIFT         8
> +#define GITS_TYPER_DEVBITS		GENMASK_ULL(13, 17)
> +#define GITS_TYPER_DEVBITS_SHIFT        13
> +#define GITS_TYPER_PTA                  BIT(19)
> +#define GITS_TYPER_CIDBITS		GENMASK_ULL(32, 35)
> +#define GITS_TYPER_CIDBITS_SHIFT	32
> +#define GITS_TYPER_CIL			BIT(36)
> +
> +#define GITS_CTLR_ENABLE		(1U << 0)
> +
> +#define GITS_CBASER_VALID		(1UL << 63)
> +
> +#define GITS_BASER_NR_REGS              8
> +#define GITS_BASER_VALID		BIT(63)
> +#define GITS_BASER_INDIRECT		BIT(62)
> +#define GITS_BASER_TYPE_SHIFT		(56)
> +#define GITS_BASER_TYPE(r)		(((r) >> GITS_BASER_TYPE_SHIFT) & 7)
> +#define GITS_BASER_ENTRY_SIZE_SHIFT	(48)
> +#define GITS_BASER_ENTRY_SIZE(r)	((((r) >> GITS_BASER_ENTRY_SIZE_SHIFT) & 0x1f) + 1)
> +#define GITS_BASER_PAGE_SIZE_SHIFT	(8)
> +#define GITS_BASER_PAGE_SIZE_4K		(0UL << GITS_BASER_PAGE_SIZE_SHIFT)
> +#define GITS_BASER_PAGE_SIZE_16K	(1UL << GITS_BASER_PAGE_SIZE_SHIFT)
> +#define GITS_BASER_PAGE_SIZE_64K	(2UL << GITS_BASER_PAGE_SIZE_SHIFT)
> +#define GITS_BASER_PAGE_SIZE_MASK	(3UL << GITS_BASER_PAGE_SIZE_SHIFT)
> +#define GITS_BASER_PAGES_MAX		256
> +#define GITS_BASER_PAGES_SHIFT		(0)
> +#define GITS_BASER_NR_PAGES(r)		(((r) & 0xff) + 1)
> +#define GITS_BASER_PHYS_ADDR_MASK	0xFFFFFFFFF000
> +#define GITS_BASER_TYPE_NONE		0
> +#define GITS_BASER_TYPE_DEVICE		1
> +#define GITS_BASER_TYPE_COLLECTION	4
> +
> +struct its_typer {
> +	unsigned int ite_size;
> +	unsigned int eventid_bits;
> +	unsigned int deviceid_bits;
> +	unsigned int collid_bits;
> +	bool pta;
> +	bool phys_lpi;
> +	bool virt_lpi;
> +};
> +
> +struct its_data {
> +	void *base;
> +	struct its_typer typer;
> +};
> +
> +extern struct its_data its_data;
> +
> +#define gicv3_its_base()		(its_data.base)
> +
> +extern void its_parse_typer(void);
> +extern void its_init(void);
> +
> +#endif /* !__ASSEMBLY__ */
> +#endif /* _ASMARM_GIC_V3_ITS_H_ */
> diff --git a/lib/arm/asm/gic.h b/lib/arm/asm/gic.h
> index 55dd84b..b44da9c 100644
> --- a/lib/arm/asm/gic.h
> +++ b/lib/arm/asm/gic.h
> @@ -40,6 +40,7 @@
>  
>  #include <asm/gic-v2.h>
>  #include <asm/gic-v3.h>
> +#include <asm/gic-v3-its.h>
>  
>  #define PPI(irq)			((irq) + 16)
>  #define SPI(irq)			((irq) + GIC_FIRST_SPI)
> diff --git a/lib/arm/gic-v3-its.c b/lib/arm/gic-v3-its.c
> new file mode 100644
> index 0000000..ce607bb
> --- /dev/null
> +++ b/lib/arm/gic-v3-its.c
> @@ -0,0 +1,39 @@
> +/*
> + * Copyright (C) 2016, Red Hat Inc, Eric Auger <eric.auger@redhat.com>

2016? Time flies...

> + *
> + * This work is licensed under the terms of the GNU LGPL, version 2.
> + */
> +#include <asm/gic.h>
> +
> +struct its_data its_data;
> +
> +void its_parse_typer(void)
> +{
> +	u64 typer = readq(gicv3_its_base() + GITS_TYPER);
> +
> +	its_data.typer.ite_size = ((typer & GITS_TYPER_ITT_ENTRY_SIZE) >>
> +					GITS_TYPER_ITT_ENTRY_SIZE_SHIFT) + 1;
> +	its_data.typer.pta = typer & GITS_TYPER_PTA;
> +	its_data.typer.eventid_bits = ((typer & GITS_TYPER_IDBITS) >>
> +						GITS_TYPER_IDBITS_SHIFT) + 1;
> +	its_data.typer.deviceid_bits = ((typer & GITS_TYPER_DEVBITS) >>
> +						GITS_TYPER_DEVBITS_SHIFT) + 1;
> +
> +	if (typer & GITS_TYPER_CIL)
> +		its_data.typer.collid_bits = ((typer & GITS_TYPER_CIDBITS) >>
> +						GITS_TYPER_CIDBITS_SHIFT) + 1;
> +	else
> +		its_data.typer.collid_bits = 16;
> +
> +	its_data.typer.virt_lpi = typer & GITS_TYPER_VLPIS;
> +	its_data.typer.phys_lpi = typer & GITS_TYPER_PLPIS;
> +}
> +
> +void its_init(void)
> +{
> +	if (!its_data.base)
> +		return;
> +
> +	its_parse_typer();
> +}
> +
> diff --git a/lib/arm/gic.c b/lib/arm/gic.c
> index 8416dde..f9a6f57 100644
> --- a/lib/arm/gic.c
> +++ b/lib/arm/gic.c
> @@ -6,6 +6,7 @@
>  #include <devicetree.h>
>  #include <asm/gic.h>
>  #include <asm/io.h>
> +#include <asm/gic-v3-its.h>
>  
>  struct gicv2_data gicv2_data;
>  struct gicv3_data gicv3_data;
> @@ -44,12 +45,14 @@ static const struct gic_common_ops gicv3_common_ops = {
>   * Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
>   */
>  static bool
> -gic_get_dt_bases(const char *compatible, void **base1, void **base2)
> +gic_get_dt_bases(const char *compatible, void **base1, void **base2,
> +		 void **base3)
>  {
>  	struct dt_pbus_reg reg;
> -	struct dt_device gic;
> +	struct dt_device gic, its;
>  	struct dt_bus bus;
> -	int node, ret, i;
> +	int node, subnode, ret, i, len;
> +	const void *fdt = dt_fdt();
>  
>  	dt_bus_init_defaults(&bus);
>  	dt_device_init(&gic, &bus, NULL);
> @@ -74,19 +77,36 @@ gic_get_dt_bases(const char *compatible, void **base1, void **base2)
>  		base2[i] = ioremap(reg.addr, reg.size);
>  	}
>  
> +	if (base3 && !strcmp(compatible, "arm,gic-v3")) {
> +		dt_for_each_subnode(node, subnode) {
> +			const struct fdt_property *prop;
> +
> +			prop = fdt_get_property(fdt, subnode,
> +						"compatible", &len);
> +			if (!strcmp((char *)prop->data, "arm,gic-v3-its")) {
> +				dt_device_bind_node(&its, subnode);
> +				ret = dt_pbus_translate(&its, 0, &reg);
> +				assert(ret == 0);
> +				*base3 = ioremap(reg.addr, reg.size);
> +				break;
> +			}
> +		}
> +
> +	}
> +
>  	return true;
>  }
>  
>  int gicv2_init(void)
>  {
>  	return gic_get_dt_bases("arm,cortex-a15-gic",
> -			&gicv2_data.dist_base, &gicv2_data.cpu_base);
> +			&gicv2_data.dist_base, &gicv2_data.cpu_base, NULL);
>  }
>  
>  int gicv3_init(void)
>  {
>  	return gic_get_dt_bases("arm,gic-v3", &gicv3_data.dist_base,
> -			&gicv3_data.redist_bases[0]);
> +			&gicv3_data.redist_bases[0], &its_data.base);
>  }
>  
>  int gic_version(void)
> @@ -104,6 +124,7 @@ int gic_init(void)
>  		gic_common_ops = &gicv2_common_ops;
>  	else if (gicv3_init())
>  		gic_common_ops = &gicv3_common_ops;
> +	its_init();
>  	return gic_version();
>  }
>  
> diff --git a/lib/arm64/asm/gic-v3-its.h b/lib/arm64/asm/gic-v3-its.h
> new file mode 100644
> index 0000000..083cba4
> --- /dev/null
> +++ b/lib/arm64/asm/gic-v3-its.h
> @@ -0,0 +1 @@
> +#include "../../arm/asm/gic-v3-its.h"
> -- 
> 2.20.1
>
Andrew Jones Jan. 13, 2020, 5:33 p.m. UTC | #2 
On Fri, Jan 10, 2020 at 03:54:01PM +0100, Eric Auger wrote:
...
> diff --git a/lib/arm/gic.c b/lib/arm/gic.c
> index 8416dde..f9a6f57 100644
> --- a/lib/arm/gic.c
> +++ b/lib/arm/gic.c
> @@ -6,6 +6,7 @@
>  #include <devicetree.h>
>  #include <asm/gic.h>
>  #include <asm/io.h>
> +#include <asm/gic-v3-its.h>
>  
>  struct gicv2_data gicv2_data;
>  struct gicv3_data gicv3_data;
> @@ -44,12 +45,14 @@ static const struct gic_common_ops gicv3_common_ops = {
>   * Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
>   */
>  static bool
> -gic_get_dt_bases(const char *compatible, void **base1, void **base2)
> +gic_get_dt_bases(const char *compatible, void **base1, void **base2,
> +		 void **base3)

Here's another place that I would prefer using our 120 chars. No need to
put base3 on a new line.

Thanks,
drew
diff mbox series

Patch

diff --git a/arm/Makefile.common b/arm/Makefile.common
index b8988f2..1aae5a3 100644
--- a/arm/Makefile.common
+++ b/arm/Makefile.common
@@ -52,6 +52,7 @@  cflatobjs += lib/arm/psci.o
 cflatobjs += lib/arm/smp.o
 cflatobjs += lib/arm/delay.o
 cflatobjs += lib/arm/gic.o lib/arm/gic-v2.o lib/arm/gic-v3.o
+cflatobjs += lib/arm/gic-v3-its.o
 
 OBJDIRS += lib/arm
 
diff --git a/arm/gic.c b/arm/gic.c
index ba43ae5..adeb981 100644
--- a/arm/gic.c
+++ b/arm/gic.c
@@ -506,6 +506,36 @@  static void gic_test_mmio(void)
 		test_targets(nr_irqs);
 }
 
+static void test_its_introspection(void)
+{
+	struct its_typer *typer = &its_data.typer;
+
+	if (!gicv3_its_base()) {
+		report_skip("No ITS, skip ...");
+		return;
+	}
+
+	/* IIDR */
+	report(test_readonly_32(gicv3_its_base() + GITS_IIDR, false),
+	       "GITS_IIDR is read-only"),
+
+	/* TYPER */
+	report(test_readonly_32(gicv3_its_base() + GITS_TYPER, false),
+	       "GITS_TYPER is read-only");
+
+	report(typer->phys_lpi, "ITS supports physical LPIs");
+	report_info("vLPI support: %s", typer->virt_lpi ? "yes" : "no");
+	report_info("ITT entry size = 0x%x", typer->ite_size);
+	report_info("Bit Count: EventID=%d DeviceId=%d CollId=%d",
+		    typer->eventid_bits, typer->deviceid_bits,
+		    typer->collid_bits);
+	report(typer->eventid_bits && typer->deviceid_bits &&
+	       typer->collid_bits, "ID spaces");
+	report(!typer->hw_collections, "collections only in ext memory");
+	report_info("Target address format %s",
+			typer->pta ? "Redist basse address" : "PE #");
+}
+
 int main(int argc, char **argv)
 {
 	if (!gic_init()) {
@@ -537,6 +567,10 @@  int main(int argc, char **argv)
 		report_prefix_push(argv[1]);
 		gic_test_mmio();
 		report_prefix_pop();
+	} else if (strcmp(argv[1], "its-introspection") == 0) {
+		report_prefix_push(argv[1]);
+		test_its_introspection();
+		report_prefix_pop();
 	} else {
 		report_abort("Unknown subtest '%s'", argv[1]);
 	}
diff --git a/arm/unittests.cfg b/arm/unittests.cfg
index daeb5a0..bd20460 100644
--- a/arm/unittests.cfg
+++ b/arm/unittests.cfg
@@ -122,6 +122,12 @@  smp = $MAX_SMP
 extra_params = -machine gic-version=3 -append 'active'
 groups = gic
 
+[its-introspection]
+file = gic.flat
+smp = $MAX_SMP
+extra_params = -machine gic-version=3 -append 'its-introspection'
+groups = its
+
 # Test PSCI emulation
 [psci]
 file = psci.flat
diff --git a/lib/arm/asm/gic-v3-its.h b/lib/arm/asm/gic-v3-its.h
new file mode 100644
index 0000000..8816d57
--- /dev/null
+++ b/lib/arm/asm/gic-v3-its.h
@@ -0,0 +1,81 @@ 
+/*
+ * All ITS* 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_ITS_H_
+#define _ASMARM_GIC_V3_ITS_H_
+
+#ifndef __ASSEMBLY__
+
+#define GITS_CTLR			0x0000
+#define GITS_IIDR			0x0004
+#define GITS_TYPER			0x0008
+#define GITS_CBASER			0x0080
+#define GITS_CWRITER			0x0088
+#define GITS_CREADR			0x0090
+#define GITS_BASER			0x0100
+
+#define GITS_TYPER_PLPIS                BIT(0)
+#define GITS_TYPER_VLPIS		BIT(1)
+#define GITS_TYPER_ITT_ENTRY_SIZE	GENMASK_ULL(7, 4)
+#define GITS_TYPER_ITT_ENTRY_SIZE_SHIFT	4
+#define GITS_TYPER_IDBITS		GENMASK_ULL(8, 12)
+#define GITS_TYPER_IDBITS_SHIFT         8
+#define GITS_TYPER_DEVBITS		GENMASK_ULL(13, 17)
+#define GITS_TYPER_DEVBITS_SHIFT        13
+#define GITS_TYPER_PTA                  BIT(19)
+#define GITS_TYPER_CIDBITS		GENMASK_ULL(32, 35)
+#define GITS_TYPER_CIDBITS_SHIFT	32
+#define GITS_TYPER_CIL			BIT(36)
+
+#define GITS_CTLR_ENABLE		(1U << 0)
+
+#define GITS_CBASER_VALID		(1UL << 63)
+
+#define GITS_BASER_NR_REGS              8
+#define GITS_BASER_VALID		BIT(63)
+#define GITS_BASER_INDIRECT		BIT(62)
+#define GITS_BASER_TYPE_SHIFT		(56)
+#define GITS_BASER_TYPE(r)		(((r) >> GITS_BASER_TYPE_SHIFT) & 7)
+#define GITS_BASER_ENTRY_SIZE_SHIFT	(48)
+#define GITS_BASER_ENTRY_SIZE(r)	((((r) >> GITS_BASER_ENTRY_SIZE_SHIFT) & 0x1f) + 1)
+#define GITS_BASER_PAGE_SIZE_SHIFT	(8)
+#define GITS_BASER_PAGE_SIZE_4K		(0UL << GITS_BASER_PAGE_SIZE_SHIFT)
+#define GITS_BASER_PAGE_SIZE_16K	(1UL << GITS_BASER_PAGE_SIZE_SHIFT)
+#define GITS_BASER_PAGE_SIZE_64K	(2UL << GITS_BASER_PAGE_SIZE_SHIFT)
+#define GITS_BASER_PAGE_SIZE_MASK	(3UL << GITS_BASER_PAGE_SIZE_SHIFT)
+#define GITS_BASER_PAGES_MAX		256
+#define GITS_BASER_PAGES_SHIFT		(0)
+#define GITS_BASER_NR_PAGES(r)		(((r) & 0xff) + 1)
+#define GITS_BASER_PHYS_ADDR_MASK	0xFFFFFFFFF000
+#define GITS_BASER_TYPE_NONE		0
+#define GITS_BASER_TYPE_DEVICE		1
+#define GITS_BASER_TYPE_COLLECTION	4
+
+struct its_typer {
+	unsigned int ite_size;
+	unsigned int eventid_bits;
+	unsigned int deviceid_bits;
+	unsigned int collid_bits;
+	bool pta;
+	bool phys_lpi;
+	bool virt_lpi;
+};
+
+struct its_data {
+	void *base;
+	struct its_typer typer;
+};
+
+extern struct its_data its_data;
+
+#define gicv3_its_base()		(its_data.base)
+
+extern void its_parse_typer(void);
+extern void its_init(void);
+
+#endif /* !__ASSEMBLY__ */
+#endif /* _ASMARM_GIC_V3_ITS_H_ */
diff --git a/lib/arm/asm/gic.h b/lib/arm/asm/gic.h
index 55dd84b..b44da9c 100644
--- a/lib/arm/asm/gic.h
+++ b/lib/arm/asm/gic.h
@@ -40,6 +40,7 @@ 
 
 #include <asm/gic-v2.h>
 #include <asm/gic-v3.h>
+#include <asm/gic-v3-its.h>
 
 #define PPI(irq)			((irq) + 16)
 #define SPI(irq)			((irq) + GIC_FIRST_SPI)
diff --git a/lib/arm/gic-v3-its.c b/lib/arm/gic-v3-its.c
new file mode 100644
index 0000000..ce607bb
--- /dev/null
+++ b/lib/arm/gic-v3-its.c
@@ -0,0 +1,39 @@ 
+/*
+ * Copyright (C) 2016, Red Hat Inc, Eric Auger <eric.auger@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.
+ */
+#include <asm/gic.h>
+
+struct its_data its_data;
+
+void its_parse_typer(void)
+{
+	u64 typer = readq(gicv3_its_base() + GITS_TYPER);
+
+	its_data.typer.ite_size = ((typer & GITS_TYPER_ITT_ENTRY_SIZE) >>
+					GITS_TYPER_ITT_ENTRY_SIZE_SHIFT) + 1;
+	its_data.typer.pta = typer & GITS_TYPER_PTA;
+	its_data.typer.eventid_bits = ((typer & GITS_TYPER_IDBITS) >>
+						GITS_TYPER_IDBITS_SHIFT) + 1;
+	its_data.typer.deviceid_bits = ((typer & GITS_TYPER_DEVBITS) >>
+						GITS_TYPER_DEVBITS_SHIFT) + 1;
+
+	if (typer & GITS_TYPER_CIL)
+		its_data.typer.collid_bits = ((typer & GITS_TYPER_CIDBITS) >>
+						GITS_TYPER_CIDBITS_SHIFT) + 1;
+	else
+		its_data.typer.collid_bits = 16;
+
+	its_data.typer.virt_lpi = typer & GITS_TYPER_VLPIS;
+	its_data.typer.phys_lpi = typer & GITS_TYPER_PLPIS;
+}
+
+void its_init(void)
+{
+	if (!its_data.base)
+		return;
+
+	its_parse_typer();
+}
+
diff --git a/lib/arm/gic.c b/lib/arm/gic.c
index 8416dde..f9a6f57 100644
--- a/lib/arm/gic.c
+++ b/lib/arm/gic.c
@@ -6,6 +6,7 @@ 
 #include <devicetree.h>
 #include <asm/gic.h>
 #include <asm/io.h>
+#include <asm/gic-v3-its.h>
 
 struct gicv2_data gicv2_data;
 struct gicv3_data gicv3_data;
@@ -44,12 +45,14 @@  static const struct gic_common_ops gicv3_common_ops = {
  * Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
  */
 static bool
-gic_get_dt_bases(const char *compatible, void **base1, void **base2)
+gic_get_dt_bases(const char *compatible, void **base1, void **base2,
+		 void **base3)
 {
 	struct dt_pbus_reg reg;
-	struct dt_device gic;
+	struct dt_device gic, its;
 	struct dt_bus bus;
-	int node, ret, i;
+	int node, subnode, ret, i, len;
+	const void *fdt = dt_fdt();
 
 	dt_bus_init_defaults(&bus);
 	dt_device_init(&gic, &bus, NULL);
@@ -74,19 +77,36 @@  gic_get_dt_bases(const char *compatible, void **base1, void **base2)
 		base2[i] = ioremap(reg.addr, reg.size);
 	}
 
+	if (base3 && !strcmp(compatible, "arm,gic-v3")) {
+		dt_for_each_subnode(node, subnode) {
+			const struct fdt_property *prop;
+
+			prop = fdt_get_property(fdt, subnode,
+						"compatible", &len);
+			if (!strcmp((char *)prop->data, "arm,gic-v3-its")) {
+				dt_device_bind_node(&its, subnode);
+				ret = dt_pbus_translate(&its, 0, &reg);
+				assert(ret == 0);
+				*base3 = ioremap(reg.addr, reg.size);
+				break;
+			}
+		}
+
+	}
+
 	return true;
 }
 
 int gicv2_init(void)
 {
 	return gic_get_dt_bases("arm,cortex-a15-gic",
-			&gicv2_data.dist_base, &gicv2_data.cpu_base);
+			&gicv2_data.dist_base, &gicv2_data.cpu_base, NULL);
 }
 
 int gicv3_init(void)
 {
 	return gic_get_dt_bases("arm,gic-v3", &gicv3_data.dist_base,
-			&gicv3_data.redist_bases[0]);
+			&gicv3_data.redist_bases[0], &its_data.base);
 }
 
 int gic_version(void)
@@ -104,6 +124,7 @@  int gic_init(void)
 		gic_common_ops = &gicv2_common_ops;
 	else if (gicv3_init())
 		gic_common_ops = &gicv3_common_ops;
+	its_init();
 	return gic_version();
 }
 
diff --git a/lib/arm64/asm/gic-v3-its.h b/lib/arm64/asm/gic-v3-its.h
new file mode 100644
index 0000000..083cba4
--- /dev/null
+++ b/lib/arm64/asm/gic-v3-its.h
@@ -0,0 +1 @@ 
+#include "../../arm/asm/gic-v3-its.h"