git: 4ab0f5ab3fd6 - main - arm64/gicv3: Check if the hardware supports LPIs

[Andrew Turner]

The branch main has been updated by andrew:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=4ab0f5ab3fd6dcd7f76c1ed1c9dc0dcd152fb64f

commit 4ab0f5ab3fd6dcd7f76c1ed1c9dc0dcd152fb64f
Author:     Andrew Turner <and...@freebsd.org>
AuthorDate: 2024-04-23 11:28:23 +0000
Commit:     Andrew Turner <and...@freebsd.org>
CommitDate: 2024-05-10 09:29:24 +0000

    arm64/gicv3: Check if the hardware supports LPIs
    
    Some simulators have the ITS in the DTB passed to the kernel, however
    it is a runtime configuration option to enable it.
    
    Check the GICD_TYPER register to see if LPIs are enabled before
    attaching the ITS driver.
    
    Sponsored by:   Arm Ltd
    Differential Revision:  https://reviews.freebsd.org/D44914
---
 sys/arm64/arm64/gic_v3.c     | 4 ++++
 sys/arm64/arm64/gic_v3_var.h | 2 ++
 sys/arm64/arm64/gicv3_its.c  | 6 ++++++
 3 files changed, 12 insertions(+)

diff --git a/sys/arm64/arm64/gic_v3.c b/sys/arm64/arm64/gic_v3.c
index b57dd9be48aa..0b25650b3fbf 100644
--- a/sys/arm64/arm64/gic_v3.c
+++ b/sys/arm64/arm64/gic_v3.c
@@ -494,6 +494,10 @@ gic_v3_read_ivar(device_t dev, device_t child, int which, 
uintptr_t *result)
        case GICV3_IVAR_REDIST:
                *result = (uintptr_t)&sc->gic_redists.pcpu[PCPU_GET(cpuid)];
                return (0);
+       case GICV3_IVAR_SUPPORT_LPIS:
+               *result =
+                   (gic_d_read(sc, 4, GICD_TYPER) & GICD_TYPER_LPIS) != 0;
+               return (0);
        case GIC_IVAR_HW_REV:
                KASSERT(
                    GICR_PIDR2_ARCH(sc->gic_pidr2) == GICR_PIDR2_ARCH_GICv3 ||
diff --git a/sys/arm64/arm64/gic_v3_var.h b/sys/arm64/arm64/gic_v3_var.h
index 81526e7cc15e..1c5d354ee217 100644
--- a/sys/arm64/arm64/gic_v3_var.h
+++ b/sys/arm64/arm64/gic_v3_var.h
@@ -102,9 +102,11 @@ MALLOC_DECLARE(M_GIC_V3);
 #define        GICV3_IVAR_NIRQS        1000
 /* 1001 was GICV3_IVAR_REDIST_VADDR */
 #define        GICV3_IVAR_REDIST       1002
+#define        GICV3_IVAR_SUPPORT_LPIS 1003
 
 __BUS_ACCESSOR(gicv3, nirqs, GICV3, NIRQS, u_int);
 __BUS_ACCESSOR(gicv3, redist, GICV3, REDIST, void *);
+__BUS_ACCESSOR(gicv3, support_lpis, GICV3, SUPPORT_LPIS, bool);
 
 /* Device methods */
 int gic_v3_attach(device_t dev);
diff --git a/sys/arm64/arm64/gicv3_its.c b/sys/arm64/arm64/gicv3_its.c
index 31a0ded6c95d..46695a415e86 100644
--- a/sys/arm64/arm64/gicv3_its.c
+++ b/sys/arm64/arm64/gicv3_its.c
@@ -2208,6 +2208,9 @@ gicv3_its_fdt_probe(device_t dev)
        if (!ofw_bus_is_compatible(dev, "arm,gic-v3-its"))
                return (ENXIO);
 
+       if (!gicv3_get_support_lpis(dev))
+               return (ENXIO);
+
        device_set_desc(dev, "ARM GIC Interrupt Translation Service");
        return (BUS_PROBE_DEFAULT);
 }
@@ -2277,6 +2280,9 @@ gicv3_its_acpi_probe(device_t dev)
        if (gic_get_hw_rev(dev) < 3)
                return (EINVAL);
 
+       if (!gicv3_get_support_lpis(dev))
+               return (ENXIO);
+
        device_set_desc(dev, "ARM GIC Interrupt Translation Service");
        return (BUS_PROBE_DEFAULT);
 }