On Tue, Sep 05, 2023 at 12:34:58PM +0100, Marc Zyngier wrote:
[...]
> > * Make sure *all* the ITS are reset before we probe any, as
> > * they may be sharing memory. If any of the ITS fails to
> > @@ -5396,7 +5405,8 @@ static int __init its_of_probe(struct device_node *node)
> > continue;
> > }
> >
> > - its_probe_one(&res, &np->fwnode, of_node_to_nid(np));
> > + its_probe_one(&res, &np->fwnode, of_node_to_nid(np),
> > + of_property_read_bool(np, "dma-noncoherent"));
> > }
> > return 0;
> > }
> > @@ -5533,7 +5543,8 @@ static int __init gic_acpi_parse_madt_its(union acpi_subtable_headers *header,
> > }
> >
> > err = its_probe_one(&res, dom_handle,
> > - acpi_get_its_numa_node(its_entry->translation_id));
> > + acpi_get_its_numa_node(its_entry->translation_id),
> > + false);
>
> I came up with the following alternative approach, which is as usual
> completely untested. It is entirely based on the quirk infrastructure,
> and doesn't touch the ACPI path at all.
Writing the ACPI bits. We can't use the quirks framework for ACPI (we
don't have "properties" and I don't think we want to attach any to the
fwnode_handle) that's why I generalized its_probe_one() above with an
extra param, that would have simplified ACPI parsing:
- we alloc struct its_node in its_probe_one() but at that stage
ACPI parsing was already done. If we have to parse the MADT(ITS) again
just to scan for non-coherent we then have to match the MADT entries
to the *current* struct its_node* we are handling (MADT parsing
callbacks don't even take a param - we have to resort to global
variables - definitely doable but it is a bit ugly).
I will post the resulting code (or something else if I find anything
nicer) but I thought I would mention the reasoning behind the additional
bool flag above.
Lorenzo
>
> Thanks,
>
> M.
>
> diff --git a/drivers/irqchip/irq-gic-common.h b/drivers/irqchip/irq-gic-common.h
> index 3db4592cda1c..00641e88aa38 100644
> --- a/drivers/irqchip/irq-gic-common.h
> +++ b/drivers/irqchip/irq-gic-common.h
> @@ -29,4 +29,8 @@ void gic_enable_quirks(u32 iidr, const struct gic_quirk *quirks,
> void gic_enable_of_quirks(const struct device_node *np,
> const struct gic_quirk *quirks, void *data);
>
> +#define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING (1 << 0)
> +#define RDIST_FLAGS_RD_TABLES_PREALLOCATED (1 << 1)
> +#define RDIST_FLAGS_FORCE_NON_SHAREABLE (1 << 2)
> +
> #endif /* _IRQ_GIC_COMMON_H */
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index e0c2b10d154d..6edf59af757b 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -44,10 +44,6 @@
> #define ITS_FLAGS_WORKAROUND_CAVIUM_23144 (1ULL << 2)
> #define ITS_FLAGS_FORCE_NON_SHAREABLE (1ULL << 3)
>
> -#define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING (1 << 0)
> -#define RDIST_FLAGS_RD_TABLES_PREALLOCATED (1 << 1)
> -#define RDIST_FLAGS_FORCE_NON_SHAREABLE (1 << 2)
> -
> #define RD_LOCAL_LPI_ENABLED BIT(0)
> #define RD_LOCAL_PENDTABLE_PREALLOCATED BIT(1)
> #define RD_LOCAL_MEMRESERVE_DONE BIT(2)
> @@ -4754,6 +4750,14 @@ static bool __maybe_unused its_enable_rk3588001(void *data)
> return true;
> }
>
> +static bool its_set_non_coherent(void *data)
> +{
> + struct its_node *its = data;
> +
> + its->flags |= ITS_FLAGS_FORCE_NON_SHAREABLE;
> + return true;
> +}
> +
> static const struct gic_quirk its_quirks[] = {
> #ifdef CONFIG_CAVIUM_ERRATUM_22375
> {
> @@ -4808,6 +4812,11 @@ static const struct gic_quirk its_quirks[] = {
> .init = its_enable_rk3588001,
> },
> #endif
> + {
> + .desc = "ITS: non-coherent attribute",
> + .property = "dma-noncoherent",
> + .init = its_set_non_coherent,
> + },
> {
> }
> };
> diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
> index eedfa8e9f077..7f518c0ae723 100644
> --- a/drivers/irqchip/irq-gic-v3.c
> +++ b/drivers/irqchip/irq-gic-v3.c
> @@ -1857,6 +1857,14 @@ static bool gic_enable_quirk_arm64_2941627(void *data)
> return true;
> }
>
> +static bool rd_set_non_coherent(void *data)
> +{
> + struct gic_chip_data *d = data;
> +
> + d->rdists.flags |= RDIST_FLAGS_FORCE_NON_SHAREABLE;
> + return true;
> +}
> +
> static const struct gic_quirk gic_quirks[] = {
> {
> .desc = "GICv3: Qualcomm MSM8996 broken firmware",
> @@ -1923,6 +1931,11 @@ static const struct gic_quirk gic_quirks[] = {
> .mask = 0xff0f0fff,
> .init = gic_enable_quirk_arm64_2941627,
> },
> + {
> + .desc = "GICv3: non-coherent attribute",
> + .property = "dma-noncoherent",
> + .init = rd_set_non_coherent,
> + },
> {
> }
> };
>
> --
> Without deviation from the norm, progress is not possible.
>
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