2023-10-27 03:10:40

by Fang Xiang

[permalink] [raw]
Subject: [PATCH v2] irqchip/gic-v3-its: Flush ITS tables before writing GITS_BASER<n> registers in non-coherent GIC designs.

In non-coherent GIC design, ITS tables should be clean and flushed
to the PoV of the ITS before writing GITS_BASER<n> registers. And
hoist the quirked non-shareable attributes earlier to save effort
in tables setup.

Signed-off-by: Fang Xiang <[email protected]>

Link to v1:
https://lore.kernel.org/all/[email protected]/

v1 -> v2:
- Flush ITS tables before writing GITS_BASER<n> registers
- Hoist the quirked non-shareable attributes earlier
---
drivers/irqchip/irq-gic-v3-its.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 75a2dd550625..d76d44ea2de1 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -2379,12 +2379,12 @@ static int its_setup_baser(struct its_node *its, struct its_baser *baser,
break;
}

+ if (!shr)
+ gic_flush_dcache_to_poc(base, PAGE_ORDER_TO_SIZE(order));
+
its_write_baser(its, baser, val);
tmp = baser->val;

- if (its->flags & ITS_FLAGS_FORCE_NON_SHAREABLE)
- tmp &= ~GITS_BASER_SHAREABILITY_MASK;
-
if ((val ^ tmp) & GITS_BASER_SHAREABILITY_MASK) {
/*
* Shareability didn't stick. Just use
@@ -2394,10 +2394,9 @@ static int its_setup_baser(struct its_node *its, struct its_baser *baser,
* non-cacheable as well.
*/
shr = tmp & GITS_BASER_SHAREABILITY_MASK;
- if (!shr) {
+ if (!shr)
cache = GITS_BASER_nC;
- gic_flush_dcache_to_poc(base, PAGE_ORDER_TO_SIZE(order));
- }
+
goto retry_baser;
}

@@ -2609,6 +2608,11 @@ static int its_alloc_tables(struct its_node *its)
/* erratum 24313: ignore memory access type */
cache = GITS_BASER_nCnB;

+ if (its->flags & ITS_FLAGS_FORCE_NON_SHAREABLE) {
+ cache = GITS_BASER_nC;
+ shr = 0;
+ }
+
for (i = 0; i < GITS_BASER_NR_REGS; i++) {
struct its_baser *baser = its->tables + i;
u64 val = its_read_baser(its, baser);
--
2.34.1


2023-10-27 08:17:26

by Thomas Gleixner

[permalink] [raw]
Subject: Re: [PATCH v2] irqchip/gic-v3-its: Flush ITS tables before writing GITS_BASER<n> registers in non-coherent GIC designs.

On Fri, Oct 27 2023 at 11:10, Fang Xiang wrote:
> In non-coherent GIC design, ITS tables should be clean and flushed
> to the PoV of the ITS before writing GITS_BASER<n> registers. And
> hoist the quirked non-shareable attributes earlier to save effort
> in tables setup.
>
> Signed-off-by: Fang Xiang <[email protected]>

Seriously? You claim authorship for a patch which was written by Marc:

https://lore.kernel.org/all/[email protected]

without even the courtesy of giving him credit via 'Originally-by' ?

That's not how it works.

Thanks,

tglx

2023-10-27 15:19:20

by Marc Zyngier

[permalink] [raw]
Subject: Re: [PATCH v2] irqchip/gic-v3-its: Flush ITS tables before writing GITS_BASER<n> registers in non-coherent GIC designs.

On Fri, 27 Oct 2023 09:16:57 +0100,
Thomas Gleixner <[email protected]> wrote:
>
> On Fri, Oct 27 2023 at 11:10, Fang Xiang wrote:
> > In non-coherent GIC design, ITS tables should be clean and flushed
> > to the PoV of the ITS before writing GITS_BASER<n> registers. And
> > hoist the quirked non-shareable attributes earlier to save effort
> > in tables setup.
> >
> > Signed-off-by: Fang Xiang <[email protected]>
>
> Seriously? You claim authorship for a patch which was written by Marc:
>
> https://lore.kernel.org/all/[email protected]
>
> without even the courtesy of giving him credit via 'Originally-by' ?
>
> That's not how it works.

Even better, some testing results on this patch, as it is what was
promised. Meh...

M.

--
Without deviation from the norm, progress is not possible.

2023-10-30 02:06:00

by Fang Xiang

[permalink] [raw]
Subject: Re: [PATCH v2] irqchip/gic-v3-its: Flush ITS tables before writing GITS_BASER<n> registers in non-coherent GIC designs.

On Fri, Oct 27, 2023 at 10:16:57AM +0200, Thomas Gleixner wrote:
> On Fri, Oct 27 2023 at 11:10, Fang Xiang wrote:
> > In non-coherent GIC design, ITS tables should be clean and flushed
> > to the PoV of the ITS before writing GITS_BASER<n> registers. And
> > hoist the quirked non-shareable attributes earlier to save effort
> > in tables setup.
> >
> > Signed-off-by: Fang Xiang <[email protected]>
>
> Seriously? You claim authorship for a patch which was written by Marc:
>
> https://lore.kernel.org/all/[email protected]
>
> without even the courtesy of giving him credit via 'Originally-by' ?
>
> That's not how it works.
>
> Thanks,
>
> tglx

I am sorry. That's a terrible mistake. Just want to fix this issue as
soon as possible and I am learning how to contribute to the community
in a right way.