* [PATCH 0/2] Check for MSI allocation
@ 2022-06-09 15:38 Julian Vetter
2022-06-09 15:38 ` [PATCH 1/2] msi: The MSI framework only supports 2048 platform MSIs Julian Vetter
2022-06-09 15:38 ` [PATCH 2/2] msi: Add sanity check if more than MAX_DEV_MSIS MSIs are requested Julian Vetter
0 siblings, 2 replies; 4+ messages in thread
From: Julian Vetter @ 2022-06-09 15:38 UTC (permalink / raw)
To: gregkh, linux-kernel, ysionneau; +Cc: Julian Vetter
Our HW has a mailbox periph that supports up to 8192 MSIs, so the currently
supported 2048 is not enough. I believe there is no real reason to
contstrain the max platform MSIs to 2048, because the value is stored in
an irq_hw_number_t which is big enough to hold more MSIs. The value is
OR'ed with the device ID of which there is also a limited number.
The second patch contains a WARN() to warn the user if a device tries to
obtain more that MAX_DEV_MSIS, because this could lead to potentially
conflicting virtual interrupt numbers (as was the case for us) without
the Linux kernel telling us.
Julian Vetter (2):
msi: The MSI framework only supports 2048 platform MSIs
msi: Add sanity check if more than MAX_DEV_MSIS MSIs are requested
drivers/base/platform-msi.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--
2.17.1
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH 1/2] msi: The MSI framework only supports 2048 platform MSIs
2022-06-09 15:38 [PATCH 0/2] Check for MSI allocation Julian Vetter
@ 2022-06-09 15:38 ` Julian Vetter
2022-06-09 15:38 ` [PATCH 2/2] msi: Add sanity check if more than MAX_DEV_MSIS MSIs are requested Julian Vetter
1 sibling, 0 replies; 4+ messages in thread
From: Julian Vetter @ 2022-06-09 15:38 UTC (permalink / raw)
To: gregkh, linux-kernel, ysionneau; +Cc: Julian Vetter
Some devices need more MSIs. To support this the number must be
increased.
Signed-off-by: Julian Vetter <jvetter@kalrayinc.com>
Reviewed-by: Yann Sionneau <ysionneau@kalrayinc.com>
---
drivers/base/platform-msi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c
index 296ea673d661..4b0b2fe3a7ff 100644
--- a/drivers/base/platform-msi.c
+++ b/drivers/base/platform-msi.c
@@ -13,7 +13,7 @@
#include <linux/msi.h>
#include <linux/slab.h>
-#define DEV_ID_SHIFT 21
+#define DEV_ID_SHIFT 19
#define MAX_DEV_MSIS (1 << (32 - DEV_ID_SHIFT))
/*
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 2/2] msi: Add sanity check if more than MAX_DEV_MSIS MSIs are requested
2022-06-09 15:38 [PATCH 0/2] Check for MSI allocation Julian Vetter
2022-06-09 15:38 ` [PATCH 1/2] msi: The MSI framework only supports 2048 platform MSIs Julian Vetter
@ 2022-06-09 15:38 ` Julian Vetter
2022-06-09 17:57 ` Greg KH
1 sibling, 1 reply; 4+ messages in thread
From: Julian Vetter @ 2022-06-09 15:38 UTC (permalink / raw)
To: gregkh, linux-kernel, ysionneau; +Cc: Julian Vetter
If a device requests more than MAX_DEV_MSIS the MSI index will collide with
the devid and might cause Linux to compute twice the same virtual interrupt
number for two different devices.
Signed-off-by: Julian Vetter <jvetter@kalrayinc.com>
Reviewed-by: Yann Sionneau <ysionneau@kalrayinc.com>
---
drivers/base/platform-msi.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c
index 4b0b2fe3a7ff..627d8f6b83ea 100644
--- a/drivers/base/platform-msi.c
+++ b/drivers/base/platform-msi.c
@@ -40,6 +40,8 @@ static irq_hw_number_t platform_msi_calc_hwirq(struct msi_desc *desc)
{
u32 devid = desc->dev->msi.data->platform_data->devid;
+ WARN_ON(desc->msi_index >= MAX_DEV_MSIS);
+
return (devid << (32 - DEV_ID_SHIFT)) | desc->msi_index;
}
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 2/2] msi: Add sanity check if more than MAX_DEV_MSIS MSIs are requested
2022-06-09 15:38 ` [PATCH 2/2] msi: Add sanity check if more than MAX_DEV_MSIS MSIs are requested Julian Vetter
@ 2022-06-09 17:57 ` Greg KH
0 siblings, 0 replies; 4+ messages in thread
From: Greg KH @ 2022-06-09 17:57 UTC (permalink / raw)
To: Julian Vetter; +Cc: linux-kernel, ysionneau
On Thu, Jun 09, 2022 at 05:38:43PM +0200, Julian Vetter wrote:
> If a device requests more than MAX_DEV_MSIS the MSI index will collide with
> the devid and might cause Linux to compute twice the same virtual interrupt
> number for two different devices.
>
> Signed-off-by: Julian Vetter <jvetter@kalrayinc.com>
> Reviewed-by: Yann Sionneau <ysionneau@kalrayinc.com>
> ---
> drivers/base/platform-msi.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c
> index 4b0b2fe3a7ff..627d8f6b83ea 100644
> --- a/drivers/base/platform-msi.c
> +++ b/drivers/base/platform-msi.c
> @@ -40,6 +40,8 @@ static irq_hw_number_t platform_msi_calc_hwirq(struct msi_desc *desc)
> {
> u32 devid = desc->dev->msi.data->platform_data->devid;
>
> + WARN_ON(desc->msi_index >= MAX_DEV_MSIS);
So you just caused a system to reboot if you have panic-on-warn? What
is someone supposed to do if this is ever hit? Why can't you handle it
as an error and properly recover instead of just ignoring it?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2022-06-09 17:57 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2022-06-09 15:38 [PATCH 0/2] Check for MSI allocation Julian Vetter
2022-06-09 15:38 ` [PATCH 1/2] msi: The MSI framework only supports 2048 platform MSIs Julian Vetter
2022-06-09 15:38 ` [PATCH 2/2] msi: Add sanity check if more than MAX_DEV_MSIS MSIs are requested Julian Vetter
2022-06-09 17:57 ` Greg KH
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