Re: [PATCH V2] PCI/MSI: Set device flag indicating only 32-bit MSI support
On 12/4/2020 1:24 AM, Bjorn Helgaas wrote:
External email: Use caution opening links or attachments
On Fri, Dec 04, 2020 at 12:33:45AM +0530, Vidya Sagar wrote:
On 12/3/2020 11:54 PM, Bjorn Helgaas wrote:
On Tue, Nov 24, 2020 at 04:20:35PM +0530, Vidya Sagar wrote:
There are devices (Ex:- Marvell SATA controller) that don't support
64-bit MSIs and the same is advertised through their MSI capability
register. Set no_64bit_msi flag explicitly for such devices in the
MSI setup code so that the msi_verify_entries() API would catch
if the MSI arch code tries to use 64-bit MSI.
This seems good to me. I'll post a possible revision to set
dev->no_64bit_msi in the device enumeration path instead of in the IRQ
allocation path, since it's really a property of the device, not of
the msi_desc.
I like the extra checking this gives us. Was this prompted by
tripping over something, or is it something you noticed by code
reading? If the former, a hint about what was wrong and how it's
being fixed would be useful.
I observed functionality issue with Marvell SATA controller (1b4b:9171) when
the allocated MSI target address was a 64-bit address. I mentioned the
Marvell SATA controller as an example in the commit message.
I know you mentioned the Marvell controller, but apparently that
device is working perfectly correctly: it does not support 64-bit MSI,
and it does not advertise support for 64-bit MSI.
So if there's a functionality issue, that means something is wrong in
Linux that caused us to assign a 64-bit MSI address to it. *That*
issue is what I want to know about. Your patch only warns about the
issue; it doesn't fix it.
The issue is in the DWC code. I pushed a generic patch to fix that issue
by specifying the limit of MSI target address to 32-bit region. Patch is
up for review at
http://patchwork.ozlabs.org/project/linux-pci/patch/20201117165312.25847-1-vid...@nvidia.com/
I don't think there's any point in specifically mentioning the Marvell
device if it is working correctly, because the same issue should
affect *any* device that doesn't support 64-bit MSI. But if there's
some arch code that incorrectly assigns a 64-bit address, it would
definitely be useful to specify the arch. And hopefully there's a fix
for that arch code, too.
Signed-off-by: Vidya Sagar
---
V2:
* Addressed Bjorn's comment and changed the error message
drivers/pci/msi.c | 11 +++
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index d52d118979a6..8de5ba6b4a59 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -581,10 +581,12 @@ msi_setup_entry(struct pci_dev *dev, int nvec, struct
irq_affinity *affd)
entry->msi_attrib.multi_cap = (control & PCI_MSI_FLAGS_QMASK) >> 1;
entry->msi_attrib.multiple = ilog2(__roundup_pow_of_two(nvec));
- if (control & PCI_MSI_FLAGS_64BIT)
+ if (control & PCI_MSI_FLAGS_64BIT) {
entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
- else
+ } else {
entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_32;
+ dev->no_64bit_msi = 1;
+ }
/* Save the initial mask status */
if (entry->msi_attrib.maskbit)
@@ -602,8 +604,9 @@ static int msi_verify_entries(struct pci_dev *dev)
for_each_pci_msi_entry(entry, dev) {
if (!dev->no_64bit_msi || !entry->msg.address_hi)
continue;
- pci_err(dev, "Device has broken 64-bit MSI but arch"
- " tried to assign one above 4G\n");
+ pci_err(dev, "Device has either broken 64-bit MSI or "
+ "only 32-bit MSI support but "
+ "arch tried to assign one above 4G\n");
return -EIO;
}
return 0;
--
2.17.1
Re: [PATCH V2] PCI/MSI: Set device flag indicating only 32-bit MSI support
On Fri, Dec 04, 2020 at 12:33:45AM +0530, Vidya Sagar wrote:
> On 12/3/2020 11:54 PM, Bjorn Helgaas wrote:
> > On Tue, Nov 24, 2020 at 04:20:35PM +0530, Vidya Sagar wrote:
> > > There are devices (Ex:- Marvell SATA controller) that don't support
> > > 64-bit MSIs and the same is advertised through their MSI capability
> > > register. Set no_64bit_msi flag explicitly for such devices in the
> > > MSI setup code so that the msi_verify_entries() API would catch
> > > if the MSI arch code tries to use 64-bit MSI.
> >
> > This seems good to me. I'll post a possible revision to set
> > dev->no_64bit_msi in the device enumeration path instead of in the IRQ
> > allocation path, since it's really a property of the device, not of
> > the msi_desc.
> >
> > I like the extra checking this gives us. Was this prompted by
> > tripping over something, or is it something you noticed by code
> > reading? If the former, a hint about what was wrong and how it's
> > being fixed would be useful.
> I observed functionality issue with Marvell SATA controller (1b4b:9171) when
> the allocated MSI target address was a 64-bit address. I mentioned the
> Marvell SATA controller as an example in the commit message.
I know you mentioned the Marvell controller, but apparently that
device is working perfectly correctly: it does not support 64-bit MSI,
and it does not advertise support for 64-bit MSI.
So if there's a functionality issue, that means something is wrong in
Linux that caused us to assign a 64-bit MSI address to it. *That*
issue is what I want to know about. Your patch only warns about the
issue; it doesn't fix it.
I don't think there's any point in specifically mentioning the Marvell
device if it is working correctly, because the same issue should
affect *any* device that doesn't support 64-bit MSI. But if there's
some arch code that incorrectly assigns a 64-bit address, it would
definitely be useful to specify the arch. And hopefully there's a fix
for that arch code, too.
> > > Signed-off-by: Vidya Sagar
> > > ---
> > > V2:
> > > * Addressed Bjorn's comment and changed the error message
> > >
> > > drivers/pci/msi.c | 11 +++
> > > 1 file changed, 7 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> > > index d52d118979a6..8de5ba6b4a59 100644
> > > --- a/drivers/pci/msi.c
> > > +++ b/drivers/pci/msi.c
> > > @@ -581,10 +581,12 @@ msi_setup_entry(struct pci_dev *dev, int nvec,
> > > struct irq_affinity *affd)
> > >entry->msi_attrib.multi_cap = (control & PCI_MSI_FLAGS_QMASK)
> > > >> 1;
> > >entry->msi_attrib.multiple =
> > > ilog2(__roundup_pow_of_two(nvec));
> > >
> > > - if (control & PCI_MSI_FLAGS_64BIT)
> > > + if (control & PCI_MSI_FLAGS_64BIT) {
> > >entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
> > > - else
> > > + } else {
> > >entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_32;
> > > + dev->no_64bit_msi = 1;
> > > + }
> > >
> > >/* Save the initial mask status */
> > >if (entry->msi_attrib.maskbit)
> > > @@ -602,8 +604,9 @@ static int msi_verify_entries(struct pci_dev *dev)
> > >for_each_pci_msi_entry(entry, dev) {
> > >if (!dev->no_64bit_msi || !entry->msg.address_hi)
> > >continue;
> > > - pci_err(dev, "Device has broken 64-bit MSI but arch"
> > > - " tried to assign one above 4G\n");
> > > + pci_err(dev, "Device has either broken 64-bit MSI or "
> > > + "only 32-bit MSI support but "
> > > + "arch tried to assign one above 4G\n");
> > >return -EIO;
> > >}
> > >return 0;
> > > --
> > > 2.17.1
> > >
Re: [PATCH V2] PCI/MSI: Set device flag indicating only 32-bit MSI support
On 12/3/2020 11:54 PM, Bjorn Helgaas wrote:
External email: Use caution opening links or attachments
On Tue, Nov 24, 2020 at 04:20:35PM +0530, Vidya Sagar wrote:
There are devices (Ex:- Marvell SATA controller) that don't support
64-bit MSIs and the same is advertised through their MSI capability
register. Set no_64bit_msi flag explicitly for such devices in the
MSI setup code so that the msi_verify_entries() API would catch
if the MSI arch code tries to use 64-bit MSI.
This seems good to me. I'll post a possible revision to set
dev->no_64bit_msi in the device enumeration path instead of in the IRQ
allocation path, since it's really a property of the device, not of
the msi_desc.
I like the extra checking this gives us. Was this prompted by
tripping over something, or is it something you noticed by code
reading? If the former, a hint about what was wrong and how it's
being fixed would be useful.
I observed functionality issue with Marvell SATA controller (1b4b:9171)
when the allocated MSI target address was a 64-bit address. I mentioned
the Marvell SATA controller as an example in the commit message.
Thanks,
Vidya Sagar
Signed-off-by: Vidya Sagar
---
V2:
* Addressed Bjorn's comment and changed the error message
drivers/pci/msi.c | 11 +++
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index d52d118979a6..8de5ba6b4a59 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -581,10 +581,12 @@ msi_setup_entry(struct pci_dev *dev, int nvec, struct
irq_affinity *affd)
entry->msi_attrib.multi_cap = (control & PCI_MSI_FLAGS_QMASK) >> 1;
entry->msi_attrib.multiple = ilog2(__roundup_pow_of_two(nvec));
- if (control & PCI_MSI_FLAGS_64BIT)
+ if (control & PCI_MSI_FLAGS_64BIT) {
entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
- else
+ } else {
entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_32;
+ dev->no_64bit_msi = 1;
+ }
/* Save the initial mask status */
if (entry->msi_attrib.maskbit)
@@ -602,8 +604,9 @@ static int msi_verify_entries(struct pci_dev *dev)
for_each_pci_msi_entry(entry, dev) {
if (!dev->no_64bit_msi || !entry->msg.address_hi)
continue;
- pci_err(dev, "Device has broken 64-bit MSI but arch"
- " tried to assign one above 4G\n");
+ pci_err(dev, "Device has either broken 64-bit MSI or "
+ "only 32-bit MSI support but "
+ "arch tried to assign one above 4G\n");
return -EIO;
}
return 0;
--
2.17.1
Re: [PATCH V2] PCI/MSI: Set device flag indicating only 32-bit MSI support
On Tue, Nov 24, 2020 at 04:20:35PM +0530, Vidya Sagar wrote:
> There are devices (Ex:- Marvell SATA controller) that don't support
> 64-bit MSIs and the same is advertised through their MSI capability
> register. Set no_64bit_msi flag explicitly for such devices in the
> MSI setup code so that the msi_verify_entries() API would catch
> if the MSI arch code tries to use 64-bit MSI.
This seems good to me. I'll post a possible revision to set
dev->no_64bit_msi in the device enumeration path instead of in the IRQ
allocation path, since it's really a property of the device, not of
the msi_desc.
I like the extra checking this gives us. Was this prompted by
tripping over something, or is it something you noticed by code
reading? If the former, a hint about what was wrong and how it's
being fixed would be useful.
> Signed-off-by: Vidya Sagar
> ---
> V2:
> * Addressed Bjorn's comment and changed the error message
>
> drivers/pci/msi.c | 11 +++
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index d52d118979a6..8de5ba6b4a59 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -581,10 +581,12 @@ msi_setup_entry(struct pci_dev *dev, int nvec, struct
> irq_affinity *affd)
> entry->msi_attrib.multi_cap = (control & PCI_MSI_FLAGS_QMASK) >> 1;
> entry->msi_attrib.multiple = ilog2(__roundup_pow_of_two(nvec));
>
> - if (control & PCI_MSI_FLAGS_64BIT)
> + if (control & PCI_MSI_FLAGS_64BIT) {
> entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
> - else
> + } else {
> entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_32;
> + dev->no_64bit_msi = 1;
> + }
>
> /* Save the initial mask status */
> if (entry->msi_attrib.maskbit)
> @@ -602,8 +604,9 @@ static int msi_verify_entries(struct pci_dev *dev)
> for_each_pci_msi_entry(entry, dev) {
> if (!dev->no_64bit_msi || !entry->msg.address_hi)
> continue;
> - pci_err(dev, "Device has broken 64-bit MSI but arch"
> - " tried to assign one above 4G\n");
> + pci_err(dev, "Device has either broken 64-bit MSI or "
> + "only 32-bit MSI support but "
> + "arch tried to assign one above 4G\n");
> return -EIO;
> }
> return 0;
> --
> 2.17.1
>
Re: [PATCH V2] PCI/MSI: Set device flag indicating only 32-bit MSI support
Hi Bjorn,
Do you have any further comments for this patch?
Thanks,
Vidya Sagar
On 11/24/2020 4:20 PM, Vidya Sagar wrote:
There are devices (Ex:- Marvell SATA controller) that don't support
64-bit MSIs and the same is advertised through their MSI capability
register. Set no_64bit_msi flag explicitly for such devices in the
MSI setup code so that the msi_verify_entries() API would catch
if the MSI arch code tries to use 64-bit MSI.
Signed-off-by: Vidya Sagar
---
V2:
* Addressed Bjorn's comment and changed the error message
drivers/pci/msi.c | 11 +++
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index d52d118979a6..8de5ba6b4a59 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -581,10 +581,12 @@ msi_setup_entry(struct pci_dev *dev, int nvec, struct
irq_affinity *affd)
entry->msi_attrib.multi_cap = (control & PCI_MSI_FLAGS_QMASK) >> 1;
entry->msi_attrib.multiple = ilog2(__roundup_pow_of_two(nvec));
- if (control & PCI_MSI_FLAGS_64BIT)
+ if (control & PCI_MSI_FLAGS_64BIT) {
entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
- else
+ } else {
entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_32;
+ dev->no_64bit_msi = 1;
+ }
/* Save the initial mask status */
if (entry->msi_attrib.maskbit)
@@ -602,8 +604,9 @@ static int msi_verify_entries(struct pci_dev *dev)
for_each_pci_msi_entry(entry, dev) {
if (!dev->no_64bit_msi || !entry->msg.address_hi)
continue;
- pci_err(dev, "Device has broken 64-bit MSI but arch"
- " tried to assign one above 4G\n");
+ pci_err(dev, "Device has either broken 64-bit MSI or "
+ "only 32-bit MSI support but "
+ "arch tried to assign one above 4G\n");
return -EIO;
}
return 0;
[PATCH V2] PCI/MSI: Set device flag indicating only 32-bit MSI support
There are devices (Ex:- Marvell SATA controller) that don't support
64-bit MSIs and the same is advertised through their MSI capability
register. Set no_64bit_msi flag explicitly for such devices in the
MSI setup code so that the msi_verify_entries() API would catch
if the MSI arch code tries to use 64-bit MSI.
Signed-off-by: Vidya Sagar
---
V2:
* Addressed Bjorn's comment and changed the error message
drivers/pci/msi.c | 11 +++
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index d52d118979a6..8de5ba6b4a59 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -581,10 +581,12 @@ msi_setup_entry(struct pci_dev *dev, int nvec, struct
irq_affinity *affd)
entry->msi_attrib.multi_cap = (control & PCI_MSI_FLAGS_QMASK) >> 1;
entry->msi_attrib.multiple = ilog2(__roundup_pow_of_two(nvec));
- if (control & PCI_MSI_FLAGS_64BIT)
+ if (control & PCI_MSI_FLAGS_64BIT) {
entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
- else
+ } else {
entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_32;
+ dev->no_64bit_msi = 1;
+ }
/* Save the initial mask status */
if (entry->msi_attrib.maskbit)
@@ -602,8 +604,9 @@ static int msi_verify_entries(struct pci_dev *dev)
for_each_pci_msi_entry(entry, dev) {
if (!dev->no_64bit_msi || !entry->msg.address_hi)
continue;
- pci_err(dev, "Device has broken 64-bit MSI but arch"
- " tried to assign one above 4G\n");
+ pci_err(dev, "Device has either broken 64-bit MSI or "
+ "only 32-bit MSI support but "
+ "arch tried to assign one above 4G\n");
return -EIO;
}
return 0;
--
2.17.1
