Re: [patch V3 01/35] PCI/MSI: Set pci_dev::msi[x]_enabled early

2021-12-13 Thread Jason Gunthorpe via iommu
On Fri, Dec 10, 2021 at 11:18:44PM +0100, Thomas Gleixner wrote:
> There are quite some places which retrieve the first MSI descriptor to
> evaluate whether the setup is for MSI or MSI-X. That's required because
> pci_dev::msi[x]_enabled is only set when the setup completed successfully.
> 
> There is no real reason why msi[x]_enabled can't be set at the beginning of
> the setup sequence and cleared in case of a failure.
> 
> Implement that so the MSI descriptor evaluations can be converted to simple
> property queries.
> 
> Signed-off-by: Thomas Gleixner 
> ---
> V3: New patch
> ---
>  drivers/pci/msi/msi.c |   23 +--
>  1 file changed, 17 insertions(+), 6 deletions(-)

Reviewed-by: Jason Gunthorpe 

Jason
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[patch V3 01/35] PCI/MSI: Set pci_dev::msi[x]_enabled early

2021-12-10 Thread Thomas Gleixner
There are quite some places which retrieve the first MSI descriptor to
evaluate whether the setup is for MSI or MSI-X. That's required because
pci_dev::msi[x]_enabled is only set when the setup completed successfully.

There is no real reason why msi[x]_enabled can't be set at the beginning of
the setup sequence and cleared in case of a failure.

Implement that so the MSI descriptor evaluations can be converted to simple
property queries.

Signed-off-by: Thomas Gleixner 
---
V3: New patch
---
 drivers/pci/msi/msi.c |   23 +--
 1 file changed, 17 insertions(+), 6 deletions(-)

--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -421,11 +421,18 @@ static int msi_capability_init(struct pc
struct msi_desc *entry;
int ret;
 
-   pci_msi_set_enable(dev, 0); /* Disable MSI during set up */
+   /*
+* Disable MSI during setup in the hardware, but mark it enabled
+* so that setup code can evaluate it.
+*/
+   pci_msi_set_enable(dev, 0);
+   dev->msi_enabled = 1;
 
entry = msi_setup_entry(dev, nvec, affd);
-   if (!entry)
-   return -ENOMEM;
+   if (!entry) {
+   ret = -ENOMEM;
+   goto fail;
+   }
 
/* All MSIs are unmasked by default; mask them all */
pci_msi_mask(entry, msi_multi_mask(entry));
@@ -452,7 +459,6 @@ static int msi_capability_init(struct pc
/* Set MSI enabled bits */
pci_intx_for_msi(dev, 0);
pci_msi_set_enable(dev, 1);
-   dev->msi_enabled = 1;
 
pcibios_free_irq(dev);
dev->irq = entry->irq;
@@ -461,6 +467,8 @@ static int msi_capability_init(struct pc
 err:
pci_msi_unmask(entry, msi_multi_mask(entry));
free_msi_irqs(dev);
+fail:
+   dev->msi_enabled = 0;
return ret;
 }
 
@@ -589,6 +597,9 @@ static int msix_capability_init(struct p
pci_msix_clear_and_set_ctrl(dev, 0, PCI_MSIX_FLAGS_MASKALL |
PCI_MSIX_FLAGS_ENABLE);
 
+   /* Mark it enabled so setup functions can query it */
+   dev->msix_enabled = 1;
+
pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, );
/* Request & Map MSI-X table region */
tsize = msix_table_size(control);
@@ -626,9 +637,8 @@ static int msix_capability_init(struct p
 
dev->msi_irq_groups = groups;
 
-   /* Set MSI-X enabled bits and unmask the function */
+   /* Disable INTX and unmask MSI-X */
pci_intx_for_msi(dev, 0);
-   dev->msix_enabled = 1;
pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0);
 
pcibios_free_irq(dev);
@@ -638,6 +648,7 @@ static int msix_capability_init(struct p
free_msi_irqs(dev);
 
 out_disable:
+   dev->msix_enabled = 0;
pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0);
 
return ret;

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