| Message ID | 20210606123044.31250-2-sbodomerle@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] PCI: iproc: fix the base vector number allocation for multi-MSI | expand |
On 2021-06-06 13:30, Sandor Bodo-Merle wrote: > The interrupt affinity scheme used by this driver is incompatible with > multi-MSI as it implies moving the doorbell address to that of another > MSI > group. This isn't possible for multi-MSI, as all the MSIs must have > the > same doorbell address. As such it is restricted to systems with a > single > CPU. > > Fixes: fc54bae28818 ("PCI: iproc: Allow allocation of multiple MSIs") > Reported-by: Marc Zyngier <maz@kernel.org> > Signed-off-by: Sandor Bodo-Merle <sbodomerle@gmail.com> Acked-by: Marc Zyngier <maz@kernel.org> M.
On 6/6/2021 5:30 AM, Sandor Bodo-Merle wrote: > The interrupt affinity scheme used by this driver is incompatible with > multi-MSI as it implies moving the doorbell address to that of another MSI > group. This isn't possible for multi-MSI, as all the MSIs must have the > same doorbell address. As such it is restricted to systems with a single > CPU. > > Fixes: fc54bae28818 ("PCI: iproc: Allow allocation of multiple MSIs") > Reported-by: Marc Zyngier <maz@kernel.org> > Signed-off-by: Sandor Bodo-Merle <sbodomerle@gmail.com> > --- > drivers/pci/controller/pcie-iproc-msi.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/controller/pcie-iproc-msi.c b/drivers/pci/controller/pcie-iproc-msi.c > index 557d93dcb3bc..81b4effeb130 100644 > --- a/drivers/pci/controller/pcie-iproc-msi.c > +++ b/drivers/pci/controller/pcie-iproc-msi.c > @@ -171,7 +171,7 @@ static struct irq_chip iproc_msi_irq_chip = { > > static struct msi_domain_info iproc_msi_domain_info = { > .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | > - MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX, > + MSI_FLAG_PCI_MSIX, > .chip = &iproc_msi_irq_chip, > }; > > @@ -250,6 +250,9 @@ static int iproc_msi_irq_domain_alloc(struct irq_domain *domain, > struct iproc_msi *msi = domain->host_data; > int hwirq, i; > > + if (msi->nr_cpus > 1 && nr_irqs > 1) > + return -EINVAL; > + This should never happen since the framework would have guarded against this. But I guess it does not hurt to have the check here. > mutex_lock(&msi->bitmap_lock); > > /* > @@ -540,6 +543,9 @@ int iproc_msi_init(struct iproc_pcie *pcie, struct device_node *node) > mutex_init(&msi->bitmap_lock); > msi->nr_cpus = num_possible_cpus(); > > + if (msi->nr_cpus == 1) > + iproc_msi_domain_info.flags |= MSI_FLAG_MULTI_PCI_MSI; > + > msi->nr_irqs = of_irq_count(node); > if (!msi->nr_irqs) { > dev_err(pcie->dev, "found no MSI GIC interrupt\n"); > Looks fine to me. Thanks. Acked-by: Ray Jui <ray.jui@broadcom.com>
On Monday 07 June 2021 09:48:21 Ray Jui wrote: > On 6/6/2021 5:30 AM, Sandor Bodo-Merle wrote: > > The interrupt affinity scheme used by this driver is incompatible with > > multi-MSI as it implies moving the doorbell address to that of another MSI > > group. This isn't possible for multi-MSI, as all the MSIs must have the > > same doorbell address. As such it is restricted to systems with a single > > CPU. > > > > Fixes: fc54bae28818 ("PCI: iproc: Allow allocation of multiple MSIs") > > Reported-by: Marc Zyngier <maz@kernel.org> > > Signed-off-by: Sandor Bodo-Merle <sbodomerle@gmail.com> > > --- > > drivers/pci/controller/pcie-iproc-msi.c | 8 +++++++- > > 1 file changed, 7 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/pci/controller/pcie-iproc-msi.c b/drivers/pci/controller/pcie-iproc-msi.c > > index 557d93dcb3bc..81b4effeb130 100644 > > --- a/drivers/pci/controller/pcie-iproc-msi.c > > +++ b/drivers/pci/controller/pcie-iproc-msi.c > > @@ -171,7 +171,7 @@ static struct irq_chip iproc_msi_irq_chip = { > > > > static struct msi_domain_info iproc_msi_domain_info = { > > .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | > > - MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX, > > + MSI_FLAG_PCI_MSIX, > > .chip = &iproc_msi_irq_chip, > > }; > > > > @@ -250,6 +250,9 @@ static int iproc_msi_irq_domain_alloc(struct irq_domain *domain, > > struct iproc_msi *msi = domain->host_data; > > int hwirq, i; > > > > + if (msi->nr_cpus > 1 && nr_irqs > 1) > > + return -EINVAL; > > + > > This should never happen since the framework would have guarded against > this. But I guess it does not hurt to have the check here. Yes, this should not happen, but I suggested to add a comment or assert or some other way to document this kind of constrain. Lot of times code is copy+pasted to new drivers and because only this one driver has .alloc function which is using nr_cpus for allocating msi bitmap, it really makes sense to document this constrain also explicitly. > > mutex_lock(&msi->bitmap_lock); > > > > /* > > @@ -540,6 +543,9 @@ int iproc_msi_init(struct iproc_pcie *pcie, struct device_node *node) > > mutex_init(&msi->bitmap_lock); > > msi->nr_cpus = num_possible_cpus(); > > > > + if (msi->nr_cpus == 1) > > + iproc_msi_domain_info.flags |= MSI_FLAG_MULTI_PCI_MSI; ^^ Just a small note: there are two spaces instead of just one Otherwise looks good to me: Acked-by: Pali Rohár <pali@kernel.org> > > + > > msi->nr_irqs = of_irq_count(node); > > if (!msi->nr_irqs) { > > dev_err(pcie->dev, "found no MSI GIC interrupt\n"); > > > > Looks fine to me. Thanks. > > Acked-by: Ray Jui <ray.jui@broadcom.com>
On Sun, Jun 06, 2021 at 02:30:44PM +0200, Sandor Bodo-Merle wrote: > The interrupt affinity scheme used by this driver is incompatible with > multi-MSI as it implies moving the doorbell address to that of another MSI > group. This isn't possible for multi-MSI, as all the MSIs must have the > same doorbell address. As such it is restricted to systems with a single > CPU. > > Fixes: fc54bae28818 ("PCI: iproc: Allow allocation of multiple MSIs") > Reported-by: Marc Zyngier <maz@kernel.org> > Signed-off-by: Sandor Bodo-Merle <sbodomerle@gmail.com> > --- > drivers/pci/controller/pcie-iproc-msi.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) Can you just resend the series with the very minor changes requested fixed please ? Please carry/apply the review tags as well. Thanks, Lorenzo > diff --git a/drivers/pci/controller/pcie-iproc-msi.c b/drivers/pci/controller/pcie-iproc-msi.c > index 557d93dcb3bc..81b4effeb130 100644 > --- a/drivers/pci/controller/pcie-iproc-msi.c > +++ b/drivers/pci/controller/pcie-iproc-msi.c > @@ -171,7 +171,7 @@ static struct irq_chip iproc_msi_irq_chip = { > > static struct msi_domain_info iproc_msi_domain_info = { > .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | > - MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX, > + MSI_FLAG_PCI_MSIX, > .chip = &iproc_msi_irq_chip, > }; > > @@ -250,6 +250,9 @@ static int iproc_msi_irq_domain_alloc(struct irq_domain *domain, > struct iproc_msi *msi = domain->host_data; > int hwirq, i; > > + if (msi->nr_cpus > 1 && nr_irqs > 1) > + return -EINVAL; > + > mutex_lock(&msi->bitmap_lock); > > /* > @@ -540,6 +543,9 @@ int iproc_msi_init(struct iproc_pcie *pcie, struct device_node *node) > mutex_init(&msi->bitmap_lock); > msi->nr_cpus = num_possible_cpus(); > > + if (msi->nr_cpus == 1) > + iproc_msi_domain_info.flags |= MSI_FLAG_MULTI_PCI_MSI; > + > msi->nr_irqs = of_irq_count(node); > if (!msi->nr_irqs) { > dev_err(pcie->dev, "found no MSI GIC interrupt\n"); > -- > 2.31.0 >
diff --git a/drivers/pci/controller/pcie-iproc-msi.c b/drivers/pci/controller/pcie-iproc-msi.c index 557d93dcb3bc..81b4effeb130 100644 --- a/drivers/pci/controller/pcie-iproc-msi.c +++ b/drivers/pci/controller/pcie-iproc-msi.c @@ -171,7 +171,7 @@ static struct irq_chip iproc_msi_irq_chip = { static struct msi_domain_info iproc_msi_domain_info = { .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | - MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX, + MSI_FLAG_PCI_MSIX, .chip = &iproc_msi_irq_chip, }; @@ -250,6 +250,9 @@ static int iproc_msi_irq_domain_alloc(struct irq_domain *domain, struct iproc_msi *msi = domain->host_data; int hwirq, i; + if (msi->nr_cpus > 1 && nr_irqs > 1) + return -EINVAL; + mutex_lock(&msi->bitmap_lock); /* @@ -540,6 +543,9 @@ int iproc_msi_init(struct iproc_pcie *pcie, struct device_node *node) mutex_init(&msi->bitmap_lock); msi->nr_cpus = num_possible_cpus(); + if (msi->nr_cpus == 1) + iproc_msi_domain_info.flags |= MSI_FLAG_MULTI_PCI_MSI; + msi->nr_irqs = of_irq_count(node); if (!msi->nr_irqs) { dev_err(pcie->dev, "found no MSI GIC interrupt\n");
The interrupt affinity scheme used by this driver is incompatible with multi-MSI as it implies moving the doorbell address to that of another MSI group. This isn't possible for multi-MSI, as all the MSIs must have the same doorbell address. As such it is restricted to systems with a single CPU. Fixes: fc54bae28818 ("PCI: iproc: Allow allocation of multiple MSIs") Reported-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Sandor Bodo-Merle <sbodomerle@gmail.com> --- drivers/pci/controller/pcie-iproc-msi.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)