[PATCH 5.10 167/243] PCI: iproc: Support multi-MSI only on uniprocessor kernel
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-07-19 17:22:42
Also in:
lkml
Subsystem:
pci native host bridge and endpoint drivers, pci subsystem, the rest · Maintainers:
Lorenzo Pieralisi, Krzysztof Wilczyński, Manivannan Sadhasivam, Bjorn Helgaas, Linus Torvalds
From: Sandor Bodo-Merle <redacted> [ Upstream commit 2dc0a201d0f59e6818ef443609f0850a32910844 ] 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. Link: https://lore.kernel.org/r/20210622152630.40842-2-sbodomerle@gmail.com (local) Fixes: fc54bae28818 ("PCI: iproc: Allow allocation of multiple MSIs") Reported-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Sandor Bodo-Merle <redacted> Signed-off-by: Lorenzo Pieralisi <redacted> Acked-by: Marc Zyngier <maz@kernel.org> Acked-by: Pali Rohár <pali@kernel.org> Acked-by: Ray Jui <redacted> Signed-off-by: Sasha Levin <sashal@kernel.org> --- 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; + 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");
--
2.30.2