From e673d697b9a234fc3544ac240e173cef8c82b349 Mon Sep 17 00:00:00 2001 From: Sandor Bodo-Merle Date: Tue, 22 Jun 2021 17:26:29 +0200 Subject: PCI: iproc: Fix multi-MSI base vector number allocation Commit fc54bae28818 ("PCI: iproc: Allow allocation of multiple MSIs") introduced multi-MSI support with a broken allocation mechanism (it failed to reserve the proper number of bits from the inner domain). Natural alignment of the base vector number was also not guaranteed. Link: https://lore.kernel.org/r/20210622152630.40842-1-sbodomerle@gmail.com Fixes: fc54bae28818 ("PCI: iproc: Allow allocation of multiple MSIs") Reported-by: Pali Rohár Signed-off-by: Sandor Bodo-Merle Signed-off-by: Lorenzo Pieralisi Acked-by: Marc Zyngier Acked-by: Pali Rohár Acked-by: Ray Jui --- drivers/pci/controller/pcie-iproc-msi.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) (limited to 'drivers') diff --git a/drivers/pci/controller/pcie-iproc-msi.c b/drivers/pci/controller/pcie-iproc-msi.c index eede4e8f3f75..557d93dcb3bc 100644 --- a/drivers/pci/controller/pcie-iproc-msi.c +++ b/drivers/pci/controller/pcie-iproc-msi.c @@ -252,18 +252,18 @@ static int iproc_msi_irq_domain_alloc(struct irq_domain *domain, mutex_lock(&msi->bitmap_lock); - /* Allocate 'nr_cpus' number of MSI vectors each time */ - hwirq = bitmap_find_next_zero_area(msi->bitmap, msi->nr_msi_vecs, 0, - msi->nr_cpus, 0); - if (hwirq < msi->nr_msi_vecs) { - bitmap_set(msi->bitmap, hwirq, msi->nr_cpus); - } else { - mutex_unlock(&msi->bitmap_lock); - return -ENOSPC; - } + /* + * Allocate 'nr_irqs' multiplied by 'nr_cpus' number of MSI vectors + * each time + */ + hwirq = bitmap_find_free_region(msi->bitmap, msi->nr_msi_vecs, + order_base_2(msi->nr_cpus * nr_irqs)); mutex_unlock(&msi->bitmap_lock); + if (hwirq < 0) + return -ENOSPC; + for (i = 0; i < nr_irqs; i++) { irq_domain_set_info(domain, virq + i, hwirq + i, &iproc_msi_bottom_irq_chip, @@ -284,7 +284,8 @@ static void iproc_msi_irq_domain_free(struct irq_domain *domain, mutex_lock(&msi->bitmap_lock); hwirq = hwirq_to_canonical_hwirq(msi, data->hwirq); - bitmap_clear(msi->bitmap, hwirq, msi->nr_cpus); + bitmap_release_region(msi->bitmap, hwirq, + order_base_2(msi->nr_cpus * nr_irqs)); mutex_unlock(&msi->bitmap_lock); -- cgit v1.2.3 From 2dc0a201d0f59e6818ef443609f0850a32910844 Mon Sep 17 00:00:00 2001 From: Sandor Bodo-Merle Date: Tue, 22 Jun 2021 17:26:30 +0200 Subject: PCI: iproc: Support multi-MSI only on uniprocessor kernel 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 Fixes: fc54bae28818 ("PCI: iproc: Allow allocation of multiple MSIs") Reported-by: Marc Zyngier Signed-off-by: Sandor Bodo-Merle Signed-off-by: Lorenzo Pieralisi Acked-by: Marc Zyngier Acked-by: Pali Rohár Acked-by: Ray Jui --- drivers/pci/controller/pcie-iproc-msi.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'drivers') 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"); -- cgit v1.2.3