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PCI/MSI: Protect MSI operations 

To prepare for dynamic extension of MSI-X vectors, protect the MSI
operations for MSI and MSI-X. This requires to move the invocation of
irq_create_affinity_masks() out of the descriptor lock section to avoid
reverse lock ordering vs. CPU hotplug lock as some callers of the PCI/MSI
allocation interfaces already hold it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20211206210747.982292705@linutronix.de
This commit is contained in:
Thomas Gleixner 2021-12-06 23:51:13 +01:00
parent 645474e2ce
commit 5512c5eaf5
2 changed files with 63 additions and 41 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/pci/msi/irqdomain.c
View File

@ -14,7 +14,7 @@ int pci_msi_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
domain = dev_get_msi_domain(&dev->dev);
if (domain && irq_domain_is_hierarchy(domain))
return msi_domain_alloc_irqs(domain, &dev->dev, nvec);
return msi_domain_alloc_irqs_descs_locked(domain, &dev->dev, nvec);
return pci_msi_legacy_setup_msi_irqs(dev, nvec, type);
}
@ -25,7 +25,7 @@ void pci_msi_teardown_msi_irqs(struct pci_dev *dev)
domain = dev_get_msi_domain(&dev->dev);
if (domain && irq_domain_is_hierarchy(domain))
msi_domain_free_irqs(domain, &dev->dev);
msi_domain_free_irqs_descs_locked(domain, &dev->dev);
else
pci_msi_legacy_teardown_msi_irqs(dev);
}

100
drivers/pci/msi/msi.c
View File

@ -320,11 +320,13 @@ static void __pci_restore_msix_state(struct pci_dev *dev)
write_msg = arch_restore_msi_irqs(dev);
msi_lock_descs(&dev->dev);
for_each_pci_msi_entry(entry, dev) {
if (write_msg)
__pci_write_msi_msg(entry, &entry->msg);
pci_msix_write_vector_ctrl(entry, entry->pci.msix_ctrl);
}
msi_unlock_descs(&dev->dev);
pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0);
}
@ -375,19 +377,15 @@ static int pci_setup_msi_context(struct pci_dev *dev)
}
static struct msi_desc *
msi_setup_entry(struct pci_dev *dev, int nvec, struct irq_affinity *affd)
msi_setup_entry(struct pci_dev *dev, int nvec, struct irq_affinity_desc *masks)
{
struct irq_affinity_desc *masks = NULL;
struct msi_desc *entry;
u16 control;
if (affd)
masks = irq_create_affinity_masks(nvec, affd);
/* MSI Entry Initialization */
entry = alloc_msi_entry(&dev->dev, nvec, masks);
if (!entry)
goto out;
return NULL;
pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
/* Lies, damned lies, and MSIs */
@ -410,8 +408,7 @@ msi_setup_entry(struct pci_dev *dev, int nvec, struct irq_affinity *affd)
if (entry->pci.msi_attrib.can_mask)
pci_read_config_dword(dev, entry->pci.mask_pos, &entry->pci.msi_mask);
out:
kfree(masks);
return entry;
}
@ -447,6 +444,7 @@ static int msi_verify_entries(struct pci_dev *dev)
static int msi_capability_init(struct pci_dev *dev, int nvec,
struct irq_affinity *affd)
{
struct irq_affinity_desc *masks = NULL;
struct msi_desc *entry;
int ret;
@ -457,7 +455,11 @@ static int msi_capability_init(struct pci_dev *dev, int nvec,
pci_msi_set_enable(dev, 0);
dev->msi_enabled = 1;
entry = msi_setup_entry(dev, nvec, affd);
if (affd)
masks = irq_create_affinity_masks(nvec, affd);
msi_lock_descs(&dev->dev);
entry = msi_setup_entry(dev, nvec, masks);
if (!entry) {
ret = -ENOMEM;
goto fail;
@ -483,13 +485,16 @@ static int msi_capability_init(struct pci_dev *dev, int nvec,
pcibios_free_irq(dev);
dev->irq = entry->irq;
return 0;
goto unlock;
err:
pci_msi_unmask(entry, msi_multi_mask(entry));
free_msi_irqs(dev);
fail:
dev->msi_enabled = 0;
unlock:
msi_unlock_descs(&dev->dev);
kfree(masks);
return ret;
}
@ -516,23 +521,18 @@ static void __iomem *msix_map_region(struct pci_dev *dev,
static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
struct msix_entry *entries, int nvec,
struct irq_affinity *affd)
struct irq_affinity_desc *masks)
{
struct irq_affinity_desc *curmsk, *masks = NULL;
int i, vec_count = pci_msix_vec_count(dev);
struct irq_affinity_desc *curmsk;
struct msi_desc *entry;
void __iomem *addr;
int ret, i;
int vec_count = pci_msix_vec_count(dev);
if (affd)
masks = irq_create_affinity_masks(nvec, affd);
for (i = 0, curmsk = masks; i < nvec; i++) {
entry = alloc_msi_entry(&dev->dev, 1, curmsk);
if (!entry) {
/* No enough memory. Don't try again */
ret = -ENOMEM;
goto out;
return -ENOMEM;
}
entry->pci.msi_attrib.is_msix = 1;
@ -560,10 +560,7 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
if (masks)
curmsk++;
}
ret = 0;
out:
kfree(masks);
return ret;
return 0;
}
static void msix_update_entries(struct pci_dev *dev, struct msix_entry *entries)
@ -590,6 +587,41 @@ static void msix_mask_all(void __iomem *base, int tsize)
writel(ctrl, base + PCI_MSIX_ENTRY_VECTOR_CTRL);
}
static int msix_setup_interrupts(struct pci_dev *dev, void __iomem *base,
struct msix_entry *entries, int nvec,
struct irq_affinity *affd)
{
struct irq_affinity_desc *masks = NULL;
int ret;
if (affd)
masks = irq_create_affinity_masks(nvec, affd);
msi_lock_descs(&dev->dev);
ret = msix_setup_entries(dev, base, entries, nvec, masks);
if (ret)
goto out_free;
ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX);
if (ret)
goto out_free;
/* Check if all MSI entries honor device restrictions */
ret = msi_verify_entries(dev);
if (ret)
goto out_free;
msix_update_entries(dev, entries);
goto out_unlock;
out_free:
free_msi_irqs(dev);
out_unlock:
msi_unlock_descs(&dev->dev);
kfree(masks);
return ret;
}
/**
* msix_capability_init - configure device's MSI-X capability
* @dev: pointer to the pci_dev data structure of MSI-X device function
@ -630,20 +662,9 @@ static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
dev->msix_base = base;
ret = msix_setup_entries(dev, base, entries, nvec, affd);
ret = msix_setup_interrupts(dev, base, entries, nvec, affd);
if (ret)
goto out_free;
ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX);
if (ret)
goto out_free;
/* Check if all MSI entries honor device restrictions */
ret = msi_verify_entries(dev);
if (ret)
goto out_free;
msix_update_entries(dev, entries);
goto out_disable;
/* Disable INTX */
pci_intx_for_msi(dev, 0);
@ -662,9 +683,6 @@ static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
pcibios_free_irq(dev);
return 0;
out_free:
free_msi_irqs(dev);
out_disable:
dev->msix_enabled = 0;
pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL | PCI_MSIX_FLAGS_ENABLE, 0);
@ -773,8 +791,10 @@ void pci_disable_msi(struct pci_dev *dev)
if (!pci_msi_enable || !dev || !dev->msi_enabled)
return;
msi_lock_descs(&dev->dev);
pci_msi_shutdown(dev);
free_msi_irqs(dev);
msi_unlock_descs(&dev->dev);
}
EXPORT_SYMBOL(pci_disable_msi);
@ -860,8 +880,10 @@ void pci_disable_msix(struct pci_dev *dev)
if (!pci_msi_enable || !dev || !dev->msix_enabled)
return;
msi_lock_descs(&dev->dev);
pci_msix_shutdown(dev);
free_msi_irqs(dev);
msi_unlock_descs(&dev->dev);
}
EXPORT_SYMBOL(pci_disable_msix);