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genirq/msi: Use lock guards for MSI descriptor locking
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Provide a lock guard for MSI descriptor locking and update the core code
accordingly.

No functional change intended.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/all/20250313130321.506045185@linutronix.de
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Thomas Gleixner committed Mar 13, 2025
1 parent 08549ff commit 5c99e02
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Showing 3 changed files with 45 additions and 69 deletions.
2 changes: 2 additions & 0 deletions include/linux/irqdomain.h
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Original file line number Diff line number Diff line change
Expand Up @@ -281,6 +281,8 @@ static inline struct fwnode_handle *irq_domain_alloc_fwnode(phys_addr_t *pa)

void irq_domain_free_fwnode(struct fwnode_handle *fwnode);

DEFINE_FREE(irq_domain_free_fwnode, struct fwnode_handle *, if (_T) irq_domain_free_fwnode(_T))

struct irq_domain_chip_generic_info;

/**
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3 changes: 3 additions & 0 deletions include/linux/msi.h
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Original file line number Diff line number Diff line change
Expand Up @@ -227,6 +227,9 @@ int msi_setup_device_data(struct device *dev);
void msi_lock_descs(struct device *dev);
void msi_unlock_descs(struct device *dev);

DEFINE_LOCK_GUARD_1(msi_descs_lock, struct device, msi_lock_descs(_T->lock),
msi_unlock_descs(_T->lock));

struct msi_desc *msi_domain_first_desc(struct device *dev, unsigned int domid,
enum msi_desc_filter filter);

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109 changes: 40 additions & 69 deletions kernel/irq/msi.c
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Original file line number Diff line number Diff line change
Expand Up @@ -443,7 +443,6 @@ EXPORT_SYMBOL_GPL(msi_next_desc);
unsigned int msi_domain_get_virq(struct device *dev, unsigned int domid, unsigned int index)
{
struct msi_desc *desc;
unsigned int ret = 0;
bool pcimsi = false;
struct xarray *xa;

Expand All @@ -457,7 +456,7 @@ unsigned int msi_domain_get_virq(struct device *dev, unsigned int domid, unsigne
if (dev_is_pci(dev) && domid == MSI_DEFAULT_DOMAIN)
pcimsi = to_pci_dev(dev)->msi_enabled;

msi_lock_descs(dev);
guard(msi_descs_lock)(dev);
xa = &dev->msi.data->__domains[domid].store;
desc = xa_load(xa, pcimsi ? 0 : index);
if (desc && desc->irq) {
Expand All @@ -466,16 +465,12 @@ unsigned int msi_domain_get_virq(struct device *dev, unsigned int domid, unsigne
* PCI-MSIX and platform MSI use a descriptor per
* interrupt.
*/
if (pcimsi) {
if (index < desc->nvec_used)
ret = desc->irq + index;
} else {
ret = desc->irq;
}
if (!pcimsi)
return desc->irq;
if (index < desc->nvec_used)
return desc->irq + index;
}

msi_unlock_descs(dev);
return ret;
return 0;
}
EXPORT_SYMBOL_GPL(msi_domain_get_virq);

Expand Down Expand Up @@ -993,17 +988,17 @@ bool msi_create_device_irq_domain(struct device *dev, unsigned int domid,
void *chip_data)
{
struct irq_domain *domain, *parent = dev->msi.domain;
struct fwnode_handle *fwnode, *fwnalloced = NULL;
struct msi_domain_template *bundle;
const struct msi_parent_ops *pops;
struct fwnode_handle *fwnode;

if (!irq_domain_is_msi_parent(parent))
return false;

if (domid >= MSI_MAX_DEVICE_IRQDOMAINS)
return false;

bundle = kmemdup(template, sizeof(*bundle), GFP_KERNEL);
struct msi_domain_template *bundle __free(kfree) =
bundle = kmemdup(template, sizeof(*bundle), GFP_KERNEL);
if (!bundle)
return false;

Expand All @@ -1026,41 +1021,36 @@ bool msi_create_device_irq_domain(struct device *dev, unsigned int domid,
* node as they are not guaranteed to have a fwnode. They are never
* looked up and always handled in the context of the device.
*/
if (bundle->info.flags & MSI_FLAG_USE_DEV_FWNODE)
fwnode = dev->fwnode;
struct fwnode_handle *fwnode_alloced __free(irq_domain_free_fwnode) = NULL;

if (!(bundle->info.flags & MSI_FLAG_USE_DEV_FWNODE))
fwnode = fwnode_alloced = irq_domain_alloc_named_fwnode(bundle->name);
else
fwnode = fwnalloced = irq_domain_alloc_named_fwnode(bundle->name);
fwnode = dev->fwnode;

if (!fwnode)
goto free_bundle;
return false;

if (msi_setup_device_data(dev))
goto free_fwnode;

msi_lock_descs(dev);
return false;

guard(msi_descs_lock)(dev);
if (WARN_ON_ONCE(msi_get_device_domain(dev, domid)))
goto fail;
return false;

if (!pops->init_dev_msi_info(dev, parent, parent, &bundle->info))
goto fail;
return false;

domain = __msi_create_irq_domain(fwnode, &bundle->info, IRQ_DOMAIN_FLAG_MSI_DEVICE, parent);
if (!domain)
goto fail;
return false;

/* @bundle and @fwnode_alloced are now in use. Prevent cleanup */
retain_ptr(bundle);
retain_ptr(fwnode_alloced);
domain->dev = dev;
dev->msi.data->__domains[domid].domain = domain;
msi_unlock_descs(dev);
return true;

fail:
msi_unlock_descs(dev);
free_fwnode:
irq_domain_free_fwnode(fwnalloced);
free_bundle:
kfree(bundle);
return false;
}

/**
Expand All @@ -1074,12 +1064,10 @@ void msi_remove_device_irq_domain(struct device *dev, unsigned int domid)
struct msi_domain_info *info;
struct irq_domain *domain;

msi_lock_descs(dev);

guard(msi_descs_lock)(dev);
domain = msi_get_device_domain(dev, domid);

if (!domain || !irq_domain_is_msi_device(domain))
goto unlock;
return;

dev->msi.data->__domains[domid].domain = NULL;
info = domain->host_data;
Expand All @@ -1088,9 +1076,6 @@ void msi_remove_device_irq_domain(struct device *dev, unsigned int domid)
irq_domain_remove(domain);
irq_domain_free_fwnode(fwnode);
kfree(container_of(info, struct msi_domain_template, info));

unlock:
msi_unlock_descs(dev);
}

/**
Expand All @@ -1106,16 +1091,14 @@ bool msi_match_device_irq_domain(struct device *dev, unsigned int domid,
{
struct msi_domain_info *info;
struct irq_domain *domain;
bool ret = false;

msi_lock_descs(dev);
guard(msi_descs_lock)(dev);
domain = msi_get_device_domain(dev, domid);
if (domain && irq_domain_is_msi_device(domain)) {
info = domain->host_data;
ret = info->bus_token == bus_token;
return info->bus_token == bus_token;
}
msi_unlock_descs(dev);
return ret;
return false;
}

static int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev,
Expand Down Expand Up @@ -1365,12 +1348,9 @@ int msi_domain_alloc_irqs_range(struct device *dev, unsigned int domid,
.last = last,
.nirqs = last + 1 - first,
};
int ret;

msi_lock_descs(dev);
ret = msi_domain_alloc_locked(dev, &ctrl);
msi_unlock_descs(dev);
return ret;
guard(msi_descs_lock)(dev);
return msi_domain_alloc_locked(dev, &ctrl);
}
EXPORT_SYMBOL_GPL(msi_domain_alloc_irqs_range);

Expand Down Expand Up @@ -1474,12 +1454,8 @@ struct msi_map msi_domain_alloc_irq_at(struct device *dev, unsigned int domid, u
const struct irq_affinity_desc *affdesc,
union msi_instance_cookie *icookie)
{
struct msi_map map;

msi_lock_descs(dev);
map = __msi_domain_alloc_irq_at(dev, domid, index, affdesc, icookie);
msi_unlock_descs(dev);
return map;
guard(msi_descs_lock)(dev);
return __msi_domain_alloc_irq_at(dev, domid, index, affdesc, icookie);
}

/**
Expand Down Expand Up @@ -1516,13 +1492,11 @@ int msi_device_domain_alloc_wired(struct irq_domain *domain, unsigned int hwirq,

icookie.value = ((u64)type << 32) | hwirq;

msi_lock_descs(dev);
guard(msi_descs_lock)(dev);
if (WARN_ON_ONCE(msi_get_device_domain(dev, domid) != domain))
map.index = -EINVAL;
else
map = __msi_domain_alloc_irq_at(dev, domid, MSI_ANY_INDEX, NULL, &icookie);
msi_unlock_descs(dev);

return map.index >= 0 ? map.virq : map.index;
}

Expand Down Expand Up @@ -1615,9 +1589,8 @@ static void msi_domain_free_irqs_range_locked(struct device *dev, unsigned int d
void msi_domain_free_irqs_range(struct device *dev, unsigned int domid,
unsigned int first, unsigned int last)
{
msi_lock_descs(dev);
guard(msi_descs_lock)(dev);
msi_domain_free_irqs_range_locked(dev, domid, first, last);
msi_unlock_descs(dev);
}
EXPORT_SYMBOL_GPL(msi_domain_free_irqs_all);

Expand Down Expand Up @@ -1647,9 +1620,8 @@ void msi_domain_free_irqs_all_locked(struct device *dev, unsigned int domid)
*/
void msi_domain_free_irqs_all(struct device *dev, unsigned int domid)
{
msi_lock_descs(dev);
guard(msi_descs_lock)(dev);
msi_domain_free_irqs_all_locked(dev, domid);
msi_unlock_descs(dev);
}

/**
Expand All @@ -1668,12 +1640,11 @@ void msi_device_domain_free_wired(struct irq_domain *domain, unsigned int virq)
if (WARN_ON_ONCE(!dev || !desc || domain->bus_token != DOMAIN_BUS_WIRED_TO_MSI))
return;

msi_lock_descs(dev);
if (!WARN_ON_ONCE(msi_get_device_domain(dev, MSI_DEFAULT_DOMAIN) != domain)) {
msi_domain_free_irqs_range_locked(dev, MSI_DEFAULT_DOMAIN, desc->msi_index,
desc->msi_index);
}
msi_unlock_descs(dev);
guard(msi_descs_lock)(dev);
if (WARN_ON_ONCE(msi_get_device_domain(dev, MSI_DEFAULT_DOMAIN) != domain))
return;
msi_domain_free_irqs_range_locked(dev, MSI_DEFAULT_DOMAIN, desc->msi_index,
desc->msi_index);
}

/**
Expand Down

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