Skip to content

L
linux
Commit aff17164 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Bjorn Helgaas
1 Browse files
Options

PCI: Provide sensible IRQ vector alloc/free routines 

Add a function to allocate and free a range of interrupt vectors, using
MSI-X, MSI or legacy vectors (in that order) based on the capabilities of
the underlying device and PCIe complex.

Additionally a new helper is provided to get the Linux IRQ number for given
device-relative vector so that the drivers don't need to allocate their own
arrays to keep track of the vectors for the multi vector MSI-X case.
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarAlexander Gordeev <agordeev@redhat.com>
parent 3ac020e0
Hide whitespace changes
Inline Side-by-side
Showing with 192 additions and 391 deletions
Documentation/PCI/MSI-HOWTO.txt
View file @ aff17164
...@@ -78,422 +78,107 @@ CONFIG_PCI_MSI option. ...@@ -78,422 +78,107 @@ CONFIG_PCI_MSI option.
4.2 Using MSI 4.2 Using MSI
Most of the hard work is done for the driver in the PCI layer. It simply Most of the hard work is done for the driver in the PCI layer. The driver
has to request that the PCI layer set up the MSI capability for this simply has to request that the PCI layer set up the MSI capability for this
device. device.
4.2.1 pci_enable_msi To automatically use MSI or MSI-X interrupt vectors, use the following
function:
int pci_enable_msi(struct pci_dev *dev) int pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
unsigned int max_vecs, unsigned int flags);
A successful call allocates ONE interrupt to the device, regardless which allocates up to max_vecs interrupt vectors for a PCI device. It
of how many MSIs the device supports. The device is switched from returns the number of vectors allocated or a negative error. If the device
pin-based interrupt mode to MSI mode. The dev->irq number is changed has a requirements for a minimum number of vectors the driver can pass a
to a new number which represents the message signaled interrupt; min_vecs argument set to this limit, and the PCI core will return -ENOSPC
consequently, this function should be called before the driver calls if it can't meet the minimum number of vectors.
request_irq(), because an MSI is delivered via a vector that is
different from the vector of a pin-based interrupt.
4.2.2 pci_enable_msi_range The flags argument should normally be set to 0, but can be used to pass the
PCI_IRQ_NOMSI and PCI_IRQ_NOMSIX flag in case a device claims to support
MSI or MSI-X, but the support is broken, or to pass PCI_IRQ_NOLEGACY in
case the device does not support legacy interrupt lines.
int pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec) To get the Linux IRQ numbers passed to request_irq() and free_irq() and the
vectors, use the following function:
This function allows a device driver to request any number of MSI int pci_irq_vector(struct pci_dev *dev, unsigned int nr);
interrupts within specified range from 'minvec' to 'maxvec'.
If this function returns a positive number it indicates the number of Any allocated resources should be freed before removing the device using
MSI interrupts that have been successfully allocated. In this case the following function:
the device is switched from pin-based interrupt mode to MSI mode and
updates dev->irq to be the lowest of the new interrupts assigned to it.
The other interrupts assigned to the device are in the range dev->irq
to dev->irq + returned value - 1. Device driver can use the returned
number of successfully allocated MSI interrupts to further allocate
and initialize device resources.
If this function returns a negative number, it indicates an error and void pci_free_irq_vectors(struct pci_dev *dev);
the driver should not attempt to request any more MSI interrupts for
this device.
This function should be called before the driver calls request_irq(), If a device supports both MSI-X and MSI capabilities, this API will use the
because MSI interrupts are delivered via vectors that are different MSI-X facilities in preference to the MSI facilities. MSI-X supports any
from the vector of a pin-based interrupt. number of interrupts between 1 and 2048. In contrast, MSI is restricted to
a maximum of 32 interrupts (and must be a power of two). In addition, the
MSI interrupt vectors must be allocated consecutively, so the system might
not be able to allocate as many vectors for MSI as it could for MSI-X. On
some platforms, MSI interrupts must all be targeted at the same set of CPUs
whereas MSI-X interrupts can all be targeted at different CPUs.
It is ideal if drivers can cope with a variable number of MSI interrupts; If a device supports neither MSI-X or MSI it will fall back to a single
there are many reasons why the platform may not be able to provide the legacy IRQ vector.
exact number that a driver asks for.
There could be devices that can not operate with just any number of MSI The typical usage of MSI or MSI-X interrupts is to allocate as many vectors
interrupts within a range. See chapter 4.3.1.3 to get the idea how to as possible, likely up to the limit supported by the device. If nvec is
handle such devices for MSI-X - the same logic applies to MSI. larger than the number supported by the device it will automatically be
capped to the supported limit, so there is no need to query the number of
vectors supported beforehand:
4.2.1.1 Maximum possible number of MSI interrupts nvec = pci_alloc_irq_vectors(pdev, 1, nvec, 0);
if (nvec < 0)
The typical usage of MSI interrupts is to allocate as many vectors as goto out_err;
possible, likely up to the limit returned by pci_msi_vec_count() function:
static int foo_driver_enable_msi(struct pci_dev *pdev, int nvec)
{
return pci_enable_msi_range(pdev, 1, nvec);
}
Note the value of 'minvec' parameter is 1. As 'minvec' is inclusive,
the value of 0 would be meaningless and could result in error.
Some devices have a minimal limit on number of MSI interrupts.
In this case the function could look like this:
static int foo_driver_enable_msi(struct pci_dev *pdev, int nvec)
{
return pci_enable_msi_range(pdev, FOO_DRIVER_MINIMUM_NVEC, nvec);
}
4.2.1.2 Exact number of MSI interrupts
If a driver is unable or unwilling to deal with a variable number of MSI If a driver is unable or unwilling to deal with a variable number of MSI
interrupts it could request a particular number of interrupts by passing interrupts it can request a particular number of interrupts by passing that
that number to pci_enable_msi_range() function as both 'minvec' and 'maxvec' number to pci_alloc_irq_vectors() function as both 'min_vecs' and
parameters: 'max_vecs' parameters:
static int foo_driver_enable_msi(struct pci_dev *pdev, int nvec)
{
return pci_enable_msi_range(pdev, nvec, nvec);
}
Note, unlike pci_enable_msi_exact() function, which could be also used to
enable a particular number of MSI-X interrupts, pci_enable_msi_range()
returns either a negative errno or 'nvec' (not negative errno or 0 - as
pci_enable_msi_exact() does).
4.2.1.3 Single MSI mode
The most notorious example of the request type described above is
enabling the single MSI mode for a device. It could be done by passing
two 1s as 'minvec' and 'maxvec':
static int foo_driver_enable_single_msi(struct pci_dev *pdev)
{
return pci_enable_msi_range(pdev, 1, 1);
}
Note, unlike pci_enable_msi() function, which could be also used to
enable the single MSI mode, pci_enable_msi_range() returns either a
negative errno or 1 (not negative errno or 0 - as pci_enable_msi()
does).
4.2.3 pci_enable_msi_exact
int pci_enable_msi_exact(struct pci_dev *dev, int nvec)
This variation on pci_enable_msi_range() call allows a device driver to
request exactly 'nvec' MSIs.
If this function returns a negative number, it indicates an error and
the driver should not attempt to request any more MSI interrupts for
this device.
By contrast with pci_enable_msi_range() function, pci_enable_msi_exact()
returns zero in case of success, which indicates MSI interrupts have been
successfully allocated.
4.2.4 pci_disable_msi
void pci_disable_msi(struct pci_dev *dev)
This function should be used to undo the effect of pci_enable_msi_range().
Calling it restores dev->irq to the pin-based interrupt number and frees
the previously allocated MSIs. The interrupts may subsequently be assigned
to another device, so drivers should not cache the value of dev->irq.
Before calling this function, a device driver must always call free_irq()
on any interrupt for which it previously called request_irq().
Failure to do so results in a BUG_ON(), leaving the device with
MSI enabled and thus leaking its vector.
4.2.4 pci_msi_vec_count
int pci_msi_vec_count(struct pci_dev *dev)
This function could be used to retrieve the number of MSI vectors the
device requested (via the Multiple Message Capable register). The MSI
specification only allows the returned value to be a power of two,
up to a maximum of 2^5 (32).
If this function returns a negative number, it indicates the device is
not capable of sending MSIs.
If this function returns a positive number, it indicates the maximum
number of MSI interrupt vectors that could be allocated.
4.3 Using MSI-X
The MSI-X capability is much more flexible than the MSI capability.
It supports up to 2048 interrupts, each of which can be controlled
independently. To support this flexibility, drivers must use an array of
`struct msix_entry':
struct msix_entry {
u16 vector; /* kernel uses to write alloc vector */
u16 entry; /* driver uses to specify entry */
};
This allows for the device to use these interrupts in a sparse fashion;
for example, it could use interrupts 3 and 1027 and yet allocate only a
two-element array. The driver is expected to fill in the 'entry' value
in each element of the array to indicate for which entries the kernel
should assign interrupts; it is invalid to fill in two entries with the
same number.
4.3.1 pci_enable_msix_range
int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
int minvec, int maxvec)
Calling this function asks the PCI subsystem to allocate any number of
MSI-X interrupts within specified range from 'minvec' to 'maxvec'.
The 'entries' argument is a pointer to an array of msix_entry structs
which should be at least 'maxvec' entries in size.
On success, the device is switched into MSI-X mode and the function
returns the number of MSI-X interrupts that have been successfully
allocated. In this case the 'vector' member in entries numbered from
0 to the returned value - 1 is populated with the interrupt number;
the driver should then call request_irq() for each 'vector' that it
decides to use. The device driver is responsible for keeping track of the
interrupts assigned to the MSI-X vectors so it can free them again later.
Device driver can use the returned number of successfully allocated MSI-X
interrupts to further allocate and initialize device resources.
If this function returns a negative number, it indicates an error and
the driver should not attempt to allocate any more MSI-X interrupts for
this device.
This function, in contrast with pci_enable_msi_range(), does not adjust
dev->irq. The device will not generate interrupts for this interrupt
number once MSI-X is enabled.
Device drivers should normally call this function once per device
during the initialization phase.
It is ideal if drivers can cope with a variable number of MSI-X interrupts;
there are many reasons why the platform may not be able to provide the
exact number that a driver asks for.
There could be devices that can not operate with just any number of MSI-X
interrupts within a range. E.g., an network adapter might need let's say
four vectors per each queue it provides. Therefore, a number of MSI-X
interrupts allocated should be a multiple of four. In this case interface
pci_enable_msix_range() can not be used alone to request MSI-X interrupts
(since it can allocate any number within the range, without any notion of
the multiple of four) and the device driver should master a custom logic
to request the required number of MSI-X interrupts.
4.3.1.1 Maximum possible number of MSI-X interrupts
The typical usage of MSI-X interrupts is to allocate as many vectors as
possible, likely up to the limit returned by pci_msix_vec_count() function:
static int foo_driver_enable_msix(struct foo_adapter *adapter, int nvec)
{
return pci_enable_msix_range(adapter->pdev, adapter->msix_entries,
1, nvec);
}
Note the value of 'minvec' parameter is 1. As 'minvec' is inclusive,
the value of 0 would be meaningless and could result in error.
Some devices have a minimal limit on number of MSI-X interrupts.
In this case the function could look like this:
static int foo_driver_enable_msix(struct foo_adapter *adapter, int nvec)
{
return pci_enable_msix_range(adapter->pdev, adapter->msix_entries,
FOO_DRIVER_MINIMUM_NVEC, nvec);
}
4.3.1.2 Exact number of MSI-X interrupts
If a driver is unable or unwilling to deal with a variable number of MSI-X
interrupts it could request a particular number of interrupts by passing
that number to pci_enable_msix_range() function as both 'minvec' and 'maxvec'
parameters:
static int foo_driver_enable_msix(struct foo_adapter *adapter, int nvec)
{
return pci_enable_msix_range(adapter->pdev, adapter->msix_entries,
nvec, nvec);
}
Note, unlike pci_enable_msix_exact() function, which could be also used to
enable a particular number of MSI-X interrupts, pci_enable_msix_range()
returns either a negative errno or 'nvec' (not negative errno or 0 - as
pci_enable_msix_exact() does).
4.3.1.3 Specific requirements to the number of MSI-X interrupts
As noted above, there could be devices that can not operate with just any
number of MSI-X interrupts within a range. E.g., let's assume a device that
is only capable sending the number of MSI-X interrupts which is a power of
two. A routine that enables MSI-X mode for such device might look like this:
/*
* Assume 'minvec' and 'maxvec' are non-zero
*/
static int foo_driver_enable_msix(struct foo_adapter *adapter,
int minvec, int maxvec)
{
int rc;
minvec = roundup_pow_of_two(minvec);
maxvec = rounddown_pow_of_two(maxvec);
if (minvec > maxvec)
return -ERANGE;
retry:
rc = pci_enable_msix_range(adapter->pdev, adapter->msix_entries,
maxvec, maxvec);
/*
* -ENOSPC is the only error code allowed to be analyzed
*/
if (rc == -ENOSPC) {
if (maxvec == 1)
return -ENOSPC;
maxvec /= 2;
if (minvec > maxvec)
return -ENOSPC;
goto retry;
}
return rc;
}
Note how pci_enable_msix_range() return value is analyzed for a fallback -
any error code other than -ENOSPC indicates a fatal error and should not
be retried.
4.3.2 pci_enable_msix_exact
int pci_enable_msix_exact(struct pci_dev *dev,
struct msix_entry *entries, int nvec)
This variation on pci_enable_msix_range() call allows a device driver to
request exactly 'nvec' MSI-Xs.
If this function returns a negative number, it indicates an error and
the driver should not attempt to allocate any more MSI-X interrupts for
this device.
By contrast with pci_enable_msix_range() function, pci_enable_msix_exact()
returns zero in case of success, which indicates MSI-X interrupts have been
successfully allocated.
Another version of a routine that enables MSI-X mode for a device with
specific requirements described in chapter 4.3.1.3 might look like this:
/*
* Assume 'minvec' and 'maxvec' are non-zero
*/
static int foo_driver_enable_msix(struct foo_adapter *adapter,
int minvec, int maxvec)
{
int rc;
minvec = roundup_pow_of_two(minvec);
maxvec = rounddown_pow_of_two(maxvec);
if (minvec > maxvec)
return -ERANGE;
retry:
rc = pci_enable_msix_exact(adapter->pdev,
adapter->msix_entries, maxvec);
/*
* -ENOSPC is the only error code allowed to be analyzed
*/
if (rc == -ENOSPC) {
if (maxvec == 1)
return -ENOSPC;
maxvec /= 2;
if (minvec > maxvec)
return -ENOSPC;
goto retry;
} else if (rc < 0) {
return rc;
}
return maxvec;
}
4.3.3 pci_disable_msix
void pci_disable_msix(struct pci_dev *dev)
This function should be used to undo the effect of pci_enable_msix_range().
It frees the previously allocated MSI-X interrupts. The interrupts may
subsequently be assigned to another device, so drivers should not cache
the value of the 'vector' elements over a call to pci_disable_msix().
Before calling this function, a device driver must always call free_irq()
on any interrupt for which it previously called request_irq().
Failure to do so results in a BUG_ON(), leaving the device with
MSI-X enabled and thus leaking its vector.
4.3.3 The MSI-X Table
The MSI-X capability specifies a BAR and offset within that BAR for the
MSI-X Table. This address is mapped by the PCI subsystem, and should not
be accessed directly by the device driver. If the driver wishes to
mask or unmask an interrupt, it should call disable_irq() / enable_irq().
4.3.4 pci_msix_vec_count ret = pci_alloc_irq_vectors(pdev, nvec, nvec, 0);
if (ret < 0)
goto out_err;
int pci_msix_vec_count(struct pci_dev *dev) The most notorious example of the request type described above is enabling
the single MSI mode for a device. It could be done by passing two 1s as
'min_vecs' and 'max_vecs':
This function could be used to retrieve number of entries in the device ret = pci_alloc_irq_vectors(pdev, 1, 1, 0);
MSI-X table. if (ret < 0)
goto out_err;
If this function returns a negative number, it indicates the device is Some devices might not support using legacy line interrupts, in which case
not capable of sending MSI-Xs. the PCI_IRQ_NOLEGACY flag can be used to fail the request if the platform
can't provide MSI or MSI-X interrupts:
If this function returns a positive number, it indicates the maximum nvec = pci_alloc_irq_vectors(pdev, 1, nvec, PCI_IRQ_NOLEGACY);
number of MSI-X interrupt vectors that could be allocated. if (nvec < 0)
goto out_err;
4.4 Handling devices implementing both MSI and MSI-X capabilities 4.3 Legacy APIs
If a device implements both MSI and MSI-X capabilities, it can The following old APIs to enable and disable MSI or MSI-X interrupts should
run in either MSI mode or MSI-X mode, but not both simultaneously. not be used in new code:
This is a requirement of the PCI spec, and it is enforced by the
PCI layer. Calling pci_enable_msi_range() when MSI-X is already
enabled or pci_enable_msix_range() when MSI is already enabled
results in an error. If a device driver wishes to switch between MSI
and MSI-X at runtime, it must first quiesce the device, then switch
it back to pin-interrupt mode, before calling pci_enable_msi_range()
or pci_enable_msix_range() and resuming operation. This is not expected
to be a common operation but may be useful for debugging or testing
during development.
4.5 Considerations when using MSIs pci_enable_msi() /* deprecated */
pci_enable_msi_range() /* deprecated */
pci_enable_msi_exact() /* deprecated */
pci_disable_msi() /* deprecated */
pci_enable_msix_range() /* deprecated */
pci_enable_msix_exact() /* deprecated */
pci_disable_msix() /* deprecated */
4.5.1 Choosing between MSI-X and MSI Additionally there are APIs to provide the number of supported MSI or MSI-X
vectors: pci_msi_vec_count() and pci_msix_vec_count(). In general these
should be avoided in favor of letting pci_alloc_irq_vectors() cap the
number of vectors. If you have a legitimate special use case for the count
of vectors we might have to revisit that decision and add a
pci_nr_irq_vectors() helper that handles MSI and MSI-X transparently.
If your device supports both MSI-X and MSI capabilities, you should use 4.4 Considerations when using MSIs
the MSI-X facilities in preference to the MSI facilities. As mentioned
above, MSI-X supports any number of interrupts between 1 and 2048.
In contrast, MSI is restricted to a maximum of 32 interrupts (and
must be a power of two). In addition, the MSI interrupt vectors must
be allocated consecutively, so the system might not be able to allocate
as many vectors for MSI as it could for MSI-X. On some platforms, MSI
interrupts must all be targeted at the same set of CPUs whereas MSI-X
interrupts can all be targeted at different CPUs.
4.5.2 Spinlocks 4.4.1 Spinlocks
Most device drivers have a per-device spinlock which is taken in the Most device drivers have a per-device spinlock which is taken in the
interrupt handler. With pin-based interrupts or a single MSI, it is not interrupt handler. With pin-based interrupts or a single MSI, it is not
...@@ -505,7 +190,7 @@ acquire the spinlock. Such deadlocks can be avoided by using ...@@ -505,7 +190,7 @@ acquire the spinlock. Such deadlocks can be avoided by using
spin_lock_irqsave() or spin_lock_irq() which disable local interrupts spin_lock_irqsave() or spin_lock_irq() which disable local interrupts
and acquire the lock (see Documentation/DocBook/kernel-locking). and acquire the lock (see Documentation/DocBook/kernel-locking).
4.6 How to tell whether MSI/MSI-X is enabled on a device 4.5 How to tell whether MSI/MSI-X is enabled on a device
Using 'lspci -v' (as root) may show some devices with "MSI", "Message Using 'lspci -v' (as root) may show some devices with "MSI", "Message
Signalled Interrupts" or "MSI-X" capabilities. Each of these capabilities Signalled Interrupts" or "MSI-X" capabilities. Each of these capabilities
......
drivers/pci/msi.c
View file @ aff17164
...@@ -4,6 +4,7 @@ ...@@ -4,6 +4,7 @@
* *
* Copyright (C) 2003-2004 Intel * Copyright (C) 2003-2004 Intel
* Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com) * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
* Copyright (C) 2016 Christoph Hellwig.
*/ */
#include <linux/err.h> #include <linux/err.h>
...@@ -1121,6 +1122,94 @@ int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries, ...@@ -1121,6 +1122,94 @@ int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
} }
EXPORT_SYMBOL(pci_enable_msix_range); EXPORT_SYMBOL(pci_enable_msix_range);
/**
* pci_alloc_irq_vectors - allocate multiple IRQs for a device
* @dev: PCI device to operate on
* @min_vecs: minimum number of vectors required (must be >= 1)
* @max_vecs: maximum (desired) number of vectors
* @flags: flags or quirks for the allocation
*
* Allocate up to @max_vecs interrupt vectors for @dev, using MSI-X or MSI
* vectors if available, and fall back to a single legacy vector
* if neither is available. Return the number of vectors allocated,
* (which might be smaller than @max_vecs) if successful, or a negative
* error code on error. If less than @min_vecs interrupt vectors are
* available for @dev the function will fail with -ENOSPC.
*
* To get the Linux IRQ number used for a vector that can be passed to
* request_irq() use the pci_irq_vector() helper.
*/
int pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
unsigned int max_vecs, unsigned int flags)
{
int vecs = -ENOSPC;
if (!(flags & PCI_IRQ_NOMSIX)) {
vecs = pci_enable_msix_range(dev, NULL, min_vecs, max_vecs);
if (vecs > 0)
return vecs;
}
if (!(flags & PCI_IRQ_NOMSI)) {
vecs = pci_enable_msi_range(dev, min_vecs, max_vecs);
if (vecs > 0)
return vecs;
}
/* use legacy irq if allowed */
if (!(flags & PCI_IRQ_NOLEGACY) && min_vecs == 1)
return 1;
return vecs;
}
EXPORT_SYMBOL(pci_alloc_irq_vectors);
/**
* pci_free_irq_vectors - free previously allocated IRQs for a device
* @dev: PCI device to operate on
*
* Undoes the allocations and enabling in pci_alloc_irq_vectors().
*/
void pci_free_irq_vectors(struct pci_dev *dev)
{
pci_disable_msix(dev);
pci_disable_msi(dev);
}
EXPORT_SYMBOL(pci_free_irq_vectors);
/**
* pci_irq_vector - return Linux IRQ number of a device vector
* @dev: PCI device to operate on
* @nr: device-relative interrupt vector index (0-based).
*/
int pci_irq_vector(struct pci_dev *dev, unsigned int nr)
{
if (dev->msix_enabled) {
struct msi_desc *entry;
int i = 0;
for_each_pci_msi_entry(entry, dev) {
if (i == nr)
return entry->irq;
i++;
}
WARN_ON_ONCE(1);
return -EINVAL;
}
if (dev->msi_enabled) {
struct msi_desc *entry = first_pci_msi_entry(dev);
if (WARN_ON_ONCE(nr >= entry->nvec_used))
return -EINVAL;
} else {
if (WARN_ON_ONCE(nr > 0))
return -EINVAL;
}
return dev->irq + nr;
}
EXPORT_SYMBOL(pci_irq_vector);
struct pci_dev *msi_desc_to_pci_dev(struct msi_desc *desc) struct pci_dev *msi_desc_to_pci_dev(struct msi_desc *desc)
{ {
return to_pci_dev(desc->dev); return to_pci_dev(desc->dev);
......
include/linux/pci.h
View file @ aff17164
...@@ -1237,6 +1237,10 @@ resource_size_t pcibios_iov_resource_alignment(struct pci_dev *dev, int resno); ...@@ -1237,6 +1237,10 @@ resource_size_t pcibios_iov_resource_alignment(struct pci_dev *dev, int resno);
int pci_set_vga_state(struct pci_dev *pdev, bool decode, int pci_set_vga_state(struct pci_dev *pdev, bool decode,
unsigned int command_bits, u32 flags); unsigned int command_bits, u32 flags);
#define PCI_IRQ_NOLEGACY (1 << 0) /* don't use legacy interrupts */
#define PCI_IRQ_NOMSI (1 << 1) /* don't use MSI interrupts */
#define PCI_IRQ_NOMSIX (1 << 2) /* don't use MSI-X interrupts */
/* kmem_cache style wrapper around pci_alloc_consistent() */ /* kmem_cache style wrapper around pci_alloc_consistent() */
#include <linux/pci-dma.h> #include <linux/pci-dma.h>
...@@ -1284,6 +1288,11 @@ static inline int pci_enable_msix_exact(struct pci_dev *dev, ...@@ -1284,6 +1288,11 @@ static inline int pci_enable_msix_exact(struct pci_dev *dev,
return rc; return rc;
return 0; return 0;
} }
int pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
unsigned int max_vecs, unsigned int flags);
void pci_free_irq_vectors(struct pci_dev *dev);
int pci_irq_vector(struct pci_dev *dev, unsigned int nr);
#else #else
static inline int pci_msi_vec_count(struct pci_dev *dev) { return -ENOSYS; } static inline int pci_msi_vec_count(struct pci_dev *dev) { return -ENOSYS; }
static inline void pci_msi_shutdown(struct pci_dev *dev) { } static inline void pci_msi_shutdown(struct pci_dev *dev) { }
...@@ -1307,6 +1316,24 @@ static inline int pci_enable_msix_range(struct pci_dev *dev, ...@@ -1307,6 +1316,24 @@ static inline int pci_enable_msix_range(struct pci_dev *dev,
static inline int pci_enable_msix_exact(struct pci_dev *dev, static inline int pci_enable_msix_exact(struct pci_dev *dev,
struct msix_entry *entries, int nvec) struct msix_entry *entries, int nvec)
{ return -ENOSYS; } { return -ENOSYS; }
static inline int pci_alloc_irq_vectors(struct pci_dev *dev,
unsigned int min_vecs, unsigned int max_vecs,
unsigned int flags)
{
if (min_vecs > 1)
return -EINVAL;
return 1;
}
static inline void pci_free_irq_vectors(struct pci_dev *dev)
{
}
static inline int pci_irq_vector(struct pci_dev *dev, unsigned int nr)
{
if (WARN_ON_ONCE(nr > 0))
return -EINVAL;
return dev->irq;
}
#endif #endif
#ifdef CONFIG_PCIEPORTBUS #ifdef CONFIG_PCIEPORTBUS
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7