Commit 77e3ae29 authored by Roland Dreier's avatar Roland Dreier Committed by Linus Torvalds

[PATCH] MSI: MSI/MSI-X API updates

Second half of MSI rewrite: fix the API and update documentation.  Split
enabling MSI and MSI-X to separate pci_enable_msi()/pci_disable_msi() and
pci_enable_msix()/pci_disable_msix() functions.  free_irq() no longer has
the side effect of freeing interrupt vectors (so a device driver can do
multiple request_irq()/free_irq() cycles on the same MSI/MSI_X vector).

From: Tom L. Nguyen <tom.l.nguyen@intel.com>
Signed-off-by: default avatarRoland Dreier <roland@topspin.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 85d559af
......@@ -3,13 +3,14 @@
10/03/2003
Revised Feb 12, 2004 by Martine Silbermann
email: Martine.Silbermann@hp.com
Revised Jun 25, 2004 by Tom L Nguyen
1. About this guide
This guide describes the basics of Message Signaled Interrupts(MSI), the
advantages of using MSI over traditional interrupt mechanisms, and how
to enable your driver to use MSI or MSI-X. Also included is a Frequently
Asked Questions.
This guide describes the basics of Message Signaled Interrupts (MSI),
the advantages of using MSI over traditional interrupt mechanisms,
and how to enable your driver to use MSI or MSI-X. Also included is
a Frequently Asked Questions.
2. Copyright 2003 Intel Corporation
......@@ -35,7 +36,7 @@ An MSI capable device function indicates MSI support by implementing
the MSI/MSI-X capability structure in its PCI capability list. The
device function may implement both the MSI capability structure and
the MSI-X capability structure; however, the bus driver should not
enable both, but instead enable only the MSI-X capability structure.
enable both.
The MSI capability structure contains Message Control register,
Message Address register and Message Data register. These registers
......@@ -86,7 +87,7 @@ support. As a result, the PCI Express technology requires MSI
support for better interrupt performance.
Using MSI enables the device functions to support two or more
vectors, which can be configure to target different CPU's to
vectors, which can be configured to target different CPU's to
increase scalability.
5. Configuring a driver to use MSI/MSI-X
......@@ -95,26 +96,53 @@ By default, the kernel will not enable MSI/MSI-X on all devices that
support this capability. The CONFIG_PCI_USE_VECTOR kernel option
must be selected to enable MSI/MSI-X support.
5.1 Including MSI support into the kernel
5.1 Including MSI/MSI-X support into the kernel
To allow MSI-Capable device drivers to selectively enable MSI (using
pci_enable_msi as described below), the VECTOR based scheme needs to
be enabled by setting CONFIG_PCI_USE_VECTOR.
To allow MSI/MSI-X capable device drivers to selectively enable
MSI/MSI-X (using pci_enable_msi()/pci_enable_msix() as described
below), the VECTOR based scheme needs to be enabled by setting
CONFIG_PCI_USE_VECTOR during kernel config.
Since the target of the inbound message is the local APIC, providing
CONFIG_PCI_USE_VECTOR is dependent on whether CONFIG_X86_LOCAL_APIC
is enabled or not.
CONFIG_X86_LOCAL_APIC must be enabled as well as CONFIG_PCI_USE_VECTOR.
int pci_enable_msi(struct pci_dev *)
5.2 Configuring for MSI support
Due to the non-contiguous fashion in vector assignment of the
existing Linux kernel, this version does not support multiple
messages regardless of a device function is capable of supporting
more than one vector. To enable MSI on a device function's MSI
capability structure requires a device driver to call the function
pci_enable_msi() explicitly.
5.2.1 API pci_enable_msi
int pci_enable_msi(struct pci_dev *dev)
With this new API, any existing device driver, which like to have
MSI enabled on its device function, must call this explicitly. A
successful call will initialize the MSI/MSI-X capability structure
with ONE vector, regardless of whether the device function is
MSI enabled on its device function, must call this API to enable MSI
A successful call will initialize the MSI capability structure
with ONE vector, regardless of whether a device function is
capable of supporting multiple messages. This vector replaces the
pre-assigned dev->irq with a new MSI vector. To avoid the conflict
of new assigned vector with existing pre-assigned vector requires
the device driver to call this API before calling request_irq(...).
a device driver to call this API before calling request_irq().
5.2.2 API pci_disable_msi
void pci_disable_msi(struct pci_dev *dev)
This API should always be used to undo the effect of pci_enable_msi()
when a device driver is unloading. This API restores dev->irq with
the pre-assigned IOAPIC vector and switches a device's interrupt
mode to PCI pin-irq assertion/INTx emulation mode.
Note that a device driver should always call free_irq() on MSI vector
it has done request_irq() on before calling this API. Failure to do
so results a BUG_ON() and a device will be left with MSI enabled and
leaks its vector.
5.2.3 MSI mode vs. legacy mode diagram
The below diagram shows the events, which switches the interrupt
mode on the MSI-capable device function between MSI mode and
......@@ -124,105 +152,258 @@ PIN-IRQ assertion mode.
| | <=============== | |
| MSI MODE | | PIN-IRQ ASSERTION MODE |
| | ===============> | |
------------ free_irq ------------------------
------------ pci_disable_msi ------------------------
5.2 Configuring for MSI support
Due to the non-contiguous fashion in vector assignment of the
existing Linux kernel, this version does not support multiple
messages regardless of the device function is capable of supporting
more than one vector. The bus driver initializes only entry 0 of
this capability if pci_enable_msi(...) is called successfully by
the device driver.
Figure 1.0 MSI Mode vs. Legacy Mode
In Figure 1.0, a device operates by default in legacy mode. Legacy
in this context means PCI pin-irq assertion or PCI-Express INTx
emulation. A successful MSI request (using pci_enable_msi()) switches
a device's interrupt mode to MSI mode. A pre-assigned IOAPIC vector
stored in dev->irq will be saved by the PCI subsystem and a new
assigned MSI vector will replace dev->irq.
To return back to its default mode, a device driver should always call
pci_disable_msi() to undo the effect of pci_enable_msi(). Note that a
device driver should always call free_irq() on MSI vector it has done
request_irq() on before calling pci_disable_msi(). Failure to do so
results a BUG_ON() and a device will be left with MSI enabled and
leaks its vector. Otherwise, the PCI subsystem restores a device's
dev->irq with a pre-assigned IOAPIC vector and marks released
MSI vector as unused.
Once being marked as unused, there is no guarantee that the PCI
subsystem will reserve this MSI vector for a device. Depending on
the availability of current PCI vector resources and the number of
MSI/MSI-X requests from other drivers, this MSI may be re-assigned.
For the case where the PCI subsystem re-assigned this MSI vector
another driver, a request to switching back to MSI mode may result
in being assigned a different MSI vector or a failure if no more
vectors are available.
5.3 Configuring for MSI-X support
Both the MSI capability structure and the MSI-X capability structure
share the same above semantics; however, due to the ability of the
system software to configure each vector of the MSI-X capability
structure with an independent message address and message data, the
non-contiguous fashion in vector assignment of the existing Linux
kernel has no impact on supporting multiple messages on an MSI-X
capable device functions. By default, as mentioned above, ONE vector
should be always allocated to the MSI-X capability structure at
entry 0. The bus driver does not initialize other entries of the
MSI-X table.
Note that the PCI subsystem should have full control of a MSI-X
table that resides in Memory Space. The software device driver
should not access this table.
To request for additional vectors, the device software driver should
call function msi_alloc_vectors(). It is recommended that the
software driver should call this function once during the
Due to the ability of the system software to configure each vector of
the MSI-X capability structure with an independent message address
and message data, the non-contiguous fashion in vector assignment of
the existing Linux kernel has no impact on supporting multiple
messages on an MSI-X capable device functions. To enable MSI-X on
a device function's MSI-X capability structure requires its device
driver to call the function pci_enable_msix() explicitly.
The function pci_enable_msix(), once invoked, enables either
all or nothing, depending on the current availability of PCI vector
resources. If the PCI vector resources are available for the number
of vectors requested by a device driver, this function will configure
the MSI-X table of the MSI-X capability structure of a device with
requested messages. To emphasize this reason, for example, a device
may be capable for supporting the maximum of 32 vectors while its
software driver usually may request 4 vectors. It is recommended
that the device driver should call this function once during the
initialization phase of the device driver.
The function msi_alloc_vectors(), once invoked, enables either
all or nothing, depending on the current availability of vector
resources. If no vector resources are available, the device function
still works with ONE vector. If the vector resources are available
for the number of vectors requested by the driver, this function
will reconfigure the MSI-X capability structure of the device with
additional messages, starting from entry 1. To emphasize this
reason, for example, the device may be capable for supporting the
maximum of 32 vectors while its software driver usually may request
4 vectors.
For each vector, after this successful call, the device driver is
responsible to call other functions like request_irq(), enable_irq(),
etc. to enable this vector with its corresponding interrupt service
handler. It is the device driver's choice to have all vectors shared
the same interrupt service handler or each vector with a unique
interrupt service handler.
In addition to the function msi_alloc_vectors(), another function
msi_free_vectors() is provided to allow the software driver to
release a number of vectors back to the vector resources. Once
invoked, the PCI subsystem disables (masks) each vector released.
These vectors are no longer valid for the hardware device and its
software driver to use. Like free_irq, it recommends that the
device driver should also call msi_free_vectors to release all
additional vectors previously requested.
int msi_alloc_vectors(struct pci_dev *dev, int *vector, int nvec)
This API enables the software driver to request the PCI subsystem
for additional messages. Depending on the number of vectors
available, the PCI subsystem enables either all or nothing.
Unlike the function pci_enable_msi(), the function pci_enable_msix()
does not replace the pre-assigned IOAPIC dev->irq with a new MSI
vector because the PCI subsystem writes the 1:1 vector-to-entry mapping
into the field vector of each element contained in a second argument.
Note that the pre-assigned IO-APIC dev->irq is valid only if the device
operates in PIN-IRQ assertion mode. In MSI-X mode, any attempt of
using dev->irq by the device driver to request for interrupt service
may result unpredictabe behavior.
For each MSI-X vector granted, a device driver is responsible to call
other functions like request_irq(), enable_irq(), etc. to enable
this vector with its corresponding interrupt service handler. It is
a device driver's choice to assign all vectors with the same
interrupt service handler or each vector with a unique interrupt
service handler.
5.3.1 Handling MMIO address space of MSI-X Table
The PCI 3.0 specification has implementation notes that MMIO address
space for a device's MSI-X structure should be isolated so that the
software system can set different page for controlling accesses to
the MSI-X structure. The implementation of MSI patch requires the PCI
subsystem, not a device driver, to maintain full control of the MSI-X
table/MSI-X PBA and MMIO address space of the MSI-X table/MSI-X PBA.
A device driver is prohibited from requesting the MMIO address space
of the MSI-X table/MSI-X PBA. Otherwise, the PCI subsystem will fail
enabling MSI-X on its hardware device when it calls the function
pci_enable_msix().
5.3.2 Handling MSI-X allocation
Determining the number of MSI-X vectors allocated to a function is
dependent on the number of MSI capable devices and MSI-X capable
devices populated in the system. The policy of allocating MSI-X
vectors to a function is defined as the following:
#of MSI-X vectors allocated to a function = (x - y)/z where
x = The number of available PCI vector resources by the time
the device driver calls pci_enable_msix(). The PCI vector
resources is the sum of the number of unassigned vectors
(new) and the number of released vectors when any MSI/MSI-X
device driver switches its hardware device back to a legacy
mode or is hot-removed. The number of unassigned vectors
may exclude some vectors reserved, as defined in parameter
NR_HP_RESERVED_VECTORS, for the case where the system is
capable of supporting hot-add/hot-remove operations. Users
may change the value defined in NR_HR_RESERVED_VECTORS to
meet their specific needs.
y = The number of MSI capable devices populated in the system.
This policy ensures that each MSI capable device has its
vector reserved to avoid the case where some MSI-X capable
drivers may attempt to claim all available vector resources.
z = The number of MSI-X capable devices pupulated in the system.
This policy ensures that maximum (x - y) is distributed
evenly among MSI-X capable devices.
Note that the PCI subsystem scans y and z during a bus enumeration.
When the PCI subsystem completes configuring MSI/MSI-X capability
structure of a device as requested by its device driver, y/z is
decremented accordingly.
5.3.3 Handling MSI-X shortages
For the case where fewer MSI-X vectors are allocated to a function
than requested, the function pci_enable_msix() will return the
maximum number of MSI-X vectors available to the caller. A device
driver may re-send its request with fewer or equal vectors indicated
in a return. For example, if a device driver requests 5 vectors, but
the number of available vectors is 3 vectors, a value of 3 will be a
return as a result of pci_enable_msix() call. A function could be
designed for its driver to use only 3 MSI-X table entries as
different combinations as ABC--, A-B-C, A--CB, etc. Note that this
patch does not support multiple entries with the same vector. Such
attempt by a device driver to use 5 MSI-X table entries with 3 vectors
as ABBCC, AABCC, BCCBA, etc will result as a failure by the function
pci_enable_msix(). Below are the reasons why supporting multiple
entries with the same vector is an undesirable solution.
- The PCI subsystem can not determine which entry, which
generated the message, to mask/unmask MSI while handling
software driver ISR. Attempting to walk through all MSI-X
table entries (2048 max) to mask/unmask any match vector
is an undesirable solution.
- Walk through all MSI-X table entries (2048 max) to handle
SMP affinity of any match vector is an undesirable solution.
5.3.4 API pci_enable_msix
int pci_enable_msix(struct pci_dev *dev, u32 *entries, int nvec)
This API enables a device driver to request the PCI subsystem
for enabling MSI-X messages on its hardware device. Depending on
the availability of PCI vectors resources, the PCI subsystem enables
either all or nothing.
Argument dev points to the device (pci_dev) structure.
Argument vector is a pointer of integer type. The number of
elements is indicated in argument nvec.
Argument entries is a pointer of unsigned integer type. The number of
elements is indicated in argument nvec. The content of each element
will be mapped to the following struct defined in /driver/pci/msi.h.
struct msix_entry {
u16 vector; /* kernel uses to write alloc vector */
u16 entry; /* driver uses to specify entry */
};
A device driver is responsible for initializing the field entry of
each element with unique entry supported by MSI-X table. Otherwise,
-EINVAL will be returned as a result. A successful return of zero
indicates the PCI subsystem completes initializing each of requested
entries of the MSI-X table with message address and message data.
Last but not least, the PCI subsystem will write the 1:1
vector-to-entry mapping into the field vector of each element. A
device driver is responsible of keeping track of allocated MSI-X
vectors in its internal data structure.
Argument nvec is an integer indicating the number of messages
requested.
A return of zero indicates that the number of allocated vector is
successfully allocated. Otherwise, indicate resources not
available.
int msi_free_vectors(struct pci_dev* dev, int *vector, int nvec)
A return of zero indicates that the number of MSI-X vectors is
successfully allocated. A return of greater than zero indicates
MSI-X vector shortage. Or a return of less than zero indicates
a failure. This failure may be a result of duplicate entries
specified in second argument, or a result of no available vector,
or a result of failing to initialize MSI-X table entries.
This API enables the software driver to inform the PCI subsystem
that it is willing to release a number of vectors back to the
MSI resource pool. Once invoked, the PCI subsystem disables each
MSI-X entry associated with each vector stored in the argument 2.
These vectors are no longer valid for the hardware device and
its software driver to use.
5.3.5 API pci_disable_msix
Argument dev points to the device (pci_dev) structure.
Argument vector is a pointer of integer type. The number of
elements is indicated in argument nvec.
Argument nvec is an integer indicating the number of messages
released.
A return of zero indicates that the number of allocated vectors
is successfully released. Otherwise, indicates a failure.
void pci_disable_msix(struct pci_dev *dev)
This API should always be used to undo the effect of pci_enable_msix()
when a device driver is unloading. Note that a device driver should
always call free_irq() on all MSI-X vectors it has done request_irq()
on before calling this API. Failure to do so results a BUG_ON() and
a device will be left with MSI-X enabled and leaks its vectors.
5.4 Hardware requirements for MSI support
MSI support requires support from both system hardware and
5.3.6 MSI-X mode vs. legacy mode diagram
The below diagram shows the events, which switches the interrupt
mode on the MSI-X capable device function between MSI-X mode and
PIN-IRQ assertion mode (legacy).
------------ pci_enable_msix(,,n) ------------------------
| | <=============== | |
| MSI-X MODE | | PIN-IRQ ASSERTION MODE |
| | ===============> | |
------------ pci_disable_msix ------------------------
Figure 2.0 MSI-X Mode vs. Legacy Mode
In Figure 2.0, a device operates by default in legacy mode. A
successful MSI-X request (using pci_enable_msix()) switches a
device's interrupt mode to MSI-X mode. A pre-assigned IOAPIC vector
stored in dev->irq will be saved by the PCI subsystem; however,
unlike MSI mode, the PCI subsystem will not replace dev->irq with
assigned MSI-X vector because the PCI subsystem already writes the 1:1
vector-to-entry mapping into the field vector of each element
specified in second argument.
To return back to its default mode, a device driver should always call
pci_disable_msix() to undo the effect of pci_enable_msix(). Note that
a device driver should always call free_irq() on all MSI-X vectors it
has done request_irq() on before calling pci_disable_msix(). Failure
to do so results a BUG_ON() and a device will be left with MSI-X
enabled and leaks its vectors. Otherwise, the PCI subsystem switches a
device function's interrupt mode from MSI-X mode to legacy mode and
marks all allocated MSI-X vectors as unused.
Once being marked as unused, there is no guarantee that the PCI
subsystem will reserve these MSI-X vectors for a device. Depending on
the availability of current PCI vector resources and the number of
MSI/MSI-X requests from other drivers, these MSI-X vectors may be
re-assigned.
For the case where the PCI subsystem re-assigned these MSI-X vectors
to other driver, a request to switching back to MSI-X mode may result
being assigned with another set of MSI-X vectors or a failure if no
more vectors are available.
5.4 Handling function implementng both MSI and MSI-X capabilities
For the case where a function implements both MSI and MSI-X
capabilities, the PCI subsystem enables a device to run either in MSI
mode or MSI-X mode but not both. A device driver determines whether it
wants MSI or MSI-X enabled on its hardware device. Once a device
driver requests for MSI, for example, it is prohibited to request for
MSI-X; in other words, a device driver is not permitted to ping-pong
between MSI mod MSI-X mode during a run-time.
5.5 Hardware requirements for MSI/MSI-X support
MSI/MSI-X support requires support from both system hardware and
individual hardware device functions.
5.4.1 System hardware support
5.5.1 System hardware support
Since the target of MSI address is the local APIC CPU, enabling
MSI support in Linux kernel is dependent on whether existing
MSI/MSI-X support in Linux kernel is dependent on whether existing
system hardware supports local APIC. Users should verify their
system whether it runs when CONFIG_X86_LOCAL_APIC=y.
......@@ -231,14 +412,14 @@ however, in UP environment, users must manually set
CONFIG_X86_LOCAL_APIC. Once CONFIG_X86_LOCAL_APIC=y, setting
CONFIG_PCI_USE_VECTOR enables the VECTOR based scheme and
the option for MSI-capable device drivers to selectively enable
MSI (using pci_enable_msi as described below).
MSI/MSI-X.
Note that CONFIG_X86_IO_APIC setting is irrelevant because MSI
vector is allocated new during runtime and MSI support does not
depend on BIOS support. This key independency enables MSI support
on future IOxAPIC free platform.
Note that CONFIG_X86_IO_APIC setting is irrelevant because MSI/MSI-X
vector is allocated new during runtime and MSI/MSI-X support does not
depend on BIOS support. This key independency enables MSI/MSI-X
support on future IOxAPIC free platform.
5.4.2 Device hardware support
5.5.2 Device hardware support
The hardware device function supports MSI by indicating the
MSI/MSI-X capability structure on its PCI capability list. By
default, this capability structure will not be initialized by
......@@ -249,17 +430,19 @@ which may result in system hang. The software driver of specific
MSI-capable hardware is responsible for whether calling
pci_enable_msi or not. A return of zero indicates the kernel
successfully initializes the MSI/MSI-X capability structure of the
device funtion. The device function is now running on MSI mode.
device funtion. The device function is now running on MSI/MSI-X mode.
5.5 How to tell whether MSI is enabled on device function
5.6 How to tell whether MSI/MSI-X is enabled on device function
At the driver level, a return of zero from pci_enable_msi(...)
indicates to the device driver that its device function is
initialized successfully and ready to run in MSI mode.
At the driver level, a return of zero from the function call of
pci_enable_msi()/pci_enable_msix() indicates to a device driver that
its device function is initialized successfully and ready to run in
MSI/MSI-X mode.
At the user level, users can use command 'cat /proc/interrupts'
to display the vector allocated for the device and its interrupt
mode, as shown below.
to display the vector allocated for a device and its interrupt
MSI/MSI-X mode ("PCI MSI"/"PCI MSIX"). Below shows below MSI mode is
enabled on a SCSI Adaptec 39320D Ultra320.
CPU0 CPU1
0: 324639 0 IO-APIC-edge timer
......
......@@ -154,13 +154,25 @@ static void unmask_MSI_irq(unsigned int vector)
static unsigned int startup_msi_irq_wo_maskbit(unsigned int vector)
{
struct msi_desc *entry;
unsigned long flags;
spin_lock_irqsave(&msi_lock, flags);
entry = msi_desc[vector];
if (!entry || !entry->dev) {
spin_unlock_irqrestore(&msi_lock, flags);
return 0;
}
entry->msi_attrib.state = 1; /* Mark it active */
spin_unlock_irqrestore(&msi_lock, flags);
return 0; /* never anything pending */
}
static void pci_disable_msi(unsigned int vector);
static void release_msi(unsigned int vector);
static void shutdown_msi_irq(unsigned int vector)
{
pci_disable_msi(vector);
release_msi(vector);
}
#define shutdown_msi_irq_wo_maskbit shutdown_msi_irq
......@@ -175,6 +187,18 @@ static void end_msi_irq_wo_maskbit(unsigned int vector)
static unsigned int startup_msi_irq_w_maskbit(unsigned int vector)
{
struct msi_desc *entry;
unsigned long flags;
spin_lock_irqsave(&msi_lock, flags);
entry = msi_desc[vector];
if (!entry || !entry->dev) {
spin_unlock_irqrestore(&msi_lock, flags);
return 0;
}
entry->msi_attrib.state = 1; /* Mark it active */
spin_unlock_irqrestore(&msi_lock, flags);
unmask_MSI_irq(vector);
return 0; /* never anything pending */
}
......@@ -196,7 +220,7 @@ static void end_msi_irq_w_maskbit(unsigned int vector)
* which implement the MSI-X Capability Structure.
*/
static struct hw_interrupt_type msix_irq_type = {
.typename = "PCI MSI-X",
.typename = "PCI-MSI-X",
.startup = startup_msi_irq_w_maskbit,
.shutdown = shutdown_msi_irq_w_maskbit,
.enable = enable_msi_irq_w_maskbit,
......@@ -212,7 +236,7 @@ static struct hw_interrupt_type msix_irq_type = {
* Mask-and-Pending Bits.
*/
static struct hw_interrupt_type msi_irq_w_maskbit_type = {
.typename = "PCI MSI",
.typename = "PCI-MSI",
.startup = startup_msi_irq_w_maskbit,
.shutdown = shutdown_msi_irq_w_maskbit,
.enable = enable_msi_irq_w_maskbit,
......@@ -228,7 +252,7 @@ static struct hw_interrupt_type msi_irq_w_maskbit_type = {
* Mask-and-Pending Bits.
*/
static struct hw_interrupt_type msi_irq_wo_maskbit_type = {
.typename = "PCI MSI",
.typename = "PCI-MSI",
.startup = startup_msi_irq_wo_maskbit,
.shutdown = shutdown_msi_irq_wo_maskbit,
.enable = enable_msi_irq_wo_maskbit,
......@@ -261,6 +285,7 @@ static void msi_address_init(struct msg_address *msi_address)
msi_address->lo_address.value |= (MSI_TARGET_CPU << MSI_TARGET_CPU_SHIFT);
}
static int msi_free_vector(struct pci_dev* dev, int vector, int reassign);
static int assign_msi_vector(void)
{
static int new_vector_avail = 1;
......@@ -274,6 +299,8 @@ static int assign_msi_vector(void)
spin_lock_irqsave(&msi_lock, flags);
if (!new_vector_avail) {
int free_vector = 0;
/*
* vector_irq[] = -1 indicates that this specific vector is:
* - assigned for MSI (since MSI have no associated IRQ) or
......@@ -290,14 +317,35 @@ static int assign_msi_vector(void)
for (vector = FIRST_DEVICE_VECTOR; vector < NR_IRQS; vector++) {
if (vector_irq[vector] != 0)
continue;
vector_irq[vector] = -1;
nr_released_vectors--;
spin_unlock_irqrestore(&msi_lock, flags);
return vector;
free_vector = vector;
if (!msi_desc[vector])
break;
else
continue;
}
if (!free_vector) {
spin_unlock_irqrestore(&msi_lock, flags);
return -EBUSY;
}
vector_irq[free_vector] = -1;
nr_released_vectors--;
spin_unlock_irqrestore(&msi_lock, flags);
if (msi_desc[free_vector] != NULL) {
struct pci_dev *dev;
int tail;
/* free all linked vectors before re-assign */
do {
spin_lock_irqsave(&msi_lock, flags);
dev = msi_desc[free_vector]->dev;
tail = msi_desc[free_vector]->link.tail;
spin_unlock_irqrestore(&msi_lock, flags);
msi_free_vector(dev, tail, 1);
} while (free_vector != tail);
}
return free_vector;
}
vector = assign_irq_vector(AUTO_ASSIGN);
last_alloc_vector = vector;
if (vector == LAST_DEVICE_VECTOR)
......@@ -329,6 +377,15 @@ static int msi_init(void)
printk(KERN_INFO "WARNING: MSI INIT FAILURE\n");
return status;
}
last_alloc_vector = assign_irq_vector(AUTO_ASSIGN);
if (last_alloc_vector < 0) {
pci_msi_enable = 0;
printk(KERN_INFO "WARNING: ALL VECTORS ARE BUSY\n");
status = -EBUSY;
return status;
}
vector_irq[last_alloc_vector] = 0;
nr_released_vectors++;
printk(KERN_INFO "MSI INIT SUCCESS\n");
return status;
......@@ -421,7 +478,7 @@ static void disable_msi_mode(struct pci_dev *dev, int pos, int type)
}
}
static int msi_lookup_vector(struct pci_dev *dev)
static int msi_lookup_vector(struct pci_dev *dev, int type)
{
int vector;
unsigned long flags;
......@@ -429,11 +486,11 @@ static int msi_lookup_vector(struct pci_dev *dev)
spin_lock_irqsave(&msi_lock, flags);
for (vector = FIRST_DEVICE_VECTOR; vector < NR_IRQS; vector++) {
if (!msi_desc[vector] || msi_desc[vector]->dev != dev ||
msi_desc[vector]->msi_attrib.entry_nr ||
msi_desc[vector]->msi_attrib.type != type ||
msi_desc[vector]->msi_attrib.default_vector != dev->irq)
continue; /* not entry 0, skip */
continue;
spin_unlock_irqrestore(&msi_lock, flags);
/* This pre-assigned entry-0 MSI vector for this device
/* This pre-assigned MSI vector for this device
already exits. Override dev->irq with this vector */
dev->irq = vector;
return 0;
......@@ -448,10 +505,9 @@ void pci_scan_msi_device(struct pci_dev *dev)
if (!dev)
return;
if (pci_find_capability(dev, PCI_CAP_ID_MSIX) > 0) {
nr_reserved_vectors++;
if (pci_find_capability(dev, PCI_CAP_ID_MSIX) > 0)
nr_msix_devices++;
} else if (pci_find_capability(dev, PCI_CAP_ID_MSI) > 0)
else if (pci_find_capability(dev, PCI_CAP_ID_MSI) > 0)
nr_reserved_vectors++;
}
......@@ -473,18 +529,7 @@ static int msi_capability_init(struct pci_dev *dev)
u16 control;
pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
if (!pos)
return -EINVAL;
pci_read_config_word(dev, msi_control_reg(pos), &control);
if (control & PCI_MSI_FLAGS_ENABLE)
return 0;
if (!msi_lookup_vector(dev)) {
/* Lookup Sucess */
enable_msi_mode(dev, pos, PCI_CAP_ID_MSI);
return 0;
}
/* MSI Entry Initialization */
if (!(entry = alloc_msi_entry()))
return -ENOMEM;
......@@ -493,11 +538,14 @@ static int msi_capability_init(struct pci_dev *dev)
kmem_cache_free(msi_cachep, entry);
return -EBUSY;
}
entry->link.head = vector;
entry->link.tail = vector;
entry->msi_attrib.type = PCI_CAP_ID_MSI;
entry->msi_attrib.state = 0; /* Mark it not active */
entry->msi_attrib.entry_nr = 0;
entry->msi_attrib.maskbit = is_mask_bit_support(control);
entry->msi_attrib.default_vector = dev->irq;
dev->irq = vector; /* save default pre-assigned ioapic vector */
entry->msi_attrib.default_vector = dev->irq; /* Save IOAPIC IRQ */
dev->irq = vector;
entry->dev = dev;
if (is_mask_bit_support(control)) {
entry->mask_base = msi_mask_bits_reg(pos,
......@@ -545,237 +593,219 @@ static int msi_capability_init(struct pci_dev *dev)
* @dev: pointer to the pci_dev data structure of MSI-X device function
*
* Setup the MSI-X capability structure of device funtion with a
* single MSI-X vector. A return of zero indicates the successful setup
* of an entry zero with the new MSI-X vector or non-zero for otherwise.
* To request for additional MSI-X vectors, the device drivers are
* required to utilize the following supported APIs:
* 1) msi_alloc_vectors(...) for requesting one or more MSI-X vectors
* 2) msi_free_vectors(...) for releasing one or more MSI-X vectors
* back to PCI subsystem before calling free_irq(...)
* single MSI-X vector. A return of zero indicates the successful setup of
* requested MSI-X entries with allocated vectors or non-zero for otherwise.
**/
static int msix_capability_init(struct pci_dev *dev)
static int msix_capability_init(struct pci_dev *dev,
struct msix_entry *entries, int nvec)
{
struct msi_desc *entry;
struct msi_desc *head = NULL, *tail = NULL, *entry = NULL;
struct msg_address address;
struct msg_data data;
int vector = 0, pos, dev_msi_cap, i;
int vector, pos, i, j, nr_entries, temp = 0;
u32 phys_addr, table_offset;
u16 control;
u8 bir;
void *base;
pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
if (!pos)
return -EINVAL;
/* Request & Map MSI-X table region */
pci_read_config_word(dev, msi_control_reg(pos), &control);
if (control & PCI_MSIX_FLAGS_ENABLE)
return 0;
if (!msi_lookup_vector(dev)) {
/* Lookup Sucess */
enable_msi_mode(dev, pos, PCI_CAP_ID_MSIX);
return 0;
}
dev_msi_cap = multi_msix_capable(control);
nr_entries = multi_msix_capable(control);
pci_read_config_dword(dev, msix_table_offset_reg(pos),
&table_offset);
bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);
phys_addr = pci_resource_start (dev, bir);
phys_addr += (u32)(table_offset & ~PCI_MSIX_FLAGS_BIRMASK);
if (!request_mem_region(phys_addr,
dev_msi_cap * PCI_MSIX_ENTRY_SIZE,
"MSI-X iomap Failure"))
nr_entries * PCI_MSIX_ENTRY_SIZE,
"MSI-X vector table"))
return -ENOMEM;
base = ioremap_nocache(phys_addr, dev_msi_cap * PCI_MSIX_ENTRY_SIZE);
if (base == NULL)
goto free_region;
/* MSI Entry Initialization */
base = ioremap_nocache(phys_addr, nr_entries * PCI_MSIX_ENTRY_SIZE);
if (base == NULL) {
release_mem_region(phys_addr, nr_entries * PCI_MSIX_ENTRY_SIZE);
return -ENOMEM;
}
/* MSI-X Table Initialization */
for (i = 0; i < nvec; i++) {
entry = alloc_msi_entry();
if (!entry)
goto free_iomap;
break;
if ((vector = get_msi_vector(dev)) < 0)
goto free_entry;
break;
j = entries[i].entry;
entries[i].vector = vector;
entry->msi_attrib.type = PCI_CAP_ID_MSIX;
entry->msi_attrib.entry_nr = 0;
entry->msi_attrib.state = 0; /* Mark it not active */
entry->msi_attrib.entry_nr = j;
entry->msi_attrib.maskbit = 1;
entry->msi_attrib.default_vector = dev->irq;
dev->irq = vector; /* save default pre-assigned ioapic vector */
entry->dev = dev;
entry->mask_base = (unsigned long)base;
/* Replace with MSI handler */
if (!head) {
entry->link.head = vector;
entry->link.tail = vector;
head = entry;
} else {
entry->link.head = temp;
entry->link.tail = tail->link.tail;
tail->link.tail = vector;
head->link.head = vector;
}
temp = vector;
tail = entry;
/* Replace with MSI-X handler */
irq_handler_init(PCI_CAP_ID_MSIX, vector, 1);
/* Configure MSI-X capability structure */
msi_address_init(&address);
msi_data_init(&data, vector);
entry->msi_attrib.current_cpu = ((address.lo_address.u.dest_id >>
entry->msi_attrib.current_cpu =
((address.lo_address.u.dest_id >>
MSI_TARGET_CPU_SHIFT) & MSI_TARGET_CPU_MASK);
writel(address.lo_address.value, base + PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET);
writel(address.hi_address, base + PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET);
writel(*(u32*)&data, base + PCI_MSIX_ENTRY_DATA_OFFSET);
/* Initialize all entries from 1 up to 0 */
for (i = 1; i < dev_msi_cap; i++) {
writel(0, base + i * PCI_MSIX_ENTRY_SIZE +
writel(address.lo_address.value,
base + j * PCI_MSIX_ENTRY_SIZE +
PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET);
writel(0, base + i * PCI_MSIX_ENTRY_SIZE +
writel(address.hi_address,
base + j * PCI_MSIX_ENTRY_SIZE +
PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET);
writel(0, base + i * PCI_MSIX_ENTRY_SIZE +
writel(*(u32*)&data,
base + j * PCI_MSIX_ENTRY_SIZE +
PCI_MSIX_ENTRY_DATA_OFFSET);
}
attach_msi_entry(entry, vector);
/* Set MSI enabled bits */
}
if (i != nvec) {
i--;
for (; i >= 0; i--) {
vector = (entries + i)->vector;
msi_free_vector(dev, vector, 0);
(entries + i)->vector = 0;
}
return -EBUSY;
}
/* Set MSI-X enabled bits */
enable_msi_mode(dev, pos, PCI_CAP_ID_MSIX);
return 0;
free_entry:
kmem_cache_free(msi_cachep, entry);
free_iomap:
iounmap(base);
free_region:
release_mem_region(phys_addr, dev_msi_cap * PCI_MSIX_ENTRY_SIZE);
return ((vector < 0) ? -EBUSY : -ENOMEM);
}
/**
* pci_enable_msi - configure device's MSI(X) capability structure
* @dev: pointer to the pci_dev data structure of MSI(X) device function
* pci_enable_msi - configure device's MSI capability structure
* @dev: pointer to the pci_dev data structure of MSI device function
*
* Setup the MSI/MSI-X capability structure of device function with
* a single MSI(X) vector upon its software driver call to request for
* MSI(X) mode enabled on its hardware device function. A return of zero
* indicates the successful setup of an entry zero with the new MSI(X)
* Setup the MSI capability structure of device function with
* a single MSI vector upon its software driver call to request for
* MSI mode enabled on its hardware device function. A return of zero
* indicates the successful setup of an entry zero with the new MSI
* vector or non-zero for otherwise.
**/
int pci_enable_msi(struct pci_dev* dev)
{
int status = -EINVAL;
int pos, temp = dev->irq, status = -EINVAL;
u16 control;
if (!pci_msi_enable || !dev)
return status;
if (msi_init() < 0)
return -ENOMEM;
if ((status = msi_init()) < 0)
return status;
if (!(pos = pci_find_capability(dev, PCI_CAP_ID_MSI)))
return -EINVAL;
if ((status = msix_capability_init(dev)) == -EINVAL)
pci_read_config_word(dev, msi_control_reg(pos), &control);
if (control & PCI_MSI_FLAGS_ENABLE)
return 0; /* Already in MSI mode */
if (!msi_lookup_vector(dev, PCI_CAP_ID_MSI)) {
/* Lookup Sucess */
unsigned long flags;
spin_lock_irqsave(&msi_lock, flags);
if (!vector_irq[dev->irq]) {
msi_desc[dev->irq]->msi_attrib.state = 0;
vector_irq[dev->irq] = -1;
nr_released_vectors--;
spin_unlock_irqrestore(&msi_lock, flags);
enable_msi_mode(dev, pos, PCI_CAP_ID_MSI);
return 0;
}
spin_unlock_irqrestore(&msi_lock, flags);
dev->irq = temp;
}
/* Check whether driver already requested for MSI-X vectors */
if ((pos = pci_find_capability(dev, PCI_CAP_ID_MSIX)) > 0 &&
!msi_lookup_vector(dev, PCI_CAP_ID_MSIX)) {
printk(KERN_INFO "Can't enable MSI. Device already had MSI-X vectors assigned\n");
dev->irq = temp;
return -EINVAL;
}
status = msi_capability_init(dev);
if (!status)
nr_reserved_vectors--;
if (!status) {
if (!pos)
nr_reserved_vectors--; /* Only MSI capable */
else if (nr_msix_devices > 0)
nr_msix_devices--; /* Both MSI and MSI-X capable,
but choose enabling MSI */
}
return status;
}
static int msi_free_vector(struct pci_dev* dev, int vector);
static void pci_disable_msi(unsigned int vector)
void pci_disable_msi(struct pci_dev* dev)
{
int head, tail, type, default_vector;
struct msi_desc *entry;
struct pci_dev *dev;
int pos, default_vector;
u16 control;
unsigned long flags;
if (!dev || !(pos = pci_find_capability(dev, PCI_CAP_ID_MSI)))
return;
pci_read_config_word(dev, msi_control_reg(pos), &control);
if (!(control & PCI_MSI_FLAGS_ENABLE))
return;
spin_lock_irqsave(&msi_lock, flags);
entry = msi_desc[vector];
if (!entry || !entry->dev) {
entry = msi_desc[dev->irq];
if (!entry || !entry->dev || entry->msi_attrib.type != PCI_CAP_ID_MSI) {
spin_unlock_irqrestore(&msi_lock, flags);
return;
}
dev = entry->dev;
type = entry->msi_attrib.type;
head = entry->link.head;
tail = entry->link.tail;
if (entry->msi_attrib.state) {
spin_unlock_irqrestore(&msi_lock, flags);
printk(KERN_DEBUG "Driver[%d:%d:%d] unloaded wo doing free_irq on vector->%d\n",
dev->bus->number, PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn),
dev->irq);
BUG_ON(entry->msi_attrib.state > 0);
} else {
vector_irq[dev->irq] = 0; /* free it */
nr_released_vectors++;
default_vector = entry->msi_attrib.default_vector;
spin_unlock_irqrestore(&msi_lock, flags);
disable_msi_mode(dev, pci_find_capability(dev, type), type);
/* Restore dev->irq to its default pin-assertion vector */
dev->irq = default_vector;
if (type == PCI_CAP_ID_MSIX && head != tail) {
/* Bad driver, which do not call msi_free_vectors before exit.
We must do a cleanup here */
while (1) {
spin_lock_irqsave(&msi_lock, flags);
entry = msi_desc[vector];
head = entry->link.head;
tail = entry->link.tail;
spin_unlock_irqrestore(&msi_lock, flags);
if (tail == head)
break;
if (msi_free_vector(dev, entry->link.tail))
break;
}
disable_msi_mode(dev, pci_find_capability(dev, PCI_CAP_ID_MSI),
PCI_CAP_ID_MSI);
}
}
static int msi_alloc_vector(struct pci_dev* dev, int head)
static void release_msi(unsigned int vector)
{
struct msi_desc *entry;
struct msg_address address;
struct msg_data data;
int i, offset, pos, dev_msi_cap, vector;
u32 low_address;
u16 control;
unsigned long base = 0L;
unsigned long flags;
spin_lock_irqsave(&msi_lock, flags);
entry = msi_desc[dev->irq];
if (!entry) {
spin_unlock_irqrestore(&msi_lock, flags);
return -EINVAL;
}
base = entry->mask_base;
entry = msi_desc[vector];
if (entry && entry->dev)
entry->msi_attrib.state = 0; /* Mark it not active */
spin_unlock_irqrestore(&msi_lock, flags);
pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
pci_read_config_word(dev, msi_control_reg(pos), &control);
dev_msi_cap = multi_msix_capable(control);
for (i = 1; i < dev_msi_cap; i++) {
if (!(low_address = readl(base + i * PCI_MSIX_ENTRY_SIZE)))
break;
}
if (i >= dev_msi_cap)
return -EINVAL;
/* MSI Entry Initialization */
if (!(entry = alloc_msi_entry()))
return -ENOMEM;
if ((vector = get_new_vector()) < 0) {
kmem_cache_free(msi_cachep, entry);
return vector;
}
entry->msi_attrib.type = PCI_CAP_ID_MSIX;
entry->msi_attrib.entry_nr = i;
entry->msi_attrib.maskbit = 1;
entry->dev = dev;
entry->link.head = head;
entry->mask_base = base;
irq_handler_init(PCI_CAP_ID_MSIX, vector, 1);
/* Configure MSI-X capability structure */
msi_address_init(&address);
msi_data_init(&data, vector);
entry->msi_attrib.current_cpu = ((address.lo_address.u.dest_id >>
MSI_TARGET_CPU_SHIFT) & MSI_TARGET_CPU_MASK);
offset = entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
writel(address.lo_address.value, base + offset +
PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET);
writel(address.hi_address, base + offset +
PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET);
writel(*(u32*)&data, base + offset + PCI_MSIX_ENTRY_DATA_OFFSET);
writel(1, base + offset + PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET);
attach_msi_entry(entry, vector);
return vector;
}
static int msi_free_vector(struct pci_dev* dev, int vector)
static int msi_free_vector(struct pci_dev* dev, int vector, int reassign)
{
struct msi_desc *entry;
int entry_nr, type;
int head, entry_nr, type;
unsigned long base = 0L;
unsigned long flags;
......@@ -787,66 +817,177 @@ static int msi_free_vector(struct pci_dev* dev, int vector)
}
type = entry->msi_attrib.type;
entry_nr = entry->msi_attrib.entry_nr;
head = entry->link.head;
base = entry->mask_base;
if (entry->link.tail != entry->link.head) {
msi_desc[entry->link.head]->link.tail = entry->link.tail;
if (entry->link.tail)
msi_desc[entry->link.tail]->link.head = entry->link.head;
}
entry->dev = NULL;
if (!reassign) {
vector_irq[vector] = 0;
nr_released_vectors++;
}
msi_desc[vector] = NULL;
spin_unlock_irqrestore(&msi_lock, flags);
kmem_cache_free(msi_cachep, entry);
if (type == PCI_CAP_ID_MSIX) {
int offset;
if (!reassign)
writel(1, base +
entry_nr * PCI_MSIX_ENTRY_SIZE +
PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET);
if (head == vector) {
/*
* Detect last MSI-X vector to be released.
* Release the MSI-X memory-mapped table.
*/
int pos, nr_entries;
u32 phys_addr, table_offset;
u16 control;
u8 bir;
pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
pci_read_config_word(dev, msi_control_reg(pos),
&control);
nr_entries = multi_msix_capable(control);
pci_read_config_dword(dev, msix_table_offset_reg(pos),
&table_offset);
bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);
phys_addr = pci_resource_start (dev, bir);
phys_addr += (u32)(table_offset &
~PCI_MSIX_FLAGS_BIRMASK);
iounmap((void*)base);
release_mem_region(phys_addr,
nr_entries * PCI_MSIX_ENTRY_SIZE);
}
}
offset = entry_nr * PCI_MSIX_ENTRY_SIZE;
writel(1, base + offset + PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET);
writel(0, base + offset + PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET);
return 0;
}
static int reroute_msix_table(int head, struct msix_entry *entries, int *nvec)
{
int vector = head, tail = 0;
int i = 0, j = 0, nr_entries = 0;
unsigned long base = 0L;
unsigned long flags;
spin_lock_irqsave(&msi_lock, flags);
while (head != tail) {
nr_entries++;
tail = msi_desc[vector]->link.tail;
if (entries[0].entry == msi_desc[vector]->msi_attrib.entry_nr)
j = vector;
vector = tail;
}
if (*nvec > nr_entries) {
spin_unlock_irqrestore(&msi_lock, flags);
*nvec = nr_entries;
return -EINVAL;
}
vector = ((j > 0) ? j : head);
for (i = 0; i < *nvec; i++) {
j = msi_desc[vector]->msi_attrib.entry_nr;
msi_desc[vector]->msi_attrib.state = 0; /* Mark it not active */
vector_irq[vector] = -1; /* Mark it busy */
nr_released_vectors--;
entries[i].vector = vector;
if (j != (entries + i)->entry) {
base = msi_desc[vector]->mask_base;
msi_desc[vector]->msi_attrib.entry_nr =
(entries + i)->entry;
writel( readl(base + j * PCI_MSIX_ENTRY_SIZE +
PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET), base +
(entries + i)->entry * PCI_MSIX_ENTRY_SIZE +
PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET);
writel( readl(base + j * PCI_MSIX_ENTRY_SIZE +
PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET), base +
(entries + i)->entry * PCI_MSIX_ENTRY_SIZE +
PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET);
writel( (readl(base + j * PCI_MSIX_ENTRY_SIZE +
PCI_MSIX_ENTRY_DATA_OFFSET) & 0xff00) | vector,
base + (entries+i)->entry*PCI_MSIX_ENTRY_SIZE +
PCI_MSIX_ENTRY_DATA_OFFSET);
}
vector = msi_desc[vector]->link.tail;
}
spin_unlock_irqrestore(&msi_lock, flags);
return 0;
}
/**
* msi_alloc_vectors - allocate additional MSI-X vectors
* pci_enable_msix - configure device's MSI-X capability structure
* @dev: pointer to the pci_dev data structure of MSI-X device function
* @vector: pointer to an array of new allocated MSI-X vectors
* @data: pointer to an array of MSI-X entries
* @nvec: number of MSI-X vectors requested for allocation by device driver
*
* Allocate additional MSI-X vectors requested by device driver. A
* return of zero indicates the successful setup of MSI-X capability
* structure with new allocated MSI-X vectors or non-zero for otherwise.
* Setup the MSI-X capability structure of device function with the number
* of requested vectors upon its software driver call to request for
* MSI-X mode enabled on its hardware device function. A return of zero
* indicates the successful configuration of MSI-X capability structure
* with new allocated MSI-X vectors. A return of < 0 indicates a failure.
* Or a return of > 0 indicates that driver request is exceeding the number
* of vectors available. Driver should use the returned value to re-send
* its request.
**/
int msi_alloc_vectors(struct pci_dev* dev, int *vector, int nvec)
int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec)
{
struct msi_desc *entry;
int i, head, pos, vec, free_vectors, alloc_vectors;
int *vectors = (int *)vector;
int status, pos, nr_entries, free_vectors;
int i, j, temp;
u16 control;
unsigned long flags;
if (!pci_msi_enable || !dev)
if (!pci_msi_enable || !dev || !entries)
return -EINVAL;
if ((status = msi_init()) < 0)
return status;
if (!(pos = pci_find_capability(dev, PCI_CAP_ID_MSIX)))
return -EINVAL;
pci_read_config_word(dev, msi_control_reg(pos), &control);
if (nvec > multi_msix_capable(control))
if (control & PCI_MSIX_FLAGS_ENABLE)
return -EINVAL; /* Already in MSI-X mode */
nr_entries = multi_msix_capable(control);
if (nvec > nr_entries)
return -EINVAL;
spin_lock_irqsave(&msi_lock, flags);
entry = msi_desc[dev->irq];
if (!entry || entry->dev != dev || /* legal call */
entry->msi_attrib.type != PCI_CAP_ID_MSIX || /* must be MSI-X */
entry->link.head != entry->link.tail) { /* already multi */
spin_unlock_irqrestore(&msi_lock, flags);
/* Check for any invalid entries */
for (i = 0; i < nvec; i++) {
if (entries[i].entry >= nr_entries)
return -EINVAL; /* invalid entry */
for (j = i + 1; j < nvec; j++) {
if (entries[i].entry == entries[j].entry)
return -EINVAL; /* duplicate entry */
}
}
temp = dev->irq;
if (!msi_lookup_vector(dev, PCI_CAP_ID_MSIX)) {
/* Lookup Sucess */
nr_entries = nvec;
/* Reroute MSI-X table */
if (reroute_msix_table(dev->irq, entries, &nr_entries)) {
/* #requested > #previous-assigned */
dev->irq = temp;
return nr_entries;
}
dev->irq = temp;
enable_msi_mode(dev, pos, PCI_CAP_ID_MSIX);
return 0;
}
/* Check whether driver already requested for MSI vector */
if (pci_find_capability(dev, PCI_CAP_ID_MSI) > 0 &&
!msi_lookup_vector(dev, PCI_CAP_ID_MSI)) {
printk(KERN_INFO "Can't enable MSI-X. Device already had MSI vector assigned\n");
dev->irq = temp;
return -EINVAL;
}
spin_lock_irqsave(&msi_lock, flags);
/*
* msi_lock is provided to ensure that enough vectors resources are
* available before granting.
......@@ -862,71 +1003,65 @@ int msi_alloc_vectors(struct pci_dev* dev, int *vector, int nvec)
free_vectors /= nr_msix_devices;
spin_unlock_irqrestore(&msi_lock, flags);
if (nvec > free_vectors)
return -EBUSY;
alloc_vectors = 0;
head = dev->irq;
for (i = 0; i < nvec; i++) {
if ((vec = msi_alloc_vector(dev, head)) < 0)
break;
*(vectors + i) = vec;
head = vec;
alloc_vectors++;
}
if (alloc_vectors != nvec) {
for (i = 0; i < alloc_vectors; i++) {
vec = *(vectors + i);
msi_free_vector(dev, vec);
}
spin_lock_irqsave(&msi_lock, flags);
msi_desc[dev->irq]->link.tail = msi_desc[dev->irq]->link.head;
spin_unlock_irqrestore(&msi_lock, flags);
if (nvec > free_vectors) {
if (free_vectors > 0)
return free_vectors;
else
return -EBUSY;
}
if (nr_msix_devices > 0)
status = msix_capability_init(dev, entries, nvec);
if (!status && nr_msix_devices > 0)
nr_msix_devices--;
return 0;
return status;
}
/**
* msi_free_vectors - reclaim MSI-X vectors to unused state
* @dev: pointer to the pci_dev data structure of MSI-X device function
* @vector: pointer to an array of released MSI-X vectors
* @nvec: number of MSI-X vectors requested for release by device driver
*
* Reclaim MSI-X vectors released by device driver to unused state,
* which may be used later on. A return of zero indicates the
* success or non-zero for otherwise. Device driver should call this
* before calling function free_irq.
**/
int msi_free_vectors(struct pci_dev* dev, int *vector, int nvec)
void pci_disable_msix(struct pci_dev* dev)
{
struct msi_desc *entry;
int i;
unsigned long flags;
int pos, temp;
u16 control;
if (!pci_msi_enable)
return -EINVAL;
if (!dev || !(pos = pci_find_capability(dev, PCI_CAP_ID_MSIX)))
return;
pci_read_config_word(dev, msi_control_reg(pos), &control);
if (!(control & PCI_MSIX_FLAGS_ENABLE))
return;
temp = dev->irq;
if (!msi_lookup_vector(dev, PCI_CAP_ID_MSIX)) {
int state, vector, head, tail = 0, warning = 0;
unsigned long flags;
vector = head = dev->irq;
spin_lock_irqsave(&msi_lock, flags);
entry = msi_desc[dev->irq];
if (!entry || entry->dev != dev ||
entry->msi_attrib.type != PCI_CAP_ID_MSIX ||
entry->link.head == entry->link.tail) { /* Nothing to free */
spin_unlock_irqrestore(&msi_lock, flags);
return -EINVAL;
while (head != tail) {
state = msi_desc[vector]->msi_attrib.state;
if (state)
warning = 1;
else {
vector_irq[vector] = 0; /* free it */
nr_released_vectors++;
}
tail = msi_desc[vector]->link.tail;
vector = tail;
}
spin_unlock_irqrestore(&msi_lock, flags);
if (warning) {
dev->irq = temp;
printk(KERN_DEBUG "Driver[%d:%d:%d] unloaded wo doing free_irq on all vectors\n",
dev->bus->number, PCI_SLOT(dev->devfn),
PCI_FUNC(dev->devfn));
BUG_ON(warning > 0);
} else {
dev->irq = temp;
disable_msi_mode(dev,
pci_find_capability(dev, PCI_CAP_ID_MSIX),
PCI_CAP_ID_MSIX);
for (i = 0; i < nvec; i++) {
if (*(vector + i) == dev->irq)
continue;/* Don't free entry 0 if mistaken by driver */
msi_free_vector(dev, *(vector + i));
}
return 0;
}
}
/**
......@@ -940,61 +1075,73 @@ int msi_free_vectors(struct pci_dev* dev, int *vector, int nvec)
**/
void msi_remove_pci_irq_vectors(struct pci_dev* dev)
{
struct msi_desc *entry;
int type, temp;
int state, pos, temp;
unsigned long flags;
if (!pci_msi_enable || !dev)
return;
if (!pci_find_capability(dev, PCI_CAP_ID_MSI)) {
if (!pci_find_capability(dev, PCI_CAP_ID_MSIX))
return;
temp = dev->irq; /* Save IOAPIC IRQ */
if ((pos = pci_find_capability(dev, PCI_CAP_ID_MSI)) > 0 &&
!msi_lookup_vector(dev, PCI_CAP_ID_MSI)) {
spin_lock_irqsave(&msi_lock, flags);
state = msi_desc[dev->irq]->msi_attrib.state;
spin_unlock_irqrestore(&msi_lock, flags);
if (state) {
printk(KERN_DEBUG "Driver[%d:%d:%d] unloaded wo doing free_irq on vector->%d\n",
dev->bus->number, PCI_SLOT(dev->devfn),
PCI_FUNC(dev->devfn), dev->irq);
BUG_ON(state > 0);
} else /* Release MSI vector assigned to this device */
msi_free_vector(dev, dev->irq, 0);
dev->irq = temp; /* Restore IOAPIC IRQ */
}
temp = dev->irq;
if (msi_lookup_vector(dev))
return;
if ((pos = pci_find_capability(dev, PCI_CAP_ID_MSIX)) > 0 &&
!msi_lookup_vector(dev, PCI_CAP_ID_MSIX)) {
int vector, head, tail = 0, warning = 0;
unsigned long base = 0L;
vector = head = dev->irq;
while (head != tail) {
spin_lock_irqsave(&msi_lock, flags);
entry = msi_desc[dev->irq];
if (!entry || entry->dev != dev) {
state = msi_desc[vector]->msi_attrib.state;
tail = msi_desc[vector]->link.tail;
base = msi_desc[vector]->mask_base;
spin_unlock_irqrestore(&msi_lock, flags);
return;
if (state)
warning = 1;
else if (vector != head) /* Release MSI-X vector */
msi_free_vector(dev, vector, 0);
vector = tail;
}
type = entry->msi_attrib.type;
spin_unlock_irqrestore(&msi_lock, flags);
msi_free_vector(dev, dev->irq);
if (type == PCI_CAP_ID_MSIX) {
int i, pos, dev_msi_cap;
msi_free_vector(dev, vector, 0);
if (warning) {
/* Force to release the MSI-X memory-mapped table */
u32 phys_addr, table_offset;
u16 control;
u8 bir;
pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
pci_read_config_word(dev, msi_control_reg(pos), &control);
dev_msi_cap = multi_msix_capable(control);
pci_read_config_dword(dev, msix_table_offset_reg(pos), &table_offset);
pci_read_config_word(dev, msi_control_reg(pos),
&control);
pci_read_config_dword(dev, msix_table_offset_reg(pos),
&table_offset);
bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);
phys_addr = pci_resource_start (dev, bir);
phys_addr += (u32)(table_offset & ~PCI_MSIX_FLAGS_BIRMASK);
for (i = FIRST_DEVICE_VECTOR; i < NR_IRQS; i++) {
spin_lock_irqsave(&msi_lock, flags);
if (!msi_desc[i] || msi_desc[i]->dev != dev) {
spin_unlock_irqrestore(&msi_lock, flags);
continue;
phys_addr += (u32)(table_offset &
~PCI_MSIX_FLAGS_BIRMASK);
iounmap((void*)base);
release_mem_region(phys_addr, PCI_MSIX_ENTRY_SIZE *
multi_msix_capable(control));
printk(KERN_DEBUG "Driver[%d:%d:%d] unloaded wo doing free_irq on all vectors\n",
dev->bus->number, PCI_SLOT(dev->devfn),
PCI_FUNC(dev->devfn));
BUG_ON(warning > 0);
}
spin_unlock_irqrestore(&msi_lock, flags);
msi_free_vector(dev, i);
}
writel(1, entry->mask_base + PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET);
iounmap((void*)entry->mask_base);
release_mem_region(phys_addr, dev_msi_cap * PCI_MSIX_ENTRY_SIZE);
dev->irq = temp; /* Restore IOAPIC IRQ */
}
dev->irq = temp;
nr_reserved_vectors++;
}
EXPORT_SYMBOL(pci_enable_msi);
EXPORT_SYMBOL(msi_alloc_vectors);
EXPORT_SYMBOL(msi_free_vectors);
EXPORT_SYMBOL(pci_disable_msi);
EXPORT_SYMBOL(pci_enable_msix);
EXPORT_SYMBOL(pci_disable_msix);
......@@ -140,7 +140,8 @@ struct msi_desc {
struct {
__u8 type : 5; /* {0: unused, 5h:MSI, 11h:MSI-X} */
__u8 maskbit : 1; /* mask-pending bit supported ? */
__u8 reserved: 2; /* reserved */
__u8 state : 1; /* {0: free, 1: busy} */
__u8 reserved: 1; /* reserved */
__u8 entry_nr; /* specific enabled entry */
__u8 default_vector; /* default pre-assigned vector */
__u8 current_cpu; /* current destination cpu */
......
......@@ -831,16 +831,27 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev * dev, int max, int pass
extern struct pci_dev *isa_bridge;
#endif
struct msix_entry {
u16 vector; /* kernel uses to write allocated vector */
u16 entry; /* driver uses to specify entry, OS writes */
};
#ifndef CONFIG_PCI_USE_VECTOR
static inline void pci_scan_msi_device(struct pci_dev *dev) {}
static inline int pci_enable_msi(struct pci_dev *dev) {return -1;}
static inline void pci_disable_msi(struct pci_dev *dev) {}
static inline int pci_enable_msix(struct pci_dev* dev,
struct msix_entry *entries, int nvec) {return -1;}
static inline void pci_disable_msix(struct pci_dev *dev) {}
static inline void msi_remove_pci_irq_vectors(struct pci_dev *dev) {}
#else
extern void pci_scan_msi_device(struct pci_dev *dev);
extern int pci_enable_msi(struct pci_dev *dev);
extern void pci_disable_msi(struct pci_dev *dev);
extern int pci_enable_msix(struct pci_dev* dev,
struct msix_entry *entries, int nvec);
extern void pci_disable_msix(struct pci_dev *dev);
extern void msi_remove_pci_irq_vectors(struct pci_dev *dev);
extern int msi_alloc_vectors(struct pci_dev* dev, int *vector, int nvec);
extern int msi_free_vectors(struct pci_dev* dev, int *vector, int nvec);
#endif
#endif /* CONFIG_PCI */
......
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