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* [PATCH v3 0/5] Retrieve MSI/MSIX cap struct for once on setup
@ 2013-04-05  2:54 Gavin Shan
  2013-04-05  2:54 ` [PATCH 1/4] PCI: Cache MSI/MSI-X cap in PCI device Gavin Shan
                   ` (4 more replies)
  0 siblings, 5 replies; 6+ messages in thread
From: Gavin Shan @ 2013-04-05  2:54 UTC (permalink / raw)
  To: linux-pci; +Cc: bhelgaas, Gavin Shan

While we setup MSI or MSI-X for specific PCI device, the address of
MSI or MSI-X capability structure is figured out from the config
space for multiple times. That's unnecessary and the patchset addresses
that. With the patchset applied, the latency for MSI or MSI-X setup
would be decreased hopefully.

v2 -> v3:
	* Remove checking on MSI/MSI-X capability offset in msi_set_enable()
	  and msix_set_enable(). Let the caller does the check
	* Using "u8" for MSI/MSI-X/PM capability
	* Let caller of pci_msi_check_device() checks MSI/MSI-X capability
	* Replace msi_control_reg() with "pos + PCI_MSI_FLAGS"
	* Merge [4/5] to [3/5]
v1 -> v2:
	* Cache the MSI/MSI-X capability offset to pci_dev directly according
	  to Bjorn's suggestion.
	* Rebase to 3.9.RC5

---

drivers/pci/msi.c   |  110 +++++++++++++++++++++++----------------------------
drivers/pci/msi.h   |    1 -
include/linux/pci.h |    4 +-
3 files changed, 52 insertions(+), 63 deletions(-)

Thanks,
Gavin


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH 1/4] PCI: Cache MSI/MSI-X cap in PCI device
  2013-04-05  2:54 [PATCH v3 0/5] Retrieve MSI/MSIX cap struct for once on setup Gavin Shan
@ 2013-04-05  2:54 ` Gavin Shan
  2013-04-05  2:54 ` [PATCH 2/4] PCI: Remove MSI/MSI-X cap check in pci_msi_check_device() Gavin Shan
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: Gavin Shan @ 2013-04-05  2:54 UTC (permalink / raw)
  To: linux-pci; +Cc: bhelgaas, Gavin Shan

The patch caches the MSI and MSI-X capability offset in PCI device
(struct pci_dev) so that we needn't poll it from the config space
upon enabling or disabling MSI or MSI-X interrupts. Besides, the
data type of cached PM capability (pm_cap), which is PCI stuff
intead of PCIe stuff, in pci_dev has been changed to "u8" according
to Bjorn's suggestion.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
---
 drivers/pci/msi.c   |   43 ++++++++++++++++++++-----------------------
 include/linux/pci.h |    4 +++-
 2 files changed, 23 insertions(+), 24 deletions(-)

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 00cc78c..5fdc5d9 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -111,32 +111,26 @@ void default_restore_msi_irqs(struct pci_dev *dev, int irq)
 }
 #endif
 
-static void msi_set_enable(struct pci_dev *dev, int pos, int enable)
+static void msi_set_enable(struct pci_dev *dev, int enable)
 {
 	u16 control;
 
-	BUG_ON(!pos);
-
-	pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control);
+	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
 	control &= ~PCI_MSI_FLAGS_ENABLE;
 	if (enable)
 		control |= PCI_MSI_FLAGS_ENABLE;
-	pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control);
+	pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control);
 }
 
 static void msix_set_enable(struct pci_dev *dev, int enable)
 {
-	int pos;
 	u16 control;
 
-	pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
-	if (pos) {
-		pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control);
-		control &= ~PCI_MSIX_FLAGS_ENABLE;
-		if (enable)
-			control |= PCI_MSIX_FLAGS_ENABLE;
-		pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
-	}
+	pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control);
+	control &= ~PCI_MSIX_FLAGS_ENABLE;
+	if (enable)
+		control |= PCI_MSIX_FLAGS_ENABLE;
+	pci_write_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, control);
 }
 
 static inline __attribute_const__ u32 msi_mask(unsigned x)
@@ -402,7 +396,7 @@ static void __pci_restore_msi_state(struct pci_dev *dev)
 	pos = entry->msi_attrib.pos;
 
 	pci_intx_for_msi(dev, 0);
-	msi_set_enable(dev, pos, 0);
+	msi_set_enable(dev, 0);
 	arch_restore_msi_irqs(dev, dev->irq);
 
 	pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control);
@@ -557,7 +551,7 @@ static int msi_capability_init(struct pci_dev *dev, int nvec)
 	unsigned mask;
 
 	pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
-	msi_set_enable(dev, pos, 0);	/* Disable MSI during set up */
+	msi_set_enable(dev, 0);	/* Disable MSI during set up */
 
 	pci_read_config_word(dev, msi_control_reg(pos), &control);
 	/* MSI Entry Initialization */
@@ -598,7 +592,7 @@ static int msi_capability_init(struct pci_dev *dev, int nvec)
 
 	/* Set MSI enabled bits	 */
 	pci_intx_for_msi(dev, 0);
-	msi_set_enable(dev, pos, 1);
+	msi_set_enable(dev, 1);
 	dev->msi_enabled = 1;
 
 	dev->irq = entry->irq;
@@ -885,7 +879,7 @@ void pci_msi_shutdown(struct pci_dev *dev)
 	desc = list_first_entry(&dev->msi_list, struct msi_desc, list);
 	pos = desc->msi_attrib.pos;
 
-	msi_set_enable(dev, pos, 0);
+	msi_set_enable(dev, 0);
 	pci_intx_for_msi(dev, 1);
 	dev->msi_enabled = 0;
 
@@ -1048,15 +1042,18 @@ EXPORT_SYMBOL(pci_msi_enabled);
 
 void pci_msi_init_pci_dev(struct pci_dev *dev)
 {
-	int pos;
 	INIT_LIST_HEAD(&dev->msi_list);
 
 	/* Disable the msi hardware to avoid screaming interrupts
 	 * during boot.  This is the power on reset default so
 	 * usually this should be a noop.
 	 */
-	pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
-	if (pos)
-		msi_set_enable(dev, pos, 0);
-	msix_set_enable(dev, 0);
+	dev->msi_cap = pci_find_capability(dev, PCI_CAP_ID_MSI);
+	if (dev->msi_cap)
+		msi_set_enable(dev, 0);
+
+	/* We needn't check if we have valid MSI-X capability here */
+	dev->msix_cap = pci_find_capability(dev, PCI_CAP_ID_MSIX);
+	if (dev->msix_cap)
+		msix_set_enable(dev, 0);
 }
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 2461033a..3e23895 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -249,7 +249,9 @@ struct pci_dev {
 	pci_power_t     current_state;  /* Current operating state. In ACPI-speak,
 					   this is D0-D3, D0 being fully functional,
 					   and D3 being off. */
-	int		pm_cap;		/* PM capability offset in the
+	u8		msi_cap;	/* MSI capability offset */
+	u8		msix_cap;	/* MSI-X capability offset */
+	u8		pm_cap;		/* PM capability offset in the
 					   configuration space */
 	unsigned int	pme_support:5;	/* Bitmask of states from which PME#
 					   can be generated */
-- 
1.7.5.4


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH 2/4] PCI: Remove MSI/MSI-X cap check in pci_msi_check_device()
  2013-04-05  2:54 [PATCH v3 0/5] Retrieve MSI/MSIX cap struct for once on setup Gavin Shan
  2013-04-05  2:54 ` [PATCH 1/4] PCI: Cache MSI/MSI-X cap in PCI device Gavin Shan
@ 2013-04-05  2:54 ` Gavin Shan
  2013-04-05  2:54 ` [PATCH 3/4] PCI: Use cached MSI cap while enabling MSI interrupts Gavin Shan
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: Gavin Shan @ 2013-04-05  2:54 UTC (permalink / raw)
  To: linux-pci; +Cc: bhelgaas, Gavin Shan

The function pci_msi_check_device() is called while enabling MSI
or MSI-X interrupts to make sure the PCI device can support MSI
or MSI-X capability. The patch removes the check on MSI or MSI-X
capability in the function and lets the caller does the check.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
---
 drivers/pci/msi.c |    5 +----
 1 files changed, 1 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 5fdc5d9..1ec1ba9 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -789,9 +789,6 @@ static int pci_msi_check_device(struct pci_dev *dev, int nvec, int type)
 	if (ret)
 		return ret;
 
-	if (!pci_find_capability(dev, type))
-		return -EINVAL;
-
 	return 0;
 }
 
@@ -942,7 +939,7 @@ int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
 	int status, nr_entries;
 	int i, j;
 
-	if (!entries)
+	if (!entries || !dev->msix_cap)
 		return -EINVAL;
 
 	status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSIX);
-- 
1.7.5.4


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH 3/4] PCI: Use cached MSI cap while enabling MSI interrupts
  2013-04-05  2:54 [PATCH v3 0/5] Retrieve MSI/MSIX cap struct for once on setup Gavin Shan
  2013-04-05  2:54 ` [PATCH 1/4] PCI: Cache MSI/MSI-X cap in PCI device Gavin Shan
  2013-04-05  2:54 ` [PATCH 2/4] PCI: Remove MSI/MSI-X cap check in pci_msi_check_device() Gavin Shan
@ 2013-04-05  2:54 ` Gavin Shan
  2013-04-05  2:54 ` [PATCH 4/4] PCI: Use cached MSI-X cap while enabling MSI-X Gavin Shan
       [not found] ` <5167564e.c628320a.6610.1710SMTPIN_ADDED_BROKEN@mx.google.com>
  4 siblings, 0 replies; 6+ messages in thread
From: Gavin Shan @ 2013-04-05  2:54 UTC (permalink / raw)
  To: linux-pci; +Cc: bhelgaas, Gavin Shan

The patch intends to use the cached MSI capability offset in
pci_dev instead of polling that from config space when enabling
MSI interrupts.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
---
 drivers/pci/msi.c |   32 +++++++++++++++-----------------
 drivers/pci/msi.h |    1 -
 2 files changed, 15 insertions(+), 18 deletions(-)

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 1ec1ba9..449db36 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -299,10 +299,10 @@ void __write_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
 		int pos = entry->msi_attrib.pos;
 		u16 msgctl;
 
-		pci_read_config_word(dev, msi_control_reg(pos), &msgctl);
+		pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
 		msgctl &= ~PCI_MSI_FLAGS_QSIZE;
 		msgctl |= entry->msi_attrib.multiple << 4;
-		pci_write_config_word(dev, msi_control_reg(pos), msgctl);
+		pci_write_config_word(dev, pos + PCI_MSI_FLAGS, msgctl);
 
 		pci_write_config_dword(dev, msi_lower_address_reg(pos),
 					msg->address_lo);
@@ -546,14 +546,14 @@ out_unroll:
 static int msi_capability_init(struct pci_dev *dev, int nvec)
 {
 	struct msi_desc *entry;
-	int pos, ret;
+	int ret;
 	u16 control;
 	unsigned mask;
 
-	pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
-	msi_set_enable(dev, 0);	/* Disable MSI during set up */
+	/* Disable MSI during set up */
+	msi_set_enable(dev, 0);
 
-	pci_read_config_word(dev, msi_control_reg(pos), &control);
+	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
 	/* MSI Entry Initialization */
 	entry = alloc_msi_entry(dev);
 	if (!entry)
@@ -564,9 +564,9 @@ static int msi_capability_init(struct pci_dev *dev, int nvec)
 	entry->msi_attrib.entry_nr	= 0;
 	entry->msi_attrib.maskbit	= is_mask_bit_support(control);
 	entry->msi_attrib.default_irq	= dev->irq;	/* Save IOAPIC IRQ */
-	entry->msi_attrib.pos		= pos;
+	entry->msi_attrib.pos		= dev->msi_cap;
 
-	entry->mask_pos = msi_mask_reg(pos, entry->msi_attrib.is_64);
+	entry->mask_pos = msi_mask_reg(dev->msi_cap, entry->msi_attrib.is_64);
 	/* All MSIs are unmasked by default, Mask them all */
 	if (entry->msi_attrib.maskbit)
 		pci_read_config_dword(dev, entry->mask_pos, &entry->masked);
@@ -807,13 +807,12 @@ static int pci_msi_check_device(struct pci_dev *dev, int nvec, int type)
  */
 int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec)
 {
-	int status, pos, maxvec;
+	int status, maxvec;
 	u16 msgctl;
 
-	pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
-	if (!pos)
+	if (!dev->msi_cap)
 		return -EINVAL;
-	pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
+	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl);
 	maxvec = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1);
 	if (nvec > maxvec)
 		return maxvec;
@@ -838,14 +837,13 @@ EXPORT_SYMBOL(pci_enable_msi_block);
 
 int pci_enable_msi_block_auto(struct pci_dev *dev, unsigned int *maxvec)
 {
-	int ret, pos, nvec;
+	int ret, nvec;
 	u16 msgctl;
 
-	pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
-	if (!pos)
+	if (!dev->msi_cap)
 		return -EINVAL;
 
-	pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
+	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl);
 	ret = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1);
 
 	if (maxvec)
@@ -915,7 +913,7 @@ int pci_msix_table_size(struct pci_dev *dev)
 	if (!pos)
 		return 0;
 
-	pci_read_config_word(dev, msi_control_reg(pos), &control);
+	pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control);
 	return multi_msix_capable(control);
 }
 
diff --git a/drivers/pci/msi.h b/drivers/pci/msi.h
index 65c42f8..6aa7b19 100644
--- a/drivers/pci/msi.h
+++ b/drivers/pci/msi.h
@@ -6,7 +6,6 @@
 #ifndef MSI_H
 #define MSI_H
 
-#define msi_control_reg(base)		(base + PCI_MSI_FLAGS)
 #define msi_lower_address_reg(base)	(base + PCI_MSI_ADDRESS_LO)
 #define msi_upper_address_reg(base)	(base + PCI_MSI_ADDRESS_HI)
 #define msi_data_reg(base, is64bit)	\
-- 
1.7.5.4


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH 4/4] PCI: Use cached MSI-X cap while enabling MSI-X
  2013-04-05  2:54 [PATCH v3 0/5] Retrieve MSI/MSIX cap struct for once on setup Gavin Shan
                   ` (2 preceding siblings ...)
  2013-04-05  2:54 ` [PATCH 3/4] PCI: Use cached MSI cap while enabling MSI interrupts Gavin Shan
@ 2013-04-05  2:54 ` Gavin Shan
       [not found] ` <5167564e.c628320a.6610.1710SMTPIN_ADDED_BROKEN@mx.google.com>
  4 siblings, 0 replies; 6+ messages in thread
From: Gavin Shan @ 2013-04-05  2:54 UTC (permalink / raw)
  To: linux-pci; +Cc: bhelgaas, Gavin Shan

The patch intends to use the cached MSI-X capability offset in
pci_dev instead of polling that from config space when enabling
MSI-X interrupts.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
---
 drivers/pci/msi.c |   34 +++++++++++++++-------------------
 1 files changed, 15 insertions(+), 19 deletions(-)

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 449db36..212cea3 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -599,14 +599,14 @@ static int msi_capability_init(struct pci_dev *dev, int nvec)
 	return 0;
 }
 
-static void __iomem *msix_map_region(struct pci_dev *dev, unsigned pos,
-							unsigned nr_entries)
+static void __iomem *msix_map_region(struct pci_dev *dev, unsigned nr_entries)
 {
 	resource_size_t phys_addr;
 	u32 table_offset;
 	u8 bir;
 
-	pci_read_config_dword(dev, msix_table_offset_reg(pos), &table_offset);
+	pci_read_config_dword(dev,
+		msix_table_offset_reg(dev->msix_cap), &table_offset);
 	bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);
 	table_offset &= ~PCI_MSIX_FLAGS_BIRMASK;
 	phys_addr = pci_resource_start(dev, bir) + table_offset;
@@ -614,9 +614,8 @@ static void __iomem *msix_map_region(struct pci_dev *dev, unsigned pos,
 	return ioremap_nocache(phys_addr, nr_entries * PCI_MSIX_ENTRY_SIZE);
 }
 
-static int msix_setup_entries(struct pci_dev *dev, unsigned pos,
-				void __iomem *base, struct msix_entry *entries,
-				int nvec)
+static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
+			      struct msix_entry *entries, int nvec)
 {
 	struct msi_desc *entry;
 	int i;
@@ -636,7 +635,7 @@ static int msix_setup_entries(struct pci_dev *dev, unsigned pos,
 		entry->msi_attrib.is_64		= 1;
 		entry->msi_attrib.entry_nr	= entries[i].entry;
 		entry->msi_attrib.default_irq	= dev->irq;
-		entry->msi_attrib.pos		= pos;
+		entry->msi_attrib.pos		= dev->msix_cap;
 		entry->mask_base		= base;
 
 		list_add_tail(&entry->list, &dev->msi_list);
@@ -676,23 +675,22 @@ static void msix_program_entries(struct pci_dev *dev,
 static int msix_capability_init(struct pci_dev *dev,
 				struct msix_entry *entries, int nvec)
 {
-	int pos, ret;
+	int ret;
 	u16 control;
 	void __iomem *base;
 
-	pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
-	pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control);
+	pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control);
 
 	/* Ensure MSI-X is disabled while it is set up */
 	control &= ~PCI_MSIX_FLAGS_ENABLE;
-	pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
+	pci_write_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, control);
 
 	/* Request & Map MSI-X table region */
-	base = msix_map_region(dev, pos, multi_msix_capable(control));
+	base = msix_map_region(dev, multi_msix_capable(control));
 	if (!base)
 		return -ENOMEM;
 
-	ret = msix_setup_entries(dev, pos, base, entries, nvec);
+	ret = msix_setup_entries(dev, base, entries, nvec);
 	if (ret)
 		return ret;
 
@@ -706,7 +704,7 @@ static int msix_capability_init(struct pci_dev *dev,
 	 * interrupts coming in before they're fully set up.
 	 */
 	control |= PCI_MSIX_FLAGS_MASKALL | PCI_MSIX_FLAGS_ENABLE;
-	pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
+	pci_write_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, control);
 
 	msix_program_entries(dev, entries);
 
@@ -721,7 +719,7 @@ static int msix_capability_init(struct pci_dev *dev,
 	dev->msix_enabled = 1;
 
 	control &= ~PCI_MSIX_FLAGS_MASKALL;
-	pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
+	pci_write_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, control);
 
 	return 0;
 
@@ -906,14 +904,12 @@ EXPORT_SYMBOL(pci_disable_msi);
  */
 int pci_msix_table_size(struct pci_dev *dev)
 {
-	int pos;
 	u16 control;
 
-	pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
-	if (!pos)
+	if (!dev->msix_cap)
 		return 0;
 
-	pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control);
+	pci_read_config_word(dev, dev->msix_cap + PCI_MSI_FLAGS, &control);
 	return multi_msix_capable(control);
 }
 
-- 
1.7.5.4


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH v3 0/5] Retrieve MSI/MSIX cap struct for once on setup
       [not found] ` <5167564e.c628320a.6610.1710SMTPIN_ADDED_BROKEN@mx.google.com>
@ 2013-04-22 23:11   ` Bjorn Helgaas
  0 siblings, 0 replies; 6+ messages in thread
From: Bjorn Helgaas @ 2013-04-22 23:11 UTC (permalink / raw)
  To: Gavin Shan; +Cc: linux-pci@vger.kernel.org

On Thu, Apr 11, 2013 at 6:33 PM, Gavin Shan <shangw@linux.vnet.ibm.com> wrote:
> On Fri, Apr 05, 2013 at 11:01:18AM +0800, Gavin Shan wrote:
>>On Fri, Apr 05, 2013 at 10:54:29AM +0800, Gavin Shan wrote:
>>
>>The subject should be "[0/4]" instead of "[0/5]". Forgot to change
>>that accordingly. Sorry for the confusion ;-)
>>
>
> Bjorn, did you get change taking a look on this? Please let me know
> if you have more comments :-)

I did look at it; it looks good, and I made some more cleanups, which
I just posted as a "v4" series.  Take a look and see if it makes sense
to you.

Bjorn

>>>While we setup MSI or MSI-X for specific PCI device, the address of
>>>MSI or MSI-X capability structure is figured out from the config
>>>space for multiple times. That's unnecessary and the patchset addresses
>>>that. With the patchset applied, the latency for MSI or MSI-X setup
>>>would be decreased hopefully.
>>>
>>>v2 -> v3:
>>>      * Remove checking on MSI/MSI-X capability offset in msi_set_enable()
>>>        and msix_set_enable(). Let the caller does the check
>>>      * Using "u8" for MSI/MSI-X/PM capability
>>>      * Let caller of pci_msi_check_device() checks MSI/MSI-X capability
>>>      * Replace msi_control_reg() with "pos + PCI_MSI_FLAGS"
>>>      * Merge [4/5] to [3/5]
>>>v1 -> v2:
>>>      * Cache the MSI/MSI-X capability offset to pci_dev directly according
>>>        to Bjorn's suggestion.
>>>      * Rebase to 3.9.RC5
>>>
>>>---
>>>
>>>drivers/pci/msi.c   |  110 +++++++++++++++++++++++----------------------------
>>>drivers/pci/msi.h   |    1 -
>>>include/linux/pci.h |    4 +-
>>>3 files changed, 52 insertions(+), 63 deletions(-)
>>>
>>>Thanks,
>>>Gavin
>>>
>

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2013-04-22 23:11 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-04-05  2:54 [PATCH v3 0/5] Retrieve MSI/MSIX cap struct for once on setup Gavin Shan
2013-04-05  2:54 ` [PATCH 1/4] PCI: Cache MSI/MSI-X cap in PCI device Gavin Shan
2013-04-05  2:54 ` [PATCH 2/4] PCI: Remove MSI/MSI-X cap check in pci_msi_check_device() Gavin Shan
2013-04-05  2:54 ` [PATCH 3/4] PCI: Use cached MSI cap while enabling MSI interrupts Gavin Shan
2013-04-05  2:54 ` [PATCH 4/4] PCI: Use cached MSI-X cap while enabling MSI-X Gavin Shan
     [not found] ` <5167564e.c628320a.6610.1710SMTPIN_ADDED_BROKEN@mx.google.com>
2013-04-22 23:11   ` [PATCH v3 0/5] Retrieve MSI/MSIX cap struct for once on setup Bjorn Helgaas

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