Re: [PATCH] PCI: MSI: Restore read_msi_msg_desc(); add get_cached_msi_msg_desc()

2012-11-20 Thread Ben Hutchings 
On Tue, 2012-11-20 at 18:20 +1100, Benjamin Herrenschmidt wrote:
 On Fri, 2010-07-23 at 14:56 +0100, Ben Hutchings wrote:
  commit 2ca1af9aa3285c6a5f103ed31ad09f7399fc65d7 PCI: MSI: Remove
  unsafe and unnecessary hardware access changed read_msi_msg_desc() to
  return the last MSI message written instead of reading it from the
  device, since it may be called while the device is in a reduced
  power state.
 
 Looks reasonable... Jesse ?
[...]

So reasonable that it was committed a couple of years ago!

Where did you dredge this from?

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

___
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev

Re: [PATCH] PCI: MSI: Restore read_msi_msg_desc(); add get_cached_msi_msg_desc()

2012-11-19 Thread Benjamin Herrenschmidt 
On Fri, 2010-07-23 at 14:56 +0100, Ben Hutchings wrote:
 commit 2ca1af9aa3285c6a5f103ed31ad09f7399fc65d7 PCI: MSI: Remove
 unsafe and unnecessary hardware access changed read_msi_msg_desc() to
 return the last MSI message written instead of reading it from the
 device, since it may be called while the device is in a reduced
 power state.

Looks reasonable... Jesse ?

Cheers,
Ben.

 However, the pSeries platform code really does need to read messages
 from the device, since they are initially written by firmware.
 Therefore:
 - Restore the previous behaviour of read_msi_msg_desc()
 - Add new functions get_cached_msi_msg{,_desc}() which return the
   last MSI message written
 - Use the new functions where appropriate
 
 Signed-off-by: Ben Hutchings bhutchi...@solarflare.com
 ---
 Compile-tested only.
 
 Ben.
 
  arch/ia64/kernel/msi_ia64.c|2 +-
  arch/ia64/sn/kernel/msi_sn.c   |2 +-
  arch/x86/kernel/apic/io_apic.c |2 +-
  drivers/pci/msi.c  |   47 +++
  include/linux/msi.h|2 +
  5 files changed, 47 insertions(+), 8 deletions(-)
 
 diff --git a/arch/ia64/kernel/msi_ia64.c b/arch/ia64/kernel/msi_ia64.c
 index 6c89228..4a746ea 100644
 --- a/arch/ia64/kernel/msi_ia64.c
 +++ b/arch/ia64/kernel/msi_ia64.c
 @@ -25,7 +25,7 @@ static int ia64_set_msi_irq_affinity(unsigned int irq,
   if (irq_prepare_move(irq, cpu))
   return -1;
  
 - read_msi_msg(irq, msg);
 + get_cached_msi_msg(irq, msg);
  
   addr = msg.address_lo;
   addr = MSI_ADDR_DEST_ID_MASK;
 diff --git a/arch/ia64/sn/kernel/msi_sn.c b/arch/ia64/sn/kernel/msi_sn.c
 index ebfdd6a..0c72dd4 100644
 --- a/arch/ia64/sn/kernel/msi_sn.c
 +++ b/arch/ia64/sn/kernel/msi_sn.c
 @@ -175,7 +175,7 @@ static int sn_set_msi_irq_affinity(unsigned int irq,
* Release XIO resources for the old MSI PCI address
*/
  
 - read_msi_msg(irq, msg);
 + get_cached_msi_msg(irq, msg);
  sn_pdev = (struct pcidev_info *)sn_irq_info-irq_pciioinfo;
   pdev = sn_pdev-pdi_linux_pcidev;
   provider = SN_PCIDEV_BUSPROVIDER(pdev);
 diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
 index e41ed24..4dc0084 100644
 --- a/arch/x86/kernel/apic/io_apic.c
 +++ b/arch/x86/kernel/apic/io_apic.c
 @@ -3397,7 +3397,7 @@ static int set_msi_irq_affinity(unsigned int irq, const 
 struct cpumask *mask)
  
   cfg = desc-chip_data;
  
 - read_msi_msg_desc(desc, msg);
 + get_cached_msi_msg_desc(desc, msg);
  
   msg.data = ~MSI_DATA_VECTOR_MASK;
   msg.data |= MSI_DATA_VECTOR(cfg-vector);
 diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
 index 4c14f31..69b7be3 100644
 --- a/drivers/pci/msi.c
 +++ b/drivers/pci/msi.c
 @@ -197,9 +197,46 @@ void read_msi_msg_desc(struct irq_desc *desc, struct 
 msi_msg *msg)
  {
   struct msi_desc *entry = get_irq_desc_msi(desc);
  
 - /* We do not touch the hardware (which may not even be
 -  * accessible at the moment) but return the last message
 -  * written.  Assert that this is valid, assuming that
 + BUG_ON(entry-dev-current_state != PCI_D0);
 +
 + if (entry-msi_attrib.is_msix) {
 + void __iomem *base = entry-mask_base +
 + entry-msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
 +
 + msg-address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR);
 + msg-address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR);
 + msg-data = readl(base + PCI_MSIX_ENTRY_DATA);
 + } else {
 + struct pci_dev *dev = entry-dev;
 + int pos = entry-msi_attrib.pos;
 + u16 data;
 +
 + pci_read_config_dword(dev, msi_lower_address_reg(pos),
 + msg-address_lo);
 + if (entry-msi_attrib.is_64) {
 + pci_read_config_dword(dev, msi_upper_address_reg(pos),
 + msg-address_hi);
 + pci_read_config_word(dev, msi_data_reg(pos, 1), data);
 + } else {
 + msg-address_hi = 0;
 + pci_read_config_word(dev, msi_data_reg(pos, 0), data);
 + }
 + msg-data = data;
 + }
 +}
 +
 +void read_msi_msg(unsigned int irq, struct msi_msg *msg)
 +{
 + struct irq_desc *desc = irq_to_desc(irq);
 +
 + read_msi_msg_desc(desc, msg);
 +}
 +
 +void get_cached_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg)
 +{
 + struct msi_desc *entry = get_irq_desc_msi(desc);
 +
 + /* Assert that the cache is valid, assuming that
* valid messages are not all-zeroes. */
   BUG_ON(!(entry-msg.address_hi | entry-msg.address_lo |
entry-msg.data));
 @@ -207,11 +244,11 @@ void read_msi_msg_desc(struct irq_desc *desc, struct 
 msi_msg *msg)
   *msg = entry-msg;
  }
  
 -void read_msi_msg(unsigned int irq, struct msi_msg *msg)
 +void get_cached_msi_msg(unsigned int irq, struct

Re: [PATCH] PCI: MSI: Restore read_msi_msg_desc(); add get_cached_msi_msg_desc()

2010-08-01 Thread Michael Ellerman 
On Fri, 2010-07-30 at 09:42 -0700, Jesse Barnes wrote:
 On Fri, 23 Jul 2010 14:56:28 +0100
 Ben Hutchings bhutchi...@solarflare.com wrote:
 
  commit 2ca1af9aa3285c6a5f103ed31ad09f7399fc65d7 PCI: MSI: Remove
  unsafe and unnecessary hardware access changed read_msi_msg_desc() to
  return the last MSI message written instead of reading it from the
  device, since it may be called while the device is in a reduced
  power state.
  
  However, the pSeries platform code really does need to read messages
  from the device, since they are initially written by firmware.
  Therefore:
  - Restore the previous behaviour of read_msi_msg_desc()
  - Add new functions get_cached_msi_msg{,_desc}() which return the
last MSI message written
  - Use the new functions where appropriate
  
  Signed-off-by: Ben Hutchings bhutchi...@solarflare.com
  ---
  Compile-tested only.
  
 
 Applied to linux-next with Michael's ack, thanks.  I hope it actually
 works, I didn't see a tested-by!

I assume Stephen has been using it, otherwise his linux-next boot tests
will all have been failing. Either way he'll test it when it gets into
linux-next proper.

cheers




signature.asc
Description: This is a digitally signed message part
___
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev

Re: [PATCH] PCI: MSI: Restore read_msi_msg_desc(); add get_cached_msi_msg_desc()

2010-07-30 Thread Jesse Barnes 
On Fri, 23 Jul 2010 14:56:28 +0100
Ben Hutchings bhutchi...@solarflare.com wrote:

 commit 2ca1af9aa3285c6a5f103ed31ad09f7399fc65d7 PCI: MSI: Remove
 unsafe and unnecessary hardware access changed read_msi_msg_desc() to
 return the last MSI message written instead of reading it from the
 device, since it may be called while the device is in a reduced
 power state.
 
 However, the pSeries platform code really does need to read messages
 from the device, since they are initially written by firmware.
 Therefore:
 - Restore the previous behaviour of read_msi_msg_desc()
 - Add new functions get_cached_msi_msg{,_desc}() which return the
   last MSI message written
 - Use the new functions where appropriate
 
 Signed-off-by: Ben Hutchings bhutchi...@solarflare.com
 ---
 Compile-tested only.
 

Applied to linux-next with Michael's ack, thanks.  I hope it actually
works, I didn't see a tested-by!

-- 
Jesse Barnes, Intel Open Source Technology Center
___
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev

Re: [PATCH] PCI: MSI: Restore read_msi_msg_desc(); add get_cached_msi_msg_desc()

2010-07-26 Thread Michael Ellerman 
On Fri, 2010-07-23 at 14:56 +0100, Ben Hutchings wrote:
 commit 2ca1af9aa3285c6a5f103ed31ad09f7399fc65d7 PCI: MSI: Remove
 unsafe and unnecessary hardware access changed read_msi_msg_desc() to
 return the last MSI message written instead of reading it from the
 device, since it may be called while the device is in a reduced
 power state.
 
 However, the pSeries platform code really does need to read messages
 from the device, since they are initially written by firmware.
 Therefore:
 - Restore the previous behaviour of read_msi_msg_desc()
 - Add new functions get_cached_msi_msg{,_desc}() which return the
   last MSI message written
 - Use the new functions where appropriate
 
 Signed-off-by: Ben Hutchings bhutchi...@solarflare.com

Looks good to me.

cheers



signature.asc
Description: This is a digitally signed message part
___
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev

[PATCH] PCI: MSI: Restore read_msi_msg_desc(); add get_cached_msi_msg_desc()

2010-07-23 Thread Ben Hutchings 
commit 2ca1af9aa3285c6a5f103ed31ad09f7399fc65d7 PCI: MSI: Remove
unsafe and unnecessary hardware access changed read_msi_msg_desc() to
return the last MSI message written instead of reading it from the
device, since it may be called while the device is in a reduced
power state.

However, the pSeries platform code really does need to read messages
from the device, since they are initially written by firmware.
Therefore:
- Restore the previous behaviour of read_msi_msg_desc()
- Add new functions get_cached_msi_msg{,_desc}() which return the
  last MSI message written
- Use the new functions where appropriate

Signed-off-by: Ben Hutchings bhutchi...@solarflare.com
---
Compile-tested only.

Ben.

 arch/ia64/kernel/msi_ia64.c|2 +-
 arch/ia64/sn/kernel/msi_sn.c   |2 +-
 arch/x86/kernel/apic/io_apic.c |2 +-
 drivers/pci/msi.c  |   47 +++
 include/linux/msi.h|2 +
 5 files changed, 47 insertions(+), 8 deletions(-)

diff --git a/arch/ia64/kernel/msi_ia64.c b/arch/ia64/kernel/msi_ia64.c
index 6c89228..4a746ea 100644
--- a/arch/ia64/kernel/msi_ia64.c
+++ b/arch/ia64/kernel/msi_ia64.c
@@ -25,7 +25,7 @@ static int ia64_set_msi_irq_affinity(unsigned int irq,
if (irq_prepare_move(irq, cpu))
return -1;
 
-   read_msi_msg(irq, msg);
+   get_cached_msi_msg(irq, msg);
 
addr = msg.address_lo;
addr = MSI_ADDR_DEST_ID_MASK;
diff --git a/arch/ia64/sn/kernel/msi_sn.c b/arch/ia64/sn/kernel/msi_sn.c
index ebfdd6a..0c72dd4 100644
--- a/arch/ia64/sn/kernel/msi_sn.c
+++ b/arch/ia64/sn/kernel/msi_sn.c
@@ -175,7 +175,7 @@ static int sn_set_msi_irq_affinity(unsigned int irq,
 * Release XIO resources for the old MSI PCI address
 */
 
-   read_msi_msg(irq, msg);
+   get_cached_msi_msg(irq, msg);
 sn_pdev = (struct pcidev_info *)sn_irq_info-irq_pciioinfo;
pdev = sn_pdev-pdi_linux_pcidev;
provider = SN_PCIDEV_BUSPROVIDER(pdev);
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index e41ed24..4dc0084 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -3397,7 +3397,7 @@ static int set_msi_irq_affinity(unsigned int irq, const 
struct cpumask *mask)
 
cfg = desc-chip_data;
 
-   read_msi_msg_desc(desc, msg);
+   get_cached_msi_msg_desc(desc, msg);
 
msg.data = ~MSI_DATA_VECTOR_MASK;
msg.data |= MSI_DATA_VECTOR(cfg-vector);
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 4c14f31..69b7be3 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -197,9 +197,46 @@ void read_msi_msg_desc(struct irq_desc *desc, struct 
msi_msg *msg)
 {
struct msi_desc *entry = get_irq_desc_msi(desc);
 
-   /* We do not touch the hardware (which may not even be
-* accessible at the moment) but return the last message
-* written.  Assert that this is valid, assuming that
+   BUG_ON(entry-dev-current_state != PCI_D0);
+
+   if (entry-msi_attrib.is_msix) {
+   void __iomem *base = entry-mask_base +
+   entry-msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
+
+   msg-address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR);
+   msg-address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR);
+   msg-data = readl(base + PCI_MSIX_ENTRY_DATA);
+   } else {
+   struct pci_dev *dev = entry-dev;
+   int pos = entry-msi_attrib.pos;
+   u16 data;
+
+   pci_read_config_dword(dev, msi_lower_address_reg(pos),
+   msg-address_lo);
+   if (entry-msi_attrib.is_64) {
+   pci_read_config_dword(dev, msi_upper_address_reg(pos),
+   msg-address_hi);
+   pci_read_config_word(dev, msi_data_reg(pos, 1), data);
+   } else {
+   msg-address_hi = 0;
+   pci_read_config_word(dev, msi_data_reg(pos, 0), data);
+   }
+   msg-data = data;
+   }
+}
+
+void read_msi_msg(unsigned int irq, struct msi_msg *msg)
+{
+   struct irq_desc *desc = irq_to_desc(irq);
+
+   read_msi_msg_desc(desc, msg);
+}
+
+void get_cached_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg)
+{
+   struct msi_desc *entry = get_irq_desc_msi(desc);
+
+   /* Assert that the cache is valid, assuming that
 * valid messages are not all-zeroes. */
BUG_ON(!(entry-msg.address_hi | entry-msg.address_lo |
 entry-msg.data));
@@ -207,11 +244,11 @@ void read_msi_msg_desc(struct irq_desc *desc, struct 
msi_msg *msg)
*msg = entry-msg;
 }
 
-void read_msi_msg(unsigned int irq, struct msi_msg *msg)
+void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg)
 {
struct irq_desc *desc = irq_to_desc(irq);
 
-   read_msi_msg_desc(desc, msg);
+