LTR: Save Max snoop/no-snoop Latency Value in pci_save_pcie_state, and restore them in pci_restore_pcie_state.
Signed-off-by: Xudong Hao <[email protected]>
---
drivers/pci/pci.c | 12 ++++++++++++
1 files changed, 12 insertions(+), 0 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 111569c..c8573c3 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -875,6 +875,12 @@ static int pci_save_pcie_state(struct pci_dev *dev)
pci_read_config_word(dev, pos + PCI_EXP_LNKCTL2, &cap[i++]);
if (pcie_cap_has_sltctl2(dev->pcie_type, flags))
pci_read_config_word(dev, pos + PCI_EXP_SLTCTL2, &cap[i++]);
+ if (pci_ltr_supported(dev)) {
+ pci_read_config_word(dev, pos + PCI_LTR_MAX_SNOOP_LAT,
+ &cap[i++]);
+ pci_read_config_word(dev, pos + PCI_LTR_MAX_NOSNOOP_LAT,
+ &cap[i++]);
+ }
return 0;
}
@@ -908,6 +914,12 @@ static void pci_restore_pcie_state(struct pci_dev *dev)
pci_write_config_word(dev, pos + PCI_EXP_LNKCTL2, cap[i++]);
if (pcie_cap_has_sltctl2(dev->pcie_type, flags))
pci_write_config_word(dev, pos + PCI_EXP_SLTCTL2, cap[i++]);
+ if (pci_ltr_supported(dev)) {
+ pci_write_config_word(dev, pos + PCI_LTR_MAX_SNOOP_LAT,
+ cap[i++]);
+ pci_write_config_word(dev, pos + PCI_LTR_MAX_NOSNOOP_LAT,
+ cap[i++]);
+ }
}
--
1.6.0.rc1
On Sun, May 6, 2012 at 8:11 AM, Xudong Hao <[email protected]> wrote:
> LTR: Save Max snoop/no-snoop Latency Value in pci_save_pcie_state, and restore them in pci_restore_pcie_state.
>
> Signed-off-by: Xudong Hao <[email protected]>
>
> ---
> ?drivers/pci/pci.c | ? 12 ++++++++++++
> ?1 files changed, 12 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 111569c..c8573c3 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -875,6 +875,12 @@ static int pci_save_pcie_state(struct pci_dev *dev)
> ? ? ? ?pci_read_config_word(dev, pos + PCI_EXP_LNKCTL2, &cap[i++]);
> ? ?if (pcie_cap_has_sltctl2(dev->pcie_type, flags))
> ? ? ? ?pci_read_config_word(dev, pos + PCI_EXP_SLTCTL2, &cap[i++]);
> + ? if (pci_ltr_supported(dev)) {
> + ? ? ? pci_read_config_word(dev, pos + PCI_LTR_MAX_SNOOP_LAT,
> + ? ? ? ? ? ? ? ? ? ? ? ? ? &cap[i++]);
> + ? ? ? pci_read_config_word(dev, pos + PCI_LTR_MAX_NOSNOOP_LAT,
> + ? ? ? ? ? ? ? ? ? ? ? ? ? &cap[i++]);
> + ? }
>
> ? ?return 0;
> ?}
> @@ -908,6 +914,12 @@ static void pci_restore_pcie_state(struct pci_dev *dev)
> ? ? ? ?pci_write_config_word(dev, pos + PCI_EXP_LNKCTL2, cap[i++]);
> ? ?if (pcie_cap_has_sltctl2(dev->pcie_type, flags))
> ? ? ? ?pci_write_config_word(dev, pos + PCI_EXP_SLTCTL2, cap[i++]);
> + ? if (pci_ltr_supported(dev)) {
> + ? ? ? pci_write_config_word(dev, pos + PCI_LTR_MAX_SNOOP_LAT,
> + ? ? ? ? ? ? ? ? ? ? ? ? ? cap[i++]);
> + ? ? ? pci_write_config_word(dev, pos + PCI_LTR_MAX_NOSNOOP_LAT,
> + ? ? ? ? ? ? ? ? ? ? ? ? ? cap[i++]);
> + ? }
> ?}
>
This doesn't make any sense to me. "pos" is the offset of the PCI
Express Capability (identifier 10h). LTR is a separate extended
capability (identifier 18h), so you at least have to look up its
offset.
Bjorn
> -----Original Message-----
> From: Bjorn Helgaas [mailto:[email protected]]
> > ?}
> >
>
> This doesn't make any sense to me. "pos" is the offset of the PCI
> Express Capability (identifier 10h). LTR is a separate extended
> capability (identifier 18h), so you at least have to look up its
> offset.
>
Sorry paste a wrong patch...
How about this patch, not a formal patch.
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 111569c..eced407 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -910,6 +910,45 @@ static void pci_restore_pcie_state(struct pci_dev *dev)
pci_write_config_word(dev, pos + PCI_EXP_SLTCTL2, cap[i++]);
}
+static int pci_save_ltr_value(struct pci_dev *dev)
+{
+ int i = 0, pos;
+ struct pci_cap_saved_state *save_state;
+ u16 *cap;
+
+ pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
+ if (!pos)
+ return -ENOTSUPP;
+
+ save_state = pci_find_saved_cap(dev, PCI_EXT_CAP_ID_LTR);
+ if (!save_state) {
+ dev_err(&dev->dev, "buffer not found in %s\n", __func__);
+ return -ENOMEM;
+ }
+ cap = (u16 *)&save_state->cap.ltr_data[0];
+
+ pci_read_config_word(dev, pos + PCI_LTR_MAX_SNOOP_LAT, &cap[i++]);
+ pci_read_config_word(dev, pos + PCI_LTR_MAX_NOSNOOP_LAT, &cap[i++]);
+}
+
+static void pci_restore_ltr_value(struct pci_dev *dev)
+{
+ int i = 0, pos;
+ struct pci_cap_saved_state *save_state;
+ u16 *cap;
+
+ if (!pci_ltr_supported(dev))
+ return;
+
+ save_state = pci_find_saved_cap(dev, PCI_EXT_CAP_ID_LTR);
+ pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
+ if (!save_state || !pos)
+ return;
+ cap = (u16 *)&save_state->cap.ltr_data[0];
+
+ pci_write_config_word(dev, pos + PCI_LTR_MAX_SNOOP_LAT, cap[i++]);
+ pci_write_config_word(dev, pos + PCI_LTR_MAX_NOSNOOP_LAT, cap[i++]);
+}
static int pci_save_pcix_state(struct pci_dev *dev)
{
@@ -964,6 +1003,10 @@ pci_save_state(struct pci_dev *dev)
return i;
if ((i = pci_save_pcix_state(dev)) != 0)
return i;
+
+ if (pci_ltr_supported(dev))
+ return pci_save_ltr_value(dev);
+
return 0;
}
@@ -1032,6 +1075,7 @@ void pci_restore_state(struct pci_dev *dev)
pci_restore_pcix_state(dev);
pci_restore_msi_state(dev);
pci_restore_iov_state(dev);
+ pci_restore_ltr_value(dev);
dev->state_saved = false;
}
diff --git a/include/linux/pci.h b/include/linux/pci.h
index e444f5b..6343aeb 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -220,6 +220,7 @@ struct pci_cap_saved_data {
char cap_nr;
unsigned int size;
u32 data[0];
+ u32 ltr_data[0];
};
struct pci_cap_saved_state {
On Tue, May 8, 2012 at 3:09 AM, Hao, Xudong <[email protected]> wrote:
>> -----Original Message-----
>> From: Bjorn Helgaas [mailto:[email protected]]
>> > ?}
>> >
>>
>> This doesn't make any sense to me. ?"pos" is the offset of the PCI
>> Express Capability (identifier 10h). ?LTR is a separate extended
>> capability (identifier 18h), so you at least have to look up its
>> offset.
>>
> Sorry paste a wrong patch...
>
> How about this patch, not a formal patch.
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 111569c..eced407 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -910,6 +910,45 @@ static void pci_restore_pcie_state(struct pci_dev *dev)
> ? ? ? ? ? ? ? ?pci_write_config_word(dev, pos + PCI_EXP_SLTCTL2, cap[i++]);
> ?}
>
> +static int pci_save_ltr_value(struct pci_dev *dev)
> +{
> + ? ? ? int i = 0, pos;
> + ? ? ? struct pci_cap_saved_state *save_state;
> + ? ? ? u16 *cap;
> +
> + ? ? ? pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
> + ? ? ? if (!pos)
> + ? ? ? ? ? ? ? return -ENOTSUPP;
> +
> + ? ? ? save_state = pci_find_saved_cap(dev, PCI_EXT_CAP_ID_LTR);
> + ? ? ? if (!save_state) {
> + ? ? ? ? ? ? ? dev_err(&dev->dev, "buffer not found in %s\n", __func__);
> + ? ? ? ? ? ? ? return -ENOMEM;
> + ? ? ? }
> + ? ? ? cap = (u16 *)&save_state->cap.ltr_data[0];
> +
> + ? ? ? pci_read_config_word(dev, pos + PCI_LTR_MAX_SNOOP_LAT, &cap[i++]);
> + ? ? ? pci_read_config_word(dev, pos + PCI_LTR_MAX_NOSNOOP_LAT, &cap[i++]);
> +}
> +
> +static void pci_restore_ltr_value(struct pci_dev *dev)
> +{
> + ? ? ? int i = 0, pos;
> + ? ? ? struct pci_cap_saved_state *save_state;
> + ? ? ? u16 *cap;
> +
> + ? ? ? if (!pci_ltr_supported(dev))
> + ? ? ? ? ? ? ? return;
> +
> + ? ? ? save_state = pci_find_saved_cap(dev, PCI_EXT_CAP_ID_LTR);
> + ? ? ? pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
> + ? ? ? if (!save_state || !pos)
> + ? ? ? ? ? ? ? return;
> + ? ? ? cap = (u16 *)&save_state->cap.ltr_data[0];
> +
> + ? ? ? pci_write_config_word(dev, pos + PCI_LTR_MAX_SNOOP_LAT, cap[i++]);
> + ? ? ? pci_write_config_word(dev, pos + PCI_LTR_MAX_NOSNOOP_LAT, cap[i++]);
> +}
>
> ?static int pci_save_pcix_state(struct pci_dev *dev)
> ?{
> @@ -964,6 +1003,10 @@ pci_save_state(struct pci_dev *dev)
> ? ? ? ? ? ? ? ?return i;
> ? ? ? ?if ((i = pci_save_pcix_state(dev)) != 0)
> ? ? ? ? ? ? ? ?return i;
> +
> + ? ? ? if (pci_ltr_supported(dev))
> + ? ? ? ? ? ? ? return pci_save_ltr_value(dev);
> +
> ? ? ? ?return 0;
> ?}
>
> @@ -1032,6 +1075,7 @@ void pci_restore_state(struct pci_dev *dev)
> ? ? ? ?pci_restore_pcix_state(dev);
> ? ? ? ?pci_restore_msi_state(dev);
> ? ? ? ?pci_restore_iov_state(dev);
> + ? ? ? pci_restore_ltr_value(dev);
>
> ? ? ? ?dev->state_saved = false;
> ?}
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index e444f5b..6343aeb 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -220,6 +220,7 @@ struct pci_cap_saved_data {
> ? ? ? ?char cap_nr;
> ? ? ? ?unsigned int size;
> ? ? ? ?u32 data[0];
> + ? ? ? u32 ltr_data[0];
> ?};
>
> ?struct pci_cap_saved_state {
Did you test this?
I can't believe this works at all. You're calling
"pci_find_saved_cap(dev, PCI_EXT_CAP_ID_LTR)", which searches the
pci_dev->saved_cap_space list, but you never add a PCI_EXT_CAP_ID_LTR
buffer to that list.
Bjorn