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Date: Fri, 8 Jun 2012 16:01:32 +0800
From: Xudong Hao <xudong.hao@...el.com>
To: bhelgaas@...gle.com
Cc: linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org,
kvm@...r.kernel.org, avi@...hat.com, alex.williamson@...hat.com,
ddutile@...hat.com, myron.stowe@...hat.com,
xiantao.zhang@...el.com, xudong.hao@...el.com
Subject: [PATCH 4/4] PCI: save/restore max Latency Value for device LTR
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 <xudong.hao@...el.com>
---
drivers/pci/pci.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++---
drivers/pci/probe.c | 5 +++-
2 files changed, 71 insertions(+), 5 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 35127c1..7172f15 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -912,6 +912,54 @@ static void pci_restore_pcie_state(struct pci_dev *dev)
pci_write_config_word(dev, pos + PCI_EXP_SLTCTL2, cap[i++]);
}
+#define PCI_LTR_SAVE_REGS 2
+
+static int pci_save_ltr_value(struct pci_dev *dev)
+{
+ int i = 0, pos;
+ struct pci_cap_saved_state *save_state;
+ u16 *cap;
+ u16 ctrl;
+
+ pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR);
+ if (!pos)
+ return -ENOTSUPP;
+
+ /* Check if LTR is eanbled before save value */
+ pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
+ if (!(ctrl & PCI_EXP_LTR_EN))
+ 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.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++]);
+ return 0;
+}
+
+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.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)
{
@@ -966,6 +1014,11 @@ pci_save_state(struct pci_dev *dev)
return i;
if ((i = pci_save_pcix_state(dev)) != 0)
return i;
+
+ if (pci_ltr_supported(dev))
+ if ((i = pci_save_ltr_value(dev)) != 0)
+ return i;
+
return 0;
}
@@ -1034,6 +1087,7 @@ 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;
}
@@ -1955,12 +2009,15 @@ static void pci_add_saved_cap(struct pci_dev *pci_dev,
* @size: requested size of the buffer
*/
static int pci_add_cap_save_buffer(
- struct pci_dev *dev, char cap, unsigned int size)
+ struct pci_dev *dev, char cap, unsigned int size, bool is_extcap)
{
int pos;
struct pci_cap_saved_state *save_state;
- pos = pci_find_capability(dev, cap);
+ if (is_extcap)
+ pos = pci_find_ext_capability(dev, cap);
+ else
+ pos = pci_find_capability(dev, cap);
if (pos <= 0)
return 0;
@@ -1984,15 +2041,21 @@ void pci_allocate_cap_save_buffers(struct pci_dev *dev)
int error;
error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_EXP,
- PCI_EXP_SAVE_REGS * sizeof(u16));
+ PCI_EXP_SAVE_REGS * sizeof(u16), 0);
if (error)
dev_err(&dev->dev,
"unable to preallocate PCI Express save buffer\n");
- error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_PCIX, sizeof(u16));
+ error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_PCIX, sizeof(u16), 0);
if (error)
dev_err(&dev->dev,
"unable to preallocate PCI-X save buffer\n");
+
+ error = pci_add_cap_save_buffer(dev, PCI_EXT_CAP_ID_LTR,
+ PCI_LTR_SAVE_REGS * sizeof(u16), 1);
+ if (error)
+ dev_err(&dev->dev,
+ "unable to preallocate LTR save buffer\n");
}
void pci_free_cap_save_buffers(struct pci_dev *dev)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 658ac97..a6eb509 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1232,7 +1232,10 @@ static void pci_init_capabilities(struct pci_dev *dev)
/* MSI/MSI-X list */
pci_msi_init_pci_dev(dev);
- /* Buffers for saving PCIe and PCI-X capabilities */
+ /*
+ * Buffers for saving PCIe and PCI-X capabilities
+ * and for saving LTR extented capabilities.
+ */
pci_allocate_cap_save_buffers(dev);
/* Power Management */
--
1.5.5
--
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