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Subject[patch 84/85] PCI: handle PCI state saving with interrupts disabled
2.6.27-stable review patch.  If anyone has any objections, please let us know.

------------------
From: Rafael J. Wysocki <rjw@sisk.pl>

commit 63f4898ace2788a89ed685672aab092e1c3e50e6 upstream.

Since interrupts will soon be disabled at PCI resume time, we need to
pre-allocate memory to save/restore PCI config space (or use GFP_ATOMIC,
but this is safer).

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/pci/pci.c | 72 ++++++++++++++++++++++++++++++++++++----------------
drivers/pci/pci.h | 1
drivers/pci/probe.c | 3 ++
3 files changed, 54 insertions(+), 22 deletions(-)
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -636,19 +636,14 @@ static int pci_save_pcie_state(struct pc
int pos, i = 0;
struct pci_cap_saved_state *save_state;
u16 *cap;
- int found = 0;

pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
if (pos <= 0)
return 0;

save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);
- if (!save_state)
- save_state = kzalloc(sizeof(*save_state) + sizeof(u16) * 4, GFP_KERNEL);
- else
- found = 1;
if (!save_state) {
- dev_err(&dev->dev, "out of memory in pci_save_pcie_state\n");
+ dev_err(&dev->dev, "buffer not found in %s\n", __FUNCTION__);
return -ENOMEM;
}
cap = (u16 *)&save_state->data[0];
@@ -657,9 +652,7 @@ static int pci_save_pcie_state(struct pc
pci_read_config_word(dev, pos + PCI_EXP_LNKCTL, &cap[i++]);
pci_read_config_word(dev, pos + PCI_EXP_SLTCTL, &cap[i++]);
pci_read_config_word(dev, pos + PCI_EXP_RTCTL, &cap[i++]);
- save_state->cap_nr = PCI_CAP_ID_EXP;
- if (!found)
- pci_add_saved_cap(dev, save_state);
+
return 0;
}

@@ -684,30 +677,21 @@ static void pci_restore_pcie_state(struc

static int pci_save_pcix_state(struct pci_dev *dev)
{
- int pos, i = 0;
+ int pos;
struct pci_cap_saved_state *save_state;
- u16 *cap;
- int found = 0;

pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
if (pos <= 0)
return 0;

save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX);
- if (!save_state)
- save_state = kzalloc(sizeof(*save_state) + sizeof(u16), GFP_KERNEL);
- else
- found = 1;
if (!save_state) {
- dev_err(&dev->dev, "out of memory in pci_save_pcie_state\n");
+ dev_err(&dev->dev, "buffer not found in %s\n", __FUNCTION__);
return -ENOMEM;
}
- cap = (u16 *)&save_state->data[0];

- pci_read_config_word(dev, pos + PCI_X_CMD, &cap[i++]);
- save_state->cap_nr = PCI_CAP_ID_PCIX;
- if (!found)
- pci_add_saved_cap(dev, save_state);
+ pci_read_config_word(dev, pos + PCI_X_CMD, (u16 *)save_state->data);
+
return 0;
}

@@ -726,6 +710,50 @@ static void pci_restore_pcix_state(struc
pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]);
}

+ /**
+ * pci_add_save_buffer - allocate buffer for saving given capability registers
+ * @dev: the PCI device
+ * @cap: the capability to allocate the buffer for
+ * @size: requested size of the buffer
+ */
+static int pci_add_cap_save_buffer(
+ struct pci_dev *dev, char cap, unsigned int size)
+{
+ int pos;
+ struct pci_cap_saved_state *save_state;
+
+ pos = pci_find_capability(dev, cap);
+ if (pos <= 0)
+ return 0;
+
+ save_state = kzalloc(sizeof(*save_state) + size, GFP_KERNEL);
+ if (!save_state)
+ return -ENOMEM;
+
+ save_state->cap_nr = cap;
+ pci_add_saved_cap(dev, save_state);
+
+ return 0;
+}
+
+/**
+ * pci_allocate_cap_save_buffers - allocate buffers for saving capabilities
+ * @dev: the PCI device
+ */
+void pci_allocate_cap_save_buffers(struct pci_dev *dev)
+{
+ int error;
+
+ error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_EXP, 4 * sizeof(u16));
+ 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));
+ if (error)
+ dev_err(&dev->dev,
+ "unable to preallocate PCI-X save buffer\n");
+}

/**
* pci_save_state - save the PCI configuration space of a device before suspending
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -35,6 +35,7 @@ struct pci_platform_pm_ops {

extern int pci_set_platform_pm(struct pci_platform_pm_ops *ops);
extern void pci_pm_init(struct pci_dev *dev);
+extern void pci_allocate_cap_save_buffers(struct pci_dev *dev);

extern int pci_user_read_config_byte(struct pci_dev *dev, int where, u8 *val);
extern int pci_user_read_config_word(struct pci_dev *dev, int where, u16 *val);
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1028,6 +1028,9 @@ void pci_device_add(struct pci_dev *dev,
/* Fix up broken headers */
pci_fixup_device(pci_fixup_header, dev);

+ /* Buffers for saving PCIe and PCI-X capabilities */
+ pci_allocate_cap_save_buffers(dev);
+
/* Initialize power management of the device */
pci_pm_init(dev);



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