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PCI: handle PCI state saving with interrupts disabled 

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>
hifive-unleashed-5.1
Rafael J. Wysocki 2008-12-07 22:02:58 +01:00 committed by Jesse Barnes
parent 894886e5d3
commit 63f4898ace
3 changed files with 55 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

73
drivers/pci/pci.c
View File

@ -640,19 +640,14 @@ static int pci_save_pcie_state(struct pci_dev *dev)
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];
@ -661,9 +656,7 @@ static int pci_save_pcie_state(struct pci_dev *dev)
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;
}
@ -688,30 +681,21 @@ static void pci_restore_pcie_state(struct pci_dev *dev)
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;
}
@ -1300,6 +1284,51 @@ void pci_pm_init(struct pci_dev *dev)
}
}
/**
* 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_enable_ari - enable ARI forwarding if hardware support it
* @dev: the PCI device

1
drivers/pci/pci.h
View File

@ -45,6 +45,7 @@ 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);

3
drivers/pci/probe.c
View File

@ -958,6 +958,9 @@ 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 */
pci_allocate_cap_save_buffers(dev);
/* Power Management */
pci_pm_init(dev);