Commit 63f4898a authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Jesse Barnes
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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: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatar"Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent 894886e5

drivers/pci/pci.c

+51 −22
Original line number Diff line number Diff line
@@ -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

drivers/pci/pci.h

+1 −0
Original line number Diff line number Diff line
@@ -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);

drivers/pci/probe.c

+3 −0
Original line number Diff line number Diff line
@@ -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);

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