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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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