981-1-PCI-Reverse-standard-ACS-vs-device-specific-ACS-enabling.patch

   1 From: Alex Williamson <alex.williamson@redhat.com>
   2 Subject: [PATCH 1/2] PCI: Reverse standard ACS vs device specific ACS enabling
   3
   4 The original thought was that if a device implemented ACS, then surely
   5 we want to use that... well, it turns out that devices can make an ACS
   6 capability so broken that we still need to fall back to quirks.
   7 Reverse the order of ACS enabling to give quirks first shot at it.
   8
   9 Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
  10 ---
  11  drivers/pci/pci.c    |   10 ++++------
  12  drivers/pci/quirks.c |    6 ++++--
  13  include/linux/pci.h  |    7 +++++--
  14  3 files changed, 13 insertions(+), 10 deletions(-)
  15
  16 diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
  17 index 25e0327..c98c4e2 100644
  18 --- a/drivers/pci/pci.c
  19 +++ b/drivers/pci/pci.c
  20 @@ -2548,7 +2548,7 @@ void pci_request_acs(void)
  21   * pci_std_enable_acs - enable ACS on devices using standard ACS capabilites
  22   * @dev: the PCI device
  23   */
  24 -static int pci_std_enable_acs(struct pci_dev *dev)
  25 +static void pci_std_enable_acs(struct pci_dev *dev)
  26  {
  27         int pos;
  28         u16 cap;
  29 @@ -2556,7 +2556,7 @@ static int pci_std_enable_acs(struct pci_dev *dev)
  30
  31         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
  32         if (!pos)
  33 -               return -ENODEV;
  34 +               return;
  35
  36         pci_read_config_word(dev, pos + PCI_ACS_CAP, &cap);
  37         pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
  38 @@ -2574,8 +2574,6 @@ static int pci_std_enable_acs(struct pci_dev *dev)
  39         ctrl |= (cap & PCI_ACS_UF);
  40
  41         pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
  42 -
  43 -       return 0;
  44  }
  45
  46  /**
  47 @@ -2585,10 +2585,10 @@ void pci_enable_acs(struct pci_dev *dev)
  48         if (!pci_acs_enable)
  49                 return;
  50
  51 -       if (!pci_std_enable_acs(dev))
  52 +       if (!pci_dev_specific_enable_acs(dev))
  53                 return;
  54
  55 -       pci_dev_specific_enable_acs(dev);
  56 +       pci_std_enable_acs(dev);
  57  }
  58
  59  static bool pci_acs_flags_enabled(struct pci_dev *pdev, u16 acs_flags)
  60 diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
  61 index 8e67802..701fad6 100644
  62 --- a/drivers/pci/quirks.c
  63 +++ b/drivers/pci/quirks.c
  64 @@ -4224,7 +4224,7 @@ static const struct pci_dev_enable_acs {
  65         { 0 }
  66  };
  67
  68 -void pci_dev_specific_enable_acs(struct pci_dev *dev)
  69 +int pci_dev_specific_enable_acs(struct pci_dev *dev)
  70  {
  71         const struct pci_dev_enable_acs *i;
  72         int ret;
  73 @@ -4236,9 +4236,11 @@ void pci_dev_specific_enable_acs(struct pci_dev *dev)
  74                      i->device == (u16)PCI_ANY_ID)) {
  75                         ret = i->enable_acs(dev);
  76                         if (ret >= 0)
  77 -                               return;
  78 +                               return ret;
  79                 }
  80         }
  81 +
  82 +       return -ENOTTY;
  83  }
  84
  85  /*
  86 diff --git a/include/linux/pci.h b/include/linux/pci.h
  87 index 004b813..aaec79a 100644
  88 --- a/include/linux/pci.h
  89 +++ b/include/linux/pci.h
  90 @@ -1657,7 +1657,7 @@ enum pci_fixup_pass {
  91  #ifdef CONFIG_PCI_QUIRKS
  92  void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev);
  93  int pci_dev_specific_acs_enabled(struct pci_dev *dev, u16 acs_flags);
  94 -void pci_dev_specific_enable_acs(struct pci_dev *dev);
  95 +int pci_dev_specific_enable_acs(struct pci_dev *dev);
  96  #else
  97  static inline void pci_fixup_device(enum pci_fixup_pass pass,
  98                                     struct pci_dev *dev) { }
  99 @@ -1666,7 +1666,10 @@ static inline int pci_dev_specific_acs_enabled(struct pci_dev *dev,
 100  {
 101         return -ENOTTY;
 102  }
 103 -static inline void pci_dev_specific_enable_acs(struct pci_dev *dev) { }
 104 +static inline int pci_dev_specific_enable_acs(struct pci_dev *dev)
 105 +{
 106 +       return -ENOTTY;
 107 +}
 108  #endif
 109
 110  void __iomem *pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen);