From: Bjorn Helgaas <bhelgaas@google.com>
Date: Fri, 6 Sep 2019 18:36:06 -0500
Subject: PCI: Unify ACS quirk desired vs provided checking
Git-commit: 7cf2cba43f15c74bac46dc5f0326805d25ef514d
Patch-mainline: 5.5-rc1
References: git-fixes
Most of the ACS quirks have a similar pattern of:
acs_flags &= ~( <controls provided by this device> );
return acs_flags ? 0 : 1;
Pull this out into a helper function to simplify the quirks slightly. The
helper function is also a convenient place for comments about what the list
of ACS controls means. No functional change intended.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/pci/quirks.c | 67 ++++++++++++++++++++++++++++++++++-----------------
1 file changed, 45 insertions(+), 22 deletions(-)
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -4379,6 +4379,24 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_C
quirk_chelsio_T5_disable_root_port_attributes);
/*
+ * pci_acs_ctrl_enabled - compare desired ACS controls with those provided
+ * by a device
+ * @acs_ctrl_req: Bitmask of desired ACS controls
+ * @acs_ctrl_ena: Bitmask of ACS controls enabled or provided implicitly by
+ * the hardware design
+ *
+ * Return 1 if all ACS controls in the @acs_ctrl_req bitmask are included
+ * in @acs_ctrl_ena, i.e., the device provides all the access controls the
+ * caller desires. Return 0 otherwise.
+ */
+static int pci_acs_ctrl_enabled(u16 acs_ctrl_req, u16 acs_ctrl_ena)
+{
+ if ((acs_ctrl_req & acs_ctrl_ena) == acs_ctrl_req)
+ return 1;
+ return 0;
+}
+
+/*
* AMD has indicated that the devices below do not support peer-to-peer
* in any system where they are found in the southbridge with an AMD
* IOMMU in the system. Multifunction devices that do not support
@@ -4421,7 +4439,7 @@ static int pci_quirk_amd_sb_acs(struct p
/* Filter out flags not applicable to multifunction */
acs_flags &= (PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_EC | PCI_ACS_DT);
- return acs_flags & ~(PCI_ACS_RR | PCI_ACS_CR) ? 0 : 1;
+ return pci_acs_ctrl_enabled(acs_flags, PCI_ACS_RR | PCI_ACS_CR);
#else
return -ENODEV;
#endif
@@ -4459,9 +4477,8 @@ static int pci_quirk_cavium_acs(struct p
* hardware implements and enables equivalent ACS functionality for
* these flags.
*/
- acs_flags &= ~(PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
-
- return acs_flags ? 0 : 1;
+ return pci_acs_ctrl_enabled(acs_flags,
+ PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
}
static int pci_quirk_xgene_acs(struct pci_dev *dev, u16 acs_flags)
@@ -4471,9 +4488,8 @@ static int pci_quirk_xgene_acs(struct pc
* transactions with others, allowing masking out these bits as if they
* were unimplemented in the ACS capability.
*/
- acs_flags &= ~(PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
-
- return acs_flags ? 0 : 1;
+ return pci_acs_ctrl_enabled(acs_flags,
+ PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
}
/*
@@ -4525,17 +4541,16 @@ static bool pci_quirk_intel_pch_acs_matc
return false;
}
-#define INTEL_PCH_ACS_FLAGS (PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF)
-
static int pci_quirk_intel_pch_acs(struct pci_dev *dev, u16 acs_flags)
{
if (!pci_quirk_intel_pch_acs_match(dev))
return -ENOTTY;
if (dev->dev_flags & PCI_DEV_FLAGS_ACS_ENABLED_QUIRK)
- acs_flags &= ~(INTEL_PCH_ACS_FLAGS);
+ return pci_acs_ctrl_enabled(acs_flags,
+ PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
- return acs_flags ? 0 : 1;
+ return pci_acs_ctrl_enabled(acs_flags, 0);
}
/*
@@ -4550,9 +4565,8 @@ static int pci_quirk_intel_pch_acs(struc
*/
static int pci_quirk_qcom_rp_acs(struct pci_dev *dev, u16 acs_flags)
{
- acs_flags &= ~(PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
-
- return acs_flags ? 0 : 1;
+ return pci_acs_ctrl_enabled(acs_flags,
+ PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
}
static int pci_quirk_al_acs(struct pci_dev *dev, u16 acs_flags)
@@ -4653,7 +4667,7 @@ static int pci_quirk_intel_spt_pch_acs(s
pci_read_config_dword(dev, pos + INTEL_SPT_ACS_CTRL, &ctrl);
- return acs_flags & ~ctrl ? 0 : 1;
+ return pci_acs_ctrl_enabled(acs_flags, ctrl);
}
static int pci_quirk_mf_endpoint_acs(struct pci_dev *dev, u16 acs_flags)
@@ -4667,10 +4681,9 @@ static int pci_quirk_mf_endpoint_acs(str
* perform peer-to-peer with other functions, allowing us to mask out
* these bits as if they were unimplemented in the ACS capability.
*/
- acs_flags &= ~(PCI_ACS_SV | PCI_ACS_TB | PCI_ACS_RR |
- PCI_ACS_CR | PCI_ACS_UF | PCI_ACS_DT);
-
- return acs_flags ? 0 : 1;
+ return pci_acs_ctrl_enabled(acs_flags,
+ PCI_ACS_SV | PCI_ACS_TB | PCI_ACS_RR |
+ PCI_ACS_CR | PCI_ACS_UF | PCI_ACS_DT);
}
static int pci_quirk_brcm_acs(struct pci_dev *dev, u16 acs_flags)
@@ -4681,9 +4694,8 @@ static int pci_quirk_brcm_acs(struct pci
* Allow each Root Port to be in a separate IOMMU group by masking
* SV/RR/CR/UF bits.
*/
- acs_flags &= ~(PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
-
- return acs_flags ? 0 : 1;
+ return pci_acs_ctrl_enabled(acs_flags,
+ PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
}
static const struct pci_dev_acs_enabled {
@@ -4783,6 +4795,17 @@ static const struct pci_dev_acs_enabled
{ 0 }
};
+/*
+ * pci_dev_specific_acs_enabled - check whether device provides ACS controls
+ * @dev: PCI device
+ * @acs_flags: Bitmask of desired ACS controls
+ *
+ * Returns:
+ * -ENOTTY: No quirk applies to this device; we can't tell whether the
+ * device provides the desired controls
+ * 0: Device does not provide all the desired controls
+ * >0: Device provides all the controls in @acs_flags
+ */
int pci_dev_specific_acs_enabled(struct pci_dev *dev, u16 acs_flags)
{
const struct pci_dev_acs_enabled *i;