This is a note to let you know that I've just added the patch titled
PCI: Unify ACS quirk desired vs provided checking
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pci-unify-acs-quirk-desired-vs-provided-checking.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 86358c02c9fdb760ea4a13e5aa3c2e5a3a67e07c
Author: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Date: Fri Sep 6 18:36:06 2019 -0500
PCI: Unify ACS quirk desired vs provided checking
commit 7cf2cba43f15c74bac46dc5f0326805d25ef514d upstream.
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@xxxxxxxxxx>
Reviewed-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Reviewed-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 2b413a3a33582..fbbf6c325d336 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -4352,6 +4352,24 @@ static void quirk_chelsio_T5_disable_root_port_attributes(struct pci_dev *pdev)
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_CHELSIO, PCI_ANY_ID,
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
@@ -4395,7 +4413,7 @@ static int pci_quirk_amd_sb_acs(struct pci_dev *dev, u16 acs_flags)
/* 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
@@ -4433,9 +4451,8 @@ static int pci_quirk_cavium_acs(struct pci_dev *dev, u16 acs_flags)
* 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)
@@ -4445,9 +4462,8 @@ static int pci_quirk_xgene_acs(struct pci_dev *dev, u16 acs_flags)
* 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);
}
/*
@@ -4499,17 +4515,16 @@ static bool pci_quirk_intel_pch_acs_match(struct pci_dev *dev)
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);
}
/*
@@ -4524,9 +4539,8 @@ static int pci_quirk_intel_pch_acs(struct pci_dev *dev, u16 acs_flags)
*/
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)
@@ -4627,7 +4641,7 @@ static int pci_quirk_intel_spt_pch_acs(struct pci_dev *dev, u16 acs_flags)
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)
@@ -4641,10 +4655,9 @@ static int pci_quirk_mf_endpoint_acs(struct pci_dev *dev, u16 acs_flags)
* 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)
@@ -4655,9 +4668,8 @@ static int pci_quirk_brcm_acs(struct pci_dev *dev, u16 acs_flags)
* 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 {
@@ -4763,6 +4775,17 @@ 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;
