[PATCH v6 2/3] PCI: Add parameter nr_devfns to pci_add_dma_alias

James Sewart
2019-12-03T15:43:58Z

pci_add_dma_alias can now be used to create a dma alias for a range of
devfns.

Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: James Sewart <jamessewart@arista.com>
---
drivers/pci/pci.c | 22 +++++++++++++++++-----
drivers/pci/quirks.c | 14 +++++++-------
include/linux/pci.h | 2 +-
3 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index d3c83248f3ce..dbb01aceafda 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5857,7 +5857,8 @@ int pci_set_vga_state(struct pci_dev *dev, bool decode,
/**
* pci_add_dma_alias - Add a DMA devfn alias for a device
* @dev: the PCI device for which alias is added
- * @devfn: alias slot and function
+ * @devfn_from: alias slot and function
+ * @nr_devfns: Number of subsequent devfns to alias
*
* This helper encodes an 8-bit devfn as a bit number in dma_alias_mask
* which is used to program permissible bus-devfn source addresses for DMA
@@ -5873,8 +5874,13 @@ int pci_set_vga_state(struct pci_dev *dev, bool decode,
* cannot be left as a userspace activity). DMA aliases should therefore
* be configured via quirks, such as the PCI fixup header quirk.
*/
-void pci_add_dma_alias(struct pci_dev *dev, u8 devfn)
+void pci_add_dma_alias(struct pci_dev *dev, u8 devfn_from, unsigned nr_devfns)
{
+ int devfn_to;
+
+ nr_devfns = min(nr_devfns, (unsigned)MAX_NR_DEVFNS);
+ devfn_to = devfn_from + nr_devfns - 1;
+
if (!dev->dma_alias_mask)
dev->dma_alias_mask = bitmap_zalloc(MAX_NR_DEVFNS, GFP_KERNEL);
if (!dev->dma_alias_mask) {
@@ -5882,9 +5888,15 @@ void pci_add_dma_alias(struct pci_dev *dev, u8 devfn)
return;
}

- set_bit(devfn, dev->dma_alias_mask);
- pci_info(dev, "Enabling fixed DMA alias to %02x.%d\n",
- PCI_SLOT(devfn), PCI_FUNC(devfn));
+ bitmap_set(dev->dma_alias_mask, devfn_from, nr_devfns);
+
+ if (nr_devfns == 1)
+ pci_info(dev, "Enabling fixed DMA alias to %02x.%d\n",
+ PCI_SLOT(devfn_from), PCI_FUNC(devfn_from));
+ else if(nr_devfns > 1)
+ pci_info(dev, "Enabling fixed DMA alias for devfn range from %02x.%d to %02x.%d\n",
+ PCI_SLOT(devfn_from), PCI_FUNC(devfn_from),
+ PCI_SLOT(devfn_to), PCI_FUNC(devfn_to));
}

bool pci_devs_are_dma_aliases(struct pci_dev *dev1, struct pci_dev *dev2)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 320255e5e8f8..0f3f5afc73fd 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3932,7 +3932,7 @@ int pci_dev_specific_reset(struct pci_dev *dev, int probe)
static void quirk_dma_func0_alias(struct pci_dev *dev)
{
if (PCI_FUNC(dev->devfn) != 0)
- pci_add_dma_alias(dev, PCI_DEVFN(PCI_SLOT(dev->devfn), 0));
+ pci_add_dma_alias(dev, PCI_DEVFN(PCI_SLOT(dev->devfn), 0), 1);
}

/*
@@ -3946,7 +3946,7 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_RICOH, 0xe476, quirk_dma_func0_alias);
static void quirk_dma_func1_alias(struct pci_dev *dev)
{
if (PCI_FUNC(dev->devfn) != 1)
- pci_add_dma_alias(dev, PCI_DEVFN(PCI_SLOT(dev->devfn), 1));
+ pci_add_dma_alias(dev, PCI_DEVFN(PCI_SLOT(dev->devfn), 1), 1);
}

/*
@@ -4031,7 +4031,7 @@ static void quirk_fixed_dma_alias(struct pci_dev *dev)

id = pci_match_id(fixed_dma_alias_tbl, dev);
if (id)
- pci_add_dma_alias(dev, id->driver_data);
+ pci_add_dma_alias(dev, id->driver_data, 1);
}

DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ADAPTEC2, 0x0285, quirk_fixed_dma_alias);
@@ -4073,9 +4073,9 @@ DECLARE_PCI_FIXUP_HEADER(0x8086, 0x244e, quirk_use_pcie_bridge_dma_alias);
*/
static void quirk_mic_x200_dma_alias(struct pci_dev *pdev)
{
- pci_add_dma_alias(pdev, PCI_DEVFN(0x10, 0x0));
- pci_add_dma_alias(pdev, PCI_DEVFN(0x11, 0x0));
- pci_add_dma_alias(pdev, PCI_DEVFN(0x12, 0x3));
+ pci_add_dma_alias(pdev, PCI_DEVFN(0x10, 0x0), 1);
+ pci_add_dma_alias(pdev, PCI_DEVFN(0x11, 0x0), 1);
+ pci_add_dma_alias(pdev, PCI_DEVFN(0x12, 0x3), 1);
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2260, quirk_mic_x200_dma_alias);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2264, quirk_mic_x200_dma_alias);
@@ -5273,7 +5273,7 @@ static void quirk_switchtec_ntb_dma_alias(struct pci_dev *pdev)
pci_dbg(pdev,
"Aliasing Partition %d Proxy ID %02x.%d\n",
pp, PCI_SLOT(devfn), PCI_FUNC(devfn));
- pci_add_dma_alias(pdev, devfn);
+ pci_add_dma_alias(pdev, devfn, 1);
}
}

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 6481da29d667..e7a9c8c92a93 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -2325,7 +2325,7 @@ static inline struct eeh_dev *pci_dev_to_eeh_dev(struct pci_dev *pdev)
}
#endif

-void pci_add_dma_alias(struct pci_dev *dev, u8 devfn);
+void pci_add_dma_alias(struct pci_dev *dev, u8 devfn_from, unsigned nr_devfns);
bool pci_devs_are_dma_aliases(struct pci_dev *dev1, struct pci_dev *dev2);
int pci_for_each_dma_alias(struct pci_dev *pdev,
int (*fn)(struct pci_dev *pdev,
--
2.24.0