diff mbox series

[v2,7/7] xen/arm: rcar4: program ATU to accesses to all functions

Message ID 10bf9a3b4489242cf9407a2f70d84be378e9c206.1741596512.git.mykyta_poturai@epam.com (mailing list archive)
State New
Headers show
Series Add support for R-Car Gen4 PCI host controller | expand

Commit Message

Mykyta Poturai March 11, 2025, 10:24 a.m. UTC 
From: Volodymyr Babchuk <volodymyr_babchuk@epam.com>

According to ATU documentation, bits [18:16] of accessed memory
address correspond to a function number. This is somewhat similar to
ECAM, but with huge holes between regions.

We can use this to minimize number of ATU re-programmings: configure
ATU to access BDF with F=0 and adjust memory address with function
number.

Taking into account the previous patch, that optimizes ATU
reprogramming by skipping call to __dw_pcie_prog_outbound_atu() if we
already configured pci_address, we can be sure that accesses to all
functions of one device will not trigger ATU reprogramming at all.

Signed-off-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com>
Signed-off-by: Mykyta Poturai <mykyta_poturai@epam.com>
---
v1->v2:
* rebased
---
 xen/arch/arm/pci/pci-designware.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/xen/arch/arm/pci/pci-designware.c b/xen/arch/arm/pci/pci-designware.c
index cec52cf81a..fec8c7296d 100644
--- a/xen/arch/arm/pci/pci-designware.c
+++ b/xen/arch/arm/pci/pci-designware.c
@@ -297,7 +297,7 @@  void __iomem *dw_pcie_child_map_bus(struct pci_host_bridge *bridge,
     uint32_t busdev;
 
     busdev = PCIE_ATU_BUS(sbdf.bus) | PCIE_ATU_DEV(PCI_SLOT(sbdf.devfn)) |
-        PCIE_ATU_FUNC(PCI_FUNC(sbdf.devfn));
+        PCIE_ATU_FUNC(0);
 
     /* FIXME: Parent is the root bus, so use PCIE_ATU_TYPE_CFG0. */
     dw_pcie_prog_outbound_atu(bridge, PCIE_ATU_REGION_INDEX1,
@@ -305,7 +305,7 @@  void __iomem *dw_pcie_child_map_bus(struct pci_host_bridge *bridge,
                               bridge->child_cfg->phys_addr,
                               busdev, bridge->child_cfg->size);
 
-    return bridge->child_cfg->win + where;
+    return bridge->child_cfg->win + ((uint32_t)sbdf.fn << 16) + where;
 }
 
 int dw_pcie_child_config_read(struct pci_host_bridge *bridge,