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

Message ID 571bf109b9db5b826eb814da603ac194e82981d4.1740382735.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 Feb. 24, 2025, 9:18 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>
---
 xen/arch/arm/pci/pci-host-rcar4.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/xen/arch/arm/pci/pci-host-rcar4.c b/xen/arch/arm/pci/pci-host-rcar4.c
index 3e3e073b09..5d006e4897 100644
--- a/xen/arch/arm/pci/pci-host-rcar4.c
+++ b/xen/arch/arm/pci/pci-host-rcar4.c
@@ -385,7 +385,7 @@  static void __iomem *rcar4_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,
@@ -393,7 +393,7 @@  static void __iomem *rcar4_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;
 }
 
 static int rcar4_child_config_read(struct pci_host_bridge *bridge,