[PATCH 6.6 130/283] PCI: Move pci_read_bridge_windows() below individual window accessors

Sasha Levin
2026-02-28T18:08:58Z

From: Bjorn Helgaas <bhelgaas@google.com>

[ Upstream commit 6f32099a91720b6d91da961858d48173f01a729d ]

Move pci_read_bridge_windows() below the functions that read the I/O,
memory, and prefetchable memory windows, so pci_read_bridge_windows() can
use them in the future. No functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Stable-dep-of: 9abf79c8d7b4 ("PCI/ACPI: Restrict program_hpx_type2() to AER bits")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/pci/probe.c | 102 ++++++++++++++++++++++----------------------
1 file changed, 51 insertions(+), 51 deletions(-)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index e51a5c38739a4..a43f9e9352e47 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -344,57 +344,6 @@ static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom)
}
}

-static void pci_read_bridge_windows(struct pci_dev *bridge)
-{
- u16 io;
- u32 pmem, tmp;
-
- pci_read_config_word(bridge, PCI_IO_BASE, &io);
- if (!io) {
- pci_write_config_word(bridge, PCI_IO_BASE, 0xe0f0);
- pci_read_config_word(bridge, PCI_IO_BASE, &io);
- pci_write_config_word(bridge, PCI_IO_BASE, 0x0);
- }
- if (io)
- bridge->io_window = 1;
-
- /*
- * DECchip 21050 pass 2 errata: the bridge may miss an address
- * disconnect boundary by one PCI data phase. Workaround: do not
- * use prefetching on this device.
- */
- if (bridge->vendor == PCI_VENDOR_ID_DEC && bridge->device == 0x0001)
- return;
-
- pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
- if (!pmem) {
- pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE,
- 0xffe0fff0);
- pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
- pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0x0);
- }
- if (!pmem)
- return;
-
- bridge->pref_window = 1;
-
- if ((pmem & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) {
-
- /*
- * Bridge claims to have a 64-bit prefetchable memory
- * window; verify that the upper bits are actually
- * writable.
- */
- pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &pmem);
- pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32,
- 0xffffffff);
- pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &tmp);
- pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, pmem);
- if (tmp)
- bridge->pref_64_window = 1;
- }
-}
-
static void pci_read_bridge_io(struct pci_bus *child)
{
struct pci_dev *dev = child->self;
@@ -510,6 +459,57 @@ static void pci_read_bridge_mmio_pref(struct pci_bus *child)
}
}

+static void pci_read_bridge_windows(struct pci_dev *bridge)
+{
+ u16 io;
+ u32 pmem, tmp;
+
+ pci_read_config_word(bridge, PCI_IO_BASE, &io);
+ if (!io) {
+ pci_write_config_word(bridge, PCI_IO_BASE, 0xe0f0);
+ pci_read_config_word(bridge, PCI_IO_BASE, &io);
+ pci_write_config_word(bridge, PCI_IO_BASE, 0x0);
+ }
+ if (io)
+ bridge->io_window = 1;
+
+ /*
+ * DECchip 21050 pass 2 errata: the bridge may miss an address
+ * disconnect boundary by one PCI data phase. Workaround: do not
+ * use prefetching on this device.
+ */
+ if (bridge->vendor == PCI_VENDOR_ID_DEC && bridge->device == 0x0001)
+ return;
+
+ pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
+ if (!pmem) {
+ pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE,
+ 0xffe0fff0);
+ pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
+ pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0x0);
+ }
+ if (!pmem)
+ return;
+
+ bridge->pref_window = 1;
+
+ if ((pmem & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) {
+
+ /*
+ * Bridge claims to have a 64-bit prefetchable memory
+ * window; verify that the upper bits are actually
+ * writable.
+ */
+ pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &pmem);
+ pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32,
+ 0xffffffff);
+ pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &tmp);
+ pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, pmem);
+ if (tmp)
+ bridge->pref_64_window = 1;
+ }
+}
+
void pci_read_bridge_bases(struct pci_bus *child)
{
struct pci_dev *dev = child->self;
--
2.51.0