x86: pci: Allow binding of some devices before relocation
At present only bridge devices are bound before relocation, to save space
in pre-relocation memory. In some cases we do actually want to bind a
device, e.g. because it provides the console UART. Add a devicetree
binding to support this.
Use the PCI_VENDEV() macro to encode the cell value. This is present in
U-Boot but not used, so move it to the binding header-file.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/doc/device-tree-bindings/pci/x86-pci.txt b/doc/device-tree-bindings/pci/x86-pci.txt
index 95e370b..cf4e5ed 100644
--- a/doc/device-tree-bindings/pci/x86-pci.txt
+++ b/doc/device-tree-bindings/pci/x86-pci.txt
@@ -20,6 +20,10 @@
output to be lost. This should not generally be used in production code,
although it is often harmless.
+- u-boot,pci-pre-reloc : List of vendor/device IDs to bind before relocation, even
+ if they are not bridges. This is useful if the device is needed (e.g. a
+ UART). The format is 0xvvvvdddd where d is the device ID and v is the
+ vendor ID.
Example:
@@ -32,7 +36,8 @@
0x42000000 0x0 0xb0000000 0xb0000000 0 0x10000000
0x01000000 0x0 0x1000 0x1000 0 0xefff>;
u-boot,skip-auto-config-until-reloc;
-
+ u-boot,pci-pre-reloc = <
+ PCI_VENDEV(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_APL_UART2)>;
serial: serial@18,2 {
reg = <0x0200c210 0 0 0 0>;
diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
index 67838b9..fb12732 100644
--- a/drivers/pci/pci-uclass.c
+++ b/drivers/pci/pci-uclass.c
@@ -21,6 +21,7 @@
#if defined(CONFIG_X86) && defined(CONFIG_HAVE_FSP)
#include <asm/fsp/fsp_support.h>
#endif
+#include <dt-bindings/pci/pci.h>
#include <linux/delay.h>
#include "pci_internal.h"
@@ -682,6 +683,34 @@
}
/**
+ * pci_need_device_pre_reloc() - Check if a device should be bound
+ *
+ * This checks a list of vendor/device-ID values indicating devices that should
+ * be bound before relocation.
+ *
+ * @bus: Bus to check
+ * @vendor: Vendor ID to check
+ * @device: Device ID to check
+ * @return true if the vendor/device is in the list, false if not
+ */
+static bool pci_need_device_pre_reloc(struct udevice *bus, uint vendor,
+ uint device)
+{
+ u32 vendev;
+ int index;
+
+ for (index = 0;
+ !dev_read_u32_index(bus, "u-boot,pci-pre-reloc", index,
+ &vendev);
+ index++) {
+ if (vendev == PCI_VENDEV(vendor, device))
+ return true;
+ }
+
+ return false;
+}
+
+/**
* pci_find_and_bind_driver() - Find and bind the right PCI driver
*
* This only looks at certain fields in the descriptor.
@@ -769,7 +798,9 @@
* precious memory space as on some platforms as that space is pretty
* limited (ie: using Cache As RAM).
*/
- if (!(gd->flags & GD_FLG_RELOC) && !bridge)
+ if (!(gd->flags & GD_FLG_RELOC) && !bridge &&
+ !pci_need_device_pre_reloc(parent, find_id->vendor,
+ find_id->device))
return log_msg_ret("notbr", -EPERM);
/* Bind a generic driver so that the device can be used */
diff --git a/include/dt-bindings/pci/pci.h b/include/dt-bindings/pci/pci.h
new file mode 100644
index 0000000..e729027
--- /dev/null
+++ b/include/dt-bindings/pci/pci.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * This header provides common constants for PCI bindings.
+ */
+
+#ifndef _DT_BINDINGS_PCI_PCI_H
+#define _DT_BINDINGS_PCI_PCI_H
+
+/* Encode a vendor and device ID into a single cell */
+#define PCI_VENDEV(v, d) (((v) << 16) | (d))
+
+#endif /* _DT_BINDINGS_PCI_PCI_H */
diff --git a/include/pci.h b/include/pci.h
index 9a8ba03..258c8f8 100644
--- a/include/pci.h
+++ b/include/pci.h
@@ -578,7 +578,6 @@
#define PCI_MASK_BUS(bdf) ((bdf) & 0xffff)
#define PCI_ADD_BUS(bus, devfn) (((bus) << 16) | (devfn))
#define PCI_BDF(b, d, f) ((b) << 16 | PCI_DEVFN(d, f))
-#define PCI_VENDEV(v, d) (((v) << 16) | (d))
#define PCI_ANY_ID (~0)
/* Convert from Linux format to U-Boot format */