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 95e370b3e72bc92e0e3042ef155c69a5fcbbcd63..cf4e5ed595a9353ee92ee73cb551e362fbdd85c1 100644 (file)
--- a/doc/device-tree-bindings/pci/x86-pci.txt
+++ b/doc/device-tree-bindings/pci/x86-pci.txt
@@ -20,6 +20,10 @@ For PCI devices the following optional property is available:
        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 @@ pci {
                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 67838b94f9beb88b2eb040ca16b1f3e5b45f6b71..fb12732926d4577c2d3c15853af4cf05afbe467d 100644 (file)
--- 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"
 
@@ -681,6 +682,34 @@ static bool pci_match_one_id(const struct pci_device_id *id,
        return false;
 }
 
+/**
+ * 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
  *
@@ -769,7 +798,9 @@ static int pci_find_and_bind_driver(struct udevice *parent,
         * 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 (file)
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 9a8ba03c8d2f692e20c3815532fabdb55d3d6b6c..258c8f831ceeb08fa41703cb707f48e151aabbca 100644 (file)
--- a/include/pci.h
+++ b/include/pci.h
@@ -578,7 +578,6 @@ typedef int pci_dev_t;
 #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 */