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>
This commit is contained in:
Simon Glass 2021-06-27 17:50:57 -06:00 committed by Bin Meng
parent e58f3a7d9b
commit f5cbb5c7cd
4 changed files with 50 additions and 3 deletions

View file

@ -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>;

View file

@ -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 */

View file

@ -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 */

View file

@ -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 */