[PATCH v6 004/102] dm: pci: Allow delaying auto-config until after relocation
Simon Glass
sjg at chromium.org
Sat Dec 7 05:41:37 CET 2019
At present PCI auto-configuration happens in U-Boot both before and after
relocation. This is a waste of time and may mess up static addresses used
in board_init_f(). Adjust the code to supporting doing auto-configuration
once, after relocation, under control of a device-tree property.
This is needed for Apollo Lake for debugging the silicon-init code. Once
the UART is moved to a different MMIO address the debug UART does not work
and any debug output in Apollo Lake's arch_fsp_init_r() causes a hang.
Signed-off-by: Simon Glass <sjg at chromium.org>
Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
---
Changes in v6: None
Changes in v5: None
Changes in v4:
- Change the behaviour to be a device-tree option
- apollolake -> Apollo Lake
Changes in v3: None
Changes in v2: None
doc/device-tree-bindings/pci/x86-pci.txt | 24 ++++++++++++++++++++++++
drivers/pci/pci-uclass.c | 15 ++++++++++-----
include/pci.h | 9 ++++++++-
3 files changed, 42 insertions(+), 6 deletions(-)
create mode 100644 doc/device-tree-bindings/pci/x86-pci.txt
diff --git a/doc/device-tree-bindings/pci/x86-pci.txt b/doc/device-tree-bindings/pci/x86-pci.txt
new file mode 100644
index 0000000000..3aa5bd9a46
--- /dev/null
+++ b/doc/device-tree-bindings/pci/x86-pci.txt
@@ -0,0 +1,24 @@
+x86 PCI DT details:
+===================
+
+Some options are available to affect how PCI operates on x86.
+
+Optional properties:
+- u-boot,skip-auto-config-until-reloc : Don't set up PCI configuration until
+ after U-Boot has relocated. Normally if PCI is used before relocation,
+ this happens before relocation also. Some platforms set up static
+ configuration in TPL/SPL to reduce code size and boot time, since these
+ phases only know about a small subset of PCI devices.
+
+Example:
+
+pci {
+ compatible = "pci-x86";
+ #address-cells = <3>;
+ #size-cells = <2>;
+ u-boot,dm-pre-reloc;
+ ranges = <0x02000000 0x0 0xc0000000 0xc0000000 0 0x10000000
+ 0x42000000 0x0 0xb0000000 0xb0000000 0 0x10000000
+ 0x01000000 0x0 0x1000 0x1000 0 0xefff>;
+ u-boot,skip-auto-config-until-reloc;
+};
diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
index fab20fc60e..8e13adb156 100644
--- a/drivers/pci/pci-uclass.c
+++ b/drivers/pci/pci-uclass.c
@@ -975,12 +975,15 @@ static int pci_uclass_pre_probe(struct udevice *bus)
hose->bus = bus;
hose->first_busno = bus->seq;
hose->last_busno = bus->seq;
+ hose->skip_auto_config_until_reloc =
+ dev_read_bool(bus, "u-boot,skip-auto-config-until-reloc");
return 0;
}
static int pci_uclass_post_probe(struct udevice *bus)
{
+ struct pci_controller *hose = dev_get_uclass_priv(bus);
int ret;
debug("%s: probing bus %d\n", __func__, bus->seq);
@@ -988,11 +991,13 @@ static int pci_uclass_post_probe(struct udevice *bus)
if (ret)
return ret;
-#if CONFIG_IS_ENABLED(PCI_PNP)
- ret = pci_auto_config_devices(bus);
- if (ret < 0)
- return ret;
-#endif
+ if (CONFIG_IS_ENABLED(PCI_PNP) &&
+ (!hose->skip_auto_config_until_reloc ||
+ (gd->flags & GD_FLG_RELOC))) {
+ ret = pci_auto_config_devices(bus);
+ if (ret < 0)
+ return log_msg_ret("pci auto-config", ret);
+ }
#if defined(CONFIG_X86) && defined(CONFIG_HAVE_FSP)
/*
diff --git a/include/pci.h b/include/pci.h
index ff59ac0e69..de17d0ffba 100644
--- a/include/pci.h
+++ b/include/pci.h
@@ -571,15 +571,22 @@ extern void pci_cfgfunc_config_device(struct pci_controller* hose, pci_dev_t dev
#define INDIRECT_TYPE_NO_PCIE_LINK 1
-/*
+/**
* Structure of a PCI controller (host bridge)
*
* With driver model this is dev_get_uclass_priv(bus)
+ *
+ * @skip_auto_config_until_reloc: true to avoid auto-config until U-Boot has
+ * relocated. Normally if PCI is used before relocation, this happens
+ * before relocation also. Some platforms set up static configuration in
+ * TPL/SPL to reduce code size and boot time, since these phases only know
+ * about a small subset of PCI devices. This is normally false.
*/
struct pci_controller {
#ifdef CONFIG_DM_PCI
struct udevice *bus;
struct udevice *ctlr;
+ bool skip_auto_config_until_reloc;
#else
struct pci_controller *next;
#endif
--
2.24.0.393.g34dc348eaf-goog
More information about the U-Boot
mailing list