Hi Bin,
>>>> +static unsigned long acpi_fill_mcfg(unsigned long current)
>>>> +{
>>>> + pci_dev_t qemu_dev;
>>>> + struct pci_device_id qemu_id[] = { { 0x8086, 0x29c0 } };
>>>> + u32 reg;
>>>> +
>>>> + qemu_dev = pci_find_devices(qemu_id, 0);
>>>> + if (!qemu_dev)
>>>> + return current;
>>>> +
>>>> + reg = pci_read_config_dword(qemu_dev, 0x60, ®);
>>>> + if ((reg & 0x07) != 0x01) // require enabled + 256MB size
>>>> + return current;
>>>> +
>>>> + current += acpi_create_mcfg_mmconfig((struct acpi_mcfg_mmconfig
>>>> *) current,
>>>> + reg & 0xf0000000, 0x0, 0x0,
>>>> 255);
>>>
>>> We need actually programming the chipset to enable the ECAM. This
>>> needs to be done in the arch/x86/cpu/qemu/qemu.c.
>>>
>>
>> Would be needing your guidance for this. Would need some info about
>> qemu working and ECAM's role.
>
> ECAM is PCIe enhanced configuration access mechanism. QEMU i440FX is a
> PCI chipset, which does not support ECAM. For QEMU Q35 which supports
> PCIe, you need check the Q35 chipset. I just checked that, it's on
> D0:F0:R60h a register called PCIEXBAR. You need hook U-Boot's PCI
> configuration RW routines to actually use ECAM to verify it is really
> working.
>
As suggested by you, I have added below patch -
diff --git a/arch/x86/cpu/qemu/pci.c b/arch/x86/cpu/qemu/pci.c
index 1a9140b..ba8f470 100644
--- a/arch/x86/cpu/qemu/pci.c
+++ b/arch/x86/cpu/qemu/pci.c
@@ -11,6 +11,8 @@
#include <asm/arch/device.h>
#include <asm/arch/qemu.h>
+#define Q35_PCIEXBAR_ADDR 0xb0000000
+
DECLARE_GLOBAL_DATA_PTR;
void board_pci_setup_hose(struct pci_controller *hose)
@@ -83,7 +85,10 @@ int board_pci_post_scan(struct pci_controller *hose)
x86_pci_write_config16(PIIX_IDE, IDE0_TIM, IDE_DECODE_EN);
x86_pci_write_config16(PIIX_IDE, IDE1_TIM, IDE_DECODE_EN);
}
-
+ else {
+ /* setup mmconfig */
+ x86_pci_write_config32(device, 0x60, Q35_PCIEXBAR_ADDR | 1);
+ }
/*
* QEMU emulated graphic card shows in the PCI configuration space with
* PCI vendor id and device id as an artificial pair 0x1234:0x1111.
In the bootup logs, with this patch applied, I am getting -
[ 0.432000] ACPI: Using PIC for interrupt routing
[ 0.436000] PCI: Using host bridge windows from ACPI; if necessary,
use "pci=nocrs" and report a bug
[ 0.486000] ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-ff])
[ 0.488000] acpi PNP0A08:00: _OSC: OS supports [ASPM ClockPM Segments MSI]
[ 0.491000] acpi PNP0A08:00: _OSC: not requesting OS control; OS
requires [ExtendedConfig ASPM ClockPM MSI]
[ 0.494000] acpi PNP0A08:00: fail to add MMCONFIG information,
can't access extended PCI configuration space under this bridge.
[ 0.496000] PCI host bridge to bus 0000:00
[ 0.497000] pci_bus 0000:00: root bus resource [bus 00-ff]
[ 0.498000] pci_bus 0000:00: root bus resource [io 0x0000-0x0cf7 window]
[ 0.498000] pci_bus 0000:00: root bus resource [io 0x0d00-0xffff window]
[ 0.500000] pci_bus 0000:00: root bus resource [mem
0x000a0000-0x000bffff window]
[ 0.501000] pci_bus 0000:00: root bus resource [mem
0xe0000000-0xfebfffff window]
In the log "fail to add MMCONFIG information, can't access extended
PCI configuration space under this bridge." shows I am still not able
to use ECAM.
Regards,
Saket Sinha
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