On 06/01/2018 10:21 AM, AKASHI Takahiro wrote:
Tuomas,
On Thu, May 31, 2018 at 01:32:20PM +0300, Tuomas Tynkkynen wrote:
Hi Akashi,
On 05/31/2018 08:05 AM, AKASHI Takahiro wrote:
Simon,
On Wed, May 30, 2018 at 01:18:30PM -0600, Simon Glass wrote:
+Tuomas
Hi Akashi,
On 28 May 2018 at 01:59, AKASHI Takahiro takahiro.akashi@linaro.org wrote:
When I tried to add a SD card to qemu's virt machine (2.10.0) as,
-device sdhci-pci \ -device sd-card,drive=my_sd \ -drive if=none,id=my_sd,format=raw,file=/path/my/sd.img ------u-boot doesn't configure a SDHCI controller properly and an attached device is never detected.
Digging into the code, I found
- reading BAR5 in dm_pciauto_setup_device() shows BAR5 is a 32-bit address,
- pciauto_region_allocate() allocates a 64-bit address (0x80.ABCD.0000) to BAR5 as res->bus_lower is 0x80.0000.0000
- Upper 32-bit value is not written back to BAR5 because of !found_mem64 (BAR5 is the last one and no succeeding BAR anyway.)
On the other hand,
Qemu defines two PCI memory regions for MMIO: (from qemu's hw/arm/virt.c) ------ [VIRT_PCIE_MMIO] = { 0x10000000, 0x2eff0000 }, [VIRT_PCIE_PIO] = { 0x3eff0000, 0x00010000 }, [VIRT_PCIE_ECAM] = { 0x3f000000, 0x01000000 }, [VIRT_MEM] = { 0x40000000, RAMLIMIT_BYTES }, /* Second PCIe window, 512GB wide at the 512GB boundary */ [VIRT_PCIE_MMIO_HIGH] = { 0x8000000000ULL, 0x8000000000ULL }, ------
A PCI card is configured in decode_regions() so that 'hose' has only one entry per each type of memory regions. This behavior was introduced by Simon's patch: ------ commit 9526d83ac5a Author: Simon Glass sjg@chromium.org Date: Thu Nov 19 20:26:58 2015 -0700
dm: pci: Support decoding ranges with duplicate entries ------As a result, MMIO region (0x1000.0000-0x2eff.0000) is overwritten and MMIO_HIGH is the only one available at runtime.
I believe that this behavior is the root cause of my issue, and by reverting the patch mentioned above, everything works fine.
While I understand a concern mentioned in the commit message, there should be a better way to manage the case.
There was a series that changed things in this area. Can you take a look?
PCI: dm: Ignore 64-bit memory regions if CONFIG_SYS_PCI_64BIT not setAh, I didn't know that, but it seems to me that it is still insufficient. This hack won't work on 32-bit PCI card. I found another patch from Tuomas:
Did you try it? As of today's master all of the patches are applied and at least the e1000 NIC and the Intel AHCI card that I tested works. The effect of the commit is to indeed avoid the problem you mentioned:
Yes, I ran my patch but *with* CONFIG_SYS_PCI_64BIT.
I meant: Did you try your QEMU command that enables the SDHCI on U-Boot master, without any patches? It should just work.
- As a result, MMIO region (0x1000.0000-0x2eff.0000) is overwritten and MMIO_HIGH is the only one available at runtime.
Note that even on aarch64, CONFIG_SYS_PCI_64BIT is *not* set by default. And on ARM we would need to skip that region in U-Boot anyway because we don't have the means to access physical addresses above the 4GB boundary with the CPU using U-Boot's identity-mapped page tables.
Maybe you're right regarding aarch64, but the issue is not about arm/arm64 but PCI configuration. Some arch/machines, freescale mostly?, have already enabled CONFIG_SYS_PCI_64BIT. I'm afraid that there may be a possibility that your patch breaks them.
Which patch?
The "PCI: dm: Ignore 64-bit memory regions if CONFIG_SYS_PCI_64BIT not set" commit adds:
+ if (!IS_ENABLED(CONFIG_SYS_PCI_64BIT) && + type == PCI_REGION_MEM && upper_32_bits(pci_addr)) { + debug(" - beyond the 32-bit boundary, ignoring\n"); + continue; + }
I.e. the patch is a no-op if CONFIG_SYS_PCI_64BIT is set. Also I don't think PowerPC uses DM PCI, so that code is not executed at all on those platforms.
If you mean in "PCI: autoconfig: Don't allocate 64-bit addresses to 32-bit only resources" that someone could have been relying on the truncation of high 32 bits of bus addresses with 32-bit only devices, none of the FSL platforms have bus addresses above 32-bits, only physical addresses (seen with git grep CONFIG_SYS_PCIE._MEM_), so that shouldn't cause a problem either.