On 08/04/2018 10:56 AM, Heinrich Schuchardt wrote: > On 08/02/2018 07:00 PM, Stephen Warren wrote: >> On 08/01/2018 11:57 PM, Heinrich Schuchardt wrote: >>> On 08/01/2018 06:17 PM, Stephen Warren wrote: >>>> On 08/01/2018 12:07 AM, Heinrich Schuchardt wrote: >>>>> On 07/31/2018 09:44 PM, Stephen Warren wrote: >>>>>> From: Stephen Warren <swar...@nvidia.com> >>>>>> >>>>>> Some boards define a maximum usable RAM top that's more restrictive >>>>>> than >>>>>> the ranges defined by U-Boot's memory bank definitions[1]. In this >>>>>> case, >>>>>> the unusable RAM isn't mapped in the page tables, and so the EFI code >>>>>> must >>>>>> not attempt to allocate RAM from outside the usable regions. Fix >>>>>> efi_find_free_memory() to detect when max_addr is unconstrained or >>>>>> out of >>>>>> range, and substitue a valid value. >>>>>> >>>>> >>>>> In this case the board has to call efi_add_memory_map() to mark the >>>>> reserved region (cf. board/raspberrypi/rpi/rpi.c) or have to mark the >>>>> memory region as reserved in the device tree (see >>>>> efi_carve_out_dt_rsv()). >>>>> >>>>> Please, check if the tegra boards with which you had problems do so. >>>> >>>> I don't think this makes sense; memory should be managed the same way >>>> within U-Boot no matter which part of U-Boot is consuming that memory. >>>> Memory regions are currently represented by the content of the memory >>>> bank definitions and gd->ram_top. Having different parts of the code >>>> define legal RAM usage in different ways is horribly inconsistent. >>> >>> Memory banks and gd->top together cannot reflect unusable memory regions >>> in the middle of the RAM area. >> >> Sure this is possible. For example, a common set of memory banks for >> Tegra is: >> >> bank 0: >> start: 0x080000000 >> length: 0x070000000 >> limit: 0x0f0000000 >> bank 1: >> start: 0x100000000 >> length: 0x080000000 >> limit: 0x180000000 >> >> gd->ram_top = 0x0f0000000 >> That is set so that U-Boot itself (not just the UEFI code) doesn't use >> RAM above 4GB due to HW peripherals that can't access such RAM. The RAM >> above 4GB is left in the DRAM banks so that the kernel can use it for >> non-DMA purposes > > Hello Stephen, > > this explanation makes the problem much clearer. Memory usable by the > operating system but not by the firmware cannot be expressed in the > device tree. > > If bank 1 cannot be used by U-Boot but can be used by the operating > system we should mark it as EFI_BOOT_SERVICES_DATA by calling > efi_add_memory_map() in arch/arm/mach-tegra/board2.c. This will indicate > to the operating system that it may use this memory after exiting boot > services and the U-Boot EFI subsystem will not use this region. This > call could be done in dram_init_banksize(). > > Could you give this a try, please.
Please revert the patch first, then we can fix this later (I sent the revert as a patch already). I'm leaving on vacation right now, so won't be able to look at this for at least 2 weeks. We need to fix the regression immediately. Equally, EFI shouldn't require boards to provide memory information to U-Boot in a different way than the rest of U-Boot as I mentioned, so even if this WAR works, it doesn't sound scalable across all boards. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
