Hi Alex,
On Sun, 27 Feb 2022 at 07:23, Alexander Graf wrote:
>
> When we allocate ACPI tables dynamically as part of the qfw ACPI loading
> code and then later want to boot a UEFI target using them, we need to make
> sure that the UEFI logic is aware that these memory regions are ACPI, so
> that the loading kernel can mark them as reserved.
>
> Since we'll never see alignment requirements more than a page, let's just
> use efi_allocate_pages when we see high memory allocation requests in a
> UEFI enabled environment. Even if we then boot using the native zImage
> later, the memory allocation will still be valid.
>
> Without this patch, Linux will refuse to consume the DSDT when passed from
> qfw's ACPI framework. With this patch, it happily uses it.
>
> Signed-off-by: Alexander Graf
> ---
> drivers/misc/qfw.c | 17 -
> 1 file changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/misc/qfw.c b/drivers/misc/qfw.c
> index 754bc6a603..7c6ed41f48 100644
> --- a/drivers/misc/qfw.c
> +++ b/drivers/misc/qfw.c
> @@ -18,6 +18,9 @@
> #if defined(CONFIG_GENERATE_ACPI_TABLE) && !defined(CONFIG_ARM)
> #include
> #endif
> +#ifdef CONFIG_EFI_LOADER
> +#include
> +#endif
>
> #if defined(CONFIG_GENERATE_ACPI_TABLE) && !defined(CONFIG_SANDBOX)
> /*
> @@ -35,7 +38,7 @@ static int bios_linker_allocate(struct udevice *dev,
> {
> uint32_t size, align;
> struct fw_file *file;
> - unsigned long aligned_addr;
> + unsigned long aligned_addr = 0;
>
> align = le32_to_cpu(entry->alloc.align);
> /* align must be power of 2 */
> @@ -59,7 +62,19 @@ static int bios_linker_allocate(struct udevice *dev,
> * in which is low memory
> */
> if (entry->alloc.zone == BIOS_LINKER_LOADER_ALLOC_ZONE_HIGH) {
> +#ifdef CONFIG_EFI_LOADER
> + efi_status_t ret;
> + u64 efi_addr = 1ULL << 32;
> +
> + ret = efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS,
> +EFI_ACPI_RECLAIM_MEMORY,
> +efi_size_in_pages(size),
> +_addr);
> + if (ret == EFI_SUCCESS)
> + aligned_addr = efi_addr;
> +#else
> aligned_addr = (unsigned long)memalign(align, size);
> +#endif
> if (!aligned_addr) {
> printf("error: allocating resource\n");
> return -ENOMEM;
> --
> 2.32.0
>
The tables are normally created on start-up, before the command line
starts, so we can examine them in U-Boot.
It is a terrible idea fo call efi_allocate_pages() in code like this.
and the #ifdef as well. Ick!!
You can put ACPI tables in a bloblist so they are continguous and then
the EFI code can present the bloblist as reserved to Linux.
See coral, which does this.
Regards,
Simon
