[PATCH v2 03/14] efi: memory: use the lmb API's for allocating and freeing memory

Simon Glass sjg at chromium.org
Mon Oct 14 17:50:34 CEST 2024


Hi Sughosh,

On Tue, 8 Oct 2024 at 12:14, Sughosh Ganu <sughosh.ganu at linaro.org> wrote:
>
> Use the LMB API's for allocating and freeing up memory. With this, the
> LMB module becomes the common backend for managing non U-Boot image
> memory that might be requested by other modules.
>
> Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
> ---
> Changes since V1: None
>
>  lib/efi_loader/Kconfig      |  1 +
>  lib/efi_loader/efi_memory.c | 74 ++++++++++---------------------------
>  2 files changed, 21 insertions(+), 54 deletions(-)
>

Please check my recent series [1] which shows how to avoid needing to
worry about lmb until the app starts, at which point I believe we can
just add the lmb map to the EFI map so we know where the images are?

But without my series, this patch is needed. I do wonder what
addresses lmb happens to allocate with this? From the top? From the
bottom?

> diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
> index e58b8825605..5a576720606 100644
> --- a/lib/efi_loader/Kconfig
> +++ b/lib/efi_loader/Kconfig
> @@ -20,6 +20,7 @@ config EFI_LOADER
>         select DM_EVENT
>         select EVENT_DYNAMIC
>         select LIB_UUID
> +       select LMB
>         imply PARTITION_UUIDS
>         select REGEX
>         imply FAT
> diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
> index c6f1dd09456..90e07ed6a2d 100644
> --- a/lib/efi_loader/efi_memory.c
> +++ b/lib/efi_loader/efi_memory.c
> @@ -9,6 +9,7 @@
>
>  #include <efi_loader.h>
>  #include <init.h>
> +#include <lmb.h>
>  #include <log.h>
>  #include <malloc.h>
>  #include <mapmem.h>
> @@ -432,53 +433,6 @@ static efi_status_t efi_check_allocated(u64 addr, bool must_be_allocated)
>         return EFI_NOT_FOUND;
>  }
>
> -/**
> - * efi_find_free_memory() - find free memory pages
> - *
> - * @len:       size of memory area needed
> - * @max_addr:  highest address to allocate
> - * Return:     pointer to free memory area or 0
> - */
> -static uint64_t efi_find_free_memory(uint64_t len, uint64_t max_addr)
> -{
> -       struct efi_mem_list *lmem;
> -
> -       /*
> -        * Prealign input max address, so we simplify our matching
> -        * logic below and can just reuse it as return pointer.
> -        */
> -       max_addr &= ~EFI_PAGE_MASK;
> -
> -       list_for_each_entry(lmem, &efi_mem, link) {
> -               struct efi_mem_desc *desc = &lmem->desc;
> -               uint64_t desc_len = desc->num_pages << EFI_PAGE_SHIFT;
> -               uint64_t desc_end = desc->physical_start + desc_len;
> -               uint64_t curmax = min(max_addr, desc_end);
> -               uint64_t ret = curmax - len;
> -
> -               /* We only take memory from free RAM */
> -               if (desc->type != EFI_CONVENTIONAL_MEMORY)
> -                       continue;
> -
> -               /* Out of bounds for max_addr */
> -               if ((ret + len) > max_addr)
> -                       continue;
> -
> -               /* Out of bounds for upper map limit */
> -               if ((ret + len) > desc_end)
> -                       continue;
> -
> -               /* Out of bounds for lower map limit */
> -               if (ret < desc->physical_start)
> -                       continue;
> -
> -               /* Return the highest address in this map within bounds */
> -               return ret;
> -       }
> -
> -       return 0;
> -}
> -
>  /**
>   * efi_allocate_pages - allocate memory pages
>   *
> @@ -493,6 +447,7 @@ efi_status_t efi_allocate_pages(enum efi_allocate_type type,
>                                 efi_uintn_t pages, uint64_t *memory)
>  {
>         u64 len;
> +       uint flags;
>         efi_status_t ret;
>         uint64_t addr;
>
> @@ -508,33 +463,35 @@ efi_status_t efi_allocate_pages(enum efi_allocate_type type,
>             (len >> EFI_PAGE_SHIFT) != (u64)pages)
>                 return EFI_OUT_OF_RESOURCES;
>
> +       flags = LMB_NOOVERWRITE | LMB_NONOTIFY;
>         switch (type) {
>         case EFI_ALLOCATE_ANY_PAGES:
>                 /* Any page */
> -               addr = efi_find_free_memory(len, -1ULL);
> +               addr = (u64)lmb_alloc_flags(len, EFI_PAGE_SIZE, flags);
>                 if (!addr)
>                         return EFI_OUT_OF_RESOURCES;
>                 break;
>         case EFI_ALLOCATE_MAX_ADDRESS:
>                 /* Max address */
> -               addr = efi_find_free_memory(len, *memory);
> +               addr = (u64)lmb_alloc_base_flags(len, EFI_PAGE_SIZE, *memory,
> +                                                flags);
>                 if (!addr)
>                         return EFI_OUT_OF_RESOURCES;
>                 break;
>         case EFI_ALLOCATE_ADDRESS:
>                 if (*memory & EFI_PAGE_MASK)
>                         return EFI_NOT_FOUND;
> -               /* Exact address, reserve it. The addr is already in *memory. */
> -               ret = efi_check_allocated(*memory, false);
> -               if (ret != EFI_SUCCESS)
> -                       return EFI_NOT_FOUND;
> -               addr = *memory;
> +
> +               addr = (u64)lmb_alloc_addr_flags(*memory, len, flags);
> +               if (!addr)
> +                       return EFI_OUT_OF_RESOURCES;
>                 break;
>         default:
>                 /* UEFI doesn't specify other allocation types */
>                 return EFI_INVALID_PARAMETER;
>         }
>
> +       addr = (u64)(uintptr_t)map_sysmem(addr, 0);
>         /* Reserve that map in our memory maps */
>         ret = efi_add_memory_map_pg(addr, pages, memory_type, true);
>         if (ret != EFI_SUCCESS)
> @@ -555,6 +512,9 @@ efi_status_t efi_allocate_pages(enum efi_allocate_type type,
>   */
>  efi_status_t efi_free_pages(uint64_t memory, efi_uintn_t pages)
>  {
> +       u64 len;
> +       uint flags;
> +       long status;
>         efi_status_t ret;
>
>         ret = efi_check_allocated(memory, true);
> @@ -568,6 +528,12 @@ efi_status_t efi_free_pages(uint64_t memory, efi_uintn_t pages)
>                 return EFI_INVALID_PARAMETER;
>         }
>
> +       flags = LMB_NOOVERWRITE | LMB_NONOTIFY;
> +       len = (u64)pages << EFI_PAGE_SHIFT;
> +       status = lmb_free_flags(memory, len, flags);
> +       if (status)
> +               return EFI_NOT_FOUND;
> +
>         ret = efi_add_memory_map_pg(memory, pages, EFI_CONVENTIONAL_MEMORY,
>                                     false);
>         if (ret != EFI_SUCCESS)
> --
> 2.34.1
>

Regards,
SImon

[1] https://patchwork.ozlabs.org/project/uboot/list/?series=427729


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