[RFC PATCH v2 13/48] lmb: make LMB memory map persistent and global

[Simon Glass]

Hi Sughosh,

On Thu, 4 Jul 2024 at 08:36, Sughosh Ganu <sughosh.ganu at linaro.org> wrote:
>
> The current LMB API's for allocating and reserving memory use a
> per-caller based memory view. Memory allocated by a caller can then be
> overwritten by another caller. Make these allocations and reservations
> persistent using the alloced list data structure.
>
> Two alloced lists are declared -- one for the available(free) memory,
> and one for the used memory. Once full, the list can then be extended
> at runtime.
>
> Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
> ---
> Changes since V1:
> * Use alloced list structure for the available and reserved memory
>   lists instead of static arrays.
> * Corresponding changes in the code made as a result of the above
>   change.
> * Rename the reserved memory list as 'used'.
>
>  include/lmb.h |  77 +++--------
>  lib/lmb.c     | 346 ++++++++++++++++++++++++++++++--------------------
>  2 files changed, 224 insertions(+), 199 deletions(-)
>
> diff --git a/include/lmb.h b/include/lmb.h
> index 99fcf5781f..27cdb18c37 100644
> --- a/include/lmb.h
> +++ b/include/lmb.h
> @@ -24,78 +24,18 @@ enum lmb_flags {
>  };
>
>  /**
> - * struct lmb_property - Description of one region.
> + * struct lmb_region - Description of one region.
>   *
>   * @base:      Base address of the region.
>   * @size:      Size of the region
>   * @flags:     memory region attributes
>   */
> -struct lmb_property {
> +struct lmb_region {
>         phys_addr_t base;
>         phys_size_t size;
>         enum lmb_flags flags;
>  };
>
> -/*
> - * For regions size management, see LMB configuration in KConfig
> - * all the #if test are done with CONFIG_LMB_USE_MAX_REGIONS (boolean)
> - *
> - * case 1. CONFIG_LMB_USE_MAX_REGIONS is defined (legacy mode)
> - *         => CONFIG_LMB_MAX_REGIONS is used to configure the region size,
> - *         directly in the array lmb_region.region[], with the same
> - *         configuration for memory and reserved regions.
> - *
> - * case 2. CONFIG_LMB_USE_MAX_REGIONS is not defined, the size of each
> - *         region is configurated *independently* with
> - *         => CONFIG_LMB_MEMORY_REGIONS: struct lmb.memory_regions
> - *         => CONFIG_LMB_RESERVED_REGIONS: struct lmb.reserved_regions
> - *         lmb_region.region is only a pointer to the correct buffer,
> - *         initialized in lmb_init(). This configuration is useful to manage
> - *         more reserved memory regions with CONFIG_LMB_RESERVED_REGIONS.
> - */
> -
> -/**
> - * struct lmb_region - Description of a set of region.
> - *
> - * @cnt: Number of regions.
> - * @max: Size of the region array, max value of cnt.
> - * @region: Array of the region properties
> - */
> -struct lmb_region {
> -       unsigned long cnt;
> -       unsigned long max;
> -#if IS_ENABLED(CONFIG_LMB_USE_MAX_REGIONS)
> -       struct lmb_property region[CONFIG_LMB_MAX_REGIONS];
> -#else
> -       struct lmb_property *region;
> -#endif
> -};
> -
> -/**
> - * struct lmb - Logical memory block handle.
> - *
> - * Clients provide storage for Logical memory block (lmb) handles.
> - * The content of the structure is managed by the lmb library.
> - * A lmb struct is  initialized by lmb_init() functions.
> - * The lmb struct is passed to all other lmb APIs.
> - *
> - * @memory: Description of memory regions.
> - * @reserved: Description of reserved regions.
> - * @memory_regions: Array of the memory regions (statically allocated)
> - * @reserved_regions: Array of the reserved regions (statically allocated)
> - */
> -struct lmb {
> -       struct lmb_region memory;
> -       struct lmb_region reserved;
> -#if !IS_ENABLED(CONFIG_LMB_USE_MAX_REGIONS)
> -       struct lmb_property memory_regions[CONFIG_LMB_MEMORY_REGIONS];
> -       struct lmb_property reserved_regions[CONFIG_LMB_RESERVED_REGIONS];
> -#endif
> -};
> -
> -void lmb_init_and_reserve(struct bd_info *bd, void *fdt_blob);
> -void lmb_init_and_reserve_range(phys_addr_t base, phys_size_t size,
> -                               void *fdt_blob);
>  long lmb_add(phys_addr_t base, phys_size_t size);
>  long lmb_reserve(phys_addr_t base, phys_size_t size);
>  /**
> @@ -134,6 +74,19 @@ void board_lmb_reserve(void);
>  void arch_lmb_reserve(void);
>  void arch_lmb_reserve_generic(ulong sp, ulong end, ulong align);
>
> +/**
> + * lmb_mem_regions_init() - Initialise the LMB memory
> + *
> + * Initialise the LMB subsystem related data structures. There are two
> + * alloced lists that are initialised, one for the free memory, and one
> + * for the used memory.
> + *
> + * Initialise the two lists as part of board init.
> + *
> + * Return: 0 if OK, -ve on failure.
> + */
> +int lmb_mem_regions_init(void);
> +
>  #endif /* __KERNEL__ */
>
>  #endif /* _LINUX_LMB_H */
> diff --git a/lib/lmb.c b/lib/lmb.c
> index 80945e3cae..a46bc8a7a3 100644
> --- a/lib/lmb.c
> +++ b/lib/lmb.c
> @@ -6,6 +6,7 @@
>   * Copyright (C) 2001 Peter Bergner.
>   */
>
> +#include <alist.h>
>  #include <efi_loader.h>
>  #include <image.h>
>  #include <mapmem.h>
> @@ -15,24 +16,30 @@
>
>  #include <asm/global_data.h>
>  #include <asm/sections.h>
> +#include <linux/kernel.h>
>
>  DECLARE_GLOBAL_DATA_PTR;
>
>  #define LMB_ALLOC_ANYWHERE     0
> +#define LMB_ALIST_INITIAL_SIZE 4
>
> -static void lmb_dump_region(struct lmb_region *rgn, char *name)
> +struct alist lmb_free_mem;
> +struct alist lmb_used_mem;

I think these should be in a struct, e.g. struct lmb, allocated with
malloc() and pointed to by gd->lmb so we can avoid making the tests
destructive, and allow use of lmb in SPL. There is a
arch_reset_for_test() which can reset the lmb back to its original
state, or perhaps just swap the pointer for tests.

I know this series is already long, but this patch seems to do quite a
bit. Perhaps it could be split into two?

Regards,
Simon