[U-Boot] [PATCH v8] [RFC] early_malloc for DM added.

[Tomas Hlavacek]

Hi Graeme!

On Mon, Sep 24, 2012 at 2:00 AM, Graeme Russ <graeme.russ at gmail.com> wrote:
> Hi Tomas,
>
> On Mon, Sep 24, 2012 at 2:15 AM, Tomas Hlavacek <tmshlvck at gmail.com> wrote:
>> early_malloc for DM with support for more heaps and lightweight
>> first heap in the same memory as an early stack.
>>
>> Adaptation layer for seamless calling of early_malloc or dlmalloc from
>> DM based on init stage added (dmmalloc() and related functions).
>>
>> Signed-off-by: Tomas Hlavacek <tmshlvck at gmail.com>
>> ---
>> Changelog since v5:
>> dmmalloc() and all dm* functions has been moved to header, made static
>> inline and preprocessor-dependent blocks are reworked.
>> early_malloc_active() corrected and made not static.
>> s/CONFIG_SYS_DM/CONFIG_DM/ applied.
>>
>> Changelog sice v6:
>> Check of first heap emptyness in early_brk() has been simplified.
>>
>> Changelog since v7:
>> dmcalloc() implmentation added.
>> Comments added to header.
>>
>>  arch/arm/include/asm/global_data.h        |    3 +
>>  arch/arm/lib/board.c                      |    8 ++
>>  arch/avr32/include/asm/global_data.h      |    3 +
>>  arch/avr32/lib/board.c                    |    9 +++
>>  arch/blackfin/include/asm/global_data.h   |    3 +
>>  arch/blackfin/lib/board.c                 |    8 ++
>>  arch/m68k/include/asm/global_data.h       |    3 +
>>  arch/m68k/lib/board.c                     |    8 ++
>>  arch/microblaze/include/asm/global_data.h |    3 +
>>  arch/microblaze/lib/board.c               |    9 +++
>>  arch/mips/include/asm/global_data.h       |    3 +
>>  arch/mips/lib/board.c                     |    8 ++
>>  arch/nds32/include/asm/global_data.h      |    3 +
>>  arch/nds32/lib/board.c                    |    8 ++
>>  arch/nios2/include/asm/global_data.h      |    3 +
>>  arch/nios2/lib/board.c                    |    8 ++
>>  arch/openrisc/include/asm/global_data.h   |    3 +
>>  arch/openrisc/lib/board.c                 |    8 ++
>>  arch/powerpc/include/asm/global_data.h    |    3 +
>>  arch/powerpc/lib/board.c                  |    8 ++
>>  arch/sandbox/include/asm/global_data.h    |    3 +
>>  arch/sandbox/lib/board.c                  |    8 ++
>>  arch/sh/include/asm/global_data.h         |    3 +
>>  arch/sh/lib/board.c                       |    8 ++
>>  arch/sparc/include/asm/global_data.h      |    3 +
>>  arch/sparc/lib/board.c                    |    8 ++
>>  arch/x86/include/asm/global_data.h        |    3 +
>>  arch/x86/lib/board.c                      |   18 +++++
>>  common/Makefile                           |    1 +
>>  common/dmmalloc.c                         |   88 ++++++++++++++++++++++
>>  include/dmmalloc.h                        |  117 +++++++++++++++++++++++++++++
>>  31 files changed, 372 insertions(+)
>>  create mode 100644 common/dmmalloc.c
>>  create mode 100644 include/dmmalloc.h
>>
>> diff --git a/arch/arm/include/asm/global_data.h b/arch/arm/include/asm/global_data.h
>> index f8088fe..ef727b0 100644
>> --- a/arch/arm/include/asm/global_data.h
>> +++ b/arch/arm/include/asm/global_data.h
>> @@ -82,6 +82,9 @@ typedef       struct  global_data {
>>         unsigned long   post_log_res; /* success of POST test */
>>         unsigned long   post_init_f_time; /* When post_init_f started */
>>  #endif
>> +#ifdef CONFIG_SYS_EARLY_MALLOC
>> +       void    *early_heap_first;      /* heap for early_malloc */
>> +#endif
>>  } gd_t;
>>
>>  #include <asm-generic/global_data_flags.h>
>> diff --git a/arch/arm/lib/board.c b/arch/arm/lib/board.c
>> index f1951e8..f73d8b2 100644
>> --- a/arch/arm/lib/board.c
>> +++ b/arch/arm/lib/board.c
>> @@ -53,6 +53,10 @@
>>  #include <post.h>
>>  #include <logbuff.h>
>>
>> +#ifdef CONFIG_DM
>> +#include <dmmalloc.h>
>> +#endif
>> +
>>  #ifdef CONFIG_BITBANGMII
>>  #include <miiphy.h>
>>  #endif
>> @@ -281,6 +285,10 @@ void board_init_f(ulong bootflag)
>>
>>         memset((void *)gd, 0, sizeof(gd_t));
>>
>> +#ifdef CONFIG_SYS_EARLY_MALLOC
>> +       gd->early_heap_first = early_brk(CONFIG_SYS_EARLY_HEAP_SIZE);
>> +#endif /* CONFIG_SYS_EARLY_MALLOC */
>> +
>
> I just realised that all these initialisers can be dumped - early_brk()
> will be called when early_malloc() is first called
>

Yes, but how can I determine the size of the new heap which the
early_brk gives out? When I have CONFIG_SYS_EARLY_HEAP_SIZE macro in
board configuration I can ignore the size passed to the "default"
early_brk and return the full-sized heap as configuration says (when
the requested size is lower than configured heap size and NULL
otherwise). But what if somebody implements at some point a dynamic
early_brk capable of returning multiple heaps? Should I safely assume
that the future dynamic early_brk would give out multiples of page
size or so?

All other comments understood and agreed.

Thanks,
Tomas