[PATCH] mm: Add infrastructure for basic memory management

[Sebastian Huber]

On 02/18/2013 06:47 PM, Gedare Bloom wrote:
> +/**
> + * @brief A managed _Memory_management_Region.
> + */
> +typedef struct {
> +  char *name;

Why not const char *?

> +  uintptr_t base;
> +  size_t size;

Why different types for base and size?

> +  bool installed;

Do we really need this state?  The entry install and uninstall functions should 
be idempotent.

> +  /* points to structure defining the BSP specific MM entry */
> +  void *bsp_mme;
> +} Memory_management_Entry;

Where does this bsp_mme value come from?  I would not use the name BSP here. 
Do we really need such a context pointer?

> +
> +#ifndef __RTEMS_APPLICATION__
> +#include <rtems/score/mm.inl>
> +#endif
> +
> +#ifdef __cplusplus
> +}
> +#endif
> +
> +/**@}*/
> +
> +#endif
> diff --git a/cpukit/score/inline/rtems/score/mm.inl b/cpukit/score/inline/rtems/score/mm.inl
> new file mode 100644
> index 0000000..abe065d
> --- /dev/null
> +++ b/cpukit/score/inline/rtems/score/mm.inl
> @@ -0,0 +1,77 @@
> +/**
> + * @file
> + *
> + * @brief Inlined Routines from the Memory Management Manager
> + */
> +
> +/*
> + * Copyright (c) 2013 Gedare Bloom.
> + *
> + * The license and distribution terms for this file may be
> + * found in the file LICENSE in this distribution or at
> + *http://www.rtems.com/license/LICENSE.
> + */
> +
> +#ifndef _RTEMS_SCORE_MM_H
> +# error "Never use <rtems/score/mm.inl> directly; include <rtems/score/mm.h> instead."
> +#endif
> +
> +#ifndef _RTEMS_SCORE_MM_INL
> +#define _RTEMS_SCORE_MM_INL
> +
> +/**
> + * @addtogroup SuperCoreMM
> + */
> +/**@{**/
> +
> +/**
> + * @brief Calls _CPU_Memory_management_Initialize.
> + */
> +RTEMS_INLINE_ROUTINE void _Memory_management_Initialize( void )
> +{
> +  _CPU_Memory_management_Initialize();
> +}
> +
> +/**
> + * @brief Calls _CPU_Memory_management_Install_entry.
> + */
> +RTEMS_INLINE_ROUTINE void _Memory_management_Install_entry(
> +  Memory_management_Entry *mme
> +)
> +{
> +  _CPU_Memory_management_Install_entry(mme);
> +}
> +
> +/**
> + * @brief Calls _CPU_Memory_management_Uninstall_entry.
> + */
> +RTEMS_INLINE_ROUTINE void _Memory_management_Uninstall_entry(
> +  Memory_management_Entry *mme
> +)
> +{
> +  _CPU_Memory_management_Uninstall_entry(mme);
> +}
> +
> +/**
> + * @brief Calls _CPU_Memory_management_Set_write.
> + */
> +RTEMS_INLINE_ROUTINE void _Memory_management_Set_write(
> +  Memory_management_Entry *mme
> +)
> +{
> +  _CPU_Memory_management_Set_write(mme);
> +}
> +
> +/**
> + * @brief Calls _CPU_Memory_management_Set_read_only
> + */
> +RTEMS_INLINE_ROUTINE void _Memory_management_Set_read_only(
> +  Memory_management_Entry *mme
> +)
> +{
> +  _CPU_Memory_management_Set_read_only(mme);
> +}

I would not use set methods for attributes.  I would use integer flags so we 
can initialize an entry completely static in read-only memory.

I miss attributes to determine cache enable/disable, cache strategy, guarded 
(non well-behaved memory), cache consistency (MSI, MESI, etc.), and executable 
for example.

-- 
Sebastian Huber, embedded brains GmbH

Address : Dornierstr. 4, D-82178 Puchheim, Germany
Phone   : +49 89 189 47 41-16
Fax     : +49 89 189 47 41-09
E-Mail  : sebastian.huber at embedded-brains.de
PGP     : Public key available on request.

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