Memory Management
[Linux DDE Common]

This module emulates the Memory Management subsystem inside the Linux kernel. More...

Modules
	Address Conversion
	Linux' __va()/__pa() macro replacements.
	Page Allocation/Deallocation
	Page allocation just triggers mapping and deallocation triggers unmapping.
	Slab Caches
	This simple slab cache emulation was introduced for the Linux USB drivers.
Functions
void *	kmalloc (size_t size, int gfp)
	kmem Allocation
void	kfree (const void *addr)
	kmem Deallocation
void *	vmalloc (unsigned long size)
	vmem Allocation
void	vfree (void *addr)
	vmem Deallocation
int	l4dde_mm_init (unsigned int max_vsize, unsigned int max_ksize)
	Initalize LMM pools and initial regions.

---

Detailed Description

This module emulates the Memory Management subsystem inside the Linux kernel.

Linux DDE manages two OSKit LMM pools for memory allocations - one for kmalloc() (kmem) and one for vmalloc() (vmem) allocations. Each pool consists of one ore more LMM regions.

Malloc functions have to keep track of chunk sizes and store them in the first dword of the chunk.

Configuration:

• setup MM_KREGIONS to change number of kernel memory regions (default 1!)
• maximum size of pools is configured via parameters of l4dde_mm_init()

---

Function Documentation

void kfree

(

const void *

addr

)

kmem Deallocation

Parameters:

addr

start address of memory chunk to free

This is Linux' kfree().

Definition at line 209 of file mm.c.

void* kmalloc	(	size_t	size,
		int	gfp
	)

kmem Allocation

Parameters:

	size	size of memory chunk
	gfp	flags

This is Linux' kmalloc().

Returns:

start address of allocated chunk; NULL on error

Definition at line 171 of file mm.c.

int l4dde_mm_init	(	unsigned int	max_vsize,
		unsigned int	max_ksize
	)

Initalize LMM pools and initial regions.

Parameters:

	max_vsize	max size of virtual memory allocations
	max_ksize	max size of kernel memory allocations

Returns:

0 on success, negative error code otherwise

Sizes are rounded up to multiples of page size.

kmem pool is divided into MM_KREGIONS regions of same size. The total size will be max_ksize (or greater because of rounding/page size). vmem pool has only one region of max_vsize.

Definition at line 377 of file mm.c.

void vfree

(

void *

addr

)

vmem Deallocation

Parameters:

addr

start address of memory chunk to release

This is Linux' vfree().

Definition at line 270 of file mm.c.

void* vmalloc

(

unsigned long

size

)

vmem Allocation

Parameters:

size

size of memory chunk

Returns:

start address of allocated chunk; NULL on error

This is Linux' vmalloc().

Definition at line 235 of file mm.c.