Logical memory blocks

LMB_NONE

LMB_NONE ()

no special request

Parameters

Description

LMB Memory region attribute flag to indicate that there are no special requests for this region. Normally used as a placeholder value.

LMB_NOMAP

LMB_NOMAP ()

do not add to MMU configuration

Parameters

Description

LMB Memory region attribute flag to indicate that the region will not be mapped by LMB. Normally used for reserved regions.

LMB_NOOVERWRITE

LMB_NOOVERWRITE ()

do not overwrite/re-reserve

Parameters

Description

LMB Memory region attribute flag to indicate that the region will not be overwritten or re-reserved. Normally used for reserved regions.

LMB_NONOTIFY

LMB_NONOTIFY ()

do not notify other modules of changes

Parameters

Description

LMB Memory region attribute flag to indicate that the region will not notify downstream allocators (currently just the EFI allocator) of changes to this region through lmb_map_update_notify().

enum lmb_map_op: memory map operation

Constants

LMB_MAP_OP_RESERVE: reserve memory
LMB_MAP_OP_FREE: free memory
LMB_MAP_OP_ADD: add memory

struct lmb_region: Description of one region

Definition

struct lmb_region {
  phys_addr_t base;
  phys_size_t size;
  u32 flags;
};

Members

base: Base address of the region
size: Size of the region
flags: Memory region attributes

struct lmb: The LMB structure

Definition

struct lmb {
  struct alist available_mem;
  struct alist used_mem;
  bool test;
};

Members

available_mem: List of memory available to LMB
used_mem: List of used/reserved memory regions
test: Is structure being used for LMB tests

int lmb_init(void): Initialise the LMB module.

Parameters

void: no arguments

Return

0 on success, negative error code on failure.

Description

Initialise the LMB lists needed for keeping the memory map. There are two lists, in form of allocated list data structure. One for the available memory, and one for the used memory. Initialise the two lists as part of board init. Add memory to the available memory list and reserve common areas by adding them to the used memory list.

void lmb_add_memory(void): Add memory range for LMB allocations.

Parameters

void: no arguments

Description

Add the entire available memory range to the pool of memory that can be used by the LMB module for allocations.

long lmb_reserve(phys_addr_t base, phys_size_t size, u32 flags): Reserve one region with a specific flags bitfield

Parameters

phys_addr_t base: Base address of the memory region
phys_size_t size: Size of the memory region
u32 flags: Flags for the memory region

Return

0 - Added successfully, or it’s already added (only if LMB_NONE)
-EEXIST - The region is already added, and flags != LMB_NONE
-1 - Failure

phys_addr_t lmb_alloc_base(phys_size_t size, ulong align, phys_addr_t max_addr, uint flags): Allocate specified memory region with specified attributes

Parameters

phys_size_t size: Size of the region requested
ulong align: Alignment of the memory region requested
phys_addr_t max_addr: Maximum address of the requested region
uint flags: Memory region attributes to be set

Description

Allocate a region of memory with the attributes specified through the parameter. The max_addr parameter is used to specify the maximum address below which the requested region should be allocated.

Return

Base address on success, 0 on error.

int lmb_alloc_addr(phys_addr_t base, phys_size_t size, u32 flags): Allocate specified memory address with specified attributes

Parameters

phys_addr_t base: Base Address requested
phys_size_t size: Size of the region requested
u32 flags: Memory region attributes to be set

Description

Allocate a region of memory with the attributes specified through the parameter. The base parameter is used to specify the base address of the requested region.

Return

0 on success -1 on error

int lmb_is_reserved_flags(phys_addr_t addr, int flags): Test if address is in reserved region with flag bits set

Parameters

phys_addr_t addr: Address to be tested
int flags: Bitmap with bits to be tested

Description

The function checks if a reserved region comprising addr exists which has all flag bits set which are set in flags.

Return

1 if matching reservation exists, 0 otherwise.

long lmb_free_flags(phys_addr_t base, phys_size_t size, uint flags): Free up a region of memory

Parameters

phys_addr_t base: Base Address of region to be freed
phys_size_t size: Size of the region to be freed
uint flags: Memory region attributes

Return

0 on success, negative error code on failure.

int io_lmb_setup(struct lmb *io_lmb): Initialize LMB struct

Parameters

struct lmb *io_lmb: IO LMB to initialize

Return

0 on success, negative error code on failure.

void io_lmb_teardown(struct lmb *io_lmb): Tear LMB struct down

Parameters

struct lmb *io_lmb: IO LMB to teardown

long io_lmb_add(struct lmb *io_lmb, phys_addr_t base, phys_size_t size): Add an IOVA range for allocations

Parameters

struct lmb *io_lmb: LMB to add the space to
phys_addr_t base: Base Address of region to add
phys_size_t size: Size of the region to add

Description

Add the IOVA space [base, base + size] to be managed by io_lmb.

Return

0 on success, negative error code on failure.

phys_addr_t io_lmb_alloc(struct lmb *io_lmb, phys_size_t size, ulong align): Allocate specified IO memory address with specified alignment

Parameters

struct lmb *io_lmb: LMB to alloc from
phys_size_t size: Size of the region requested
ulong align: Required address and size alignment

Description

Allocate a region of IO memory. The base parameter is used to specify the base address of the requested region.

Return

Base IO address on success, 0 on error.

long io_lmb_free(struct lmb *io_lmb, phys_addr_t base, phys_size_t size): Free up a region of IOVA space

Parameters

struct lmb *io_lmb: LMB to return the IO address space to
phys_addr_t base: Base Address of region to be freed
phys_size_t size: Size of the region to be freed

Return

0 on success, negative error code on failure.