Provide descriptions of:
* efi_get_memory_map()
* efi_low_alloc_above()
* efi_free()
Signed-off-by: Heinrich Schuchardt <xypron.glpk@xxxxxx>
---
v3:
add missing colons for parameter descriptions
v2:
point out how efi_free() is rounding up the memory size
---
drivers/firmware/efi/libstub/mem.c | 36 ++++++++++++++++++++++++++++--
1 file changed, 34 insertions(+), 2 deletions(-)
diff --git a/drivers/firmware/efi/libstub/mem.c b/drivers/firmware/efi/libstub/mem.c
index c25fd9174b74..7cf2823bdedc 100644
--- a/drivers/firmware/efi/libstub/mem.c
+++ b/drivers/firmware/efi/libstub/mem.c
@@ -16,6 +16,15 @@ static inline bool mmap_has_headroom(unsigned long buff_size,
return slack / desc_size >= EFI_MMAP_NR_SLACK_SLOTS;
}
+/**
+ * efi_get_memory_map() - get memory map
+ * @map: on return pointer to memory map
+ *
+ * Retrieve the UEFI memory map. The allocated memory leaves room for
+ * up to EFI_MMAP_NR_SLACK_SLOTS additional memory map entries.
+ *
+ * Return: status code
+ */
efi_status_t efi_get_memory_map(struct efi_boot_memmap *map)
{
efi_memory_desc_t *m = NULL;
@@ -109,8 +118,20 @@ efi_status_t efi_allocate_pages(unsigned long size, unsigned long *addr,
}
return EFI_SUCCESS;
}
-/*
- * Allocate at the lowest possible address that is not below 'min'.
+/**
+ * efi_low_alloc_above() - allocate pages at or above given address
+ * @size: size of the memory area to allocate
+ * @align: minimum alignment of the allocated memory area. It should
+ * a power of two.
+ * @addr: on exit the address of the allocated memory
+ * @min: minimum address to used for the memory allocation
+ *
+ * Allocate at the lowest possible address that is not below 'min' as
+ * EFI_LOADER_DATA. The allocated pages are aligned according to 'align' but at
+ * least EFI_ALLOC_ALIGN. The first allocated page will not below the address
+ * given by 'min'.
+ *
+ * Return: status code
*/
efi_status_t efi_low_alloc_above(unsigned long size, unsigned long align,
unsigned long *addr, unsigned long min)
@@ -187,6 +208,17 @@ efi_status_t efi_low_alloc_above(unsigned long size, unsigned long align,
return status;
}
+/**
+ * efi_free() - free memory pages
+ * @size: size of the memory area to free in bytes
+ * @addr: start of the memory area to free (must be EFI_PAGE_SIZE
+ * aligned)
+ *
+ * 'size' is rounded up to a multiple of EFI_ALLOC_ALIGN which is an
+ * architecture specific multiple of EFI_PAGE_SIZE. So this function should
+ * only be used to return pages allocated with efi_allocate_pages() or
+ * efi_low_alloc_above().
+ */
void efi_free(unsigned long size, unsigned long addr)
{
unsigned long nr_pages;
--
2.25.0
