[U-Boot] [PATCH 09/16] efi_loader: Implement memory allocation and map
Leif Lindholm
leif.lindholm at linaro.org
Tue Feb 2 18:35:55 CET 2016
On Tue, Feb 02, 2016 at 03:45:07AM +0100, Alexander Graf wrote:
> The EFI loader needs to maintain views of memory - general system memory
> windows as well as used locations inside those and potential runtime service
> MMIO windows.
>
> To manage all of these, add a few helpers that maintain an internal
> representation of the map the similar to how the EFI API later on reports
> it to the application.
>
> For allocations, the scheme is very simple. We basically allow allocations
> to replace chunks of previously done maps, so that a new LOADER_DATA
> allocation for example can remove a piece of the RAM map. When no specific
> address is given, we just take the highest possible address in the lowest
> RAM map that fits the allocation size.
>
> Signed-off-by: Alexander Graf <agraf at suse.de>
>
> ---
>
> v2 -> v3:
>
> - Rewrite memory allocation and map
> - Document header
> ---
> common/board_r.c | 3 +
> include/efi_loader.h | 19 +++
> lib/efi_loader/efi_memory.c | 314 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 336 insertions(+)
> create mode 100644 lib/efi_loader/efi_memory.c
>
> diff --git a/common/board_r.c b/common/board_r.c
> index 420e2c8..2ed8e4b 100644
> --- a/common/board_r.c
> +++ b/common/board_r.c
> @@ -785,6 +785,9 @@ init_fnc_t init_sequence_r[] = {
> #ifdef CONFIG_CLOCKS
> set_cpu_clk_info, /* Setup clock information */
> #endif
> +#ifdef CONFIG_EFI_LOADER
> + efi_memory_init,
> +#endif
> stdio_init_tables,
> initr_serial,
> initr_announce,
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index 91ab6cb..e38be12 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -109,6 +109,25 @@ efi_status_t efi_exit_func(efi_status_t ret);
> /* Call this to relocate the runtime section to an address space */
> void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map);
>
> +/* Generic EFI memory allocator, call this to get memory */
> +void *efi_alloc(uint64_t len, int memory_type);
> +/* More specific EFI memory allocator, called by EFI payloads */
> +efi_status_t efi_allocate_pages(int type, int memory_type, unsigned long pages,
> + uint64_t *memory);
> +/* EFI memory free function. Not implemented today */
> +efi_status_t efi_free_pages(uint64_t memory, unsigned long pages);
> +/* Returns the EFI memory map */
> +efi_status_t efi_get_memory_map(unsigned long *memory_map_size,
> + struct efi_mem_desc *memory_map,
> + unsigned long *map_key,
> + unsigned long *descriptor_size,
> + uint32_t *descriptor_version);
> +/* Adds a range into the EFI memory map */
> +uint64_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
> + bool overlap_only_ram);
> +/* Called by board init to initialize the EFI memory map */
> +int efi_memory_init(void);
> +
> /*
> * Use these to indicate that your code / data should go into the EFI runtime
> * section and thus still be available when the OS is running
> diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
> new file mode 100644
> index 0000000..e58d190
> --- /dev/null
> +++ b/lib/efi_loader/efi_memory.c
> @@ -0,0 +1,314 @@
> +/*
> + * EFI application memory management
> + *
> + * Copyright (c) 2016 Alexander Graf
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +
> +/* #define DEBUG_EFI */
> +
> +#include <common.h>
> +#include <efi_loader.h>
> +#include <malloc.h>
> +#include <asm/global_data.h>
> +#include <libfdt_env.h>
> +#include <inttypes.h>
> +#include <watchdog.h>
> +
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +struct efi_mem_list {
> + struct list_head link;
> + struct efi_mem_desc desc;
> +};
> +
> +/* This list contains all memory map items */
> +LIST_HEAD(efi_mem);
> +
> +/*
> + * Unmaps all memory occupied by the carve_desc region from the
> + * list entry pointed to by map.
> + *
> + * Returns 1 if carving was performed or 0 if the regions don't overlap.
> + * Returns -1 if it would affect non-RAM regions but overlap_only_ram is set.
> + * Carving is only guaranteed to complete when all regions return 0.
> + */
> +static int efi_mem_carve_out(struct efi_mem_list *map,
> + struct efi_mem_desc *carve_desc,
> + bool overlap_only_ram)
> +{
> + struct efi_mem_list *newmap;
> + struct efi_mem_desc *map_desc = &map->desc;
> + uint64_t map_start = map_desc->physical_start;
> + uint64_t map_end = map_start + (map_desc->num_pages << 12);
Can we replace the magic 12 with an EFI_PAGE_SHIFT define?
> + uint64_t carve_start = carve_desc->physical_start;
> + uint64_t carve_end = carve_start + (carve_desc->num_pages << 12);
> +
> + /* check whether we're overlapping */
> + if ((carve_end <= map_start) || (carve_start >= map_end))
> + return 0;
> +
> + /* We're overlapping with non-RAM, warn the caller if desired */
> + if (overlap_only_ram && (map_desc->type != EFI_CONVENTIONAL_MEMORY))
> + return -1;
> +
> + /* Sanitize carve_start and carve_end to lie within our bounds */
> + carve_start = max(carve_start, map_start);
> + carve_end = min(carve_end, map_end);
> +
> + /* Carving at the beginning of our map? Just move it! */
> + if (carve_start == map_start) {
> + if (map_end == carve_end) {
> + /* Full overlap, just remove map */
> + list_del(&map->link);
> + }
> +
> + map_desc->physical_start = carve_end;
> + map_desc->num_pages = (map_end - carve_end) >> 12;
> + return 1;
> + }
> +
> + /*
> + * Overlapping maps, just split the list map at carve_start,
> + * it will get moved or removed in the next iteration.
> + *
> + * [ map_desc |__carve_start__| newmap ]
> + */
> +
> + /* Create a new map from [ carve_start ... map_end ] */
> + newmap = calloc(1, sizeof(*newmap));
> + newmap->desc = map->desc;
> + newmap->desc.physical_start = carve_start;
> + newmap->desc.num_pages = (map_end - carve_start) >> 12;
> + list_add_tail(&newmap->link, &efi_mem);
> +
> + /* Shrink the map to [ map_start ... carve_start ] */
> + map_desc->num_pages = (carve_start - map_start) >> 12;
> +
> + return 1;
> +}
> +
> +uint64_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
> + bool overlap_only_ram)
> +{
> + struct list_head *lhandle;
> + struct efi_mem_list *newlist;
> + bool do_carving;
> +
> + if (!pages)
> + return start;
> +
> + newlist = calloc(1, sizeof(*newlist));
> + newlist->desc.type = memory_type;
> + newlist->desc.physical_start = start;
> + newlist->desc.virtual_start = start;
> + newlist->desc.num_pages = pages;
> +
> + switch (memory_type) {
> + case EFI_RUNTIME_SERVICES_CODE:
> + case EFI_RUNTIME_SERVICES_DATA:
> + newlist->desc.attribute = (1 << EFI_MEMORY_WB_SHIFT) |
> + (1ULL << EFI_MEMORY_RUNTIME_SHIFT);
> + break;
> + case EFI_MMAP_IO:
> + newlist->desc.attribute = 1ULL << EFI_MEMORY_RUNTIME_SHIFT;
> + break;
> + default:
> + newlist->desc.attribute = 1 << EFI_MEMORY_WB_SHIFT;
> + break;
> + }
> +
> + /* Add our new map */
> + do {
> + do_carving = false;
> + list_for_each(lhandle, &efi_mem) {
> + struct efi_mem_list *lmem;
> + int r;
> +
> + lmem = list_entry(lhandle, struct efi_mem_list, link);
> + r = efi_mem_carve_out(lmem, &newlist->desc,
> + overlap_only_ram);
> + if (r < 0) {
> + return 0;
> + } else if (r) {
> + do_carving = true;
> + break;
> + }
> + }
> + } while (do_carving);
> +
> + /* Add our new map */
> + list_add_tail(&newlist->link, &efi_mem);
> +
> + return start;
> +}
> +
> +static uint64_t efi_find_free_memory(uint64_t len, uint64_t max_addr)
> +{
> + struct list_head *lhandle;
> +
> + list_for_each(lhandle, &efi_mem) {
> + struct efi_mem_list *lmem = list_entry(lhandle,
> + struct efi_mem_list, link);
> + struct efi_mem_desc *desc = &lmem->desc;
> + uint64_t desc_len = desc->num_pages << 12;
> + uint64_t desc_end = desc->physical_start + desc_len;
> + uint64_t curmax = min(max_addr, desc_end);
> + uint64_t ret = curmax - len;
> +
> + /* We only take memory from free RAM */
> + if (desc->type != EFI_CONVENTIONAL_MEMORY)
> + continue;
> +
> + /* Out of bounds for max_addr */
> + if ((ret + len) > max_addr)
> + continue;
> +
> + /* Out of bounds for upper map limit */
> + if ((ret + len) > desc_end)
> + continue;
> +
> + /* Out of bounds for lower map limit */
> + if (ret < desc->physical_start)
> + continue;
> +
> + /* Return the highest address in this map within bounds */
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +efi_status_t efi_allocate_pages(int type, int memory_type,
> + unsigned long pages, uint64_t *memory)
> +{
> + u64 len = pages << 12;
> + efi_status_t r = EFI_SUCCESS;
> + uint64_t addr;
> +
> + switch (type) {
> + case 0:
> + /* Any page */
> + addr = efi_find_free_memory(len, gd->ram_top);
> + if (!addr) {
> + r = EFI_NOT_FOUND;
> + break;
> + }
> + break;
> + case 1:
> + /* Max address */
> + addr = efi_find_free_memory(len, *memory);
> + if (!addr) {
> + r = EFI_NOT_FOUND;
> + break;
> + }
> + break;
> + case 2:
> + /* Exact address, reserve it. The addr is already in *memory. */
> + addr = *memory;
> + break;
Still concerned over the lack of checking for clashes with existing
allocations. Ah, no, you trap that below. Sneaky :)
> + default:
> + /* UEFI doesn't specify other allocation types */
> + r = EFI_INVALID_PARAMETER;
> + break;
> + }
> +
> + if (r == EFI_SUCCESS) {
> + uint64_t ret;
> +
> + /* Reserve that map in our memory maps */
> + ret = efi_add_memory_map(addr, pages, memory_type, true);
> + if (ret == addr) {
> + *memory = addr;
> + } else {
> + /* Map would overlap, bail out */
> + r = EFI_NOT_FOUND;
EFI_OUT_OF_RESOURCES?
> + }
> + }
> +
> + return r;
> +}
> +
> +void *efi_alloc(uint64_t len, int memory_type)
> +{
> + uint64_t ret = 0;
> + efi_status_t r;
> +
> + r = efi_allocate_pages(0, memory_type, (len + 0xfff) >> 12, &ret);
A define for the 0xfff value as well? (EFI_PAGE_SIZE - 1)?
> + if (r == EFI_SUCCESS)
> + return (void*)(uintptr_t)ret;
> +
> + return NULL;
> +}
> +
> +efi_status_t efi_free_pages(uint64_t memory, unsigned long pages)
> +{
> + /* We don't free, let's cross our fingers we have plenty RAM */
> + return EFI_SUCCESS;
> +}
This would actually be quite easy to implement correctly now with your
latest changes :)
But I won't insist it needs to be fixed for initial inclusion.
> +
> +efi_status_t efi_get_memory_map(unsigned long *memory_map_size,
> + struct efi_mem_desc *memory_map,
> + unsigned long *map_key,
> + unsigned long *descriptor_size,
> + uint32_t *descriptor_version)
> +{
> + ulong map_size = 0;
> + struct list_head *lhandle;
> +
> + list_for_each(lhandle, &efi_mem)
> + map_size += sizeof(struct efi_mem_desc);
> +
> + *memory_map_size = map_size;
> +
> + if (descriptor_size)
> + *descriptor_size = sizeof(struct efi_mem_desc);
> +
> + if (*memory_map_size < map_size)
> + return EFI_BUFFER_TOO_SMALL;
> +
> + /* Copy list into array */
> + if (memory_map) {
> + list_for_each(lhandle, &efi_mem) {
> + struct efi_mem_list *lmem;
> +
> + lmem = list_entry(lhandle, struct efi_mem_list, link);
> + *memory_map = lmem->desc;
> + memory_map++;
> + }
> + }
> +
> + return EFI_SUCCESS;
> +}
> +
> +int efi_memory_init(void)
> +{
> + uint64_t runtime_start, runtime_end, runtime_pages;
> + uint64_t uboot_start, uboot_pages;
> + uint64_t uboot_stack_size = 16 * 1024 * 1024;
> + int i;
> +
> + /* Add RAM */
> + for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
> + ulong start = (gd->bd->bi_dram[i].start + 0xfff) & ~0xfffULL;
> + ulong pages = (gd->bd->bi_dram[i].size + 0xfff) >> 12;
(EFI_PAGE_SIZE -1)
> +
> + efi_add_memory_map(start, pages, EFI_CONVENTIONAL_MEMORY,
> + false);
> + }
Much prettier with the multi-bank handling. Thanks.
> +
> + /* Add U-Boot */
> + uboot_start = (gd->start_addr_sp - uboot_stack_size) & ~0xfffULL;
> + uboot_pages = (gd->ram_top - uboot_start) >> 12;
> + efi_add_memory_map(uboot_start, uboot_pages, EFI_LOADER_DATA, false);
> +
> + /* Add Runtime Services */
> + runtime_start = (ulong)&__efi_runtime_start & ~0xfffULL;
> + runtime_end = ((ulong)&__efi_runtime_stop + 0xfff) & ~0xfffULL;
> + runtime_pages = (runtime_end - runtime_start) >> 12;
> + efi_add_memory_map(runtime_start, runtime_pages,
> + EFI_RUNTIME_SERVICES_CODE, false);
> +
> + return 0;
> +}
> --
> 2.6.2
>
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