[PATCH 09/11] efi/runtime-map: Use efi.memmap directly instead of a copy

From: Matt Fleming
Date: Thu Jun 23 2016 - 07:36:43 EST


Now that efi.memmap is available all of the time there's no need to
allocate and build a separate copy of the EFI memory map.

Furthermore, efi.memmap contains boot services regions but only those
regions that have been reserved via efi_mem_reserve(). Using
efi.memmap allows us to pass boot services across kexec reboot so that
the ESRT and BGRT drivers will now work.

Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Cc: Leif Lindholm <leif.lindholm@xxxxxxxxxx>
Cc: Peter Jones <pjones@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Dave Young <dyoung@xxxxxxxxxx>
Signed-off-by: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/platform/efi/efi.c | 40 --------------------------------------
drivers/firmware/efi/runtime-map.c | 35 +++++++++++++--------------------
include/linux/efi.h | 4 ----
3 files changed, 13 insertions(+), 66 deletions(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 33bc6c12702c..8ac32128ca94 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -608,42 +608,6 @@ static void __init get_systab_virt_addr(efi_memory_desc_t *md)
}
}

-static void __init save_runtime_map(void)
-{
-#ifdef CONFIG_KEXEC_CORE
- unsigned long desc_size;
- efi_memory_desc_t *md;
- void *tmp, *q = NULL;
- int count = 0;
-
- if (efi_enabled(EFI_OLD_MEMMAP))
- return;
-
- desc_size = efi.memmap.desc_size;
-
- for_each_efi_memory_desc(md) {
- if (!(md->attribute & EFI_MEMORY_RUNTIME) ||
- (md->type == EFI_BOOT_SERVICES_CODE) ||
- (md->type == EFI_BOOT_SERVICES_DATA))
- continue;
- tmp = krealloc(q, (count + 1) * desc_size, GFP_KERNEL);
- if (!tmp)
- goto out;
- q = tmp;
-
- memcpy(q + count * desc_size, md, desc_size);
- count++;
- }
-
- efi_runtime_map_setup(q, count, desc_size);
- return;
-
-out:
- kfree(q);
- pr_err("Error saving runtime map, efi runtime on kexec non-functional!!\n");
-#endif
-}
-
static void *realloc_pages(void *old_memmap, int old_shift)
{
void *ret;
@@ -856,8 +820,6 @@ static void __init kexec_enter_virtual_mode(void)
return;
}

- save_runtime_map();
-
BUG_ON(!efi.systab);

num_pages = ALIGN(efi.memmap.nr_map * efi.memmap.desc_size, PAGE_SIZE);
@@ -950,8 +912,6 @@ static void __init __efi_enter_virtual_mode(void)
return;
}

- save_runtime_map();
-
BUG_ON(!efi.systab);

if (efi_setup_page_tables(pa, 1 << pg_shift)) {
diff --git a/drivers/firmware/efi/runtime-map.c b/drivers/firmware/efi/runtime-map.c
index 5c55227a34c8..8e64b77aeac9 100644
--- a/drivers/firmware/efi/runtime-map.c
+++ b/drivers/firmware/efi/runtime-map.c
@@ -14,10 +14,6 @@

#include <asm/setup.h>

-static void *efi_runtime_map;
-static int nr_efi_runtime_map;
-static u32 efi_memdesc_size;
-
struct efi_runtime_map_entry {
efi_memory_desc_t md;
struct kobject kobj; /* kobject for each entry */
@@ -106,7 +102,8 @@ static struct kobj_type __refdata map_ktype = {
static struct kset *map_kset;

static struct efi_runtime_map_entry *
-add_sysfs_runtime_map_entry(struct kobject *kobj, int nr)
+add_sysfs_runtime_map_entry(struct kobject *kobj, int nr,
+ efi_memory_desc_t *md)
{
int ret;
struct efi_runtime_map_entry *entry;
@@ -124,8 +121,7 @@ add_sysfs_runtime_map_entry(struct kobject *kobj, int nr)
return ERR_PTR(-ENOMEM);
}

- memcpy(&entry->md, efi_runtime_map + nr * efi_memdesc_size,
- sizeof(efi_memory_desc_t));
+ memcpy(&entry->md, md, sizeof(efi_memory_desc_t));

kobject_init(&entry->kobj, &map_ktype);
entry->kobj.kset = map_kset;
@@ -142,12 +138,12 @@ add_sysfs_runtime_map_entry(struct kobject *kobj, int nr)

int efi_get_runtime_map_size(void)
{
- return nr_efi_runtime_map * efi_memdesc_size;
+ return efi.memmap.nr_map * efi.memmap.desc_size;
}

int efi_get_runtime_map_desc_size(void)
{
- return efi_memdesc_size;
+ return efi.memmap.desc_size;
}

int efi_runtime_map_copy(void *buf, size_t bufsz)
@@ -157,38 +153,33 @@ int efi_runtime_map_copy(void *buf, size_t bufsz)
if (sz > bufsz)
sz = bufsz;

- memcpy(buf, efi_runtime_map, sz);
+ memcpy(buf, efi.memmap.map, sz);
return 0;
}

-void efi_runtime_map_setup(void *map, int nr_entries, u32 desc_size)
-{
- efi_runtime_map = map;
- nr_efi_runtime_map = nr_entries;
- efi_memdesc_size = desc_size;
-}
-
int __init efi_runtime_map_init(struct kobject *efi_kobj)
{
int i, j, ret = 0;
struct efi_runtime_map_entry *entry;
+ efi_memory_desc_t *md;

- if (!efi_runtime_map)
+ if (!efi_enabled(EFI_MEMMAP))
return 0;

- map_entries = kzalloc(nr_efi_runtime_map * sizeof(entry), GFP_KERNEL);
+ map_entries = kzalloc(efi.memmap.nr_map * sizeof(entry), GFP_KERNEL);
if (!map_entries) {
ret = -ENOMEM;
goto out;
}

- for (i = 0; i < nr_efi_runtime_map; i++) {
- entry = add_sysfs_runtime_map_entry(efi_kobj, i);
+ i = 0;
+ for_each_efi_memory_desc(md) {
+ entry = add_sysfs_runtime_map_entry(efi_kobj, i, md);
if (IS_ERR(entry)) {
ret = PTR_ERR(entry);
goto out_add_entry;
}
- *(map_entries + i) = entry;
+ *(map_entries + i++) = entry;
}

return 0;
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 9f955dab9f77..729ce6f1af13 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1431,7 +1431,6 @@ extern int efi_capsule_update(efi_capsule_header_t *capsule,

#ifdef CONFIG_EFI_RUNTIME_MAP
int efi_runtime_map_init(struct kobject *);
-void efi_runtime_map_setup(void *, int, u32);
int efi_get_runtime_map_size(void);
int efi_get_runtime_map_desc_size(void);
int efi_runtime_map_copy(void *buf, size_t bufsz);
@@ -1441,9 +1440,6 @@ static inline int efi_runtime_map_init(struct kobject *kobj)
return 0;
}

-static inline void
-efi_runtime_map_setup(void *map, int nr_entries, u32 desc_size) {}
-
static inline int efi_get_runtime_map_size(void)
{
return 0;
--
2.7.3