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x86/efi: Split efi_enter_virtual_mode
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... into a kexec flavor for better code readability and simplicity. The
original one was getting ugly with ifdeffery.

Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
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Borislav Petkov authored and Matt Fleming committed Mar 4, 2014
1 parent b7b898a commit fabb37c
Showing 1 changed file with 98 additions and 50 deletions.
148 changes: 98 additions & 50 deletions arch/x86/platform/efi/efi.c
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Original file line number Diff line number Diff line change
Expand Up @@ -879,8 +879,9 @@ static void __init get_systab_virt_addr(efi_memory_desc_t *md)
}
}

static int __init save_runtime_map(void)
static void __init save_runtime_map(void)
{
#ifdef CONFIG_KEXEC
efi_memory_desc_t *md;
void *tmp, *p, *q = NULL;
int count = 0;
Expand All @@ -902,28 +903,12 @@ static int __init save_runtime_map(void)
}

efi_runtime_map_setup(q, count, memmap.desc_size);
return;

return 0;
out:
kfree(q);
return -ENOMEM;
}

/*
* Map efi regions which were passed via setup_data. The virt_addr is a fixed
* addr which was used in first kernel of a kexec boot.
*/
static void __init efi_map_regions_fixed(void)
{
void *p;
efi_memory_desc_t *md;

for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
md = p;
efi_map_region_fixed(md); /* FIXME: add error handling */
get_systab_virt_addr(md);
}

pr_err("Error saving runtime map, efi runtime on kexec non-functional!!\n");
#endif
}

static void *realloc_pages(void *old_memmap, int old_shift)
Expand Down Expand Up @@ -989,6 +974,72 @@ static void * __init efi_map_regions(int *count, int *pg_shift)
return new_memmap;
}

static void __init kexec_enter_virtual_mode(void)
{
#ifdef CONFIG_KEXEC
efi_memory_desc_t *md;
void *p;

efi.systab = NULL;

/*
* We don't do virtual mode, since we don't do runtime services, on
* non-native EFI
*/
if (!efi_is_native()) {
efi_unmap_memmap();
return;
}

/*
* Map efi regions which were passed via setup_data. The virt_addr is a
* fixed addr which was used in first kernel of a kexec boot.
*/
for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
md = p;
efi_map_region_fixed(md); /* FIXME: add error handling */
get_systab_virt_addr(md);
}

save_runtime_map();

BUG_ON(!efi.systab);

efi_sync_low_kernel_mappings();

/*
* Now that EFI is in virtual mode, update the function
* pointers in the runtime service table to the new virtual addresses.
*
* Call EFI services through wrapper functions.
*/
efi.runtime_version = efi_systab.hdr.revision;
efi.get_time = virt_efi_get_time;
efi.set_time = virt_efi_set_time;
efi.get_wakeup_time = virt_efi_get_wakeup_time;
efi.set_wakeup_time = virt_efi_set_wakeup_time;
efi.get_variable = virt_efi_get_variable;
efi.get_next_variable = virt_efi_get_next_variable;
efi.set_variable = virt_efi_set_variable;
efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
efi.reset_system = virt_efi_reset_system;
efi.set_virtual_address_map = NULL;
efi.query_variable_info = virt_efi_query_variable_info;
efi.update_capsule = virt_efi_update_capsule;
efi.query_capsule_caps = virt_efi_query_capsule_caps;

if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX))
runtime_code_page_mkexec();

/* clean DUMMY object */
efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
EFI_VARIABLE_NON_VOLATILE |
EFI_VARIABLE_BOOTSERVICE_ACCESS |
EFI_VARIABLE_RUNTIME_ACCESS,
0, NULL);
#endif
}

/*
* This function will switch the EFI runtime services to virtual mode.
* Essentially, we look through the EFI memmap and map every region that
Expand All @@ -1008,11 +1059,12 @@ static void * __init efi_map_regions(int *count, int *pg_shift)
*
* Specially for kexec boot, efi runtime maps in previous kernel should
* be passed in via setup_data. In that case runtime ranges will be mapped
* to the same virtual addresses as the first kernel.
* to the same virtual addresses as the first kernel, see
* kexec_enter_virtual_mode().
*/
void __init efi_enter_virtual_mode(void)
static void __init __efi_enter_virtual_mode(void)
{
int err, count = 0, pg_shift = 0;
int count = 0, pg_shift = 0;
void *new_memmap = NULL;
efi_status_t status;

Expand All @@ -1027,43 +1079,33 @@ void __init efi_enter_virtual_mode(void)
return;
}

if (efi_setup) {
efi_map_regions_fixed();
} else {
efi_merge_regions();
new_memmap = efi_map_regions(&count, &pg_shift);
if (!new_memmap) {
pr_err("Error reallocating memory, EFI runtime non-functional!\n");
return;
}

err = save_runtime_map();
if (err)
pr_err("Error saving runtime map, efi runtime on kexec non-functional!!\n");
efi_merge_regions();
new_memmap = efi_map_regions(&count, &pg_shift);
if (!new_memmap) {
pr_err("Error reallocating memory, EFI runtime non-functional!\n");
return;
}

save_runtime_map();

BUG_ON(!efi.systab);

if (!efi_setup) {
if (efi_setup_page_tables(__pa(new_memmap), 1 << pg_shift))
return;
}
if (efi_setup_page_tables(__pa(new_memmap), 1 << pg_shift))
return;

efi_sync_low_kernel_mappings();
efi_dump_pagetable();

if (!efi_setup) {
status = phys_efi_set_virtual_address_map(
status = phys_efi_set_virtual_address_map(
memmap.desc_size * count,
memmap.desc_size,
memmap.desc_version,
(efi_memory_desc_t *)__pa(new_memmap));

if (status != EFI_SUCCESS) {
pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n",
status);
panic("EFI call to SetVirtualAddressMap() failed!");
}
if (status != EFI_SUCCESS) {
pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n",
status);
panic("EFI call to SetVirtualAddressMap() failed!");
}

/*
Expand All @@ -1089,7 +1131,6 @@ void __init efi_enter_virtual_mode(void)

efi_runtime_mkexec();


/*
* We mapped the descriptor array into the EFI pagetable above but we're
* not unmapping it here. Here's why:
Expand All @@ -1116,8 +1157,7 @@ void __init efi_enter_virtual_mode(void)
*
* efi_cleanup_page_tables(__pa(new_memmap), 1 << pg_shift);
*/
if (!efi_setup)
free_pages((unsigned long)new_memmap, pg_shift);
free_pages((unsigned long)new_memmap, pg_shift);

/* clean DUMMY object */
efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
Expand All @@ -1127,6 +1167,14 @@ void __init efi_enter_virtual_mode(void)
0, NULL);
}

void __init efi_enter_virtual_mode(void)
{
if (efi_setup)
kexec_enter_virtual_mode();
else
__efi_enter_virtual_mode();
}

/*
* Convenience functions to obtain memory types and attributes
*/
Expand Down

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