efi: Pass boot services variable info to runtime code

EFI variables can be flagged as being accessible only within boot services.
This makes it awkward for us to figure out how much space they use at
runtime. In theory we could figure this out by simply comparing the results
from QueryVariableInfo() to the space used by all of our variables, but
that fails if the platform doesn't garbage collect on every boot. Thankfully,
calling QueryVariableInfo() while still inside boot services gives a more
reliable answer. This patch passes that information from the EFI boot stub
up to the efi platform code.

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

1 files changed, 47 insertions, 0 deletions

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index c205035a6b96..8615f7581820 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -251,6 +251,51 @@ static void find_bits(unsigned long mask, u8 *pos, u8 *size)
         *size = len;
 }
 
+static efi_status_t setup_efi_vars(struct boot_params *params)
+{
+        struct setup_data *data;
+        struct efi_var_bootdata *efidata;
+        u64 store_size, remaining_size, var_size;
+        efi_status_t status;
+
+        if (!sys_table->runtime->query_variable_info)
+                return EFI_UNSUPPORTED;
+
+        data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
+
+        while (data && data->next)
+                data = (struct setup_data *)(unsigned long)data->next;
+
+        status = efi_call_phys4(sys_table->runtime->query_variable_info,
+                                EFI_VARIABLE_NON_VOLATILE |
+                                EFI_VARIABLE_BOOTSERVICE_ACCESS |
+                                EFI_VARIABLE_RUNTIME_ACCESS, &store_size,
+                                &remaining_size, &var_size);
+
+        if (status != EFI_SUCCESS)
+                return status;
+
+        status = efi_call_phys3(sys_table->boottime->allocate_pool,
+                                EFI_LOADER_DATA, sizeof(*efidata), &efidata);
+
+        if (status != EFI_SUCCESS)
+                return status;
+
+        efidata->data.type = SETUP_EFI_VARS;
+        efidata->data.len = sizeof(struct efi_var_bootdata) -
+                sizeof(struct setup_data);
+        efidata->data.next = 0;
+        efidata->store_size = store_size;
+        efidata->remaining_size = remaining_size;
+        efidata->max_var_size = var_size;
+
+        if (data)
+                data->next = (unsigned long)efidata;
+        else
+                params->hdr.setup_data = (unsigned long)efidata;
+
+}
+
 static efi_status_t setup_efi_pci(struct boot_params *params)
 {
         efi_pci_io_protocol *pci;
@@ -1157,6 +1202,8 @@ struct boot_params *efi_main(void *handle, efi_system_table_t *_table,
 
         setup_graphics(boot_params);
 
+        setup_efi_vars(boot_params);
+
         setup_efi_pci(boot_params);
 
         status = efi_call_phys3(sys_table->boottime->allocate_pool,