[PATCH v2 09/23] efi: create efi_enabled()

[Daniel Kiper <daniel.kiper@oracle.com>]

We need more fine grained knowledge about EFI environment and check
for EFI platform and EFI loader separately to properly support
multiboot2 protocol. In general Xen loaded by this protocol uses
memory mappings and loaded modules in similar way to Xen loaded
by multiboot (v1) protocol. Hence, create efi_enabled() which
checks available features in efi.flags. This patch only defines
EFI_PLATFORM feature which is equal to old efi_enabled == 1.
Following patch will define EFI_LOADER feature accordingly.

Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
---
 xen/arch/x86/dmi_scan.c    |    4 ++--
 xen/arch/x86/domain_page.c |    2 +-
 xen/arch/x86/efi/stub.c    |   11 ++++++++---
 xen/arch/x86/mpparse.c     |    4 ++--
 xen/arch/x86/setup.c       |   10 +++++-----
 xen/arch/x86/shutdown.c    |    2 +-
 xen/arch/x86/time.c        |    2 +-
 xen/arch/x86/xen.lds.S     |    2 --
 xen/common/efi/boot.c      |    4 ++++
 xen/common/efi/runtime.c   |   17 +++++++----------
 xen/drivers/acpi/osl.c     |    2 +-
 xen/include/xen/efi.h      |   16 ++++++++++++++--
 12 files changed, 46 insertions(+), 30 deletions(-)

diff --git a/xen/arch/x86/dmi_scan.c b/xen/arch/x86/dmi_scan.c
index 269168c..95c5a77 100644
--- a/xen/arch/x86/dmi_scan.c
+++ b/xen/arch/x86/dmi_scan.c
@@ -229,7 +229,7 @@ const char *__init dmi_get_table(paddr_t *base, u32 *len)
 {
 	static unsigned int __initdata instance;
 
-	if (efi_enabled) {
+	if (efi_enabled(EFI_PLATFORM)) {
 		if (efi_smbios3_size && !(instance & 1)) {
 			*base = efi_smbios3_address;
 			*len = efi_smbios3_size;
@@ -693,7 +693,7 @@ static void __init dmi_decode(struct dmi_header *dm)
 
 void __init dmi_scan_machine(void)
 {
-	if ((!efi_enabled ? dmi_iterate(dmi_decode) :
+	if ((!efi_enabled(EFI_PLATFORM) ? dmi_iterate(dmi_decode) :
 	                    dmi_efi_iterate(dmi_decode)) == 0)
  		dmi_check_system(dmi_blacklist);
 	else
diff --git a/xen/arch/x86/domain_page.c b/xen/arch/x86/domain_page.c
index d86f8fe..fdf0d8a 100644
--- a/xen/arch/x86/domain_page.c
+++ b/xen/arch/x86/domain_page.c
@@ -36,7 +36,7 @@ static inline struct vcpu *mapcache_current_vcpu(void)
      * domain's page tables but current may point at another domain's VCPU.
      * Return NULL as though current is not properly set up yet.
      */
-    if ( efi_enabled && efi_rs_using_pgtables() )
+    if ( efi_enabled(EFI_PLATFORM) && efi_rs_using_pgtables() )
         return NULL;
 
     /*
diff --git a/xen/arch/x86/efi/stub.c b/xen/arch/x86/efi/stub.c
index 07c2bd0..c5ae369 100644
--- a/xen/arch/x86/efi/stub.c
+++ b/xen/arch/x86/efi/stub.c
@@ -4,9 +4,14 @@
 #include <xen/lib.h>
 #include <asm/page.h>
 
-#ifndef efi_enabled
-const bool_t efi_enabled = 0;
-#endif
+struct efi __read_mostly efi = {
+	.flags   = 0, /* Initialized later. */
+	.acpi    = EFI_INVALID_TABLE_ADDR,
+	.acpi20  = EFI_INVALID_TABLE_ADDR,
+	.mps     = EFI_INVALID_TABLE_ADDR,
+	.smbios  = EFI_INVALID_TABLE_ADDR,
+	.smbios3 = EFI_INVALID_TABLE_ADDR
+};
 
 void __init efi_init_memory(void) { }
 
diff --git a/xen/arch/x86/mpparse.c b/xen/arch/x86/mpparse.c
index 8609f4a..5223579 100644
--- a/xen/arch/x86/mpparse.c
+++ b/xen/arch/x86/mpparse.c
@@ -557,7 +557,7 @@ static inline void __init construct_default_ISA_mptable(int mpc_default_type)
 
 static __init void efi_unmap_mpf(void)
 {
-	if (efi_enabled)
+	if (efi_enabled(EFI_PLATFORM))
 		clear_fixmap(FIX_EFI_MPF);
 }
 
@@ -715,7 +715,7 @@ void __init find_smp_config (void)
 {
 	unsigned int address;
 
-	if (efi_enabled) {
+	if (efi_enabled(EFI_PLATFORM)) {
 		efi_check_config();
 		return;
 	}
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index ff34670..bce708c 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -444,8 +444,8 @@ static void __init parse_video_info(void)
 {
     struct boot_video_info *bvi = &bootsym(boot_vid_info);
 
-    /* The EFI loader fills vga_console_info directly. */
-    if ( efi_enabled )
+    /* vga_console_info is filled directly on EFI platform. */
+    if ( efi_enabled(EFI_PLATFORM) )
         return;
 
     if ( (bvi->orig_video_isVGA == 1) && (bvi->orig_video_mode == 3) )
@@ -695,7 +695,7 @@ void __init noreturn __start_xen(unsigned long mbi_p)
     if ( !(mbi->flags & MBI_MODULES) || (mbi->mods_count == 0) )
         panic("dom0 kernel not specified. Check bootloader configuration.");
 
-    if ( efi_enabled )
+    if ( efi_enabled(EFI_PLATFORM) )
     {
         set_pdx_range(xen_phys_start >> PAGE_SHIFT,
                       (xen_phys_start + BOOTSTRAP_MAP_BASE) >> PAGE_SHIFT);
@@ -806,7 +806,7 @@ void __init noreturn __start_xen(unsigned long mbi_p)
      * we can relocate the dom0 kernel and other multiboot modules. Also, on
      * x86/64, we relocate Xen to higher memory.
      */
-    for ( i = 0; !efi_enabled && i < mbi->mods_count; i++ )
+    for ( i = 0; !efi_enabled(EFI_PLATFORM) && i < mbi->mods_count; i++ )
     {
         if ( mod[i].mod_start & (PAGE_SIZE - 1) )
             panic("Bootloader didn't honor module alignment request.");
@@ -994,7 +994,7 @@ void __init noreturn __start_xen(unsigned long mbi_p)
 
     if ( !xen_phys_start )
         panic("Not enough memory to relocate Xen.");
-    reserve_e820_ram(&boot_e820, efi_enabled ? mbi->mem_upper : __pa(&_start),
+    reserve_e820_ram(&boot_e820, efi_enabled(EFI_PLATFORM) ? mbi->mem_upper : __pa(&_start),
                      __pa(&_end));
 
     /* Late kexec reservation (dynamic start address). */
diff --git a/xen/arch/x86/shutdown.c b/xen/arch/x86/shutdown.c
index 0e1499d..79dcd16 100644
--- a/xen/arch/x86/shutdown.c
+++ b/xen/arch/x86/shutdown.c
@@ -116,7 +116,7 @@ void machine_halt(void)
 static void default_reboot_type(void)
 {
     if ( reboot_type == BOOT_INVALID )
-        reboot_type = efi_enabled ? BOOT_EFI
+        reboot_type = efi_enabled(EFI_PLATFORM) ? BOOT_EFI
                                   : acpi_disabled ? BOOT_KBD
                                                   : BOOT_ACPI;
 }
diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c
index bbb7e6c..11e7e11 100644
--- a/xen/arch/x86/time.c
+++ b/xen/arch/x86/time.c
@@ -690,7 +690,7 @@ static unsigned long get_cmos_time(void)
     static bool_t __read_mostly cmos_rtc_probe;
     boolean_param("cmos-rtc-probe", cmos_rtc_probe);
 
-    if ( efi_enabled )
+    if ( efi_enabled(EFI_PLATFORM) )
     {
         res = efi_get_time();
         if ( res )
diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S
index 3e1f2af..87f3e83 100644
--- a/xen/arch/x86/xen.lds.S
+++ b/xen/arch/x86/xen.lds.S
@@ -191,8 +191,6 @@ SECTIONS
   .pad : {
     . = ALIGN(MB(16));
   } :text
-#else
-  efi = .;
 #endif
 
   /* Sections to be discarded */
diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c
index 75a939f..1f188fe 100644
--- a/xen/common/efi/boot.c
+++ b/xen/common/efi/boot.c
@@ -717,6 +717,10 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
     char *option_str;
     bool_t use_cfg_file;
 
+#ifndef CONFIG_ARM /* Disabled until runtime services implemented. */
+    set_bit(EFI_PLATFORM, &efi.flags);
+#endif
+
     efi_ih = ImageHandle;
     efi_bs = SystemTable->BootServices;
     efi_bs_revision = efi_bs->Hdr.Revision;
diff --git a/xen/common/efi/runtime.c b/xen/common/efi/runtime.c
index ae87557..aa064e7 100644
--- a/xen/common/efi/runtime.c
+++ b/xen/common/efi/runtime.c
@@ -10,14 +10,10 @@ DEFINE_XEN_GUEST_HANDLE(CHAR16);
 
 #ifndef COMPAT
 
-#ifdef CONFIG_ARM  /* Disabled until runtime services implemented */
-const bool_t efi_enabled = 0;
-#else
+#ifndef CONFIG_ARM
 # include <asm/i387.h>
 # include <asm/xstate.h>
 # include <public/platform.h>
-
-const bool_t efi_enabled = 1;
 #endif
 
 unsigned int __read_mostly efi_num_ct;
@@ -42,11 +38,12 @@ UINT64 __read_mostly efi_boot_remain_var_store_size;
 UINT64 __read_mostly efi_boot_max_var_size;
 
 struct efi __read_mostly efi = {
-	.acpi   = EFI_INVALID_TABLE_ADDR,
-	.acpi20 = EFI_INVALID_TABLE_ADDR,
-	.mps    = EFI_INVALID_TABLE_ADDR,
-	.smbios = EFI_INVALID_TABLE_ADDR,
-	.smbios3 = EFI_INVALID_TABLE_ADDR,
+	.flags   = 0, /* Initialized later. */
+	.acpi    = EFI_INVALID_TABLE_ADDR,
+	.acpi20  = EFI_INVALID_TABLE_ADDR,
+	.mps     = EFI_INVALID_TABLE_ADDR,
+	.smbios  = EFI_INVALID_TABLE_ADDR,
+	.smbios3 = EFI_INVALID_TABLE_ADDR
 };
 
 const struct efi_pci_rom *__read_mostly efi_pci_roms;
diff --git a/xen/drivers/acpi/osl.c b/xen/drivers/acpi/osl.c
index 4c09859..f4f6628 100644
--- a/xen/drivers/acpi/osl.c
+++ b/xen/drivers/acpi/osl.c
@@ -66,7 +66,7 @@ void __init acpi_os_vprintf(const char *fmt, va_list args)
 
 acpi_physical_address __init acpi_os_get_root_pointer(void)
 {
-	if (efi_enabled) {
+	if (efi_enabled(EFI_PLATFORM)) {
 		if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
 			return efi.acpi20;
 		else if (efi.acpi != EFI_INVALID_TABLE_ADDR)
diff --git a/xen/include/xen/efi.h b/xen/include/xen/efi.h
index e74dad1..318bbec 100644
--- a/xen/include/xen/efi.h
+++ b/xen/include/xen/efi.h
@@ -2,15 +2,17 @@
 #define __XEN_EFI_H__
 
 #ifndef __ASSEMBLY__
+#include <xen/bitops.h>
 #include <xen/types.h>
 #endif
 
-extern const bool_t efi_enabled;
-
 #define EFI_INVALID_TABLE_ADDR (~0UL)
 
+#define EFI_PLATFORM	0
+
 /* Add fields here only if they need to be referenced from non-EFI code. */
 struct efi {
+    unsigned long flags;
     unsigned long mps;          /* MPS table */
     unsigned long acpi;         /* ACPI table (IA64 ext 0.71) */
     unsigned long acpi20;       /* ACPI table (ACPI 2.0) */
@@ -40,6 +42,16 @@ int efi_runtime_call(struct xenpf_efi_runtime_call *);
 int efi_compat_get_info(uint32_t idx, union compat_pf_efi_info *);
 int efi_compat_runtime_call(struct compat_pf_efi_runtime_call *);
 
+/*
+ * Test whether the above EFI_* bits are enabled.
+ *
+ * Stolen from Linux Kernel.
+ */
+static inline bool_t efi_enabled(int feature)
+{
+    return test_bit(feature, &efi.flags) != 0;
+}
+
 #endif /* !__ASSEMBLY__ */
 
 #endif /* __XEN_EFI_H__ */
-- 
1.7.10.4