Message-ID: <20120725145307.GA31782@gmail.com>
Date:	Wed, 25 Jul 2012 16:53:07 +0200
From:	Ingo Molnar <mingo@...nel.org>
To:	Linus Torvalds <torvalds@...ux-foundation.org>
Cc:	linux-kernel@...r.kernel.org, "H. Peter Anvin" <hpa@...or.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: [GIT PULL] x86/efi changes for v3.6

Linus,

Please pull the latest x86-efi-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-efi-for-linus

   HEAD: 9ca8f72a9297f2052d806bd1111e176533aa69bd x86, efi: Handover Protocol

This tree adds an EFI bootloader handover protocol, which, once 
supported on the bootloader side, will make bootup faster and 
might result in simpler bootloaders. The other change activates 
the EFI wall clock time accessors on x86-64 as well, instead of 
the legacy RTC readout.

 Thanks,

	Ingo

------------------>
Jan Beulich (1):
      x86-64/efi: Use EFI to deal with platform wall clock

Matt Fleming (1):
      x86, efi: Handover Protocol


 Documentation/x86/boot.txt         |   41 ++++++++
 arch/x86/boot/compressed/eboot.c   |  198 ++++++++++++++++++++++--------------
 arch/x86/boot/compressed/head_32.S |   10 ++
 arch/x86/boot/compressed/head_64.S |   10 ++
 arch/x86/boot/header.S             |    4 +-
 arch/x86/include/asm/bootparam.h   |    1 +
 arch/x86/mm/pageattr.c             |   10 +-
 arch/x86/platform/efi/efi.c        |   30 +-----
 include/linux/efi.h                |    2 -
 init/main.c                        |    8 +-
 10 files changed, 199 insertions(+), 115 deletions(-)

diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt
index 7c3a880..c6539a4 100644
--- a/Documentation/x86/boot.txt
+++ b/Documentation/x86/boot.txt
@@ -54,6 +54,9 @@ Protocol 2.10:	(Kernel 2.6.31) Added a protocol for relaxed alignment
 		beyond the kernel_alignment added, new init_size and
 		pref_address fields.  Added extended boot loader IDs.
 
+Protocol 2.11:	(Kernel 3.6) Added a field for offset of EFI handover
+		protocol entry point.
+
 **** MEMORY LAYOUT
 
 The traditional memory map for the kernel loader, used for Image or
@@ -189,6 +192,7 @@ Offset	Proto	Name		Meaning
 				of struct setup_data
 0258/8	2.10+	pref_address	Preferred loading address
 0260/4	2.10+	init_size	Linear memory required during initialization
+0264/4	2.11+	handover_offset	Offset of handover entry point
 
 (1) For backwards compatibility, if the setup_sects field contains 0, the
     real value is 4.
@@ -690,6 +694,16 @@ Offset/size:	0x260/4
   else
 	runtime_start = pref_address
 
+Field name:	handover_offset
+Type:		read
+Offset/size:	0x264/4
+
+  This field is the offset from the beginning of the kernel image to
+  the EFI handover protocol entry point. Boot loaders using the EFI
+  handover protocol to boot the kernel should jump to this offset.
+
+  See EFI HANDOVER PROTOCOL below for more details.
+
 
 **** THE IMAGE CHECKSUM
 
@@ -1010,3 +1024,30 @@ segment; __BOOS_CS must have execute/read permission, and __BOOT_DS
 must have read/write permission; CS must be __BOOT_CS and DS, ES, SS
 must be __BOOT_DS; interrupt must be disabled; %esi must hold the base
 address of the struct boot_params; %ebp, %edi and %ebx must be zero.
+
+**** EFI HANDOVER PROTOCOL
+
+This protocol allows boot loaders to defer initialisation to the EFI
+boot stub. The boot loader is required to load the kernel/initrd(s)
+from the boot media and jump to the EFI handover protocol entry point
+which is hdr->handover_offset bytes from the beginning of
+startup_{32,64}.
+
+The function prototype for the handover entry point looks like this,
+
+    efi_main(void *handle, efi_system_table_t *table, struct boot_params *bp)
+
+'handle' is the EFI image handle passed to the boot loader by the EFI
+firmware, 'table' is the EFI system table - these are the first two
+arguments of the "handoff state" as described in section 2.3 of the
+UEFI specification. 'bp' is the boot loader-allocated boot params.
+
+The boot loader *must* fill out the following fields in bp,
+
+    o hdr.code32_start
+    o hdr.cmd_line_ptr
+    o hdr.cmdline_size
+    o hdr.ramdisk_image (if applicable)
+    o hdr.ramdisk_size  (if applicable)
+
+All other fields should be zero.
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index 4e85f5f..b3e0227 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -729,32 +729,68 @@ fail:
  * need to create one ourselves (usually the bootloader would create
  * one for us).
  */
-static efi_status_t make_boot_params(struct boot_params *boot_params,
-				     efi_loaded_image_t *image,
-				     void *handle)
+struct boot_params *make_boot_params(void *handle, efi_system_table_t *_table)
 {
-	struct efi_info *efi = &boot_params->efi_info;
-	struct apm_bios_info *bi = &boot_params->apm_bios_info;
-	struct sys_desc_table *sdt = &boot_params->sys_desc_table;
-	struct e820entry *e820_map = &boot_params->e820_map[0];
-	struct e820entry *prev = NULL;
-	struct setup_header *hdr = &boot_params->hdr;
-	unsigned long size, key, desc_size, _size;
-	efi_memory_desc_t *mem_map;
-	void *options = image->load_options;
-	u32 load_options_size = image->load_options_size / 2; /* ASCII */
+	struct boot_params *boot_params;
+	struct sys_desc_table *sdt;
+	struct apm_bios_info *bi;
+	struct setup_header *hdr;
+	struct efi_info *efi;
+	efi_loaded_image_t *image;
+	void *options;
+	u32 load_options_size;
+	efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
 	int options_size = 0;
 	efi_status_t status;
-	__u32 desc_version;
 	unsigned long cmdline;
-	u8 nr_entries;
 	u16 *s2;
 	u8 *s1;
 	int i;
 
+	sys_table = _table;
+
+	/* Check if we were booted by the EFI firmware */
+	if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
+		return NULL;
+
+	status = efi_call_phys3(sys_table->boottime->handle_protocol,
+				handle, &proto, (void *)&image);
+	if (status != EFI_SUCCESS) {
+		efi_printk("Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
+		return NULL;
+	}
+
+	status = low_alloc(0x4000, 1, (unsigned long *)&boot_params);
+	if (status != EFI_SUCCESS) {
+		efi_printk("Failed to alloc lowmem for boot params\n");
+		return NULL;
+	}
+
+	memset(boot_params, 0x0, 0x4000);
+
+	hdr = &boot_params->hdr;
+	efi = &boot_params->efi_info;
+	bi = &boot_params->apm_bios_info;
+	sdt = &boot_params->sys_desc_table;
+
+	/* Copy the second sector to boot_params */
+	memcpy(&hdr->jump, image->image_base + 512, 512);
+
+	/*
+	 * Fill out some of the header fields ourselves because the
+	 * EFI firmware loader doesn't load the first sector.
+	 */
+	hdr->root_flags = 1;
+	hdr->vid_mode = 0xffff;
+	hdr->boot_flag = 0xAA55;
+
+	hdr->code32_start = (__u64)(unsigned long)image->image_base;
+
 	hdr->type_of_loader = 0x21;
 
 	/* Convert unicode cmdline to ascii */
+	options = image->load_options;
+	load_options_size = image->load_options_size / 2; /* ASCII */
 	cmdline = 0;
 	s2 = (u16 *)options;
 
@@ -791,18 +827,36 @@ static efi_status_t make_boot_params(struct boot_params *boot_params,
 	hdr->ramdisk_image = 0;
 	hdr->ramdisk_size = 0;
 
-	status = handle_ramdisks(image, hdr);
-	if (status != EFI_SUCCESS)
-		goto free_cmdline;
-
-	setup_graphics(boot_params);
-
 	/* Clear APM BIOS info */
 	memset(bi, 0, sizeof(*bi));
 
 	memset(sdt, 0, sizeof(*sdt));
 
-	memcpy(&efi->efi_loader_signature, EFI_LOADER_SIGNATURE, sizeof(__u32));
+	status = handle_ramdisks(image, hdr);
+	if (status != EFI_SUCCESS)
+		goto fail2;
+
+	return boot_params;
+fail2:
+	if (options_size)
+		low_free(options_size, hdr->cmd_line_ptr);
+fail:
+	low_free(0x4000, (unsigned long)boot_params);
+	return NULL;
+}
+
+static efi_status_t exit_boot(struct boot_params *boot_params,
+			      void *handle)
+{
+	struct efi_info *efi = &boot_params->efi_info;
+	struct e820entry *e820_map = &boot_params->e820_map[0];
+	struct e820entry *prev = NULL;
+	unsigned long size, key, desc_size, _size;
+	efi_memory_desc_t *mem_map;
+	efi_status_t status;
+	__u32 desc_version;
+	u8 nr_entries;
+	int i;
 
 	size = sizeof(*mem_map) * 32;
 
@@ -811,7 +865,7 @@ again:
 	_size = size;
 	status = low_alloc(size, 1, (unsigned long *)&mem_map);
 	if (status != EFI_SUCCESS)
-		goto free_cmdline;
+		return status;
 
 	status = efi_call_phys5(sys_table->boottime->get_memory_map, &size,
 				mem_map, &key, &desc_size, &desc_version);
@@ -823,6 +877,7 @@ again:
 	if (status != EFI_SUCCESS)
 		goto free_mem_map;
 
+	memcpy(&efi->efi_loader_signature, EFI_LOADER_SIGNATURE, sizeof(__u32));
 	efi->efi_systab = (unsigned long)sys_table;
 	efi->efi_memdesc_size = desc_size;
 	efi->efi_memdesc_version = desc_version;
@@ -906,61 +961,13 @@ again:
 
 free_mem_map:
 	low_free(_size, (unsigned long)mem_map);
-free_cmdline:
-	if (options_size)
-		low_free(options_size, hdr->cmd_line_ptr);
-fail:
 	return status;
 }
 
-/*
- * On success we return a pointer to a boot_params structure, and NULL
- * on failure.
- */
-struct boot_params *efi_main(void *handle, efi_system_table_t *_table)
+static efi_status_t relocate_kernel(struct setup_header *hdr)
 {
-	struct boot_params *boot_params;
 	unsigned long start, nr_pages;
-	struct desc_ptr *gdt, *idt;
-	efi_loaded_image_t *image;
-	struct setup_header *hdr;
 	efi_status_t status;
-	efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
-	struct desc_struct *desc;
-
-	sys_table = _table;
-
-	/* Check if we were booted by the EFI firmware */
-	if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
-		goto fail;
-
-	status = efi_call_phys3(sys_table->boottime->handle_protocol,
-				handle, &proto, (void *)&image);
-	if (status != EFI_SUCCESS) {
-		efi_printk("Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
-		goto fail;
-	}
-
-	status = low_alloc(0x4000, 1, (unsigned long *)&boot_params);
-	if (status != EFI_SUCCESS) {
-		efi_printk("Failed to alloc lowmem for boot params\n");
-		goto fail;
-	}
-
-	memset(boot_params, 0x0, 0x4000);
-
-	hdr = &boot_params->hdr;
-
-	/* Copy the second sector to boot_params */
-	memcpy(&hdr->jump, image->image_base + 512, 512);
-
-	/*
-	 * Fill out some of the header fields ourselves because the
-	 * EFI firmware loader doesn't load the first sector.
-	 */
-	hdr->root_flags = 1;
-	hdr->vid_mode = 0xffff;
-	hdr->boot_flag = 0xAA55;
 
 	/*
 	 * The EFI firmware loader could have placed the kernel image
@@ -978,16 +985,40 @@ struct boot_params *efi_main(void *handle, efi_system_table_t *_table)
 	if (status != EFI_SUCCESS) {
 		status = low_alloc(hdr->init_size, hdr->kernel_alignment,
 				   &start);
-		if (status != EFI_SUCCESS) {
+		if (status != EFI_SUCCESS)
 			efi_printk("Failed to alloc mem for kernel\n");
-			goto fail;
-		}
 	}
 
+	if (status == EFI_SUCCESS)
+		memcpy((void *)start, (void *)(unsigned long)hdr->code32_start,
+		       hdr->init_size);
+
+	hdr->pref_address = hdr->code32_start;
 	hdr->code32_start = (__u32)start;
-	hdr->pref_address = (__u64)(unsigned long)image->image_base;
 
-	memcpy((void *)start, image->image_base, image->image_size);
+	return status;
+}
+
+/*
+ * On success we return a pointer to a boot_params structure, and NULL
+ * on failure.
+ */
+struct boot_params *efi_main(void *handle, efi_system_table_t *_table,
+			     struct boot_params *boot_params)
+{
+	struct desc_ptr *gdt, *idt;
+	efi_loaded_image_t *image;
+	struct setup_header *hdr = &boot_params->hdr;
+	efi_status_t status;
+	struct desc_struct *desc;
+
+	sys_table = _table;
+
+	/* Check if we were booted by the EFI firmware */
+	if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
+		goto fail;
+
+	setup_graphics(boot_params);
 
 	status = efi_call_phys3(sys_table->boottime->allocate_pool,
 				EFI_LOADER_DATA, sizeof(*gdt),
@@ -1015,7 +1046,18 @@ struct boot_params *efi_main(void *handle, efi_system_table_t *_table)
 	idt->size = 0;
 	idt->address = 0;
 
-	status = make_boot_params(boot_params, image, handle);
+	/*
+	 * If the kernel isn't already loaded at the preferred load
+	 * address, relocate it.
+	 */
+	if (hdr->pref_address != hdr->code32_start) {
+		status = relocate_kernel(hdr);
+
+		if (status != EFI_SUCCESS)
+			goto fail;
+	}
+
+	status = exit_boot(boot_params, handle);
 	if (status != EFI_SUCCESS)
 		goto fail;
 
diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
index c85e3ac..aa4aaf1 100644
--- a/arch/x86/boot/compressed/head_32.S
+++ b/arch/x86/boot/compressed/head_32.S
@@ -42,6 +42,16 @@ ENTRY(startup_32)
 	 */
 	add	$0x4, %esp
 
+	call	make_boot_params
+	cmpl	$0, %eax
+	je	1f
+	movl	0x4(%esp), %esi
+	movl	(%esp), %ecx
+	pushl	%eax
+	pushl	%esi
+	pushl	%ecx
+
+	.org 0x30,0x90
 	call	efi_main
 	cmpl	$0, %eax
 	movl	%eax, %esi
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 87e03a1..2c4b171 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -209,6 +209,16 @@ ENTRY(startup_64)
 	.org 0x210
 	mov	%rcx, %rdi
 	mov	%rdx, %rsi
+	pushq	%rdi
+	pushq	%rsi
+	call	make_boot_params
+	cmpq	$0,%rax
+	je	1f
+	mov	%rax, %rdx
+	popq	%rsi
+	popq	%rdi
+
+	.org 0x230,0x90
 	call	efi_main
 	movq	%rax,%rsi
 	cmpq	$0,%rax
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 8bbea6a..097f476 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -263,7 +263,7 @@ _start:
 	# Part 2 of the header, from the old setup.S
 
 		.ascii	"HdrS"		# header signature
-		.word	0x020a		# header version number (>= 0x0105)
+		.word	0x020b		# header version number (>= 0x0105)
 					# or else old loadlin-1.5 will fail)
 		.globl realmode_swtch
 realmode_swtch:	.word	0, 0		# default_switch, SETUPSEG
@@ -381,6 +381,8 @@ pref_address:		.quad LOAD_PHYSICAL_ADDR	# preferred load addr
 #define INIT_SIZE VO_INIT_SIZE
 #endif
 init_size:		.long INIT_SIZE		# kernel initialization size
+handover_offset:	.long 0x30		# offset to the handover
+						# protocol entry point
 
 # End of setup header #####################################################
 
diff --git a/arch/x86/include/asm/bootparam.h b/arch/x86/include/asm/bootparam.h
index eb45aa6..2ad874c 100644
--- a/arch/x86/include/asm/bootparam.h
+++ b/arch/x86/include/asm/bootparam.h
@@ -66,6 +66,7 @@ struct setup_header {
 	__u64	setup_data;
 	__u64	pref_address;
 	__u32	init_size;
+	__u32	handover_offset;
 } __attribute__((packed));
 
 struct sys_desc_table {
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index e1ebde3..ee09aca 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -919,11 +919,13 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages,
 
 	/*
 	 * On success we use clflush, when the CPU supports it to
-	 * avoid the wbindv. If the CPU does not support it and in the
-	 * error case we fall back to cpa_flush_all (which uses
-	 * wbindv):
+	 * avoid the wbindv. If the CPU does not support it, in the
+	 * error case, and during early boot (for EFI) we fall back
+	 * to cpa_flush_all (which uses wbinvd):
 	 */
-	if (!ret && cpu_has_clflush) {
+	if (early_boot_irqs_disabled)
+		__cpa_flush_all((void *)(long)cache);
+	else if (!ret && cpu_has_clflush) {
 		if (cpa.flags & (CPA_PAGES_ARRAY | CPA_ARRAY)) {
 			cpa_flush_array(addr, numpages, cache,
 					cpa.flags, pages);
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 92660eda..2dc29f5 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -234,22 +234,7 @@ static efi_status_t __init phys_efi_set_virtual_address_map(
 	return status;
 }
 
-static efi_status_t __init phys_efi_get_time(efi_time_t *tm,
-					     efi_time_cap_t *tc)
-{
-	unsigned long flags;
-	efi_status_t status;
-
-	spin_lock_irqsave(&rtc_lock, flags);
-	efi_call_phys_prelog();
-	status = efi_call_phys2(efi_phys.get_time, virt_to_phys(tm),
-				virt_to_phys(tc));
-	efi_call_phys_epilog();
-	spin_unlock_irqrestore(&rtc_lock, flags);
-	return status;
-}
-
-int efi_set_rtc_mmss(unsigned long nowtime)
+static int efi_set_rtc_mmss(unsigned long nowtime)
 {
 	int real_seconds, real_minutes;
 	efi_status_t 	status;
@@ -278,7 +263,7 @@ int efi_set_rtc_mmss(unsigned long nowtime)
 	return 0;
 }
 
-unsigned long efi_get_time(void)
+static unsigned long efi_get_time(void)
 {
 	efi_status_t status;
 	efi_time_t eft;
@@ -621,18 +606,13 @@ static int __init efi_runtime_init(void)
 	}
 	/*
 	 * We will only need *early* access to the following
-	 * two EFI runtime services before set_virtual_address_map
+	 * EFI runtime service before set_virtual_address_map
 	 * is invoked.
 	 */
-	efi_phys.get_time = (efi_get_time_t *)runtime->get_time;
 	efi_phys.set_virtual_address_map =
 		(efi_set_virtual_address_map_t *)
 		runtime->set_virtual_address_map;
-	/*
-	 * Make efi_get_time can be called before entering
-	 * virtual mode.
-	 */
-	efi.get_time = phys_efi_get_time;
+
 	early_iounmap(runtime, sizeof(efi_runtime_services_t));
 
 	return 0;
@@ -720,12 +700,10 @@ void __init efi_init(void)
 		efi_enabled = 0;
 		return;
 	}
-#ifdef CONFIG_X86_32
 	if (efi_native) {
 		x86_platform.get_wallclock = efi_get_time;
 		x86_platform.set_wallclock = efi_set_rtc_mmss;
 	}
-#endif
 
 #if EFI_DEBUG
 	print_efi_memmap();
diff --git a/include/linux/efi.h b/include/linux/efi.h
index ec45ccd..103adc6 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -503,8 +503,6 @@ extern u64 efi_mem_attribute (unsigned long phys_addr, unsigned long size);
 extern int __init efi_uart_console_only (void);
 extern void efi_initialize_iomem_resources(struct resource *code_resource,
 		struct resource *data_resource, struct resource *bss_resource);
-extern unsigned long efi_get_time(void);
-extern int efi_set_rtc_mmss(unsigned long nowtime);
 extern void efi_reserve_boot_services(void);
 extern struct efi_memory_map memmap;
 
diff --git a/init/main.c b/init/main.c
index 1ca6b32..eef3012 100644
--- a/init/main.c
+++ b/init/main.c
@@ -460,6 +460,10 @@ static void __init mm_init(void)
 	percpu_init_late();
 	pgtable_cache_init();
 	vmalloc_init();
+#ifdef CONFIG_X86
+	if (efi_enabled)
+		efi_enter_virtual_mode();
+#endif
 }
 
 asmlinkage void __init start_kernel(void)
@@ -601,10 +605,6 @@ asmlinkage void __init start_kernel(void)
 	calibrate_delay();
 	pidmap_init();
 	anon_vma_init();
-#ifdef CONFIG_X86
-	if (efi_enabled)
-		efi_enter_virtual_mode();
-#endif
 	thread_info_cache_init();
 	cred_init();
 	fork_init(totalram_pages);
--
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