[patch 6/7 v2] passing kexec necessary efi data via setup_data

[dyoung]

Add a new setup_data type SETUP_EFI for kexec use.
Passing the saved fw_vendor, runtime, config tables and
efi runtime mappings.

When entering virtual mode, directly mapping the efi
runtime ragions which we passed in previously. And skip
the step to call SetVirtualAddressMap.

Specially for HP z420 workstation it need another variable
saving, it's the smbios physical address, the HP bios
also update the SMBIOS address after entering virtual mode
besides of the standard fw_vendor,runtime and config table.

Tested on ovmf+qemu, lenovo thinkpad, a dell laptop and an
HP z420 workstation.

Signed-off-by: Dave Young <dyoung@xxxxxxxxxx>
---
 arch/x86/include/asm/efi.h            |   12 ++
 arch/x86/include/uapi/asm/bootparam.h |    1 
 arch/x86/kernel/setup.c               |    3 
 arch/x86/platform/efi/efi.c           |  151 ++++++++++++++++++++++++++++++----
 4 files changed, 152 insertions(+), 15 deletions(-)

--- linux-2.6.orig/arch/x86/kernel/setup.c
+++ linux-2.6/arch/x86/kernel/setup.c
@@ -447,6 +447,9 @@ static void __init parse_setup_data(void
 		case SETUP_DTB:
 			add_dtb(pa_data);
 			break;
+		case SETUP_EFI:
+			parse_efi_setup(pa_data, data_len);
+			break;
 		default:
 			break;
 		}
--- linux-2.6.orig/arch/x86/platform/efi/efi.c
+++ linux-2.6/arch/x86/platform/efi/efi.c
@@ -78,6 +78,7 @@ static __initdata efi_config_table_type_
 
 efi_memory_desc_t *efi_runtime_map;
 int nr_efi_runtime_map;
+struct efi_setup_data *esdata;
 
 /*
  * Returns 1 if 'facility' is enabled, 0 otherwise.
@@ -115,6 +116,32 @@ static int __init setup_storage_paranoia
 }
 early_param("efi_no_storage_paranoia", setup_storage_paranoia);
 
+void parse_efi_setup(u64 phys_addr, u32 data_len)
+{
+	int size;
+	struct setup_data *sdata;
+	u64 esdata_phys;
+
+	if (!efi_enabled(EFI_64BIT)) {
+		pr_warn("skipping setup_data on EFI 32BIT!");
+		return;
+	}
+
+	sdata = early_memremap(phys_addr, data_len);
+	if (!sdata)
+		return;
+
+	size = data_len - sizeof(struct setup_data);
+
+	esdata_phys = phys_addr + sizeof(struct setup_data);
+
+	nr_efi_runtime_map = (size - sizeof(struct efi_setup_data)) /
+			sizeof(efi_memory_desc_t);
+	early_iounmap(sdata, data_len);
+
+	/* setup data regions have been reserved by default */
+	esdata = phys_to_virt(esdata_phys);
+}
 
 static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
 {
@@ -504,8 +531,12 @@ static int __init efi_systab_init(void *
 		}
 
 		efi_systab.hdr = systab64->hdr;
-		efi_systab.fw_vendor = systab64->fw_vendor;
-		tmp |= systab64->fw_vendor;
+
+		if (esdata)
+			efi_systab.fw_vendor = (unsigned long)esdata->fw_vendor;
+		else
+			efi_systab.fw_vendor = systab64->fw_vendor;
+		tmp |= efi_systab.fw_vendor;
 		efi_systab.fw_revision = systab64->fw_revision;
 		efi_systab.con_in_handle = systab64->con_in_handle;
 		tmp |= systab64->con_in_handle;
@@ -519,13 +550,21 @@ static int __init efi_systab_init(void *
 		tmp |= systab64->stderr_handle;
 		efi_systab.stderr = systab64->stderr;
 		tmp |= systab64->stderr;
-		efi_systab.runtime = (void *)(unsigned long)systab64->runtime;
-		tmp |= systab64->runtime;
+		if (esdata)
+			efi_systab.runtime =
+				(void *)(unsigned long)esdata->runtime;
+		else
+			efi_systab.runtime =
+				(void *)(unsigned long)systab64->runtime;
+		tmp |= (unsigned long)efi_systab.runtime;
 		efi_systab.boottime = (void *)(unsigned long)systab64->boottime;
 		tmp |= systab64->boottime;
 		efi_systab.nr_tables = systab64->nr_tables;
-		efi_systab.tables = systab64->tables;
-		tmp |= systab64->tables;
+		if (esdata)
+			efi_systab.tables = (unsigned long)esdata->tables;
+		else
+			efi_systab.tables = systab64->tables;
+		tmp |= efi_systab.tables;
 
 		early_iounmap(systab64, sizeof(*systab64));
 #ifdef CONFIG_X86_32
@@ -631,6 +670,41 @@ static int __init efi_memmap_init(void)
 	return 0;
 }
 
+static int __init efi_reuse_config(u64 tables, int nr_tables)
+{
+	void *p, *tablep;
+	int i, sz;
+
+	if (!efi_enabled(EFI_64BIT))
+		return 0;
+
+	sz = sizeof(efi_config_table_64_t);
+
+	p = tablep = early_memremap(tables, nr_tables * sz);
+	if (!p) {
+		pr_err("Could not map Configuration table!\n");
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < efi.systab->nr_tables; i++) {
+		efi_guid_t guid;
+
+		guid = ((efi_config_table_64_t *)p)->guid;
+
+		/*
+		HP z420 workstation smbios will be convert to
+		virtual address after enter virtual mode.
+		Thus in case kexec/kdump the physical address
+		will be passed in setup_data.
+		*/
+		if (!efi_guidcmp(guid, SMBIOS_TABLE_GUID))
+			((efi_config_table_64_t *)p)->table = esdata->smbios;
+		p += sz;
+	}
+	early_iounmap(tablep, nr_tables * sz);
+	return 0;
+}
+
 void __init efi_init(void)
 {
 	efi_char16_t *c16;
@@ -676,6 +750,9 @@ void __init efi_init(void)
 		efi.systab->hdr.revision >> 16,
 		efi.systab->hdr.revision & 0xffff, vendor);
 
+	if (esdata && esdata->smbios)
+		efi_reuse_config(efi.systab->tables, efi.systab->nr_tables);
+
 	if (efi_config_init(arch_tables))
 		return;
 
@@ -871,6 +948,39 @@ err_out:
 }
 
 /*
+ * map efi regions which was passed via setup_data
+ * the virt_addr is a fixed addr which was used in
+ * 1st kernel of kexec boot.
+ */
+void efi_map_regions_fixed(void)
+{
+	int i;
+	unsigned long size;
+	efi_memory_desc_t *md;
+	u64 end, systab;
+
+	for (i = 0; i < nr_efi_runtime_map; i++) {
+		md = esdata->map + i;
+		efi_map_region_fixed(md);
+		size = md->num_pages << PAGE_SHIFT;
+		end = md->phys_addr + size;
+
+		systab = (u64) (unsigned long) efi_phys.systab;
+		if (md->phys_addr <= systab && systab < end) {
+			systab += md->virt_addr - md->phys_addr;
+			efi.systab =
+				(efi_system_table_t *) (unsigned long) systab;
+		}
+	}
+
+	efi_runtime_map = kmalloc(nr_efi_runtime_map *
+			sizeof(efi_memory_desc_t), GFP_KERNEL);
+
+	memcpy(efi_runtime_map, esdata->map,
+		nr_efi_runtime_map * sizeof(efi_memory_desc_t));
+}
+
+/*
  * This function will switch the EFI runtime services to virtual mode.
  * Essentially, we look through the EFI memmap and map every region that
  * has the runtime attribute bit set in its memory descriptor into the
@@ -886,11 +996,15 @@ err_out:
  * so that we're in a different address space when calling a runtime
  * function. For function arguments passing we do copy the PGDs of the
  * kernel page table into ->trampoline_pgd prior to each call.
+ *
+ * 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 fixed virtual addresses exactly same as the ones in previous kernel.
  */
 void __init efi_enter_virtual_mode(void)
 {
 	efi_status_t status;
-	void *p, *new_memmap = NULL;
+	void *new_memmap = NULL;
 	int count = 0;
 
 	efi.systab = NULL;
@@ -904,20 +1018,26 @@ void __init efi_enter_virtual_mode(void)
 		return;
 	}
 
-	efi_merge_regions();
-
-	efi_map_regions(&new_memmap, &count);
+	if (esdata)
+		efi_map_regions_fixed();
+	else {
+		efi_merge_regions();
+		efi_map_regions(&new_memmap, &count);
+	}
 
 	BUG_ON(!efi.systab);
 
 	efi_setup_page_tables();
 	efi_sync_low_kernel_mappings();
 
-	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 (esdata)
+		status = EFI_SUCCESS;
+	else
+		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 "
@@ -925,6 +1045,7 @@ void __init efi_enter_virtual_mode(void)
 		panic("EFI call to SetVirtualAddressMap() failed!");
 	}
 
+
 	/*
 	 * Now that EFI is in virtual mode, update the function
 	 * pointers in the runtime service table to the new virtual addresses.
--- linux-2.6.orig/arch/x86/include/uapi/asm/bootparam.h
+++ linux-2.6/arch/x86/include/uapi/asm/bootparam.h
@@ -6,6 +6,7 @@
 #define SETUP_E820_EXT			1
 #define SETUP_DTB			2
 #define SETUP_PCI			3
+#define SETUP_EFI			4
 
 /* ram_size flags */
 #define RAMDISK_IMAGE_START_MASK	0x07FF
--- linux-2.6.orig/arch/x86/include/asm/efi.h
+++ linux-2.6/arch/x86/include/asm/efi.h
@@ -136,6 +136,18 @@ extern void __init old_map_region(efi_me
 extern efi_memory_desc_t *efi_runtime_map;
 extern int nr_efi_runtime_map;
 
+struct efi_setup_data {
+	u64 fw_vendor;
+	u64 runtime;
+	u64 tables;
+	u64 smbios;
+	u64 reserved[8];
+	efi_memory_desc_t map[0];
+};
+
+extern void parse_efi_setup(u64 phys_addr, u32 data_len);
+extern struct efi_setup_data *esdata;
+
 #ifdef CONFIG_EFI
 
 static inline bool efi_is_native(void)

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