linux-kernel - [PATCH 13/18] efi/x86: remove runtime table address from kexec EFI setup data

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Date:   Sun, 16 Feb 2020 19:23:29 +0100
From:   Ard Biesheuvel <ardb@...nel.org>
To:     linux-efi@...r.kernel.org
Cc:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Ard Biesheuvel <ardb@...nel.org>, nivedita@...m.mit.edu,
        x86@...nel.org
Subject: [PATCH 13/18] efi/x86: remove runtime table address from kexec EFI setup data

Since commit 33b85447fa61946b ("efi/x86: Drop two near identical versions
of efi_runtime_init()"), we no longer map the EFI runtime services table
before calling SetVirtualAddressMap(), which means we don't need the 1:1
mapped physical address of this table, and so there is no point in passing
the address via EFI setup data on kexec boot.

Note that the kexec tools will still look for this address in sysfs, so
we still need to provide it.

Signed-off-by: Ard Biesheuvel <ardb@...nel.org>
---
 arch/x86/include/asm/efi.h        | 1 -
 arch/x86/kernel/kexec-bzimage64.c | 1 -
 arch/x86/platform/efi/efi.c       | 4 +---
 3 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index fcb21e3d13c5..ee867f01b2f6 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -178,7 +178,6 @@ extern void __init efi_uv1_memmap_phys_epilog(pgd_t *save_pgd);
 
 struct efi_setup_data {
 	u64 fw_vendor;
-	u64 runtime;
 	u64 tables;
 	u64 smbios;
 	u64 reserved[8];
diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index f293d872602a..f400678bd345 100644
--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -142,7 +142,6 @@ prepare_add_efi_setup_data(struct boot_params *params,
 	struct efi_setup_data *esd = (void *)sd + sizeof(struct setup_data);
 
 	esd->fw_vendor = efi.fw_vendor;
-	esd->runtime = efi.runtime;
 	esd->tables = efi.config_table;
 	esd->smbios = efi.smbios;
 
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index f7025b9075b4..c1f5f229cb02 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -379,6 +379,7 @@ static int __init efi_systab_init(u64 phys)
 			 systab64->con_out		> U32_MAX ||
 			 systab64->stderr_handle	> U32_MAX ||
 			 systab64->stderr		> U32_MAX ||
+			 systab64->runtime		> U32_MAX ||
 			 systab64->boottime		> U32_MAX;
 
 		if (efi_setup) {
@@ -391,17 +392,14 @@ static int __init efi_systab_init(u64 phys)
 			}
 
 			efi_systab.fw_vendor	= (unsigned long)data->fw_vendor;
-			efi_systab.runtime	= (void *)(unsigned long)data->runtime;
 			efi_systab.tables	= (unsigned long)data->tables;
 
 			over4g |= data->fw_vendor	> U32_MAX ||
-				  data->runtime		> U32_MAX ||
 				  data->tables		> U32_MAX;
 
 			early_memunmap(data, sizeof(*data));
 		} else {
 			over4g |= systab64->fw_vendor	> U32_MAX ||
-				  systab64->runtime	> U32_MAX ||
 				  systab64->tables	> U32_MAX;
 		}
 	} else {
-- 
2.17.1