linux-kernel - [PATCH 05/18] efi: move mem_attr

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Date:   Sun, 16 Feb 2020 19:23:21 +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 05/18] efi: move mem_attr_table out of struct efi

The memory attributes table is only used at init time by the core EFI
code, so there is no need to carry its address in struct efi that is
shared with the world. So move it out, and make it __ro_after_init as
well, considering that the value is set during early boot.

Signed-off-by: Ard Biesheuvel <ardb@...nel.org>
---
 arch/x86/platform/efi/efi.c    |  2 +-
 drivers/firmware/efi/efi.c     |  3 +--
 drivers/firmware/efi/memattr.c | 13 +++++++------
 include/linux/efi.h            |  3 ++-
 4 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 70efb75607aa..db4c14f62978 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -83,7 +83,7 @@ static const unsigned long * const efi_tables[] = {
 	&efi.config_table,
 	&efi.esrt,
 	&prop_phys,
-	&efi.mem_attr_table,
+	&efi_mem_attr_table,
 #ifdef CONFIG_EFI_RCI2_TABLE
 	&rci2_table_phys,
 #endif
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index bbb6246d08be..1fc4e174f11d 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -43,7 +43,6 @@ struct efi __read_mostly efi = {
 	.runtime		= EFI_INVALID_TABLE_ADDR,
 	.config_table		= EFI_INVALID_TABLE_ADDR,
 	.esrt			= EFI_INVALID_TABLE_ADDR,
-	.mem_attr_table		= EFI_INVALID_TABLE_ADDR,
 	.tpm_log		= EFI_INVALID_TABLE_ADDR,
 	.tpm_final_log		= EFI_INVALID_TABLE_ADDR,
 	.mem_reserve		= EFI_INVALID_TABLE_ADDR,
@@ -467,7 +466,7 @@ static __initdata efi_config_table_type_t common_tables[] = {
 	{SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
 	{SMBIOS3_TABLE_GUID, "SMBIOS 3.0", &efi.smbios3},
 	{EFI_SYSTEM_RESOURCE_TABLE_GUID, "ESRT", &efi.esrt},
-	{EFI_MEMORY_ATTRIBUTES_TABLE_GUID, "MEMATTR", &efi.mem_attr_table},
+	{EFI_MEMORY_ATTRIBUTES_TABLE_GUID, "MEMATTR", &efi_mem_attr_table},
 	{LINUX_EFI_RANDOM_SEED_TABLE_GUID, "RNG", &rng_seed},
 	{LINUX_EFI_TPM_EVENT_LOG_GUID, "TPMEventLog", &efi.tpm_log},
 	{LINUX_EFI_TPM_FINAL_LOG_GUID, "TPMFinalLog", &efi.tpm_final_log},
diff --git a/drivers/firmware/efi/memattr.c b/drivers/firmware/efi/memattr.c
index 58452fde92cc..3045120acf8e 100644
--- a/drivers/firmware/efi/memattr.c
+++ b/drivers/firmware/efi/memattr.c
@@ -13,6 +13,7 @@
 #include <asm/early_ioremap.h>
 
 static int __initdata tbl_size;
+unsigned long __ro_after_init efi_mem_attr_table;
 
 /*
  * Reserve the memory associated with the Memory Attributes configuration
@@ -22,13 +23,13 @@ int __init efi_memattr_init(void)
 {
 	efi_memory_attributes_table_t *tbl;
 
-	if (efi.mem_attr_table == EFI_INVALID_TABLE_ADDR)
+	if (efi_mem_attr_table == EFI_INVALID_TABLE_ADDR)
 		return 0;
 
-	tbl = early_memremap(efi.mem_attr_table, sizeof(*tbl));
+	tbl = early_memremap(efi_mem_attr_table, sizeof(*tbl));
 	if (!tbl) {
 		pr_err("Failed to map EFI Memory Attributes table @ 0x%lx\n",
-		       efi.mem_attr_table);
+		       efi_mem_attr_table);
 		return -ENOMEM;
 	}
 
@@ -39,7 +40,7 @@ int __init efi_memattr_init(void)
 	}
 
 	tbl_size = sizeof(*tbl) + tbl->num_entries * tbl->desc_size;
-	memblock_reserve(efi.mem_attr_table, tbl_size);
+	memblock_reserve(efi_mem_attr_table, tbl_size);
 	set_bit(EFI_MEM_ATTR, &efi.flags);
 
 unmap:
@@ -147,10 +148,10 @@ int __init efi_memattr_apply_permissions(struct mm_struct *mm,
 	if (WARN_ON(!efi_enabled(EFI_MEMMAP)))
 		return 0;
 
-	tbl = memremap(efi.mem_attr_table, tbl_size, MEMREMAP_WB);
+	tbl = memremap(efi_mem_attr_table, tbl_size, MEMREMAP_WB);
 	if (!tbl) {
 		pr_err("Failed to map EFI Memory Attributes table @ 0x%lx\n",
-		       efi.mem_attr_table);
+		       efi_mem_attr_table);
 		return -ENOMEM;
 	}
 
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 36380542e054..b093fce1cf59 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -539,7 +539,6 @@ extern struct efi {
 	unsigned long runtime;		/* runtime table */
 	unsigned long config_table;	/* config tables */
 	unsigned long esrt;		/* ESRT table */
-	unsigned long mem_attr_table;	/* memory attributes table */
 	unsigned long tpm_log;		/* TPM2 Event Log table */
 	unsigned long tpm_final_log;	/* TPM2 Final Events Log table */
 	unsigned long mem_reserve;	/* Linux EFI memreserve table */
@@ -641,6 +640,8 @@ extern void __init efi_fake_memmap(void);
 static inline void efi_fake_memmap(void) { }
 #endif
 
+extern unsigned long efi_mem_attr_table;
+
 /*
  * efi_memattr_perm_setter - arch specific callback function passed into
  *                           efi_memattr_apply_permissions() that updates the
-- 
2.17.1