arm64: ignore DT memreserve entries when booting in UEFI mode

PATCH New Leif Lindholm 3 participants 4 messages Jul 28, 2014 – Aug 18, 2014

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arm64 EFI

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Leif Lindholm

author

2014-07-28 18:03 UTC #0 lore raw

PATCH 1/1 arm64: ignore DT memreserve entries when booting in UEFI mode

UEFI provides its own method for marking regions to reserve, via the memory map which is also used to initialise memblock. So when using the UEFI memory map, ignore any memreserve entries present in the DT.

Reported-by Mark Rutland <[email protected]>

Signed-off-by Leif Lindholm <[email protected]>

---
 arch/arm64/kernel/efi.c |    2 ++
 arch/arm64/mm/init.c    |    4 +++-
 2 files changed, 5 insertions(+), 1 deletion(-)

arch/arm64/kernel/efi.c +2 -0

index 14db1f6..7ad17b2 100644
@@ -188,6 +188,8 @@ static __init void reserve_regions(void)
 		if (uefi_debug)
 			pr_cont("\n");
 	}
+
+	set_bit(EFI_MEMMAP, &efi.flags);
 }

arch/arm64/mm/init.c +3 -1

index e90c542..58dbf2e 100644
@@ -32,6 +32,7 @@
 #include <linux/of_fdt.h>
 #include <linux/dma-mapping.h>
 #include <linux/dma-contiguous.h>
+#include <linux/efi.h>
 
 #include <asm/sections.h>
 #include <asm/setup.h>

@@ -151,7 +152,8 @@ void __init arm64_memblock_init(void)
 	memblock_reserve(__pa(swapper_pg_dir), SWAPPER_DIR_SIZE);
 	memblock_reserve(__pa(idmap_pg_dir), IDMAP_DIR_SIZE);
 
-	early_init_fdt_scan_reserved_mem();
+	if (!efi_enabled(EFI_MEMMAP))
+		early_init_fdt_scan_reserved_mem();
 
 	/* 4GB maximum for 32-bit only capable devices */
 	if (IS_ENABLED(CONFIG_ZONE_DMA))

Signature · 1 line

1.7.10.4

Mark Rutland

reviewer

2014-07-28 18:14 UTC #1 lore raw

PATCH 1/1 arm64: ignore DT memreserve entries when booting in UEFI mode

Quoted 3 lines · Leif Lindholm

UEFI provides its own method for marking regions to reserve, via the memory map which is also used to initialise memblock. So when using the UEFI memory map, ignore any memreserve entries present in the DT.

It's worth noting that no-one is relying on this at present, and were they it would imply that their UEFI implementation is broken (providing a dodgy memory map).

So before people start doing dodgy things, let's, close that hole. If we need a way of modifying the memory map we should come up with a more general plan.

Quoted 12 lines

Reported-by Mark Rutland <[email protected]>
Signed-off-by Leif Lindholm <[email protected]>
---
 arch/arm64/kernel/efi.c |    2 ++
 arch/arm64/mm/init.c    |    4 +++-
 2 files changed, 5 insertions(+), 1 deletion(-)
arch/arm64/kernel/efi.c +0 -0
index 14db1f6..7ad17b2 100644

arch/arm64/kernel/efi.c static __init void reserve_regions(void) · line 192

Quoted 5 lines

arch/arm64/kernel/efi.c +2 -0

@@ -188,6 +188,8 @@ static __init void reserve_regions(void)
 		if (uefi_debug)
 			pr_cont("\n");
 	}
+
+	set_bit(EFI_MEMMAP, &efi.flags);

Nothing outside of arch/x86 seems to hang off this, so using it here looks fine.

Quoted 16 lines

arch/arm64/kernel/efi.c +0 -0

arch/arm64/mm/init.c +1 -0

index e90c542..58dbf2e 100644
@@ -32,6 +32,7 @@
 #include <linux/of_fdt.h>
 #include <linux/dma-mapping.h>
 #include <linux/dma-contiguous.h>
+#include <linux/efi.h>
 
 #include <asm/sections.h>
 #include <asm/setup.h>

arch/arm64/mm/init.c void __init arm64_memblock_init(void) · line 156

Quoted 6 lines

arch/arm64/mm/init.c +2 -1

@@ -151,7 +152,8 @@ void __init arm64_memblock_init(void)
 	memblock_reserve(__pa(swapper_pg_dir), SWAPPER_DIR_SIZE);
 	memblock_reserve(__pa(idmap_pg_dir), IDMAP_DIR_SIZE);
 
-	early_init_fdt_scan_reserved_mem();
+	if (!efi_enabled(EFI_MEMMAP))
+		early_init_fdt_scan_reserved_mem();

And this is a false stub for !EFI, so that looks fine.

FWIW:

Reviewed-by Mark Rutland <[email protected]>

I wonder if we have any other flat tree uses we need to be careful of when booting via EFI.

Thanks
Mark.

Quoted 7 lines

arch/arm64/mm/init.c +0 -0

 	/* 4GB maximum for 32-bit only capable devices */
 	if (IS_ENABLED(CONFIG_ZONE_DMA))

Signature · 1 line

1.7.10.4

Leif Lindholm

author

2014-08-13 12:22 UTC #2 lore raw

PATCH 1/1 arm64: ignore DT memreserve entries when booting in UEFI mode

Quoted 5 lines · Mark Rutland

Quoted 3 lines · Leif Lindholm
UEFI provides its own method for marking regions to reserve, via the memory map which is also used to initialise memblock. So when using the UEFI memory map, ignore any memreserve entries present in the DT.

Quoted 7 lines

It's worth noting that no-one is relying on this at present, and were they it would imply that their UEFI implementation is broken (providing a dodgy memory map).
So before people start doing dodgy things, let's, close that hole. If we need a way of modifying the memory map we should come up with a more general plan.

Catalin - any comments?
As it is a bugfix, can it go into 3.17?

/
Leif

Quoted 52 lines

Quoted 12 lines
Reported-by Mark Rutland <[email protected]>
Signed-off-by Leif Lindholm <[email protected]>
---
 arch/arm64/kernel/efi.c |    2 ++
 arch/arm64/mm/init.c    |    4 +++-
 2 files changed, 5 insertions(+), 1 deletion(-)
arch/arm64/kernel/efi.c +0 -0
index 14db1f6..7ad17b2 100644
arch/arm64/kernel/efi.c static __init void reserve_regions(void) · line 192
Quoted 5 lines
arch/arm64/kernel/efi.c +2 -0
@@ -188,6 +188,8 @@ static __init void reserve_regions(void)
 		if (uefi_debug)
 			pr_cont("\n");
 	}
+
+	set_bit(EFI_MEMMAP, &efi.flags);
Nothing outside of arch/x86 seems to hang off this, so using it here looks fine.
Quoted 16 lines
arch/arm64/kernel/efi.c +0 -0
 }
 
 
arch/arm64/mm/init.c +1 -0
index e90c542..58dbf2e 100644
@@ -32,6 +32,7 @@
 #include <linux/of_fdt.h>
 #include <linux/dma-mapping.h>
 #include <linux/dma-contiguous.h>
+#include <linux/efi.h>
 
 #include <asm/sections.h>
 #include <asm/setup.h>
arch/arm64/mm/init.c void __init arm64_memblock_init(void) · line 156
Quoted 6 lines
arch/arm64/mm/init.c +2 -1
@@ -151,7 +152,8 @@ void __init arm64_memblock_init(void)
 	memblock_reserve(__pa(swapper_pg_dir), SWAPPER_DIR_SIZE);
 	memblock_reserve(__pa(idmap_pg_dir), IDMAP_DIR_SIZE);
 
-	early_init_fdt_scan_reserved_mem();
+	if (!efi_enabled(EFI_MEMMAP))
+		early_init_fdt_scan_reserved_mem();
And this is a false stub for !EFI, so that looks fine.
FWIW:
Reviewed-by Mark Rutland <[email protected]>
I wonder if we have any other flat tree uses we need to be careful of when booting via EFI.

Catalin Marinas

maintainer

2014-08-18 14:24 UTC #3 lore raw

PATCH 1/1 arm64: ignore DT memreserve entries when booting in UEFI mode

Quoted 10 lines · Leif Lindholm

Quoted 9 lines · Mark Rutland
Quoted 3 lines · Leif Lindholm
UEFI provides its own method for marking regions to reserve, via the memory map which is also used to initialise memblock. So when using the UEFI memory map, ignore any memreserve entries present in the DT.
It's worth noting that no-one is relying on this at present, and were they it would imply that their UEFI implementation is broken (providing a dodgy memory map).

Quoted 6 lines

Quoted 3 lines
So before people start doing dodgy things, let's, close that hole. If we need a way of modifying the memory map we should come up with a more general plan.
Catalin - any comments?
As it is a bugfix, can it go into 3.17?

It looks fine to me:

Acked-by Catalin Marinas <[email protected]>

(cc'ing Will who handles the 3.17 merging)

Quoted 39 lines

Reported-by Mark Rutland <[email protected]>

Signed-off-by Leif Lindholm <[email protected]>

---
 arch/arm64/kernel/efi.c |    2 ++
 arch/arm64/mm/init.c    |    4 +++-
 2 files changed, 5 insertions(+), 1 deletion(-)

arch/arm64/kernel/efi.c +2 -0

index 14db1f6..7ad17b2 100644
@@ -188,6 +188,8 @@ static __init void reserve_regions(void)
 		if (uefi_debug)
 			pr_cont("\n");
 	}
+
+	set_bit(EFI_MEMMAP, &efi.flags);
 }

arch/arm64/mm/init.c +3 -1

index e90c542..58dbf2e 100644
@@ -32,6 +32,7 @@
 #include <linux/of_fdt.h>
 #include <linux/dma-mapping.h>
 #include <linux/dma-contiguous.h>
+#include <linux/efi.h>
 
 #include <asm/sections.h>
 #include <asm/setup.h>

@@ -151,7 +152,8 @@ void __init arm64_memblock_init(void)
 	memblock_reserve(__pa(swapper_pg_dir), SWAPPER_DIR_SIZE);
 	memblock_reserve(__pa(idmap_pg_dir), IDMAP_DIR_SIZE);
 
-	early_init_fdt_scan_reserved_mem();
+	if (!efi_enabled(EFI_MEMMAP))
+		early_init_fdt_scan_reserved_mem();