[RFC GIT PULL] EFI fixes, memblock quirk

[RFC GIT PULL] EFI fixes, memblock quirk

[Ingo Molnar]

Linus,

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

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

   # HEAD: 582a32e708823e5957fd73ccd78dc4a9e49d21ea efi/arm: Revert "Defer persistent reservations until after paging_init()"

This tree reverts a GICv3 commit (which was broken) and fixes it in 
another way, by adding a memblock build-time entries quirk for ARM64.

I marked it RFC: please have a second look at the mm/memblock.c change, 
which adds a INIT_MEMBLOCK_RESERVED_REGIONS detour that ARM64 takes for 
these systems.

Perhaps we should upgrade the build time sizing of all platforms to 
INIT_MEMBLOCK_REGIONS+NR_CPUS+1 and thus centrally give an extra 
allocation entry per CPU configured?

Or is there some cleaner solution?

 Thanks,

	Ingo

------------------>
Ard Biesheuvel (2):
      arm64, mm, efi: Account for GICv3 LPI tables in static memblock reserve table
      efi/arm: Revert "Defer persistent reservations until after paging_init()"


 arch/arm64/include/asm/memory.h         | 11 +++++++++++
 arch/arm64/kernel/setup.c               |  1 -
 drivers/firmware/efi/efi.c              |  4 ----
 drivers/firmware/efi/libstub/arm-stub.c |  3 ---
 include/linux/efi.h                     |  7 -------
 include/linux/memblock.h                |  3 ---
 mm/memblock.c                           | 11 +++++++++--
 7 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index e1ec947e7c0c..0c656850eeea 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -332,6 +332,17 @@ static inline void *phys_to_virt(phys_addr_t x)
 #define virt_addr_valid(kaddr)		\
 	(_virt_addr_is_linear(kaddr) && _virt_addr_valid(kaddr))
 
+/*
+ * Given that the GIC architecture permits ITS implementations that can only be
+ * configured with a LPI table address once, GICv3 systems with many CPUs may
+ * end up reserving a lot of different regions after a kexec for their LPI
+ * tables (one per CPU), as we are forced to reuse the same memory after kexec
+ * (and thus reserve it persistently with EFI beforehand)
+ */
+#if defined(CONFIG_EFI) && defined(CONFIG_ARM_GIC_V3_ITS)
+# define INIT_MEMBLOCK_RESERVED_REGIONS	(INIT_MEMBLOCK_REGIONS + NR_CPUS + 1)
+#endif
+
 #include <asm-generic/memory_model.h>
 
 #endif
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 4b0e1231625c..d09ec76f08cf 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -313,7 +313,6 @@ void __init setup_arch(char **cmdline_p)
 	arm64_memblock_init();
 
 	paging_init();
-	efi_apply_persistent_mem_reservations();
 
 	acpi_table_upgrade();
 
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 4c46ff6f2242..55b77c576c42 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -592,11 +592,7 @@ int __init efi_config_parse_tables(void *config_tables, int count, int sz,
 
 		early_memunmap(tbl, sizeof(*tbl));
 	}
-	return 0;
-}
 
-int __init efi_apply_persistent_mem_reservations(void)
-{
 	if (efi.mem_reserve != EFI_INVALID_TABLE_ADDR) {
 		unsigned long prsv = efi.mem_reserve;
 
diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c
index eee42d5e25ee..c037c6c5d0b7 100644
--- a/drivers/firmware/efi/libstub/arm-stub.c
+++ b/drivers/firmware/efi/libstub/arm-stub.c
@@ -75,9 +75,6 @@ void install_memreserve_table(efi_system_table_t *sys_table_arg)
 	efi_guid_t memreserve_table_guid = LINUX_EFI_MEMRESERVE_TABLE_GUID;
 	efi_status_t status;
 
-	if (IS_ENABLED(CONFIG_ARM))
-		return;
-
 	status = efi_call_early(allocate_pool, EFI_LOADER_DATA, sizeof(*rsv),
 				(void **)&rsv);
 	if (status != EFI_SUCCESS) {
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 45ff763fba76..28604a8d0aa9 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1198,8 +1198,6 @@ static inline bool efi_enabled(int feature)
 extern void efi_reboot(enum reboot_mode reboot_mode, const char *__unused);
 
 extern bool efi_is_table_address(unsigned long phys_addr);
-
-extern int efi_apply_persistent_mem_reservations(void);
 #else
 static inline bool efi_enabled(int feature)
 {
@@ -1218,11 +1216,6 @@ static inline bool efi_is_table_address(unsigned long phys_addr)
 {
 	return false;
 }
-
-static inline int efi_apply_persistent_mem_reservations(void)
-{
-	return 0;
-}
 #endif
 
 extern int efi_status_to_err(efi_status_t status);
diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 64c41cf45590..859b55b66db2 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -29,9 +29,6 @@ extern unsigned long max_pfn;
  */
 extern unsigned long long max_possible_pfn;
 
-#define INIT_MEMBLOCK_REGIONS	128
-#define INIT_PHYSMEM_REGIONS	4
-
 /**
  * enum memblock_flags - definition of memory region attributes
  * @MEMBLOCK_NONE: no special request
diff --git a/mm/memblock.c b/mm/memblock.c
index 022d4cbb3618..ea31045ba704 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -26,6 +26,13 @@
 
 #include "internal.h"
 
+#define INIT_MEMBLOCK_REGIONS			128
+#define INIT_PHYSMEM_REGIONS			4
+
+#ifndef INIT_MEMBLOCK_RESERVED_REGIONS
+# define INIT_MEMBLOCK_RESERVED_REGIONS		INIT_MEMBLOCK_REGIONS
+#endif
+
 /**
  * DOC: memblock overview
  *
@@ -92,7 +99,7 @@ unsigned long max_pfn;
 unsigned long long max_possible_pfn;
 
 static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock;
-static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock;
+static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_RESERVED_REGIONS] __initdata_memblock;
 #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP
 static struct memblock_region memblock_physmem_init_regions[INIT_PHYSMEM_REGIONS] __initdata_memblock;
 #endif
@@ -105,7 +112,7 @@ struct memblock memblock __initdata_memblock = {
 
 	.reserved.regions	= memblock_reserved_init_regions,
 	.reserved.cnt		= 1,	/* empty dummy entry */
-	.reserved.max		= INIT_MEMBLOCK_REGIONS,
+	.reserved.max		= INIT_MEMBLOCK_RESERVED_REGIONS,
 	.reserved.name		= "reserved",
 
 #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP

Re: [RFC GIT PULL] EFI fixes, memblock quirk

[Linus Torvalds]

On Sun, Feb 17, 2019 at 2:59 AM Ingo Molnar <mingo@kernel.org> wrote:
>
> I marked it RFC: please have a second look at the mm/memblock.c change,
> which adds a INIT_MEMBLOCK_RESERVED_REGIONS detour that ARM64 takes for
> these systems.

It's not pretty, but it looks minimal for now. Pulled.

> Perhaps we should upgrade the build time sizing of all platforms to
> INIT_MEMBLOCK_REGIONS+NR_CPUS+1 and thus centrally give an extra
> allocation entry per CPU configured?
>
> Or is there some cleaner solution?

Is there some reason other platforms might want that kind of thing?
If not, then the current hack seems sufficient.

                    Linus

Re: [RFC GIT PULL] EFI fixes, memblock quirk

[Ingo Molnar]

* Linus Torvalds <torvalds@linux-foundation.org> wrote:

> On Sun, Feb 17, 2019 at 2:59 AM Ingo Molnar <mingo@kernel.org> wrote:
> >
> > I marked it RFC: please have a second look at the mm/memblock.c change,
> > which adds a INIT_MEMBLOCK_RESERVED_REGIONS detour that ARM64 takes for
> > these systems.
> 
> It's not pretty, but it looks minimal for now. Pulled.

Thanks!

> > Perhaps we should upgrade the build time sizing of all platforms to
> > INIT_MEMBLOCK_REGIONS+NR_CPUS+1 and thus centrally give an extra
> > allocation entry per CPU configured?
> >
> > Or is there some cleaner solution?
> 
> Is there some reason other platforms might want that kind of thing?

Not that I'm aware of.

> If not, then the current hack seems sufficient.

Ok!

Thanks,

	Ingo

Re: [RFC GIT PULL] EFI fixes, memblock quirk

[Ard Biesheuvel]

On Tue, 19 Feb 2019 at 16:16, Ingo Molnar <mingo@kernel.org> wrote:
>
>
> * Linus Torvalds <torvalds@linux-foundation.org> wrote:
>
> > On Sun, Feb 17, 2019 at 2:59 AM Ingo Molnar <mingo@kernel.org> wrote:
> > >
> > > I marked it RFC: please have a second look at the mm/memblock.c change,
> > > which adds a INIT_MEMBLOCK_RESERVED_REGIONS detour that ARM64 takes for
> > > these systems.
> >
> > It's not pretty, but it looks minimal for now. Pulled.
>
> Thanks!
>
> > > Perhaps we should upgrade the build time sizing of all platforms to
> > > INIT_MEMBLOCK_REGIONS+NR_CPUS+1 and thus centrally give an extra
> > > allocation entry per CPU configured?
> > >
> > > Or is there some cleaner solution?
> >
> > Is there some reason other platforms might want that kind of thing?
>
> Not that I'm aware of.
>

Nor me.

> > If not, then the current hack seems sufficient.
>
> Ok!
>

Thanks. It's a bit of a hack indeed, but every other option I explored
was a lot nastier. We might be able to tweak the LPI table allocation
logic so that they are adjacent, taking up only a single slot in the
reservation table, but that will have to wait for v5.2