* [PATCH 1/2] arm64: account for GICv3 LPI tables in static memblock reserve table
2019-02-15 12:33 [GIT PULL 0/2] EFI fixes for v5.0-rc Ard Biesheuvel
@ 2019-02-15 12:33 ` Ard Biesheuvel
2019-02-15 12:33 ` [PATCH 2/2] efi/arm: Revert "Defer persistent reservations until after paging_init()" Ard Biesheuvel
1 sibling, 0 replies; 3+ messages in thread
From: Ard Biesheuvel @ 2019-02-15 12:33 UTC (permalink / raw)
To: linux-arm-kernel, Ingo Molnar, Thomas Gleixner
Cc: linux-efi, Ard Biesheuvel, Marc Zyngier, Will Deacon,
linux-kernel, Mike Rapoport
In the irqchip and EFI code, we have what basically amounts to a quirk
to work around a peculiarity in the GICv3 architecture, which permits
the system memory address of LPI tables to be programmable only once
after a CPU reset. This means kexec kernels must use the same memory
as the first kernel, and thus ensure that this memory has not been
given out for other purposes by the time the ITS init code runs, which
is not very early for secondary CPUs.
On systems with many CPUs, these reservations could overflow the
memblock reservation table, and this was addressed in commit
eff896288872 ("efi/arm: Defer persistent reservations until after
paging_init()"). However, this turns out to have made things worse,
since the allocation of page tables and heap space for the resized
memblock reservation table itself may overwrite the regions we are
attempting to reserve, which may cause all kinds of corruption,
also considering that the ITS will still be poking bits into that
memory in response to incoming MSIs.
So instead, let's grow the static memblock reservation table on such
systems so it can accommodate these reservations at an earlier time.
This will permit us to revert the above commit in a subsequent patch.
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
arch/arm64/include/asm/memory.h | 11 +++++++++++
include/linux/memblock.h | 3 ---
mm/memblock.c | 10 ++++++++--
3 files changed, 19 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index e1ec947e7c0c..ada877f56551 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/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..a526c3ab8390 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -26,6 +26,12 @@
#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 +98,7 @@ 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 +111,7 @@ 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
--
2.20.1
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^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH 2/2] efi/arm: Revert "Defer persistent reservations until after paging_init()"
2019-02-15 12:33 [GIT PULL 0/2] EFI fixes for v5.0-rc Ard Biesheuvel
2019-02-15 12:33 ` [PATCH 1/2] arm64: account for GICv3 LPI tables in static memblock reserve table Ard Biesheuvel
@ 2019-02-15 12:33 ` Ard Biesheuvel
1 sibling, 0 replies; 3+ messages in thread
From: Ard Biesheuvel @ 2019-02-15 12:33 UTC (permalink / raw)
To: linux-arm-kernel, Ingo Molnar, Thomas Gleixner
Cc: linux-efi, Ard Biesheuvel, Marc Zyngier, Will Deacon,
linux-kernel, Mike Rapoport
This reverts commit eff896288872d687d9662000ec9ae11b6d61766f, which
deferred the processing of persistent memory reservations to a point
where the memory may have already been allocated and overwritten,
defeating the purpose.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
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 -------
4 files changed, 15 deletions(-)
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);
--
2.20.1
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^ permalink raw reply related [flat|nested] 3+ messages in thread