[v2] arm: Handle >4GB memory sizes in device tree and mem=size@start option

Commit Message

Peter Maydell July 11, 2012, 9:39 a.m. UTC

The memory regions which are passed to arm_add_memory() from
device tree blobs via early_init_dt_add_memory_arch() can
have sizes which are larger than will fit in a 32 bit integer,
so switch to using a phys_addr_t to hold them, to avoid
silently dropping the top 32 bits of the size. Similarly, use
phys_addr_t in early_mem() so that mem=size@start command line
options specifying more than 4GB behave sensibly.

Signed-off-by: Peter Maydell <[e-mail]>
---
Changes v1->v2:
 * fixed spacing round '-'
 * made early_mem() handle large sizes too

 arch/arm/include/asm/setup.h |    4 ++--
 arch/arm/kernel/setup.c      |    6 +++---
 2 files changed, 5 insertions(+), 5 deletions(-)

Comments

Will Deacon July 12, 2012, 4:36 p.m. UTC | #1

On Wed, Jul 11, 2012 at 10:39:48AM +0100, Peter Maydell wrote:
> The memory regions which are passed to arm_add_memory() from
> device tree blobs via early_init_dt_add_memory_arch() can
> have sizes which are larger than will fit in a 32 bit integer,
> so switch to using a phys_addr_t to hold them, to avoid
> silently dropping the top 32 bits of the size. Similarly, use
> phys_addr_t in early_mem() so that mem=size@start command line
> options specifying more than 4GB behave sensibly.
> 
> Signed-off-by: Peter Maydell <[e-mail]>
> ---
> Changes v1->v2:
>  * fixed spacing round '-'
>  * made early_mem() handle large sizes too

Acked-by: Will Deacon <[e-mail]>

Please can you put this into the patch system?

Will

Patch

diff --git a/arch/arm/include/asm/setup.h b/arch/arm/include/asm/setup.h
index 23ebc0c..24d284a 100644
--- a/arch/arm/include/asm/setup.h
+++ b/arch/arm/include/asm/setup.h
@@ -196,7 +196,7 @@  static const struct tagtable __tagtable_##fn __tag = { tag, fn }
 
 struct membank {
 	phys_addr_t start;
-	unsigned long size;
+	phys_addr_t size;
 	unsigned int highmem;
 };
 
@@ -217,7 +217,7 @@  extern struct meminfo meminfo;
 #define bank_phys_end(bank)	((bank)->start + (bank)->size)
 #define bank_phys_size(bank)	(bank)->size
 
-extern int arm_add_memory(phys_addr_t start, unsigned long size);
+extern int arm_add_memory(phys_addr_t start, phys_addr_t size);
 extern void early_print(const char *str, ...);
 extern void dump_machine_table(void);
 
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index e15d83b..a81dcec 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -508,7 +508,7 @@  void __init dump_machine_table(void)
 		/* can't use cpu_relax() here as it may require MMU setup */;
 }
 
-int __init arm_add_memory(phys_addr_t start, unsigned long size)
+int __init arm_add_memory(phys_addr_t start, phys_addr_t size)
 {
 	struct membank *bank = &meminfo.bank[meminfo.nr_banks];
 
@@ -538,7 +538,7 @@  int __init arm_add_memory(phys_addr_t start, unsigned long size)
 	}
 #endif
 
-	bank->size = size & PAGE_MASK;
+	bank->size = size & ~(phys_addr_t)(PAGE_SIZE - 1);
 
 	/*
 	 * Check whether this memory region has non-zero size or
@@ -558,7 +558,7 @@  int __init arm_add_memory(phys_addr_t start, unsigned long size)
 static int __init early_mem(char *p)
 {
 	static int usermem __initdata = 0;
-	unsigned long size;
+	phys_addr_t size;
 	phys_addr_t start;
 	char *endp;