powerpc: allow ioremap within reserved memory regions

Add a flag to let a platform ioremap memory regions marked as reserved.

This flag will be used later by the Nintendo Wii support code to allow
ioremapping the I/O region sitting between MEM1 and MEM2 and marked
as reserved RAM in the patch "wii: use both mem1 and mem2 as ram".

This will no longer be needed when proper discontig memory support
for 32-bit PowerPC is added to the kernel.

Signed-off-by: Albert Herranz <albert_herranz@yahoo.es>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This commit is contained in:
Albert Herranz 2009-12-12 06:31:54 +00:00 committed by Grant Likely
parent de32400dd2
commit c5df7f7751
5 changed files with 16 additions and 2 deletions

View file

@ -82,6 +82,11 @@ extern struct task_struct *current_set[NR_CPUS];
int __map_without_bats;
int __map_without_ltlbs;
/*
* This tells the system to allow ioremapping memory marked as reserved.
*/
int __allow_ioremap_reserved;
/* max amount of low RAM to map in */
unsigned long __max_low_memory = MAX_LOW_MEM;

View file

@ -115,6 +115,7 @@ extern void settlbcam(int index, unsigned long virt, phys_addr_t phys,
extern void invalidate_tlbcam_entry(int index);
extern int __map_without_bats;
extern int __allow_ioremap_reserved;
extern unsigned long ioremap_base;
extern unsigned int rtas_data, rtas_size;

View file

@ -26,6 +26,7 @@
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/highmem.h>
#include <linux/lmb.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
@ -191,7 +192,8 @@ __ioremap_caller(phys_addr_t addr, unsigned long size, unsigned long flags,
* Don't allow anybody to remap normal RAM that we're using.
* mem_init() sets high_memory so only do the check after that.
*/
if (mem_init_done && (p < virt_to_phys(high_memory))) {
if (mem_init_done && (p < virt_to_phys(high_memory)) &&
!(__allow_ioremap_reserved && lmb_is_region_reserved(p, size))) {
printk("__ioremap(): phys addr 0x%llx is RAM lr %p\n",
(unsigned long long)p, __builtin_return_address(0));
return NULL;

View file

@ -54,6 +54,7 @@ extern u64 __init lmb_phys_mem_size(void);
extern u64 lmb_end_of_DRAM(void);
extern void __init lmb_enforce_memory_limit(u64 memory_limit);
extern int __init lmb_is_reserved(u64 addr);
extern int lmb_is_region_reserved(u64 base, u64 size);
extern int lmb_find(struct lmb_property *res);
extern void lmb_dump_all(void);

View file

@ -263,7 +263,7 @@ long __init lmb_reserve(u64 base, u64 size)
return lmb_add_region(_rgn, base, size);
}
long __init lmb_overlaps_region(struct lmb_region *rgn, u64 base, u64 size)
long lmb_overlaps_region(struct lmb_region *rgn, u64 base, u64 size)
{
unsigned long i;
@ -493,6 +493,11 @@ int __init lmb_is_reserved(u64 addr)
return 0;
}
int lmb_is_region_reserved(u64 base, u64 size)
{
return lmb_overlaps_region(&lmb.reserved, base, size);
}
/*
* Given a <base, len>, find which memory regions belong to this range.
* Adjust the request and return a contiguous chunk.