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[POWERPC] Provide walk_memory_resource() for powerpc

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Provide walk_memory_resource() for 64-bit powerpc.  PowerPC maintains
logical memory region mapping in the lmb.memory structure.  Walk
through these structures and do the callbacks for the contiguous
chunks.

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Badari Pulavarty 2008-04-18 13:33:53 -07:00 committed by Paul Mackerras
parent 98d5c21c81
commit 9d88a2eb6e
3 changed files with 57 additions and 7 deletions
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30
arch/powerpc/mm/mem.c
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@ -154,19 +154,35 @@ out:
/*
* walk_memory_resource() needs to make sure there is no holes in a given
* memory range. On PPC64, since this range comes from /sysfs, the range
* is guaranteed to be valid, non-overlapping and can not contain any
* holes. By the time we get here (memory add or remove), /proc/device-tree
* is updated and correct. Only reason we need to check against device-tree
* would be if we allow user-land to specify a memory range through a
* system call/ioctl etc. instead of doing offline/online through /sysfs.
* memory range. PPC64 does not maintain the memory layout in /proc/iomem.
* Instead it maintains it in lmb.memory structures. Walk through the
* memory regions, find holes and callback for contiguous regions.
*/
int
walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg,
int (*func)(unsigned long, unsigned long, void *))
{
return (*func)(start_pfn, nr_pages, arg);
struct lmb_property res;
unsigned long pfn, len;
u64 end;
int ret = -1;
res.base = (u64) start_pfn << PAGE_SHIFT;
res.size = (u64) nr_pages << PAGE_SHIFT;
end = res.base + res.size - 1;
while ((res.base < end) && (lmb_find(&res) >= 0)) {
pfn = (unsigned long)(res.base >> PAGE_SHIFT);
len = (unsigned long)(res.size >> PAGE_SHIFT);
ret = (*func)(pfn, len, arg);
if (ret)
break;
res.base += (res.size + 1);
res.size = (end - res.base + 1);
}
return ret;
}
EXPORT_SYMBOL_GPL(walk_memory_resource);
#endif /* CONFIG_MEMORY_HOTPLUG */

1
include/linux/lmb.h
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@ -54,6 +54,7 @@ extern u64 __init lmb_phys_mem_size(void);
extern u64 __init 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_find(struct lmb_property *res);
extern void lmb_dump_all(void);

33
lib/lmb.c
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@ -474,3 +474,36 @@ int __init lmb_is_reserved(u64 addr)
}
return 0;
}
/*
* Given a <base, len>, find which memory regions belong to this range.
* Adjust the request and return a contiguous chunk.
*/
int lmb_find(struct lmb_property *res)
{
int i;
u64 rstart, rend;
rstart = res->base;
rend = rstart + res->size - 1;
for (i = 0; i < lmb.memory.cnt; i++) {
u64 start = lmb.memory.region[i].base;
u64 end = start + lmb.memory.region[i].size - 1;
if (start > rend)
return -1;
if ((end >= rstart) && (start < rend)) {
/* adjust the request */
if (rstart < start)
rstart = start;
if (rend > end)
rend = end;
res->base = rstart;
res->size = rend - rstart + 1;
return 0;
}
}
return -1;
}