[PATCH 10/13] memblock, x86: Reimplement memblock_find_dma_reserve() using iterators

Tejun Heo
2011-07-12T09:17:34Z

memblock_find_dma_reserve() wants to find out how much memory is
reserved under MAX_DMA_PFN. memblock_x86_memory_[free_]in_range() are
used to find out the amounts of all available and free memory in the
area, which are then subtracted to find out the amount of reservation.

memblock_x86_memblock_[free_]in_range() are implemented using
__memblock_x86_memory_in_range() which builds ranges from memblock and
then count them, which is rather unnecessarily complex.

This patch open codes the counting logic directly in
memblock_find_dma_reserve() using memblock iterators and removes now
unused __memblock_x86_memory_in_range() and find_range_array().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
---
arch/x86/include/asm/memblock.h | 2 -
arch/x86/kernel/e820.c | 25 +++++++++--
arch/x86/mm/memblock.c | 87 ---------------------------------------
3 files changed, 20 insertions(+), 94 deletions(-)

diff --git a/arch/x86/include/asm/memblock.h b/arch/x86/include/asm/memblock.h
index bc9e44b..a0cc7d6 100644
--- a/arch/x86/include/asm/memblock.h
+++ b/arch/x86/include/asm/memblock.h
@@ -7,7 +7,5 @@ void memblock_x86_reserve_range(u64 start, u64 end, char *name);
void memblock_x86_free_range(u64 start, u64 end);

u64 memblock_x86_hole_size(u64 start, u64 end);
-u64 memblock_x86_free_memory_in_range(u64 addr, u64 limit);
-u64 memblock_x86_memory_in_range(u64 addr, u64 limit);

#endif
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index b99d940..84475f1 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -1093,15 +1093,30 @@ void __init memblock_x86_fill(void)
void __init memblock_find_dma_reserve(void)
{
#ifdef CONFIG_X86_64
- u64 free_size_pfn;
- u64 mem_size_pfn;
+ u64 nr_pages = 0, nr_free_pages = 0;
+ unsigned long start_pfn, end_pfn;
+ phys_addr_t start, end;
+ int i;
+ u64 u;
+
/*
* need to find out used area below MAX_DMA_PFN
* need to use memblock to get free size in [0, MAX_DMA_PFN]
* at first, and assume boot_mem will not take below MAX_DMA_PFN
*/
- mem_size_pfn = memblock_x86_memory_in_range(0, MAX_DMA_PFN << PAGE_SHIFT) >> PAGE_SHIFT;
- free_size_pfn = memblock_x86_free_memory_in_range(0, MAX_DMA_PFN << PAGE_SHIFT) >> PAGE_SHIFT;
- set_dma_reserve(mem_size_pfn - free_size_pfn);
+ for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
+ start_pfn = min_t(unsigned long, start_pfn, MAX_DMA_PFN);
+ end_pfn = min_t(unsigned long, end_pfn, MAX_DMA_PFN);
+ nr_pages += end_pfn - start_pfn;
+ }
+
+ for_each_free_mem_range(u, MAX_NUMNODES, &start, &end, NULL) {
+ start_pfn = min_t(unsigned long, PFN_UP(start), MAX_DMA_PFN);
+ end_pfn = min_t(unsigned long, PFN_DOWN(end), MAX_DMA_PFN);
+ if (start_pfn < end_pfn)
+ nr_free_pages += end_pfn - start_pfn;
+ }
+
+ set_dma_reserve(nr_pages - nr_free_pages);
#endif
}
diff --git a/arch/x86/mm/memblock.c b/arch/x86/mm/memblock.c
index 4107c1a..a9d0972 100644
--- a/arch/x86/mm/memblock.c
+++ b/arch/x86/mm/memblock.c
@@ -7,93 +7,6 @@
#include <linux/mm.h>
#include <linux/range.h>

-static __init struct range *find_range_array(int count)
-{
- u64 end, size, mem;
- struct range *range;
-
- size = sizeof(struct range) * count;
- end = memblock.current_limit;
-
- mem = memblock_find_in_range(0, end, size, sizeof(struct range));
- if (!mem)
- panic("can not find more space for range array");
-
- /*
- * This range is tempoaray, so don't reserve it, it will not be
- * overlapped because We will not alloccate new buffer before
- * We discard this one
- */
- range = __va(mem);
- memset(range, 0, size);
-
- return range;
-}
-
-static u64 __init __memblock_x86_memory_in_range(u64 addr, u64 limit, bool get_free)
-{
- int i, count;
- struct range *range;
- int nr_range;
- u64 final_start, final_end;
- u64 free_size;
- struct memblock_region *r;
-
- count = (memblock.reserved.cnt + memblock.memory.cnt) * 2;
-
- range = find_range_array(count);
- nr_range = 0;
-
- addr = PFN_UP(addr);
- limit = PFN_DOWN(limit);
-
- for_each_memblock(memory, r) {
- final_start = PFN_UP(r->base);
- final_end = PFN_DOWN(r->base + r->size);
- if (final_start >= final_end)
- continue;
- if (final_start >= limit || final_end <= addr)
- continue;
-
- nr_range = add_range(range, count, nr_range, final_start, final_end);
- }
- subtract_range(range, count, 0, addr);
- subtract_range(range, count, limit, -1ULL);
-
- /* Subtract memblock.reserved.region in range ? */
- if (!get_free)
- goto sort_and_count_them;
- for_each_memblock(reserved, r) {
- final_start = PFN_DOWN(r->base);
- final_end = PFN_UP(r->base + r->size);
- if (final_start >= final_end)
- continue;
- if (final_start >= limit || final_end <= addr)
- continue;
-
- subtract_range(range, count, final_start, final_end);
- }
-
-sort_and_count_them:
- nr_range = clean_sort_range(range, count);
-
- free_size = 0;
- for (i = 0; i < nr_range; i++)
- free_size += range[i].end - range[i].start;
-
- return free_size << PAGE_SHIFT;
-}
-
-u64 __init memblock_x86_free_memory_in_range(u64 addr, u64 limit)
-{
- return __memblock_x86_memory_in_range(addr, limit, true);
-}
-
-u64 __init memblock_x86_memory_in_range(u64 addr, u64 limit)
-{
- return __memblock_x86_memory_in_range(addr, limit, false);
-}
-
void __init memblock_x86_reserve_range(u64 start, u64 end, char *name)
{
if (start == end)
--
1.7.6