[Patch v2 5/6] x86/mm: Use address directly in split_mem_range()

From: Wei Yang
Date: Wed Dec 04 2019 - 21:16:00 EST


This is not necessary to convert address to pfn to split range. And
finally, convert back to address and store it to map_range.

Signed-off-by: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
---
arch/x86/mm/init.c | 73 +++++++++++++++++++++++-----------------------
1 file changed, 36 insertions(+), 37 deletions(-)

diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index ded58a31c679..5fe3f645f02c 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -259,14 +259,14 @@ static void setup_pcid(void)
#endif

static int __meminit save_mr(struct map_range *mr, int nr_range,
- unsigned long start_pfn, unsigned long end_pfn,
+ unsigned long start, unsigned long end,
unsigned long page_size_mask)
{
if (start_pfn < end_pfn) {
if (nr_range >= NR_RANGE_MR)
panic("run out of range for init_memory_mapping\n");
- mr[nr_range].start = start_pfn<<PAGE_SHIFT;
- mr[nr_range].end = end_pfn<<PAGE_SHIFT;
+ mr[nr_range].start = start_pfn;
+ mr[nr_range].end = end_pfn;
mr[nr_range].page_size_mask = page_size_mask;
nr_range++;
}
@@ -328,14 +328,13 @@ static int __meminit split_mem_range(struct map_range *mr,
unsigned long start,
unsigned long end)
{
- unsigned long start_pfn, end_pfn, limit_pfn;
- unsigned long pfn;
+ unsigned long addr, limit;
int i, nr_range = 0;

- limit_pfn = PFN_DOWN(end);
+ limit = end;

/* head if not big page alignment ? */
- pfn = start_pfn = PFN_DOWN(start);
+ addr = start;
#ifdef CONFIG_X86_32
/*
* Don't use a large page for the first 2/4MB of memory
@@ -343,61 +342,61 @@ static int __meminit split_mem_range(struct map_range *mr,
* and overlapping MTRRs into large pages can cause
* slowdowns.
*/
- if (pfn == 0)
- end_pfn = PFN_DOWN(PMD_SIZE);
+ if (addr == 0)
+ end = PMD_SIZE;
else
- end_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
+ end = round_up(addr, PMD_SIZE);
#else /* CONFIG_X86_64 */
- end_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
+ end = round_up(addr, PMD_SIZE);
#endif
- if (end_pfn > limit_pfn)
- end_pfn = limit_pfn;
- if (start_pfn < end_pfn) {
- nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
- pfn = end_pfn;
+ if (end > limit)
+ end = limit;
+ if (start < end) {
+ nr_range = save_mr(mr, nr_range, start, end, 0);
+ addr = end;
}

/* big page (2M) range */
- start_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
+ start = round_up(addr, PMD_SIZE);
#ifdef CONFIG_X86_32
- end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE));
+ end = round_down(limit, PMD_SIZE);
#else /* CONFIG_X86_64 */
- end_pfn = round_up(pfn, PFN_DOWN(PUD_SIZE));
- if (end_pfn > round_down(limit_pfn, PFN_DOWN(PMD_SIZE)))
- end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE));
+ end = round_up(addr, PUD_SIZE);
+ if (end > round_down(limit, PMD_SIZE))
+ end = round_down(limit, PMD_SIZE);
#endif

- if (start_pfn < end_pfn) {
- nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
+ if (start < end) {
+ nr_range = save_mr(mr, nr_range, start, end,
page_size_mask & (1U<<PG_LEVEL_2M));
- pfn = end_pfn;
+ addr = end;
}

#ifdef CONFIG_X86_64
/* big page (1G) range */
- start_pfn = round_up(pfn, PFN_DOWN(PUD_SIZE));
- end_pfn = round_down(limit_pfn, PFN_DOWN(PUD_SIZE));
- if (start_pfn < end_pfn) {
- nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
+ start = round_up(addr, PUD_SIZE);
+ end = round_down(limit, PUD_SIZE);
+ if (start < end) {
+ nr_range = save_mr(mr, nr_range, start, end,
page_size_mask &
((1U<<PG_LEVEL_2M)|(1U<<PG_LEVEL_1G)));
- pfn = end_pfn;
+ addr = end;
}

/* tail is not big page (1G) alignment */
- start_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
- end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE));
- if (start_pfn < end_pfn) {
- nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
+ start = round_up(addr, PMD_SIZE);
+ end = round_down(limit, PMD_SIZE);
+ if (start < end) {
+ nr_range = save_mr(mr, nr_range, start, end,
page_size_mask & (1U<<PG_LEVEL_2M));
- pfn = end_pfn;
+ addr = end;
}
#endif

/* tail is not big page (2M) alignment */
- start_pfn = pfn;
- end_pfn = limit_pfn;
- nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
+ start = addr;
+ end = limit;
+ nr_range = save_mr(mr, nr_range, start, end, 0);

if (!after_bootmem)
adjust_range_page_size_mask(mr, nr_range);
--
2.17.1