memblock vs early_res

[Jeremy Fitzhardinge]

 Hi Yinghai,

I have the patch below floating around in my tree to make sure that
early-reserved highmem is honoured when freeing unreserved memory.  I
was trying to rebase it to current linux-next and noticed that all the
early_res stuff has been replaced with memblock.

Is this still an issue?  What would the memblock version of this patch
look like?

Thanks,
    J

From 0a1c234a9fabcc2e71dc7a6da7ae1cb073207281 Mon Sep 17 00:00:00 2001
From: Gianluca Guida <gianluca.guida@xxxxxxxxxx>
Date: Sun, 2 Aug 2009 01:25:48 +0100
Subject: [PATCH] x86/32: honor reservations of high memory

Make high memory initialization honor early reserved ranges.

Signed-off-by: Gianluca Guida <gianluca.guida@xxxxxxxxxx>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>

diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index bca7909..573bc7f 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -432,22 +432,45 @@ static int __init add_highpages_work_fn(unsigned long start_pfn,
 {
 	int node_pfn;
 	struct page *page;
+	phys_addr_t chunk_end, chunk_max;
 	unsigned long final_start_pfn, final_end_pfn;
-	struct add_highpages_data *data;
-
-	data = (struct add_highpages_data *)datax;
+	struct add_highpages_data *data = (struct add_highpages_data *)datax;
 
 	final_start_pfn = max(start_pfn, data->start_pfn);
 	final_end_pfn = min(end_pfn, data->end_pfn);
 	if (final_start_pfn >= final_end_pfn)
 		return 0;
 
-	for (node_pfn = final_start_pfn; node_pfn < final_end_pfn;
-	     node_pfn++) {
-		if (!pfn_valid(node_pfn))
-			continue;
-		page = pfn_to_page(node_pfn);
-		add_one_highpage_init(page);
+	chunk_end = PFN_PHYS(final_start_pfn);
+	chunk_max = PFN_PHYS(final_end_pfn);
+
+	/*
+	 * Check for reserved areas.
+	 */
+	for (;;) {
+		phys_addr_t chunk_start;
+		chunk_start = early_res_next_free(chunk_end);
+		
+		/*
+		 * Reserved area. Just count high mem pages.
+		 */
+		for (node_pfn = PFN_DOWN(chunk_end);
+		     node_pfn < PFN_DOWN(chunk_start); node_pfn++) {
+			if (pfn_valid(node_pfn))
+				totalhigh_pages++;
+		}
+
+		if (chunk_start >= chunk_max)
+			break;
+
+		chunk_end = early_res_next_reserved(chunk_start, chunk_max);
+		for (node_pfn = PFN_DOWN(chunk_start);
+		     node_pfn < PFN_DOWN(chunk_end); node_pfn++) {
+			if (!pfn_valid(node_pfn))
+				continue;
+			page = pfn_to_page(node_pfn);
+			add_one_highpage_init(page);
+		}
 	}
 
 	return 0;
@@ -461,7 +484,6 @@ void __init add_highpages_with_active_regions(int nid, unsigned long start_pfn,
 
 	data.start_pfn = start_pfn;
 	data.end_pfn = end_pfn;
-
 	work_with_active_regions(nid, add_highpages_work_fn, &data);
 }
 
diff --git a/include/linux/early_res.h b/include/linux/early_res.h
index 29c09f5..37317e1 100644
--- a/include/linux/early_res.h
+++ b/include/linux/early_res.h
@@ -8,6 +8,9 @@ extern void free_early(u64 start, u64 end);
 void free_early_partial(u64 start, u64 end);
 extern void early_res_to_bootmem(u64 start, u64 end);
 
+extern u64 early_res_next_free(u64 start);
+extern u64 early_res_next_reserved(u64 addr, u64 max);
+
 void reserve_early_without_check(u64 start, u64 end, char *name);
 u64 find_early_area(u64 ei_start, u64 ei_last, u64 start, u64 end,
 			 u64 size, u64 align);
diff --git a/kernel/early_res.c b/kernel/early_res.c
index 7bfae88..b663c62 100644
--- a/kernel/early_res.c
+++ b/kernel/early_res.c
@@ -44,6 +44,36 @@ static int __init find_overlapped_early(u64 start, u64 end)
 	return i;
 }
 
+u64 __init early_res_next_free(u64 addr)
+{
+	int i;
+	u64 end = addr;
+	struct early_res *r;
+
+	for (i = 0; i < max_early_res; i++) {
+		r = &early_res[i];
+		if (addr >= r->start && addr < r->end) {
+			end = r->end;
+			break;
+		}
+	}
+	return end;
+}
+
+u64 __init early_res_next_reserved(u64 addr, u64 max)
+{
+	int i;
+	struct early_res *r;
+	u64 next_res = max;
+
+	for (i = 0; i < max_early_res && early_res[i].end; i++) {
+		r = &early_res[i];
+		if ((r->start >= addr) && (r->start < next_res))
+			next_res = r->start;
+	}
+	return next_res;
+}
+
 /*
  * Drop the i-th range from the early reservation map,
  * by copying any higher ranges down one over it, and