x86/e820: implement e820__range_remove() using __e820__ranage_update()x86/e820-update-range

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>

2 files changed, 21 insertions, 58 deletions

diff --git a/arch/x86/include/asm/e820/types.h b/arch/x86/include/asm/e820/types.h
index 314f75d886d08a..85c4b3276c90e3 100644
--- a/arch/x86/include/asm/e820/types.h
+++ b/arch/x86/include/asm/e820/types.h
@@ -8,6 +8,12 @@
  * These are the E820 types known to the kernel:
  */
 enum e820_type {
+	/*
+	 * Special value that indicates that a range must be removed during
+	 * updates of e820 table
+	 */
+	E820_TYPE_NONE		= 0,
+
 	E820_TYPE_RAM		= 1,
 	E820_TYPE_RESERVED	= 2,
 	E820_TYPE_ACPI		= 3,
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index e3594690466b59..f431d7bbd737ac 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -187,6 +187,7 @@ void __init e820__range_add(u64 start, u64 size, enum e820_type type)
 static void __init e820_print_type(enum e820_type type)
 {
 	switch (type) {
+	case E820_TYPE_NONE:		pr_cont("none");			break;
 	case E820_TYPE_RAM:		/* Fall through: */
 	case E820_TYPE_RESERVED_KERN:	pr_cont("usable");			break;
 	case E820_TYPE_RESERVED:	pr_cont("reserved");			break;
@@ -462,6 +463,7 @@ static int __init append_e820_table(struct boot_e820_entry *entries, u32 nr_entr
 struct e820_update_params {
 	enum e820_type old_type;
 	enum e820_type new_type;
+	int check_type;
 };
 
 static u64 __init
@@ -469,6 +471,7 @@ __e820__range_update(struct e820_table *table, u64 start, u64 size, struct e820_
 {
 	enum e820_type old_type = params->old_type;
 	enum e820_type new_type = params->new_type;
+	int check_type = params->check_type;
 
 	u64 end;
 	unsigned int i;
@@ -481,6 +484,7 @@ __e820__range_update(struct e820_table *table, u64 start, u64 size, struct e820_
 
 	end = start + size;
 	printk(KERN_DEBUG "e820: update [mem %#010Lx-%#010Lx] ", start, end - 1);
+
 	e820_print_type(old_type);
 	pr_cont(" ==> ");
 	e820_print_type(new_type);
@@ -491,7 +495,7 @@ __e820__range_update(struct e820_table *table, u64 start, u64 size, struct e820_
 		u64 final_start, final_end;
 		u64 entry_end;
 
-		if (entry->type != old_type)
+		if (check_type && entry->type != old_type)
 			continue;
 
 		entry_end = entry->addr + entry->size;
@@ -500,12 +504,15 @@ __e820__range_update(struct e820_table *table, u64 start, u64 size, struct e820_
 		if (entry->addr >= start && entry_end <= end) {
 			entry->type = new_type;
 			real_updated_size += entry->size;
+			if (new_type == E820_TYPE_NONE)
+				memset(entry, 0, sizeof(*entry));
 			continue;
 		}
 
 		/* New range is completely covered? */
 		if (entry->addr < start && entry_end > end) {
-			__e820__range_add(table, start, size, new_type);
+			if (new_type != E820_TYPE_NONE)
+				__e820__range_add(table, start, size, new_type);
 			__e820__range_add(table, end, entry_end - end, entry->type);
 			entry->size = start - entry->addr;
 			real_updated_size += size;
@@ -558,63 +565,13 @@ static u64 __init e820__range_update_kexec(u64 start, u64 size, enum e820_type o
 /* Remove a range of memory from the E820 table: */
 u64 __init e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type)
 {
-	int i;
-	u64 end;
-	u64 real_removed_size = 0;
-
-	if (size > (ULLONG_MAX - start))
-		size = ULLONG_MAX - start;
-
-	end = start + size;
-	printk(KERN_DEBUG "e820: remove [mem %#010Lx-%#010Lx] ", start, end - 1);
-	if (check_type)
-		e820_print_type(old_type);
-	pr_cont("\n");
-
-	for (i = 0; i < e820_table->nr_entries; i++) {
-		struct e820_entry *entry = &e820_table->entries[i];
-		u64 final_start, final_end;
-		u64 entry_end;
-
-		if (check_type && entry->type != old_type)
-			continue;
-
-		entry_end = entry->addr + entry->size;
-
-		/* Completely covered? */
-		if (entry->addr >= start && entry_end <= end) {
-			real_removed_size += entry->size;
-			memset(entry, 0, sizeof(*entry));
-			continue;
-		}
-
-		/* Is the new range completely covered? */
-		if (entry->addr < start && entry_end > end) {
-			e820__range_add(end, entry_end - end, entry->type);
-			entry->size = start - entry->addr;
-			real_removed_size += size;
-			continue;
-		}
-
-		/* Partially covered: */
-		final_start = max(start, entry->addr);
-		final_end = min(end, entry_end);
-		if (final_start >= final_end)
-			continue;
-
-		real_removed_size += final_end - final_start;
-
-		/*
-		 * Left range could be head or tail, so need to update
-		 * the size first:
-		 */
-		entry->size -= final_end - final_start;
-		if (entry->addr < final_start)
-			continue;
+	struct e820_update_params params = {
+		.old_type = old_type,
+		.new_type = E820_TYPE_NONE,
+		.check_type = check_type,
+	};
 
-		entry->addr = final_end;
-	}
-	return real_removed_size;
+	return __e820__range_update(e820_table, start, size, &params);
 }
 
 void __init e820__update_table_print(void)