[PATCH v3 1/2] mm: memblock Add some new functions to address the mem limit issue

Signed-off-by: Dennis Chen <redacted>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Steve Capper <redacted>
Cc: Ard Biesheuvel <redacted>
Cc: Will Deacon <redacted>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Rafael J. Wysocki <redacted>
Cc: Matt Fleming <redacted>
Cc: linux-mm at kvack.org
Cc: linux-acpi at vger.kernel.org
Cc: linux-efi at vger.kernel.org
---
 include/linux/memblock.h |  1 +
 mm/memblock.c            | 55 +++++++++++++++++++++++++++++++++++++++++-------
 2 files changed, 48 insertions(+), 8 deletions(-)

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 6c14b61..2925da2 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h

@@ -332,6 +332,7 @@ phys_addr_t memblock_mem_size(unsigned long limit_pfn);
 phys_addr_t memblock_start_of_DRAM(void);
 phys_addr_t memblock_end_of_DRAM(void);
 void memblock_enforce_memory_limit(phys_addr_t memory_limit);
+void memblock_mem_limit_remove_map(phys_addr_t limit);
 bool memblock_is_memory(phys_addr_t addr);
 int memblock_is_map_memory(phys_addr_t addr);
 int memblock_is_region_memory(phys_addr_t base, phys_addr_t size);

diff --git a/mm/memblock.c b/mm/memblock.c
index ca09915..8099f1a 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c

@@ -1465,14 +1465,11 @@ phys_addr_t __init_memblock memblock_end_of_DRAM(void)
 	return (memblock.memory.regions[idx].base + memblock.memory.regions[idx].size);
 }
 
-void __init memblock_enforce_memory_limit(phys_addr_t limit)
+static phys_addr_t __init_memblock __find_max_addr(phys_addr_t limit)
 {
 	phys_addr_t max_addr = (phys_addr_t)ULLONG_MAX;
 	struct memblock_region *r;
 
-	if (!limit)
-		return;
-
 	/* find out max address */
 	for_each_memblock(memory, r) {
 		if (limit <= r->size) {

@@ -1482,6 +1479,20 @@ void __init memblock_enforce_memory_limit(phys_addr_t limit)
 		limit -= r->size;
 	}
 
+	return max_addr;
+}
+
+void __init memblock_enforce_memory_limit(phys_addr_t limit)
+{
+	phys_addr_t max_addr;
+
+	if (!limit)
+		return;
+
+	max_addr = __find_max_addr(limit);
+	if (max_addr == (phys_addr_t)ULLONG_MAX)
+		return;

+
 	/* truncate both memory and reserved regions */
 	memblock_remove_range(&memblock.memory, max_addr,
 			      (phys_addr_t)ULLONG_MAX);

@@ -1489,6 +1500,32 @@ void __init memblock_enforce_memory_limit(phys_addr_t limit)
 			      (phys_addr_t)ULLONG_MAX);
 }
 
+void __init memblock_mem_limit_remove_map(phys_addr_t limit)
+{
+	struct memblock_type *type = &memblock.memory;
+	phys_addr_t max_addr;
+	int i, ret, start_rgn, end_rgn;
+
+	if (!limit)
+		return;
+
+	max_addr = __find_max_addr(limit);
+	if (max_addr == (phys_addr_t)ULLONG_MAX)
+		return;

+
 static int __init_memblock memblock_search(struct memblock_type *type, phys_addr_t addr)
 {
 	unsigned int left = 0, right = type->cnt;

@@ -1677,13 +1714,15 @@ static int memblock_debug_show(struct seq_file *m, void *private)
 		reg = &type->regions[i];
 		seq_printf(m, "%4d: ", i);
 		if (sizeof(phys_addr_t) == 4)
-			seq_printf(m, "0x%08lx..0x%08lx\n",
+			seq_printf(m, "0x%08lx..0x%08lx  0x%08lx  0x%lx\n",
 				   (unsigned long)reg->base,
-				   (unsigned long)(reg->base + reg->size - 1));
+				   (unsigned long)(reg->base + reg->size - 1),
+				   (unsigned long)reg->size, reg->flags);
 		else
-			seq_printf(m, "0x%016llx..0x%016llx\n",
+			seq_printf(m, "0x%016llx..0x%016llx  0x%016llx  0x%lx\n",
 				   (unsigned long long)reg->base,
-				   (unsigned long long)(reg->base + reg->size - 1));
+				   (unsigned long long)(reg->base + reg->size - 1),
+				   (unsigned long long)reg->size, reg->flags);