arm64: Request resources for reserved memory via memmap

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4NYPZ
CVE: NA

-------------------------------------------------

A new flag MEMBLOCK_MEMMAP is added into memblock_flags, which is
used to identify reserved memory for memmap. This flag is limited
for arm64. When memmap memory is reserved by memblock_reserve, it
is subsequently marked with flag MEMBLOCK_MEMMAP. Therefore,
for_each_mem_region can find memmap memory and request resources
for it.
Signed-off-by: NPeng Liu <liupeng256@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

arch/arm64/kernel/setup.c

@@ -215,6 +215,22 @@ static void __init setup_machine_fdt(phys_addr_t dt_phys)
 	dump_stack_set_arch_desc("%s (DT)", name);
 }
 
+static void __init request_memmap_resources(struct resource *res)
+{
+	struct resource *memmap_res;
+
+	memmap_res = memblock_alloc(sizeof(*memmap_res), SMP_CACHE_BYTES);
+	if (!memmap_res)
+		panic("%s: Failed to allocate memmap_res\n", __func__);
+
+	memmap_res->name = "memmap reserved";
+	memmap_res->flags = IORESOURCE_MEM;
+	memmap_res->start = res->start;
+	memmap_res->end = res->end;
+
+	request_resource(res, memmap_res);
+}
+
 static void __init request_standard_resources(void)
 {
 	struct memblock_region *region;
@@ -253,6 +269,9 @@ static void __init request_standard_resources(void)
 		if (kernel_data.start >= res->start &&
 		    kernel_data.end <= res->end)
 			request_resource(res, &kernel_data);
+		if (memblock_is_memmap(region))
+			request_memmap_resources(res);
+
 #ifdef CONFIG_KEXEC_CORE
 		/*
 		 * Userspace will find "Crash kernel" or "Crash kernel (low)"

arch/arm64/mm/init.c

@@ -441,6 +441,7 @@ static int __init parse_memmap_one(char *p)
 	} else if (*p == '$') {
 		start_at = memparse(p + 1, &p);
 		memblock_reserve(start_at, mem_size);
+		memblock_mark_memmap(start_at, mem_size);
 	} else
 		pr_info("Unrecognized memmap option, please check the parameter.\n");
 

include/linux/memblock.h

@@ -37,6 +37,7 @@ enum memblock_flags {
 	MEMBLOCK_HOTPLUG	= 0x1,	/* hotpluggable region */
 	MEMBLOCK_MIRROR		= 0x2,	/* mirrored region */
 	MEMBLOCK_NOMAP		= 0x4,	/* don't add to kernel direct mapping */
+	MEMBLOCK_MEMMAP		= 0x8,	/* memmap reserved region */
 };
 
 /**
@@ -116,6 +117,7 @@ int memblock_clear_hotplug(phys_addr_t base, phys_addr_t size);
 int memblock_mark_mirror(phys_addr_t base, phys_addr_t size);
 int memblock_mark_nomap(phys_addr_t base, phys_addr_t size);
 int memblock_clear_nomap(phys_addr_t base, phys_addr_t size);
+int memblock_mark_memmap(phys_addr_t base, phys_addr_t size);
 
 unsigned long memblock_free_all(void);
 void reset_node_managed_pages(pg_data_t *pgdat);
@@ -248,6 +250,11 @@ static inline bool memblock_is_nomap(struct memblock_region *m)
 	return m->flags & MEMBLOCK_NOMAP;
 }
 
+static inline bool memblock_is_memmap(struct memblock_region *m)
+{
+	return m->flags & MEMBLOCK_MEMMAP;
+}
+
 int memblock_search_pfn_nid(unsigned long pfn, unsigned long *start_pfn,
 			    unsigned long  *end_pfn);
 void __next_mem_pfn_range(int *idx, int nid, unsigned long *out_start_pfn,

mm/memblock.c

@@ -925,6 +925,18 @@ int __init_memblock memblock_clear_nomap(phys_addr_t base, phys_addr_t size)
 	return memblock_setclr_flag(base, size, 0, MEMBLOCK_NOMAP);
 }
 
+/**
+ * memblock_mark_memmap - Mark a memory region with flag MEMBLOCK_MEMMAP.
+ * @base: the base phys addr of the region
+ * @size: the size of the region
+ *
+ * Return: 0 on success, -errno on failure.
+ */
+int __init_memblock memblock_mark_memmap(phys_addr_t base, phys_addr_t size)
+{
+	return memblock_setclr_flag(base, size, 1, MEMBLOCK_MEMMAP);
+}
+
 static bool should_skip_region(struct memblock_type *type,
 			       struct memblock_region *m,
 			       int nid, int flags)