arm64: Reserve memory for quick kexec

hulk inclusion
category: feature
bugzilla: 48159
CVE: N/A

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

Reserve memory for quick kexec on arm64
with cmdline "quickkexec=".
Signed-off-by: NSang Yan <sangyan@huawei.com>
Reviewed-by: NJing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

arch/arm64/kernel/setup.c

@@ -253,6 +253,12 @@ static void __init request_standard_resources(void)
 		if (crashk_res.end && crashk_res.start >= res->start &&
 		    crashk_res.end <= res->end)
 			request_resource(res, &crashk_res);
+#endif
+#ifdef CONFIG_QUICK_KEXEC
+		if (quick_kexec_res.end &&
+		    quick_kexec_res.start >= res->start &&
+		    quick_kexec_res.end <= res->end)
+			request_resource(res, &quick_kexec_res);
 #endif
 	}
 }

arch/arm64/mm/init.c

@@ -129,6 +129,45 @@ static void __init reserve_elfcorehdr(void)
 }
 #endif /* CONFIG_CRASH_DUMP */
 
+#ifdef CONFIG_QUICK_KEXEC
+static int __init parse_quick_kexec(char *p)
+{
+	if (!p)
+		return 0;
+
+	quick_kexec_res.end = PAGE_ALIGN(memparse(p, NULL));
+
+	return 0;
+}
+early_param("quickkexec", parse_quick_kexec);
+
+static void __init reserve_quick_kexec(void)
+{
+	unsigned long long mem_start, mem_len;
+
+	mem_len = quick_kexec_res.end;
+	if (mem_len == 0)
+		return;
+
+	/* Current arm64 boot protocol requires 2MB alignment */
+	mem_start = memblock_find_in_range(0, arm64_dma32_phys_limit,
+			mem_len, SZ_2M);
+	if (mem_start == 0) {
+		pr_warn("cannot allocate quick kexec mem (size:0x%llx)\n",
+			mem_len);
+		quick_kexec_res.end = 0;
+		return;
+	}
+
+	memblock_reserve(mem_start, mem_len);
+	pr_info("quick kexec mem reserved: 0x%016llx - 0x%016llx (%lld MB)\n",
+		mem_start, mem_start + mem_len,	mem_len >> 20);
+
+	quick_kexec_res.start = mem_start;
+	quick_kexec_res.end = mem_start + mem_len - 1;
+}
+#endif
+
 /*
  * Return the maximum physical address for a zone with a given address size
  * limit. It currently assumes that for memory starting above 4G, 32-bit
@@ -357,6 +396,10 @@ void __init arm64_memblock_init(void)
 
 	reserve_crashkernel();
 
+#ifdef CONFIG_QUICK_KEXEC
+	reserve_quick_kexec();
+#endif
+
 	reserve_elfcorehdr();
 
 	high_memory = __va(memblock_end_of_DRAM() - 1) + 1;