[PATCH 2/2] of: reserved_mem: Remove reserved regions count restriction

[Calvin Zhang <calvinzhang.cool@gmail.com>]

Change to allocate reserved_mems dynamically. Static reserved regions
must be reserved before any memblock allocations. The reserved_mems
array couldn't be allocated until memblock and linear mapping are ready.

So move the allocation and initialization of records and reserved memory
from early_init_fdt_scan_reserved_mem() to of_reserved_mem_init().

Signed-off-by: Calvin Zhang <calvinzhang.cool@gmail.com>
---
 arch/arc/mm/init.c                 |  3 ++
 arch/arm/kernel/setup.c            |  2 +
 arch/arm64/kernel/setup.c          |  3 ++
 arch/csky/kernel/setup.c           |  3 ++
 arch/h8300/kernel/setup.c          |  2 +
 arch/mips/kernel/setup.c           |  3 ++
 arch/nds32/kernel/setup.c          |  3 ++
 arch/nios2/kernel/setup.c          |  2 +
 arch/openrisc/kernel/setup.c       |  3 ++
 arch/powerpc/kernel/setup-common.c |  3 ++
 arch/riscv/kernel/setup.c          |  2 +
 arch/sh/kernel/setup.c             |  3 ++
 arch/xtensa/kernel/setup.c         |  2 +
 drivers/of/fdt.c                   |  1 -
 drivers/of/of_reserved_mem.c       | 66 ++++++++++++++++++++----------
 15 files changed, 79 insertions(+), 22 deletions(-)

diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
index ce4e939a7f07..a75f0e693f37 100644
--- a/arch/arc/mm/init.c
+++ b/arch/arc/mm/init.c
@@ -10,6 +10,7 @@
 #include <linux/initrd.h>
 #endif
 #include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/swap.h>
 #include <linux/module.h>
 #include <linux/highmem.h>
@@ -165,6 +166,8 @@ void __init setup_arch_memory(void)
 
 #endif /* CONFIG_HIGHMEM */
 
+	of_reserved_mem_init();
+
 	free_area_init(max_zone_pfn);
 }
 
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 284a80c0b6e1..e76737effbf4 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -20,6 +20,7 @@
 #include <linux/kexec.h>
 #include <linux/libfdt.h>
 #include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/cpu.h>
 #include <linux/interrupt.h>
 #include <linux/smp.h>
@@ -1153,6 +1154,7 @@ void __init setup_arch(char **cmdline_p)
 	early_ioremap_reset();
 
 	paging_init(mdesc);
+	of_reserved_mem_init();
 	kasan_init();
 	request_standard_resources(mdesc);
 
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index be5f85b0a24d..4624e5193d6e 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -27,6 +27,7 @@
 #include <linux/proc_fs.h>
 #include <linux/memblock.h>
 #include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/efi.h>
 #include <linux/psci.h>
 #include <linux/sched/task.h>
@@ -339,6 +340,8 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p)
 
 	paging_init();
 
+	of_reserved_mem_init();
+
 	acpi_table_upgrade();
 
 	/* Parse the ACPI tables for possible boot-time configuration */
diff --git a/arch/csky/kernel/setup.c b/arch/csky/kernel/setup.c
index c64e7be2045b..40878906644d 100644
--- a/arch/csky/kernel/setup.c
+++ b/arch/csky/kernel/setup.c
@@ -6,6 +6,7 @@
 #include <linux/initrd.h>
 #include <linux/of.h>
 #include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/start_kernel.h>
 #include <linux/dma-map-ops.h>
 #include <linux/screen_info.h>
@@ -64,6 +65,8 @@ static void __init csky_memblock_init(void)
 #endif
 	memblock_set_current_limit(PFN_PHYS(max_low_pfn));
 
+	of_reserved_mem_init();
+
 	dma_contiguous_reserve(0);
 
 	free_area_init(max_zone_pfn);
diff --git a/arch/h8300/kernel/setup.c b/arch/h8300/kernel/setup.c
index 61091a76eb7e..0f0ec72a260e 100644
--- a/arch/h8300/kernel/setup.c
+++ b/arch/h8300/kernel/setup.c
@@ -24,6 +24,7 @@
 #include <linux/of.h>
 #include <linux/of_fdt.h>
 #include <linux/of_address.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/clk-provider.h>
 #include <linux/memblock.h>
 #include <linux/screen_info.h>
@@ -87,6 +88,7 @@ static void __init bootmem_init(void)
 
 	early_init_fdt_reserve_self();
 	early_init_fdt_scan_reserved_mem();
+	of_reserved_mem_init();
 
 	memblock_dump_all();
 }
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index f979adfd4fc2..053a10d80cb9 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -27,6 +27,7 @@
 #include <linux/dma-map-ops.h>
 #include <linux/decompress/generic.h>
 #include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/dmi.h>
 #include <linux/crash_dump.h>
 
@@ -776,6 +777,8 @@ void __init setup_arch(char **cmdline_p)
 	cpu_cache_init();
 	paging_init();
 
+	of_reserved_mem_init();
+
 	memblock_dump_all();
 }
 
diff --git a/arch/nds32/kernel/setup.c b/arch/nds32/kernel/setup.c
index b3d34d646652..1054804526c5 100644
--- a/arch/nds32/kernel/setup.c
+++ b/arch/nds32/kernel/setup.c
@@ -10,6 +10,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/of_fdt.h>
 #include <linux/of_platform.h>
+#include <linux/of_reserved_mem.h>
 #include <asm/setup.h>
 #include <asm/sections.h>
 #include <asm/proc-fns.h>
@@ -301,6 +302,8 @@ void __init setup_arch(char **cmdline_p)
 	/* paging_init() sets up the MMU and marks all pages as reserved */
 	paging_init();
 
+	of_reserved_mem_init();
+
 	/* invalidate all TLB entries because the new mapping is created */
 	__nds32__tlbop_flua();
 
diff --git a/arch/nios2/kernel/setup.c b/arch/nios2/kernel/setup.c
index 40bc8fb75e0b..7e40e90bc3cd 100644
--- a/arch/nios2/kernel/setup.c
+++ b/arch/nios2/kernel/setup.c
@@ -19,6 +19,7 @@
 #include <linux/memblock.h>
 #include <linux/initrd.h>
 #include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/screen_info.h>
 
 #include <asm/mmu_context.h>
@@ -173,6 +174,7 @@ void __init setup_arch(char **cmdline_p)
 
 	early_init_fdt_reserve_self();
 	early_init_fdt_scan_reserved_mem();
+	of_reserved_mem_init();
 
 	unflatten_and_copy_device_tree();
 
diff --git a/arch/openrisc/kernel/setup.c b/arch/openrisc/kernel/setup.c
index 0cd04d936a7a..6830bd110ac4 100644
--- a/arch/openrisc/kernel/setup.c
+++ b/arch/openrisc/kernel/setup.c
@@ -32,6 +32,7 @@
 #include <linux/initrd.h>
 #include <linux/of_fdt.h>
 #include <linux/of.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/device.h>
 
 #include <asm/sections.h>
@@ -299,6 +300,8 @@ void __init setup_arch(char **cmdline_p)
 	/* paging_init() sets up the MMU and marks all pages as reserved */
 	paging_init();
 
+	of_reserved_mem_init();
+
 	*cmdline_p = boot_command_line;
 
 	printk(KERN_INFO "OpenRISC Linux -- http://openrisc.io\n");
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 4f1322b65760..1902b4472991 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -31,6 +31,7 @@
 #include <linux/percpu.h>
 #include <linux/memblock.h>
 #include <linux/of_platform.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/hugetlb.h>
 #include <linux/pgtable.h>
 #include <asm/io.h>
@@ -840,6 +841,8 @@ void __init setup_arch(char **cmdline_p)
 	/* Set a half-reasonable default so udelay does something sensible */
 	loops_per_jiffy = 500000000 / HZ;
 
+	of_reserved_mem_init();
+
 	/* Unflatten the device-tree passed by prom_init or kexec */
 	unflatten_device_tree();
 
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index b42bfdc67482..e3a211cdf5e1 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -16,6 +16,7 @@
 #include <linux/screen_info.h>
 #include <linux/of_fdt.h>
 #include <linux/of_platform.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/sched/task.h>
 #include <linux/smp.h>
 #include <linux/efi.h>
@@ -273,6 +274,7 @@ void __init setup_arch(char **cmdline_p)
 
 	efi_init();
 	paging_init();
+	of_reserved_mem_init();
 #if IS_ENABLED(CONFIG_BUILTIN_DTB)
 	unflatten_and_copy_device_tree();
 #else
diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c
index 1fcb6659822a..51e85a17c202 100644
--- a/arch/sh/kernel/setup.c
+++ b/arch/sh/kernel/setup.c
@@ -31,6 +31,7 @@
 #include <linux/memblock.h>
 #include <linux/of.h>
 #include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/uaccess.h>
 #include <uapi/linux/mount.h>
 #include <asm/io.h>
@@ -326,6 +327,8 @@ void __init setup_arch(char **cmdline_p)
 	/* Let earlyprintk output early console messages */
 	sh_early_platform_driver_probe("earlyprintk", 1, 1);
 
+	of_reserved_mem_init();
+
 #ifdef CONFIG_OF_FLATTREE
 #ifdef CONFIG_USE_BUILTIN_DTB
 	unflatten_and_copy_device_tree();
diff --git a/arch/xtensa/kernel/setup.c b/arch/xtensa/kernel/setup.c
index 8db20cfb44ab..527d425490fd 100644
--- a/arch/xtensa/kernel/setup.c
+++ b/arch/xtensa/kernel/setup.c
@@ -25,6 +25,7 @@
 #include <linux/cpu.h>
 #include <linux/of.h>
 #include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
 
 #if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE)
 # include <linux/console.h>
@@ -356,6 +357,7 @@ void __init setup_arch(char **cmdline_p)
 	parse_early_param();
 	bootmem_init();
 	kasan_init();
+	of_reserved_mem_init();
 	unflatten_and_copy_device_tree();
 
 #ifdef CONFIG_SMP
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 445af4e69300..715ce8ec6ac6 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -540,7 +540,6 @@ void __init early_init_fdt_scan_reserved_mem(void)
 	}
 
 	fdt_scan_reserved_mem();
-	of_reserved_mem_init();
 	fdt_reserve_elfcorehdr();
 }
 
diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 784cfc5cd251..6dc22a1ad472 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -26,9 +26,8 @@
 
 #include "of_private.h"
 
-#define MAX_RESERVED_REGIONS	64
-static struct reserved_mem reserved_mems[MAX_RESERVED_REGIONS];
-static int reserved_mem_count;
+static struct reserved_mem *reserved_mems;
+static int reserved_mem_count, reserved_mem_max_count;
 
 static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
 	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
@@ -62,7 +61,7 @@ static void __init fdt_reserved_mem_save_node(unsigned long node, const char *un
 {
 	struct reserved_mem *rmem = &reserved_mems[reserved_mem_count];
 
-	if (reserved_mem_count == ARRAY_SIZE(reserved_mems)) {
+	if (reserved_mem_count == reserved_mem_max_count) {
 		pr_err("not enough space for all defined regions.\n");
 		return;
 	}
@@ -200,13 +199,12 @@ static int __init __reserved_mem_check_root(unsigned long node)
  * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property
  */
 static int __init __reserved_mem_reserve_reg(unsigned long node,
-					     const char *uname)
+					     const char *uname, bool reserve_only)
 {
 	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
 	phys_addr_t base, size;
 	int len;
 	const __be32 *prop;
-	int first = 1;
 	bool nomap;
 
 	prop = of_get_flat_dt_prop(node, "reg", &len);
@@ -225,30 +223,35 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
 		base = dt_mem_next_cell(dt_root_addr_cells, &prop);
 		size = dt_mem_next_cell(dt_root_size_cells, &prop);
 
-		if (size &&
-		    early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
-			pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n",
-				uname, &base, (unsigned long)(size / SZ_1M));
-		else
-			pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n",
-				uname, &base, (unsigned long)(size / SZ_1M));
-
-		len -= t_len;
-		if (first) {
+		if (reserve_only) {
+			if (size &&
+				early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
+				pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n",
+					uname, &base, (unsigned long)(size / SZ_1M));
+			else
+				pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n",
+					uname, &base, (unsigned long)(size / SZ_1M));
+		} else {
 			fdt_reserved_mem_save_node(node, uname, base, size);
-			first = 0;
+			break;
 		}
+		len -= t_len;
 	}
 	return 0;
 }
 
 /*
- * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
+ * fdt_scan_reserved_mem() - scan /reserved-memory node
+ *
+ * Get the max count of regions in the first pass. Early allocator is
+ * not fully available yet. Store information of reserved region to
+ * reserved_mems array in the second pass.
  */
 int __init fdt_scan_reserved_mem(void)
 {
-	int node, child;
+	int node, child, regions = 0;
 	const void *fdt = initial_boot_params;
+	static bool first = true;
 
 	node = fdt_path_offset(fdt, "/reserved-memory");
 	if (node < 0)
@@ -266,12 +269,19 @@ int __init fdt_scan_reserved_mem(void)
 		if (!of_fdt_device_is_available(fdt, child))
 			continue;
 
+		regions++;
 		uname = fdt_get_name(fdt, child, NULL);
 
-		err = __reserved_mem_reserve_reg(child, uname);
-		if (err == -ENOENT && of_get_flat_dt_prop(child, "size", NULL))
+		err = __reserved_mem_reserve_reg(child, uname, first);
+		if (err == -ENOENT && of_get_flat_dt_prop(child, "size", NULL) && !first)
 			fdt_reserved_mem_save_node(child, uname, 0, 0);
 	}
+
+	if (first) {
+		reserved_mem_max_count = regions;
+		first = false;
+	}
+
 	return 0;
 }
 
@@ -358,6 +368,20 @@ void __init of_reserved_mem_init(void)
 {
 	int i;
 
+	if (!reserved_mem_max_count)
+		return;
+
+	reserved_mems = memblock_alloc(
+			sizeof(struct reserved_mem) * reserved_mem_max_count,
+			SMP_CACHE_BYTES);
+	if (!reserved_mems) {
+		reserved_mem_max_count = 0;
+		pr_err("failed to allocate reserved_mems array.\n");
+		return;
+	}
+
+	fdt_scan_reserved_mem();
+
 	/* check for overlapping reserved regions */
 	__rmem_check_for_overlap();
 
-- 
2.30.2