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

From: Calvin Zhang <hidden>
Date: 2021-11-19 08:02:21
Also in: linux-mips, linux-riscv, linux-sh, linuxppc-dev, lkml
Subsystem: arm port, arm64 port (aarch64 architecture), c-sky architecture, linux for powerpc (32-bit and 64-bit), mips, nios2 architecture, open firmware and flattened device tree, openrisc architecture, risc-v architecture, superh, synopsys arc architecture, tensilica xtensa port (xtensa), the rest · Maintainers: Russell King, Catalin Marinas, Will Deacon, Guo Ren, Madhavan Srinivasan, Michael Ellerman, Thomas Bogendoerfer, Dinh Nguyen, Rob Herring, Saravana Kannan, Jonas Bonn, Stefan Kristiansson, Stafford Horne, Paul Walmsley, Palmer Dabbelt, Albert Ou, Yoshinori Sato, Rich Felker, John Paul Adrian Glaubitz, Vineet Gupta, Chris Zankel, Max Filippov, Linus Torvalds

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 <redacted>
---
 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

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