Unverified Commit 00ab027a authored by Nick Kossifidis's avatar Nick Kossifidis Committed by Palmer Dabbelt
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RISC-V: Add kernel image sections to the resource tree 



This patch (previously part of my kexec/kdump series) populates
/proc/iomem with the various sections of the kernel image. We need
this for kexec-tools to be able to prepare the crashkernel image
for kdump to work. Since resource tree initialization is not
related to memory initialization I added the code to kernel/setup.c
and removed the original code (derived from the arm64 tree) from
mm/init.c.

Signed-off-by: default avatarNick Kossifidis <mick@ics.forth.gr>
Signed-off-by: default avatarPalmer Dabbelt <palmerdabbelt@google.com>
parent 3650b228

arch/riscv/kernel/setup.c

+160 −0
Original line number Diff line number Diff line
@@ -4,6 +4,8 @@ 
 *  Chen Liqin <liqin.chen@sunplusct.com>

 *  Lennox Wu <lennox.wu@sunplusct.com>

 * Copyright (C) 2012 Regents of the University of California

 * Copyright (C) 2020 FORTH-ICS/CARV

 *  Nick Kossifidis <mick@ics.forth.gr>

 */



#include <linux/init.h>
@@ -51,6 +53,163 @@ atomic_t hart_lottery __section(".sdata"); 
unsigned long boot_cpu_hartid;

static DEFINE_PER_CPU(struct cpu, cpu_devices);



/*

 * Place kernel memory regions on the resource tree so that

 * kexec-tools can retrieve them from /proc/iomem. While there

 * also add "System RAM" regions for compatibility with other

 * archs, and the rest of the known regions for completeness.

 */

static struct resource code_res = { .name = "Kernel code", };

static struct resource data_res = { .name = "Kernel data", };

static struct resource rodata_res = { .name = "Kernel rodata", };

static struct resource bss_res = { .name = "Kernel bss", };



static int __init add_resource(struct resource *parent,

				struct resource *res)

{

	int ret = 0;



	ret = insert_resource(parent, res);

	if (ret < 0) {

		pr_err("Failed to add a %s resource at %llx\n",

			res->name, (unsigned long long) res->start);

		return ret;

	}



	return 1;

}



static int __init add_kernel_resources(struct resource *res)

{

	int ret = 0;



	/*

	 * The memory region of the kernel image is continuous and

	 * was reserved on setup_bootmem, find it here and register

	 * it as a resource, then register the various segments of

	 * the image as child nodes

	 */

	if (!(res->start <= code_res.start && res->end >= data_res.end))

		return 0;



	res->name = "Kernel image";

	res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;



	/*

	 * We removed a part of this region on setup_bootmem so

	 * we need to expand the resource for the bss to fit in.

	 */

	res->end = bss_res.end;



	ret = add_resource(&iomem_resource, res);

	if (ret < 0)

		return ret;



	ret = add_resource(res, &code_res);

	if (ret < 0)

		return ret;



	ret = add_resource(res, &rodata_res);

	if (ret < 0)

		return ret;



	ret = add_resource(res, &data_res);

	if (ret < 0)

		return ret;



	ret = add_resource(res, &bss_res);



	return ret;

}



static void __init init_resources(void)

{

	struct memblock_region *region = NULL;

	struct resource *res = NULL;

	int ret = 0;



	code_res.start = __pa_symbol(_text);

	code_res.end = __pa_symbol(_etext) - 1;

	code_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;



	rodata_res.start = __pa_symbol(__start_rodata);

	rodata_res.end = __pa_symbol(__end_rodata) - 1;

	rodata_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;



	data_res.start = __pa_symbol(_data);

	data_res.end = __pa_symbol(_edata) - 1;

	data_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;



	bss_res.start = __pa_symbol(__bss_start);

	bss_res.end = __pa_symbol(__bss_stop) - 1;

	bss_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;



	/*

	 * Start by adding the reserved regions, if they overlap

	 * with /memory regions, insert_resource later on will take

	 * care of it.

	 */

	for_each_reserved_mem_region(region) {

		res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);

		if (!res)

			panic("%s: Failed to allocate %zu bytes\n", __func__,

			      sizeof(struct resource));



		res->name = "Reserved";

		res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;

		res->start = __pfn_to_phys(memblock_region_reserved_base_pfn(region));

		res->end = __pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1;



		ret = add_kernel_resources(res);

		if (ret < 0)

			goto error;

		else if (ret)

			continue;



		/*

		 * Ignore any other reserved regions within

		 * system memory.

		 */

		if (memblock_is_memory(res->start))

			continue;



		ret = add_resource(&iomem_resource, res);

		if (ret < 0)

			goto error;

	}



	/* Add /memory regions to the resource tree */

	for_each_mem_region(region) {

		res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);

		if (!res)

			panic("%s: Failed to allocate %zu bytes\n", __func__,

			      sizeof(struct resource));



		if (unlikely(memblock_is_nomap(region))) {

			res->name = "Reserved";

			res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;

		} else {

			res->name = "System RAM";

			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;

		}



		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));

		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;



		ret = add_resource(&iomem_resource, res);

		if (ret < 0)

			goto error;

	}



	return;



 error:

	memblock_free((phys_addr_t) res, sizeof(struct resource));

	/* Better an empty resource tree than an inconsistent one */

	release_child_resources(&iomem_resource);

}





static void __init parse_dtb(void)

{

	/* Early scan of device tree from init memory */
@@ -80,6 +239,7 @@ void __init setup_arch(char **cmdline_p) 
	efi_init();

	setup_bootmem();

	paging_init();

	init_resources();

#if IS_ENABLED(CONFIG_BUILTIN_DTB)

	unflatten_and_copy_device_tree();

#else

arch/riscv/mm/init.c

+0 −27
Original line number Diff line number Diff line
@@ -625,39 +625,12 @@ void mark_rodata_ro(void) 
}

#endif



static void __init resource_init(void)

{

	struct memblock_region *region;



	for_each_mem_region(region) {

		struct resource *res;



		res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);

		if (!res)

			panic("%s: Failed to allocate %zu bytes\n", __func__,

			      sizeof(struct resource));



		if (memblock_is_nomap(region)) {

			res->name = "reserved";

			res->flags = IORESOURCE_MEM;

		} else {

			res->name = "System RAM";

			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;

		}

		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));

		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;



		request_resource(&iomem_resource, res);

	}

}



void __init paging_init(void)

{

	setup_vm_final();

	sparse_init();

	setup_zero_page();

	zone_sizes_init();

	resource_init();

}



#ifdef CONFIG_SPARSEMEM_VMEMMAP

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