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RISC-V: Add kernel image sections to the resource tree

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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: Nick Kossifidis <mick@ics.forth.gr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
This commit is contained in:
Nick Kossifidis 2020-10-12 17:24:10 +03:00 committed by Palmer Dabbelt
parent 3650b228f8
commit 00ab027a3b
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GPG Key ID: 2E1319F35FBB1889
2 changed files with 160 additions and 27 deletions
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160
arch/riscv/kernel/setup.c
View File

@ -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

27
arch/riscv/mm/init.c
View File

@ -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