From 00ab027a3b82dbad0a698fef1e359ebcab4c205b Mon Sep 17 00:00:00 2001 From: Nick Kossifidis Date: Mon, 12 Oct 2020 17:24:10 +0300 Subject: 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: Nick Kossifidis Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/setup.c | 160 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 160 insertions(+) (limited to 'arch/riscv/kernel/setup.c') diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c index c424cc6dd833..515b5a662706 100644 --- a/arch/riscv/kernel/setup.c +++ b/arch/riscv/kernel/setup.c @@ -4,6 +4,8 @@ * Chen Liqin * Lennox Wu * Copyright (C) 2012 Regents of the University of California + * Copyright (C) 2020 FORTH-ICS/CARV + * Nick Kossifidis */ #include @@ -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 -- cgit