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-rw-r--r--arch/powerpc/kernel/fadump.c1742
1 files changed, 1742 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
new file mode 100644
index 0000000000..3ff2da7b12
--- /dev/null
+++ b/arch/powerpc/kernel/fadump.c
@@ -0,0 +1,1742 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Firmware Assisted dump: A robust mechanism to get reliable kernel crash
+ * dump with assistance from firmware. This approach does not use kexec,
+ * instead firmware assists in booting the kdump kernel while preserving
+ * memory contents. The most of the code implementation has been adapted
+ * from phyp assisted dump implementation written by Linas Vepstas and
+ * Manish Ahuja
+ *
+ * Copyright 2011 IBM Corporation
+ * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
+ */
+
+#undef DEBUG
+#define pr_fmt(fmt) "fadump: " fmt
+
+#include <linux/string.h>
+#include <linux/memblock.h>
+#include <linux/delay.h>
+#include <linux/seq_file.h>
+#include <linux/crash_dump.h>
+#include <linux/kobject.h>
+#include <linux/sysfs.h>
+#include <linux/slab.h>
+#include <linux/cma.h>
+#include <linux/hugetlb.h>
+#include <linux/debugfs.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+
+#include <asm/page.h>
+#include <asm/fadump.h>
+#include <asm/fadump-internal.h>
+#include <asm/setup.h>
+#include <asm/interrupt.h>
+
+/*
+ * The CPU who acquired the lock to trigger the fadump crash should
+ * wait for other CPUs to enter.
+ *
+ * The timeout is in milliseconds.
+ */
+#define CRASH_TIMEOUT 500
+
+static struct fw_dump fw_dump;
+
+static void __init fadump_reserve_crash_area(u64 base);
+
+#ifndef CONFIG_PRESERVE_FA_DUMP
+
+static struct kobject *fadump_kobj;
+
+static atomic_t cpus_in_fadump;
+static DEFINE_MUTEX(fadump_mutex);
+
+static struct fadump_mrange_info crash_mrange_info = { "crash", NULL, 0, 0, 0, false };
+
+#define RESERVED_RNGS_SZ 16384 /* 16K - 128 entries */
+#define RESERVED_RNGS_CNT (RESERVED_RNGS_SZ / \
+ sizeof(struct fadump_memory_range))
+static struct fadump_memory_range rngs[RESERVED_RNGS_CNT];
+static struct fadump_mrange_info
+reserved_mrange_info = { "reserved", rngs, RESERVED_RNGS_SZ, 0, RESERVED_RNGS_CNT, true };
+
+static void __init early_init_dt_scan_reserved_ranges(unsigned long node);
+
+#ifdef CONFIG_CMA
+static struct cma *fadump_cma;
+
+/*
+ * fadump_cma_init() - Initialize CMA area from a fadump reserved memory
+ *
+ * This function initializes CMA area from fadump reserved memory.
+ * The total size of fadump reserved memory covers for boot memory size
+ * + cpu data size + hpte size and metadata.
+ * Initialize only the area equivalent to boot memory size for CMA use.
+ * The remaining portion of fadump reserved memory will be not given
+ * to CMA and pages for those will stay reserved. boot memory size is
+ * aligned per CMA requirement to satisy cma_init_reserved_mem() call.
+ * But for some reason even if it fails we still have the memory reservation
+ * with us and we can still continue doing fadump.
+ */
+static int __init fadump_cma_init(void)
+{
+ unsigned long long base, size;
+ int rc;
+
+ if (!fw_dump.fadump_enabled)
+ return 0;
+
+ /*
+ * Do not use CMA if user has provided fadump=nocma kernel parameter.
+ * Return 1 to continue with fadump old behaviour.
+ */
+ if (fw_dump.nocma)
+ return 1;
+
+ base = fw_dump.reserve_dump_area_start;
+ size = fw_dump.boot_memory_size;
+
+ if (!size)
+ return 0;
+
+ rc = cma_init_reserved_mem(base, size, 0, "fadump_cma", &fadump_cma);
+ if (rc) {
+ pr_err("Failed to init cma area for firmware-assisted dump,%d\n", rc);
+ /*
+ * Though the CMA init has failed we still have memory
+ * reservation with us. The reserved memory will be
+ * blocked from production system usage. Hence return 1,
+ * so that we can continue with fadump.
+ */
+ return 1;
+ }
+
+ /*
+ * If CMA activation fails, keep the pages reserved, instead of
+ * exposing them to buddy allocator. Same as 'fadump=nocma' case.
+ */
+ cma_reserve_pages_on_error(fadump_cma);
+
+ /*
+ * So we now have successfully initialized cma area for fadump.
+ */
+ pr_info("Initialized 0x%lx bytes cma area at %ldMB from 0x%lx "
+ "bytes of memory reserved for firmware-assisted dump\n",
+ cma_get_size(fadump_cma),
+ (unsigned long)cma_get_base(fadump_cma) >> 20,
+ fw_dump.reserve_dump_area_size);
+ return 1;
+}
+#else
+static int __init fadump_cma_init(void) { return 1; }
+#endif /* CONFIG_CMA */
+
+/* Scan the Firmware Assisted dump configuration details. */
+int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
+ int depth, void *data)
+{
+ if (depth == 0) {
+ early_init_dt_scan_reserved_ranges(node);
+ return 0;
+ }
+
+ if (depth != 1)
+ return 0;
+
+ if (strcmp(uname, "rtas") == 0) {
+ rtas_fadump_dt_scan(&fw_dump, node);
+ return 1;
+ }
+
+ if (strcmp(uname, "ibm,opal") == 0) {
+ opal_fadump_dt_scan(&fw_dump, node);
+ return 1;
+ }
+
+ return 0;
+}
+
+/*
+ * If fadump is registered, check if the memory provided
+ * falls within boot memory area and reserved memory area.
+ */
+int is_fadump_memory_area(u64 addr, unsigned long size)
+{
+ u64 d_start, d_end;
+
+ if (!fw_dump.dump_registered)
+ return 0;
+
+ if (!size)
+ return 0;
+
+ d_start = fw_dump.reserve_dump_area_start;
+ d_end = d_start + fw_dump.reserve_dump_area_size;
+ if (((addr + size) > d_start) && (addr <= d_end))
+ return 1;
+
+ return (addr <= fw_dump.boot_mem_top);
+}
+
+int should_fadump_crash(void)
+{
+ if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
+ return 0;
+ return 1;
+}
+
+int is_fadump_active(void)
+{
+ return fw_dump.dump_active;
+}
+
+/*
+ * Returns true, if there are no holes in memory area between d_start to d_end,
+ * false otherwise.
+ */
+static bool is_fadump_mem_area_contiguous(u64 d_start, u64 d_end)
+{
+ phys_addr_t reg_start, reg_end;
+ bool ret = false;
+ u64 i, start, end;
+
+ for_each_mem_range(i, &reg_start, &reg_end) {
+ start = max_t(u64, d_start, reg_start);
+ end = min_t(u64, d_end, reg_end);
+ if (d_start < end) {
+ /* Memory hole from d_start to start */
+ if (start > d_start)
+ break;
+
+ if (end == d_end) {
+ ret = true;
+ break;
+ }
+
+ d_start = end + 1;
+ }
+ }
+
+ return ret;
+}
+
+/*
+ * Returns true, if there are no holes in boot memory area,
+ * false otherwise.
+ */
+bool is_fadump_boot_mem_contiguous(void)
+{
+ unsigned long d_start, d_end;
+ bool ret = false;
+ int i;
+
+ for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
+ d_start = fw_dump.boot_mem_addr[i];
+ d_end = d_start + fw_dump.boot_mem_sz[i];
+
+ ret = is_fadump_mem_area_contiguous(d_start, d_end);
+ if (!ret)
+ break;
+ }
+
+ return ret;
+}
+
+/*
+ * Returns true, if there are no holes in reserved memory area,
+ * false otherwise.
+ */
+bool is_fadump_reserved_mem_contiguous(void)
+{
+ u64 d_start, d_end;
+
+ d_start = fw_dump.reserve_dump_area_start;
+ d_end = d_start + fw_dump.reserve_dump_area_size;
+ return is_fadump_mem_area_contiguous(d_start, d_end);
+}
+
+/* Print firmware assisted dump configurations for debugging purpose. */
+static void __init fadump_show_config(void)
+{
+ int i;
+
+ pr_debug("Support for firmware-assisted dump (fadump): %s\n",
+ (fw_dump.fadump_supported ? "present" : "no support"));
+
+ if (!fw_dump.fadump_supported)
+ return;
+
+ pr_debug("Fadump enabled : %s\n",
+ (fw_dump.fadump_enabled ? "yes" : "no"));
+ pr_debug("Dump Active : %s\n",
+ (fw_dump.dump_active ? "yes" : "no"));
+ pr_debug("Dump section sizes:\n");
+ pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
+ pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size);
+ pr_debug(" Boot memory size : %lx\n", fw_dump.boot_memory_size);
+ pr_debug(" Boot memory top : %llx\n", fw_dump.boot_mem_top);
+ pr_debug("Boot memory regions cnt: %llx\n", fw_dump.boot_mem_regs_cnt);
+ for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
+ pr_debug("[%03d] base = %llx, size = %llx\n", i,
+ fw_dump.boot_mem_addr[i], fw_dump.boot_mem_sz[i]);
+ }
+}
+
+/**
+ * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
+ *
+ * Function to find the largest memory size we need to reserve during early
+ * boot process. This will be the size of the memory that is required for a
+ * kernel to boot successfully.
+ *
+ * This function has been taken from phyp-assisted dump feature implementation.
+ *
+ * returns larger of 256MB or 5% rounded down to multiples of 256MB.
+ *
+ * TODO: Come up with better approach to find out more accurate memory size
+ * that is required for a kernel to boot successfully.
+ *
+ */
+static __init u64 fadump_calculate_reserve_size(void)
+{
+ u64 base, size, bootmem_min;
+ int ret;
+
+ if (fw_dump.reserve_bootvar)
+ pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n");
+
+ /*
+ * Check if the size is specified through crashkernel= cmdline
+ * option. If yes, then use that but ignore base as fadump reserves
+ * memory at a predefined offset.
+ */
+ ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
+ &size, &base);
+ if (ret == 0 && size > 0) {
+ unsigned long max_size;
+
+ if (fw_dump.reserve_bootvar)
+ pr_info("Using 'crashkernel=' parameter for memory reservation.\n");
+
+ fw_dump.reserve_bootvar = (unsigned long)size;
+
+ /*
+ * Adjust if the boot memory size specified is above
+ * the upper limit.
+ */
+ max_size = memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO;
+ if (fw_dump.reserve_bootvar > max_size) {
+ fw_dump.reserve_bootvar = max_size;
+ pr_info("Adjusted boot memory size to %luMB\n",
+ (fw_dump.reserve_bootvar >> 20));
+ }
+
+ return fw_dump.reserve_bootvar;
+ } else if (fw_dump.reserve_bootvar) {
+ /*
+ * 'fadump_reserve_mem=' is being used to reserve memory
+ * for firmware-assisted dump.
+ */
+ return fw_dump.reserve_bootvar;
+ }
+
+ /* divide by 20 to get 5% of value */
+ size = memblock_phys_mem_size() / 20;
+
+ /* round it down in multiples of 256 */
+ size = size & ~0x0FFFFFFFUL;
+
+ /* Truncate to memory_limit. We don't want to over reserve the memory.*/
+ if (memory_limit && size > memory_limit)
+ size = memory_limit;
+
+ bootmem_min = fw_dump.ops->fadump_get_bootmem_min();
+ return (size > bootmem_min ? size : bootmem_min);
+}
+
+/*
+ * Calculate the total memory size required to be reserved for
+ * firmware-assisted dump registration.
+ */
+static unsigned long __init get_fadump_area_size(void)
+{
+ unsigned long size = 0;
+
+ size += fw_dump.cpu_state_data_size;
+ size += fw_dump.hpte_region_size;
+ /*
+ * Account for pagesize alignment of boot memory area destination address.
+ * This faciliates in mmap reading of first kernel's memory.
+ */
+ size = PAGE_ALIGN(size);
+ size += fw_dump.boot_memory_size;
+ size += sizeof(struct fadump_crash_info_header);
+ size += sizeof(struct elfhdr); /* ELF core header.*/
+ size += sizeof(struct elf_phdr); /* place holder for cpu notes */
+ /* Program headers for crash memory regions. */
+ size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
+
+ size = PAGE_ALIGN(size);
+
+ /* This is to hold kernel metadata on platforms that support it */
+ size += (fw_dump.ops->fadump_get_metadata_size ?
+ fw_dump.ops->fadump_get_metadata_size() : 0);
+ return size;
+}
+
+static int __init add_boot_mem_region(unsigned long rstart,
+ unsigned long rsize)
+{
+ int i = fw_dump.boot_mem_regs_cnt++;
+
+ if (fw_dump.boot_mem_regs_cnt > FADUMP_MAX_MEM_REGS) {
+ fw_dump.boot_mem_regs_cnt = FADUMP_MAX_MEM_REGS;
+ return 0;
+ }
+
+ pr_debug("Added boot memory range[%d] [%#016lx-%#016lx)\n",
+ i, rstart, (rstart + rsize));
+ fw_dump.boot_mem_addr[i] = rstart;
+ fw_dump.boot_mem_sz[i] = rsize;
+ return 1;
+}
+
+/*
+ * Firmware usually has a hard limit on the data it can copy per region.
+ * Honour that by splitting a memory range into multiple regions.
+ */
+static int __init add_boot_mem_regions(unsigned long mstart,
+ unsigned long msize)
+{
+ unsigned long rstart, rsize, max_size;
+ int ret = 1;
+
+ rstart = mstart;
+ max_size = fw_dump.max_copy_size ? fw_dump.max_copy_size : msize;
+ while (msize) {
+ if (msize > max_size)
+ rsize = max_size;
+ else
+ rsize = msize;
+
+ ret = add_boot_mem_region(rstart, rsize);
+ if (!ret)
+ break;
+
+ msize -= rsize;
+ rstart += rsize;
+ }
+
+ return ret;
+}
+
+static int __init fadump_get_boot_mem_regions(void)
+{
+ unsigned long size, cur_size, hole_size, last_end;
+ unsigned long mem_size = fw_dump.boot_memory_size;
+ phys_addr_t reg_start, reg_end;
+ int ret = 1;
+ u64 i;
+
+ fw_dump.boot_mem_regs_cnt = 0;
+
+ last_end = 0;
+ hole_size = 0;
+ cur_size = 0;
+ for_each_mem_range(i, &reg_start, &reg_end) {
+ size = reg_end - reg_start;
+ hole_size += (reg_start - last_end);
+
+ if ((cur_size + size) >= mem_size) {
+ size = (mem_size - cur_size);
+ ret = add_boot_mem_regions(reg_start, size);
+ break;
+ }
+
+ mem_size -= size;
+ cur_size += size;
+ ret = add_boot_mem_regions(reg_start, size);
+ if (!ret)
+ break;
+
+ last_end = reg_end;
+ }
+ fw_dump.boot_mem_top = PAGE_ALIGN(fw_dump.boot_memory_size + hole_size);
+
+ return ret;
+}
+
+/*
+ * Returns true, if the given range overlaps with reserved memory ranges
+ * starting at idx. Also, updates idx to index of overlapping memory range
+ * with the given memory range.
+ * False, otherwise.
+ */
+static bool __init overlaps_reserved_ranges(u64 base, u64 end, int *idx)
+{
+ bool ret = false;
+ int i;
+
+ for (i = *idx; i < reserved_mrange_info.mem_range_cnt; i++) {
+ u64 rbase = reserved_mrange_info.mem_ranges[i].base;
+ u64 rend = rbase + reserved_mrange_info.mem_ranges[i].size;
+
+ if (end <= rbase)
+ break;
+
+ if ((end > rbase) && (base < rend)) {
+ *idx = i;
+ ret = true;
+ break;
+ }
+ }
+
+ return ret;
+}
+
+/*
+ * Locate a suitable memory area to reserve memory for FADump. While at it,
+ * lookup reserved-ranges & avoid overlap with them, as they are used by F/W.
+ */
+static u64 __init fadump_locate_reserve_mem(u64 base, u64 size)
+{
+ struct fadump_memory_range *mrngs;
+ phys_addr_t mstart, mend;
+ int idx = 0;
+ u64 i, ret = 0;
+
+ mrngs = reserved_mrange_info.mem_ranges;
+ for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
+ &mstart, &mend, NULL) {
+ pr_debug("%llu) mstart: %llx, mend: %llx, base: %llx\n",
+ i, mstart, mend, base);
+
+ if (mstart > base)
+ base = PAGE_ALIGN(mstart);
+
+ while ((mend > base) && ((mend - base) >= size)) {
+ if (!overlaps_reserved_ranges(base, base+size, &idx)) {
+ ret = base;
+ goto out;
+ }
+
+ base = mrngs[idx].base + mrngs[idx].size;
+ base = PAGE_ALIGN(base);
+ }
+ }
+
+out:
+ return ret;
+}
+
+int __init fadump_reserve_mem(void)
+{
+ u64 base, size, mem_boundary, bootmem_min;
+ int ret = 1;
+
+ if (!fw_dump.fadump_enabled)
+ return 0;
+
+ if (!fw_dump.fadump_supported) {
+ pr_info("Firmware-Assisted Dump is not supported on this hardware\n");
+ goto error_out;
+ }
+
+ /*
+ * Initialize boot memory size
+ * If dump is active then we have already calculated the size during
+ * first kernel.
+ */
+ if (!fw_dump.dump_active) {
+ fw_dump.boot_memory_size =
+ PAGE_ALIGN(fadump_calculate_reserve_size());
+#ifdef CONFIG_CMA
+ if (!fw_dump.nocma) {
+ fw_dump.boot_memory_size =
+ ALIGN(fw_dump.boot_memory_size,
+ CMA_MIN_ALIGNMENT_BYTES);
+ }
+#endif
+
+ bootmem_min = fw_dump.ops->fadump_get_bootmem_min();
+ if (fw_dump.boot_memory_size < bootmem_min) {
+ pr_err("Can't enable fadump with boot memory size (0x%lx) less than 0x%llx\n",
+ fw_dump.boot_memory_size, bootmem_min);
+ goto error_out;
+ }
+
+ if (!fadump_get_boot_mem_regions()) {
+ pr_err("Too many holes in boot memory area to enable fadump\n");
+ goto error_out;
+ }
+ }
+
+ /*
+ * Calculate the memory boundary.
+ * If memory_limit is less than actual memory boundary then reserve
+ * the memory for fadump beyond the memory_limit and adjust the
+ * memory_limit accordingly, so that the running kernel can run with
+ * specified memory_limit.
+ */
+ if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
+ size = get_fadump_area_size();
+ if ((memory_limit + size) < memblock_end_of_DRAM())
+ memory_limit += size;
+ else
+ memory_limit = memblock_end_of_DRAM();
+ printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
+ " dump, now %#016llx\n", memory_limit);
+ }
+ if (memory_limit)
+ mem_boundary = memory_limit;
+ else
+ mem_boundary = memblock_end_of_DRAM();
+
+ base = fw_dump.boot_mem_top;
+ size = get_fadump_area_size();
+ fw_dump.reserve_dump_area_size = size;
+ if (fw_dump.dump_active) {
+ pr_info("Firmware-assisted dump is active.\n");
+
+#ifdef CONFIG_HUGETLB_PAGE
+ /*
+ * FADump capture kernel doesn't care much about hugepages.
+ * In fact, handling hugepages in capture kernel is asking for
+ * trouble. So, disable HugeTLB support when fadump is active.
+ */
+ hugetlb_disabled = true;
+#endif
+ /*
+ * If last boot has crashed then reserve all the memory
+ * above boot memory size so that we don't touch it until
+ * dump is written to disk by userspace tool. This memory
+ * can be released for general use by invalidating fadump.
+ */
+ fadump_reserve_crash_area(base);
+
+ pr_debug("fadumphdr_addr = %#016lx\n", fw_dump.fadumphdr_addr);
+ pr_debug("Reserve dump area start address: 0x%lx\n",
+ fw_dump.reserve_dump_area_start);
+ } else {
+ /*
+ * Reserve memory at an offset closer to bottom of the RAM to
+ * minimize the impact of memory hot-remove operation.
+ */
+ base = fadump_locate_reserve_mem(base, size);
+
+ if (!base || (base + size > mem_boundary)) {
+ pr_err("Failed to find memory chunk for reservation!\n");
+ goto error_out;
+ }
+ fw_dump.reserve_dump_area_start = base;
+
+ /*
+ * Calculate the kernel metadata address and register it with
+ * f/w if the platform supports.
+ */
+ if (fw_dump.ops->fadump_setup_metadata &&
+ (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
+ goto error_out;
+
+ if (memblock_reserve(base, size)) {
+ pr_err("Failed to reserve memory!\n");
+ goto error_out;
+ }
+
+ pr_info("Reserved %lldMB of memory at %#016llx (System RAM: %lldMB)\n",
+ (size >> 20), base, (memblock_phys_mem_size() >> 20));
+
+ ret = fadump_cma_init();
+ }
+
+ return ret;
+error_out:
+ fw_dump.fadump_enabled = 0;
+ fw_dump.reserve_dump_area_size = 0;
+ return 0;
+}
+
+/* Look for fadump= cmdline option. */
+static int __init early_fadump_param(char *p)
+{
+ if (!p)
+ return 1;
+
+ if (strncmp(p, "on", 2) == 0)
+ fw_dump.fadump_enabled = 1;
+ else if (strncmp(p, "off", 3) == 0)
+ fw_dump.fadump_enabled = 0;
+ else if (strncmp(p, "nocma", 5) == 0) {
+ fw_dump.fadump_enabled = 1;
+ fw_dump.nocma = 1;
+ }
+
+ return 0;
+}
+early_param("fadump", early_fadump_param);
+
+/*
+ * Look for fadump_reserve_mem= cmdline option
+ * TODO: Remove references to 'fadump_reserve_mem=' parameter,
+ * the sooner 'crashkernel=' parameter is accustomed to.
+ */
+static int __init early_fadump_reserve_mem(char *p)
+{
+ if (p)
+ fw_dump.reserve_bootvar = memparse(p, &p);
+ return 0;
+}
+early_param("fadump_reserve_mem", early_fadump_reserve_mem);
+
+void crash_fadump(struct pt_regs *regs, const char *str)
+{
+ unsigned int msecs;
+ struct fadump_crash_info_header *fdh = NULL;
+ int old_cpu, this_cpu;
+ /* Do not include first CPU */
+ unsigned int ncpus = num_online_cpus() - 1;
+
+ if (!should_fadump_crash())
+ return;
+
+ /*
+ * old_cpu == -1 means this is the first CPU which has come here,
+ * go ahead and trigger fadump.
+ *
+ * old_cpu != -1 means some other CPU has already on it's way
+ * to trigger fadump, just keep looping here.
+ */
+ this_cpu = smp_processor_id();
+ old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu);
+
+ if (old_cpu != -1) {
+ atomic_inc(&cpus_in_fadump);
+
+ /*
+ * We can't loop here indefinitely. Wait as long as fadump
+ * is in force. If we race with fadump un-registration this
+ * loop will break and then we go down to normal panic path
+ * and reboot. If fadump is in force the first crashing
+ * cpu will definitely trigger fadump.
+ */
+ while (fw_dump.dump_registered)
+ cpu_relax();
+ return;
+ }
+
+ fdh = __va(fw_dump.fadumphdr_addr);
+ fdh->crashing_cpu = crashing_cpu;
+ crash_save_vmcoreinfo();
+
+ if (regs)
+ fdh->regs = *regs;
+ else
+ ppc_save_regs(&fdh->regs);
+
+ fdh->cpu_mask = *cpu_online_mask;
+
+ /*
+ * If we came in via system reset, wait a while for the secondary
+ * CPUs to enter.
+ */
+ if (TRAP(&(fdh->regs)) == INTERRUPT_SYSTEM_RESET) {
+ msecs = CRASH_TIMEOUT;
+ while ((atomic_read(&cpus_in_fadump) < ncpus) && (--msecs > 0))
+ mdelay(1);
+ }
+
+ fw_dump.ops->fadump_trigger(fdh, str);
+}
+
+u32 *__init fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
+{
+ struct elf_prstatus prstatus;
+
+ memset(&prstatus, 0, sizeof(prstatus));
+ /*
+ * FIXME: How do i get PID? Do I really need it?
+ * prstatus.pr_pid = ????
+ */
+ elf_core_copy_regs(&prstatus.pr_reg, regs);
+ buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS,
+ &prstatus, sizeof(prstatus));
+ return buf;
+}
+
+void __init fadump_update_elfcore_header(char *bufp)
+{
+ struct elf_phdr *phdr;
+
+ bufp += sizeof(struct elfhdr);
+
+ /* First note is a place holder for cpu notes info. */
+ phdr = (struct elf_phdr *)bufp;
+
+ if (phdr->p_type == PT_NOTE) {
+ phdr->p_paddr = __pa(fw_dump.cpu_notes_buf_vaddr);
+ phdr->p_offset = phdr->p_paddr;
+ phdr->p_filesz = fw_dump.cpu_notes_buf_size;
+ phdr->p_memsz = fw_dump.cpu_notes_buf_size;
+ }
+ return;
+}
+
+static void *__init fadump_alloc_buffer(unsigned long size)
+{
+ unsigned long count, i;
+ struct page *page;
+ void *vaddr;
+
+ vaddr = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
+ if (!vaddr)
+ return NULL;
+
+ count = PAGE_ALIGN(size) / PAGE_SIZE;
+ page = virt_to_page(vaddr);
+ for (i = 0; i < count; i++)
+ mark_page_reserved(page + i);
+ return vaddr;
+}
+
+static void fadump_free_buffer(unsigned long vaddr, unsigned long size)
+{
+ free_reserved_area((void *)vaddr, (void *)(vaddr + size), -1, NULL);
+}
+
+s32 __init fadump_setup_cpu_notes_buf(u32 num_cpus)
+{
+ /* Allocate buffer to hold cpu crash notes. */
+ fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
+ fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
+ fw_dump.cpu_notes_buf_vaddr =
+ (unsigned long)fadump_alloc_buffer(fw_dump.cpu_notes_buf_size);
+ if (!fw_dump.cpu_notes_buf_vaddr) {
+ pr_err("Failed to allocate %ld bytes for CPU notes buffer\n",
+ fw_dump.cpu_notes_buf_size);
+ return -ENOMEM;
+ }
+
+ pr_debug("Allocated buffer for cpu notes of size %ld at 0x%lx\n",
+ fw_dump.cpu_notes_buf_size,
+ fw_dump.cpu_notes_buf_vaddr);
+ return 0;
+}
+
+void fadump_free_cpu_notes_buf(void)
+{
+ if (!fw_dump.cpu_notes_buf_vaddr)
+ return;
+
+ fadump_free_buffer(fw_dump.cpu_notes_buf_vaddr,
+ fw_dump.cpu_notes_buf_size);
+ fw_dump.cpu_notes_buf_vaddr = 0;
+ fw_dump.cpu_notes_buf_size = 0;
+}
+
+static void fadump_free_mem_ranges(struct fadump_mrange_info *mrange_info)
+{
+ if (mrange_info->is_static) {
+ mrange_info->mem_range_cnt = 0;
+ return;
+ }
+
+ kfree(mrange_info->mem_ranges);
+ memset((void *)((u64)mrange_info + RNG_NAME_SZ), 0,
+ (sizeof(struct fadump_mrange_info) - RNG_NAME_SZ));
+}
+
+/*
+ * Allocate or reallocate mem_ranges array in incremental units
+ * of PAGE_SIZE.
+ */
+static int fadump_alloc_mem_ranges(struct fadump_mrange_info *mrange_info)
+{
+ struct fadump_memory_range *new_array;
+ u64 new_size;
+
+ new_size = mrange_info->mem_ranges_sz + PAGE_SIZE;
+ pr_debug("Allocating %llu bytes of memory for %s memory ranges\n",
+ new_size, mrange_info->name);
+
+ new_array = krealloc(mrange_info->mem_ranges, new_size, GFP_KERNEL);
+ if (new_array == NULL) {
+ pr_err("Insufficient memory for setting up %s memory ranges\n",
+ mrange_info->name);
+ fadump_free_mem_ranges(mrange_info);
+ return -ENOMEM;
+ }
+
+ mrange_info->mem_ranges = new_array;
+ mrange_info->mem_ranges_sz = new_size;
+ mrange_info->max_mem_ranges = (new_size /
+ sizeof(struct fadump_memory_range));
+ return 0;
+}
+static inline int fadump_add_mem_range(struct fadump_mrange_info *mrange_info,
+ u64 base, u64 end)
+{
+ struct fadump_memory_range *mem_ranges = mrange_info->mem_ranges;
+ bool is_adjacent = false;
+ u64 start, size;
+
+ if (base == end)
+ return 0;
+
+ /*
+ * Fold adjacent memory ranges to bring down the memory ranges/
+ * PT_LOAD segments count.
+ */
+ if (mrange_info->mem_range_cnt) {
+ start = mem_ranges[mrange_info->mem_range_cnt - 1].base;
+ size = mem_ranges[mrange_info->mem_range_cnt - 1].size;
+
+ /*
+ * Boot memory area needs separate PT_LOAD segment(s) as it
+ * is moved to a different location at the time of crash.
+ * So, fold only if the region is not boot memory area.
+ */
+ if ((start + size) == base && start >= fw_dump.boot_mem_top)
+ is_adjacent = true;
+ }
+ if (!is_adjacent) {
+ /* resize the array on reaching the limit */
+ if (mrange_info->mem_range_cnt == mrange_info->max_mem_ranges) {
+ int ret;
+
+ if (mrange_info->is_static) {
+ pr_err("Reached array size limit for %s memory ranges\n",
+ mrange_info->name);
+ return -ENOSPC;
+ }
+
+ ret = fadump_alloc_mem_ranges(mrange_info);
+ if (ret)
+ return ret;
+
+ /* Update to the new resized array */
+ mem_ranges = mrange_info->mem_ranges;
+ }
+
+ start = base;
+ mem_ranges[mrange_info->mem_range_cnt].base = start;
+ mrange_info->mem_range_cnt++;
+ }
+
+ mem_ranges[mrange_info->mem_range_cnt - 1].size = (end - start);
+ pr_debug("%s_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
+ mrange_info->name, (mrange_info->mem_range_cnt - 1),
+ start, end - 1, (end - start));
+ return 0;
+}
+
+static int fadump_exclude_reserved_area(u64 start, u64 end)
+{
+ u64 ra_start, ra_end;
+ int ret = 0;
+
+ ra_start = fw_dump.reserve_dump_area_start;
+ ra_end = ra_start + fw_dump.reserve_dump_area_size;
+
+ if ((ra_start < end) && (ra_end > start)) {
+ if ((start < ra_start) && (end > ra_end)) {
+ ret = fadump_add_mem_range(&crash_mrange_info,
+ start, ra_start);
+ if (ret)
+ return ret;
+
+ ret = fadump_add_mem_range(&crash_mrange_info,
+ ra_end, end);
+ } else if (start < ra_start) {
+ ret = fadump_add_mem_range(&crash_mrange_info,
+ start, ra_start);
+ } else if (ra_end < end) {
+ ret = fadump_add_mem_range(&crash_mrange_info,
+ ra_end, end);
+ }
+ } else
+ ret = fadump_add_mem_range(&crash_mrange_info, start, end);
+
+ return ret;
+}
+
+static int fadump_init_elfcore_header(char *bufp)
+{
+ struct elfhdr *elf;
+
+ elf = (struct elfhdr *) bufp;
+ bufp += sizeof(struct elfhdr);
+ memcpy(elf->e_ident, ELFMAG, SELFMAG);
+ elf->e_ident[EI_CLASS] = ELF_CLASS;
+ elf->e_ident[EI_DATA] = ELF_DATA;
+ elf->e_ident[EI_VERSION] = EV_CURRENT;
+ elf->e_ident[EI_OSABI] = ELF_OSABI;
+ memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
+ elf->e_type = ET_CORE;
+ elf->e_machine = ELF_ARCH;
+ elf->e_version = EV_CURRENT;
+ elf->e_entry = 0;
+ elf->e_phoff = sizeof(struct elfhdr);
+ elf->e_shoff = 0;
+
+ if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2))
+ elf->e_flags = 2;
+ else if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V1))
+ elf->e_flags = 1;
+ else
+ elf->e_flags = 0;
+
+ elf->e_ehsize = sizeof(struct elfhdr);
+ elf->e_phentsize = sizeof(struct elf_phdr);
+ elf->e_phnum = 0;
+ elf->e_shentsize = 0;
+ elf->e_shnum = 0;
+ elf->e_shstrndx = 0;
+
+ return 0;
+}
+
+/*
+ * Traverse through memblock structure and setup crash memory ranges. These
+ * ranges will be used create PT_LOAD program headers in elfcore header.
+ */
+static int fadump_setup_crash_memory_ranges(void)
+{
+ u64 i, start, end;
+ int ret;
+
+ pr_debug("Setup crash memory ranges.\n");
+ crash_mrange_info.mem_range_cnt = 0;
+
+ /*
+ * Boot memory region(s) registered with firmware are moved to
+ * different location at the time of crash. Create separate program
+ * header(s) for this memory chunk(s) with the correct offset.
+ */
+ for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
+ start = fw_dump.boot_mem_addr[i];
+ end = start + fw_dump.boot_mem_sz[i];
+ ret = fadump_add_mem_range(&crash_mrange_info, start, end);
+ if (ret)
+ return ret;
+ }
+
+ for_each_mem_range(i, &start, &end) {
+ /*
+ * skip the memory chunk that is already added
+ * (0 through boot_memory_top).
+ */
+ if (start < fw_dump.boot_mem_top) {
+ if (end > fw_dump.boot_mem_top)
+ start = fw_dump.boot_mem_top;
+ else
+ continue;
+ }
+
+ /* add this range excluding the reserved dump area. */
+ ret = fadump_exclude_reserved_area(start, end);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+/*
+ * If the given physical address falls within the boot memory region then
+ * return the relocated address that points to the dump region reserved
+ * for saving initial boot memory contents.
+ */
+static inline unsigned long fadump_relocate(unsigned long paddr)
+{
+ unsigned long raddr, rstart, rend, rlast, hole_size;
+ int i;
+
+ hole_size = 0;
+ rlast = 0;
+ raddr = paddr;
+ for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
+ rstart = fw_dump.boot_mem_addr[i];
+ rend = rstart + fw_dump.boot_mem_sz[i];
+ hole_size += (rstart - rlast);
+
+ if (paddr >= rstart && paddr < rend) {
+ raddr += fw_dump.boot_mem_dest_addr - hole_size;
+ break;
+ }
+
+ rlast = rend;
+ }
+
+ pr_debug("vmcoreinfo: paddr = 0x%lx, raddr = 0x%lx\n", paddr, raddr);
+ return raddr;
+}
+
+static int fadump_create_elfcore_headers(char *bufp)
+{
+ unsigned long long raddr, offset;
+ struct elf_phdr *phdr;
+ struct elfhdr *elf;
+ int i, j;
+
+ fadump_init_elfcore_header(bufp);
+ elf = (struct elfhdr *)bufp;
+ bufp += sizeof(struct elfhdr);
+
+ /*
+ * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
+ * will be populated during second kernel boot after crash. Hence
+ * this PT_NOTE will always be the first elf note.
+ *
+ * NOTE: Any new ELF note addition should be placed after this note.
+ */
+ phdr = (struct elf_phdr *)bufp;
+ bufp += sizeof(struct elf_phdr);
+ phdr->p_type = PT_NOTE;
+ phdr->p_flags = 0;
+ phdr->p_vaddr = 0;
+ phdr->p_align = 0;
+
+ phdr->p_offset = 0;
+ phdr->p_paddr = 0;
+ phdr->p_filesz = 0;
+ phdr->p_memsz = 0;
+
+ (elf->e_phnum)++;
+
+ /* setup ELF PT_NOTE for vmcoreinfo */
+ phdr = (struct elf_phdr *)bufp;
+ bufp += sizeof(struct elf_phdr);
+ phdr->p_type = PT_NOTE;
+ phdr->p_flags = 0;
+ phdr->p_vaddr = 0;
+ phdr->p_align = 0;
+
+ phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note());
+ phdr->p_offset = phdr->p_paddr;
+ phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE;
+
+ /* Increment number of program headers. */
+ (elf->e_phnum)++;
+
+ /* setup PT_LOAD sections. */
+ j = 0;
+ offset = 0;
+ raddr = fw_dump.boot_mem_addr[0];
+ for (i = 0; i < crash_mrange_info.mem_range_cnt; i++) {
+ u64 mbase, msize;
+
+ mbase = crash_mrange_info.mem_ranges[i].base;
+ msize = crash_mrange_info.mem_ranges[i].size;
+ if (!msize)
+ continue;
+
+ phdr = (struct elf_phdr *)bufp;
+ bufp += sizeof(struct elf_phdr);
+ phdr->p_type = PT_LOAD;
+ phdr->p_flags = PF_R|PF_W|PF_X;
+ phdr->p_offset = mbase;
+
+ if (mbase == raddr) {
+ /*
+ * The entire real memory region will be moved by
+ * firmware to the specified destination_address.
+ * Hence set the correct offset.
+ */
+ phdr->p_offset = fw_dump.boot_mem_dest_addr + offset;
+ if (j < (fw_dump.boot_mem_regs_cnt - 1)) {
+ offset += fw_dump.boot_mem_sz[j];
+ raddr = fw_dump.boot_mem_addr[++j];
+ }
+ }
+
+ phdr->p_paddr = mbase;
+ phdr->p_vaddr = (unsigned long)__va(mbase);
+ phdr->p_filesz = msize;
+ phdr->p_memsz = msize;
+ phdr->p_align = 0;
+
+ /* Increment number of program headers. */
+ (elf->e_phnum)++;
+ }
+ return 0;
+}
+
+static unsigned long init_fadump_header(unsigned long addr)
+{
+ struct fadump_crash_info_header *fdh;
+
+ if (!addr)
+ return 0;
+
+ fdh = __va(addr);
+ addr += sizeof(struct fadump_crash_info_header);
+
+ memset(fdh, 0, sizeof(struct fadump_crash_info_header));
+ fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
+ fdh->elfcorehdr_addr = addr;
+ /* We will set the crashing cpu id in crash_fadump() during crash. */
+ fdh->crashing_cpu = FADUMP_CPU_UNKNOWN;
+ /*
+ * When LPAR is terminated by PYHP, ensure all possible CPUs'
+ * register data is processed while exporting the vmcore.
+ */
+ fdh->cpu_mask = *cpu_possible_mask;
+
+ return addr;
+}
+
+static int register_fadump(void)
+{
+ unsigned long addr;
+ void *vaddr;
+ int ret;
+
+ /*
+ * If no memory is reserved then we can not register for firmware-
+ * assisted dump.
+ */
+ if (!fw_dump.reserve_dump_area_size)
+ return -ENODEV;
+
+ ret = fadump_setup_crash_memory_ranges();
+ if (ret)
+ return ret;
+
+ addr = fw_dump.fadumphdr_addr;
+
+ /* Initialize fadump crash info header. */
+ addr = init_fadump_header(addr);
+ vaddr = __va(addr);
+
+ pr_debug("Creating ELF core headers at %#016lx\n", addr);
+ fadump_create_elfcore_headers(vaddr);
+
+ /* register the future kernel dump with firmware. */
+ pr_debug("Registering for firmware-assisted kernel dump...\n");
+ return fw_dump.ops->fadump_register(&fw_dump);
+}
+
+void fadump_cleanup(void)
+{
+ if (!fw_dump.fadump_supported)
+ return;
+
+ /* Invalidate the registration only if dump is active. */
+ if (fw_dump.dump_active) {
+ pr_debug("Invalidating firmware-assisted dump registration\n");
+ fw_dump.ops->fadump_invalidate(&fw_dump);
+ } else if (fw_dump.dump_registered) {
+ /* Un-register Firmware-assisted dump if it was registered. */
+ fw_dump.ops->fadump_unregister(&fw_dump);
+ fadump_free_mem_ranges(&crash_mrange_info);
+ }
+
+ if (fw_dump.ops->fadump_cleanup)
+ fw_dump.ops->fadump_cleanup(&fw_dump);
+}
+
+static void fadump_free_reserved_memory(unsigned long start_pfn,
+ unsigned long end_pfn)
+{
+ unsigned long pfn;
+ unsigned long time_limit = jiffies + HZ;
+
+ pr_info("freeing reserved memory (0x%llx - 0x%llx)\n",
+ PFN_PHYS(start_pfn), PFN_PHYS(end_pfn));
+
+ for (pfn = start_pfn; pfn < end_pfn; pfn++) {
+ free_reserved_page(pfn_to_page(pfn));
+
+ if (time_after(jiffies, time_limit)) {
+ cond_resched();
+ time_limit = jiffies + HZ;
+ }
+ }
+}
+
+/*
+ * Skip memory holes and free memory that was actually reserved.
+ */
+static void fadump_release_reserved_area(u64 start, u64 end)
+{
+ unsigned long reg_spfn, reg_epfn;
+ u64 tstart, tend, spfn, epfn;
+ int i;
+
+ spfn = PHYS_PFN(start);
+ epfn = PHYS_PFN(end);
+
+ for_each_mem_pfn_range(i, MAX_NUMNODES, &reg_spfn, &reg_epfn, NULL) {
+ tstart = max_t(u64, spfn, reg_spfn);
+ tend = min_t(u64, epfn, reg_epfn);
+
+ if (tstart < tend) {
+ fadump_free_reserved_memory(tstart, tend);
+
+ if (tend == epfn)
+ break;
+
+ spfn = tend;
+ }
+ }
+}
+
+/*
+ * Sort the mem ranges in-place and merge adjacent ranges
+ * to minimize the memory ranges count.
+ */
+static void sort_and_merge_mem_ranges(struct fadump_mrange_info *mrange_info)
+{
+ struct fadump_memory_range *mem_ranges;
+ u64 base, size;
+ int i, j, idx;
+
+ if (!reserved_mrange_info.mem_range_cnt)
+ return;
+
+ /* Sort the memory ranges */
+ mem_ranges = mrange_info->mem_ranges;
+ for (i = 0; i < mrange_info->mem_range_cnt; i++) {
+ idx = i;
+ for (j = (i + 1); j < mrange_info->mem_range_cnt; j++) {
+ if (mem_ranges[idx].base > mem_ranges[j].base)
+ idx = j;
+ }
+ if (idx != i)
+ swap(mem_ranges[idx], mem_ranges[i]);
+ }
+
+ /* Merge adjacent reserved ranges */
+ idx = 0;
+ for (i = 1; i < mrange_info->mem_range_cnt; i++) {
+ base = mem_ranges[i-1].base;
+ size = mem_ranges[i-1].size;
+ if (mem_ranges[i].base == (base + size))
+ mem_ranges[idx].size += mem_ranges[i].size;
+ else {
+ idx++;
+ if (i == idx)
+ continue;
+
+ mem_ranges[idx] = mem_ranges[i];
+ }
+ }
+ mrange_info->mem_range_cnt = idx + 1;
+}
+
+/*
+ * Scan reserved-ranges to consider them while reserving/releasing
+ * memory for FADump.
+ */
+static void __init early_init_dt_scan_reserved_ranges(unsigned long node)
+{
+ const __be32 *prop;
+ int len, ret = -1;
+ unsigned long i;
+
+ /* reserved-ranges already scanned */
+ if (reserved_mrange_info.mem_range_cnt != 0)
+ return;
+
+ prop = of_get_flat_dt_prop(node, "reserved-ranges", &len);
+ if (!prop)
+ return;
+
+ /*
+ * Each reserved range is an (address,size) pair, 2 cells each,
+ * totalling 4 cells per range.
+ */
+ for (i = 0; i < len / (sizeof(*prop) * 4); i++) {
+ u64 base, size;
+
+ base = of_read_number(prop + (i * 4) + 0, 2);
+ size = of_read_number(prop + (i * 4) + 2, 2);
+
+ if (size) {
+ ret = fadump_add_mem_range(&reserved_mrange_info,
+ base, base + size);
+ if (ret < 0) {
+ pr_warn("some reserved ranges are ignored!\n");
+ break;
+ }
+ }
+ }
+
+ /* Compact reserved ranges */
+ sort_and_merge_mem_ranges(&reserved_mrange_info);
+}
+
+/*
+ * Release the memory that was reserved during early boot to preserve the
+ * crash'ed kernel's memory contents except reserved dump area (permanent
+ * reservation) and reserved ranges used by F/W. The released memory will
+ * be available for general use.
+ */
+static void fadump_release_memory(u64 begin, u64 end)
+{
+ u64 ra_start, ra_end, tstart;
+ int i, ret;
+
+ ra_start = fw_dump.reserve_dump_area_start;
+ ra_end = ra_start + fw_dump.reserve_dump_area_size;
+
+ /*
+ * If reserved ranges array limit is hit, overwrite the last reserved
+ * memory range with reserved dump area to ensure it is excluded from
+ * the memory being released (reused for next FADump registration).
+ */
+ if (reserved_mrange_info.mem_range_cnt ==
+ reserved_mrange_info.max_mem_ranges)
+ reserved_mrange_info.mem_range_cnt--;
+
+ ret = fadump_add_mem_range(&reserved_mrange_info, ra_start, ra_end);
+ if (ret != 0)
+ return;
+
+ /* Get the reserved ranges list in order first. */
+ sort_and_merge_mem_ranges(&reserved_mrange_info);
+
+ /* Exclude reserved ranges and release remaining memory */
+ tstart = begin;
+ for (i = 0; i < reserved_mrange_info.mem_range_cnt; i++) {
+ ra_start = reserved_mrange_info.mem_ranges[i].base;
+ ra_end = ra_start + reserved_mrange_info.mem_ranges[i].size;
+
+ if (tstart >= ra_end)
+ continue;
+
+ if (tstart < ra_start)
+ fadump_release_reserved_area(tstart, ra_start);
+ tstart = ra_end;
+ }
+
+ if (tstart < end)
+ fadump_release_reserved_area(tstart, end);
+}
+
+static void fadump_invalidate_release_mem(void)
+{
+ mutex_lock(&fadump_mutex);
+ if (!fw_dump.dump_active) {
+ mutex_unlock(&fadump_mutex);
+ return;
+ }
+
+ fadump_cleanup();
+ mutex_unlock(&fadump_mutex);
+
+ fadump_release_memory(fw_dump.boot_mem_top, memblock_end_of_DRAM());
+ fadump_free_cpu_notes_buf();
+
+ /*
+ * Setup kernel metadata and initialize the kernel dump
+ * memory structure for FADump re-registration.
+ */
+ if (fw_dump.ops->fadump_setup_metadata &&
+ (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
+ pr_warn("Failed to setup kernel metadata!\n");
+ fw_dump.ops->fadump_init_mem_struct(&fw_dump);
+}
+
+static ssize_t release_mem_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ int input = -1;
+
+ if (!fw_dump.dump_active)
+ return -EPERM;
+
+ if (kstrtoint(buf, 0, &input))
+ return -EINVAL;
+
+ if (input == 1) {
+ /*
+ * Take away the '/proc/vmcore'. We are releasing the dump
+ * memory, hence it will not be valid anymore.
+ */
+#ifdef CONFIG_PROC_VMCORE
+ vmcore_cleanup();
+#endif
+ fadump_invalidate_release_mem();
+
+ } else
+ return -EINVAL;
+ return count;
+}
+
+/* Release the reserved memory and disable the FADump */
+static void __init unregister_fadump(void)
+{
+ fadump_cleanup();
+ fadump_release_memory(fw_dump.reserve_dump_area_start,
+ fw_dump.reserve_dump_area_size);
+ fw_dump.fadump_enabled = 0;
+ kobject_put(fadump_kobj);
+}
+
+static ssize_t enabled_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
+}
+
+static ssize_t mem_reserved_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%ld\n", fw_dump.reserve_dump_area_size);
+}
+
+static ssize_t registered_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%d\n", fw_dump.dump_registered);
+}
+
+static ssize_t registered_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ int ret = 0;
+ int input = -1;
+
+ if (!fw_dump.fadump_enabled || fw_dump.dump_active)
+ return -EPERM;
+
+ if (kstrtoint(buf, 0, &input))
+ return -EINVAL;
+
+ mutex_lock(&fadump_mutex);
+
+ switch (input) {
+ case 0:
+ if (fw_dump.dump_registered == 0) {
+ goto unlock_out;
+ }
+
+ /* Un-register Firmware-assisted dump */
+ pr_debug("Un-register firmware-assisted dump\n");
+ fw_dump.ops->fadump_unregister(&fw_dump);
+ break;
+ case 1:
+ if (fw_dump.dump_registered == 1) {
+ /* Un-register Firmware-assisted dump */
+ fw_dump.ops->fadump_unregister(&fw_dump);
+ }
+ /* Register Firmware-assisted dump */
+ ret = register_fadump();
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+unlock_out:
+ mutex_unlock(&fadump_mutex);
+ return ret < 0 ? ret : count;
+}
+
+static int fadump_region_show(struct seq_file *m, void *private)
+{
+ if (!fw_dump.fadump_enabled)
+ return 0;
+
+ mutex_lock(&fadump_mutex);
+ fw_dump.ops->fadump_region_show(&fw_dump, m);
+ mutex_unlock(&fadump_mutex);
+ return 0;
+}
+
+static struct kobj_attribute release_attr = __ATTR_WO(release_mem);
+static struct kobj_attribute enable_attr = __ATTR_RO(enabled);
+static struct kobj_attribute register_attr = __ATTR_RW(registered);
+static struct kobj_attribute mem_reserved_attr = __ATTR_RO(mem_reserved);
+
+static struct attribute *fadump_attrs[] = {
+ &enable_attr.attr,
+ &register_attr.attr,
+ &mem_reserved_attr.attr,
+ NULL,
+};
+
+ATTRIBUTE_GROUPS(fadump);
+
+DEFINE_SHOW_ATTRIBUTE(fadump_region);
+
+static void __init fadump_init_files(void)
+{
+ int rc = 0;
+
+ fadump_kobj = kobject_create_and_add("fadump", kernel_kobj);
+ if (!fadump_kobj) {
+ pr_err("failed to create fadump kobject\n");
+ return;
+ }
+
+ debugfs_create_file("fadump_region", 0444, arch_debugfs_dir, NULL,
+ &fadump_region_fops);
+
+ if (fw_dump.dump_active) {
+ rc = sysfs_create_file(fadump_kobj, &release_attr.attr);
+ if (rc)
+ pr_err("unable to create release_mem sysfs file (%d)\n",
+ rc);
+ }
+
+ rc = sysfs_create_groups(fadump_kobj, fadump_groups);
+ if (rc) {
+ pr_err("sysfs group creation failed (%d), unregistering FADump",
+ rc);
+ unregister_fadump();
+ return;
+ }
+
+ /*
+ * The FADump sysfs are moved from kernel_kobj to fadump_kobj need to
+ * create symlink at old location to maintain backward compatibility.
+ *
+ * - fadump_enabled -> fadump/enabled
+ * - fadump_registered -> fadump/registered
+ * - fadump_release_mem -> fadump/release_mem
+ */
+ rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj,
+ "enabled", "fadump_enabled");
+ if (rc) {
+ pr_err("unable to create fadump_enabled symlink (%d)", rc);
+ return;
+ }
+
+ rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj,
+ "registered",
+ "fadump_registered");
+ if (rc) {
+ pr_err("unable to create fadump_registered symlink (%d)", rc);
+ sysfs_remove_link(kernel_kobj, "fadump_enabled");
+ return;
+ }
+
+ if (fw_dump.dump_active) {
+ rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj,
+ fadump_kobj,
+ "release_mem",
+ "fadump_release_mem");
+ if (rc)
+ pr_err("unable to create fadump_release_mem symlink (%d)",
+ rc);
+ }
+ return;
+}
+
+/*
+ * Prepare for firmware-assisted dump.
+ */
+int __init setup_fadump(void)
+{
+ if (!fw_dump.fadump_supported)
+ return 0;
+
+ fadump_init_files();
+ fadump_show_config();
+
+ if (!fw_dump.fadump_enabled)
+ return 1;
+
+ /*
+ * If dump data is available then see if it is valid and prepare for
+ * saving it to the disk.
+ */
+ if (fw_dump.dump_active) {
+ /*
+ * if dump process fails then invalidate the registration
+ * and release memory before proceeding for re-registration.
+ */
+ if (fw_dump.ops->fadump_process(&fw_dump) < 0)
+ fadump_invalidate_release_mem();
+ }
+ /* Initialize the kernel dump memory structure and register with f/w */
+ else if (fw_dump.reserve_dump_area_size) {
+ fw_dump.ops->fadump_init_mem_struct(&fw_dump);
+ register_fadump();
+ }
+
+ /*
+ * In case of panic, fadump is triggered via ppc_panic_event()
+ * panic notifier. Setting crash_kexec_post_notifiers to 'true'
+ * lets panic() function take crash friendly path before panic
+ * notifiers are invoked.
+ */
+ crash_kexec_post_notifiers = true;
+
+ return 1;
+}
+/*
+ * Use subsys_initcall_sync() here because there is dependency with
+ * crash_save_vmcoreinfo_init(), which must run first to ensure vmcoreinfo initialization
+ * is done before registering with f/w.
+ */
+subsys_initcall_sync(setup_fadump);
+#else /* !CONFIG_PRESERVE_FA_DUMP */
+
+/* Scan the Firmware Assisted dump configuration details. */
+int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
+ int depth, void *data)
+{
+ if ((depth != 1) || (strcmp(uname, "ibm,opal") != 0))
+ return 0;
+
+ opal_fadump_dt_scan(&fw_dump, node);
+ return 1;
+}
+
+/*
+ * When dump is active but PRESERVE_FA_DUMP is enabled on the kernel,
+ * preserve crash data. The subsequent memory preserving kernel boot
+ * is likely to process this crash data.
+ */
+int __init fadump_reserve_mem(void)
+{
+ if (fw_dump.dump_active) {
+ /*
+ * If last boot has crashed then reserve all the memory
+ * above boot memory to preserve crash data.
+ */
+ pr_info("Preserving crash data for processing in next boot.\n");
+ fadump_reserve_crash_area(fw_dump.boot_mem_top);
+ } else
+ pr_debug("FADump-aware kernel..\n");
+
+ return 1;
+}
+#endif /* CONFIG_PRESERVE_FA_DUMP */
+
+/* Preserve everything above the base address */
+static void __init fadump_reserve_crash_area(u64 base)
+{
+ u64 i, mstart, mend, msize;
+
+ for_each_mem_range(i, &mstart, &mend) {
+ msize = mend - mstart;
+
+ if ((mstart + msize) < base)
+ continue;
+
+ if (mstart < base) {
+ msize -= (base - mstart);
+ mstart = base;
+ }
+
+ pr_info("Reserving %lluMB of memory at %#016llx for preserving crash data",
+ (msize >> 20), mstart);
+ memblock_reserve(mstart, msize);
+ }
+}
+
+unsigned long __init arch_reserved_kernel_pages(void)
+{
+ return memblock_reserved_size() / PAGE_SIZE;
+}