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linux-zen-desktop/arch/powerpc/kexec/file_load_64.c

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Initial commit
2023-08-30 17:31:07 +02:00
// SPDX-License-Identifier: GPL-2.0-only
/*
* ppc64 code to implement the kexec_file_load syscall
*
* Copyright (C) 2004 Adam Litke (agl@us.ibm.com)
* Copyright (C) 2004 IBM Corp.
* Copyright (C) 2004,2005 Milton D Miller II, IBM Corporation
* Copyright (C) 2005 R Sharada (sharada@in.ibm.com)
* Copyright (C) 2006 Mohan Kumar M (mohan@in.ibm.com)
* Copyright (C) 2020 IBM Corporation
*
* Based on kexec-tools' kexec-ppc64.c, kexec-elf-rel-ppc64.c, fs2dt.c.
* Heavily modified for the kernel by
* Hari Bathini, IBM Corporation.
*/
#include <linux/kexec.h>
#include <linux/of_fdt.h>
#include <linux/libfdt.h>
#include <linux/of_device.h>
#include <linux/memblock.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <asm/setup.h>
#include <asm/drmem.h>
#include <asm/firmware.h>
#include <asm/kexec_ranges.h>
#include <asm/crashdump-ppc64.h>
#include <asm/mmzone.h>
#include <asm/prom.h>
#include <asm/plpks.h>
struct umem_info {
u64 *buf; /* data buffer for usable-memory property */
u32 size; /* size allocated for the data buffer */
u32 max_entries; /* maximum no. of entries */
u32 idx; /* index of current entry */
/* usable memory ranges to look up */
unsigned int nr_ranges;
const struct range *ranges;
};
const struct kexec_file_ops * const kexec_file_loaders[] = {
&kexec_elf64_ops,
NULL
};
/**
* get_exclude_memory_ranges - Get exclude memory ranges. This list includes
* regions like opal/rtas, tce-table, initrd,
* kernel, htab which should be avoided while
* setting up kexec load segments.
* @mem_ranges: Range list to add the memory ranges to.
*
* Returns 0 on success, negative errno on error.
*/
static int get_exclude_memory_ranges(struct crash_mem **mem_ranges)
{
int ret;
ret = add_tce_mem_ranges(mem_ranges);
if (ret)
goto out;
ret = add_initrd_mem_range(mem_ranges);
if (ret)
goto out;
ret = add_htab_mem_range(mem_ranges);
if (ret)
goto out;
ret = add_kernel_mem_range(mem_ranges);
if (ret)
goto out;
ret = add_rtas_mem_range(mem_ranges);
if (ret)
goto out;
ret = add_opal_mem_range(mem_ranges);
if (ret)
goto out;
ret = add_reserved_mem_ranges(mem_ranges);
if (ret)
goto out;
/* exclude memory ranges should be sorted for easy lookup */
sort_memory_ranges(*mem_ranges, true);
out:
if (ret)
pr_err("Failed to setup exclude memory ranges\n");
return ret;
}
/**
* get_usable_memory_ranges - Get usable memory ranges. This list includes
* regions like crashkernel, opal/rtas & tce-table,
* that kdump kernel could use.
* @mem_ranges: Range list to add the memory ranges to.
*
* Returns 0 on success, negative errno on error.
*/
static int get_usable_memory_ranges(struct crash_mem **mem_ranges)
{
int ret;
/*
* Early boot failure observed on guests when low memory (first memory
* block?) is not added to usable memory. So, add [0, crashk_res.end]
* instead of [crashk_res.start, crashk_res.end] to workaround it.
* Also, crashed kernel's memory must be added to reserve map to
* avoid kdump kernel from using it.
*/
ret = add_mem_range(mem_ranges, 0, crashk_res.end + 1);
if (ret)
goto out;
ret = add_rtas_mem_range(mem_ranges);
if (ret)
goto out;
ret = add_opal_mem_range(mem_ranges);
if (ret)
goto out;
ret = add_tce_mem_ranges(mem_ranges);
out:
if (ret)
pr_err("Failed to setup usable memory ranges\n");
return ret;
}
/**
* get_crash_memory_ranges - Get crash memory ranges. This list includes
* first/crashing kernel's memory regions that
* would be exported via an elfcore.
* @mem_ranges: Range list to add the memory ranges to.
*
* Returns 0 on success, negative errno on error.
*/
static int get_crash_memory_ranges(struct crash_mem **mem_ranges)
{
phys_addr_t base, end;
struct crash_mem *tmem;
u64 i;
int ret;
for_each_mem_range(i, &base, &end) {
u64 size = end - base;
/* Skip backup memory region, which needs a separate entry */
if (base == BACKUP_SRC_START) {
if (size > BACKUP_SRC_SIZE) {
base = BACKUP_SRC_END + 1;
size -= BACKUP_SRC_SIZE;
} else
continue;
}
ret = add_mem_range(mem_ranges, base, size);
if (ret)
goto out;
/* Try merging adjacent ranges before reallocation attempt */
if ((*mem_ranges)->nr_ranges == (*mem_ranges)->max_nr_ranges)
sort_memory_ranges(*mem_ranges, true);
}
/* Reallocate memory ranges if there is no space to split ranges */
tmem = *mem_ranges;
if (tmem && (tmem->nr_ranges == tmem->max_nr_ranges)) {
tmem = realloc_mem_ranges(mem_ranges);
if (!tmem)
goto out;
}
/* Exclude crashkernel region */
ret = crash_exclude_mem_range(tmem, crashk_res.start, crashk_res.end);
if (ret)
goto out;
/*
* FIXME: For now, stay in parity with kexec-tools but if RTAS/OPAL
* regions are exported to save their context at the time of
* crash, they should actually be backed up just like the
* first 64K bytes of memory.
*/
ret = add_rtas_mem_range(mem_ranges);
if (ret)
goto out;
ret = add_opal_mem_range(mem_ranges);
if (ret)
goto out;
/* create a separate program header for the backup region */
ret = add_mem_range(mem_ranges, BACKUP_SRC_START, BACKUP_SRC_SIZE);
if (ret)
goto out;
sort_memory_ranges(*mem_ranges, false);
out:
if (ret)
pr_err("Failed to setup crash memory ranges\n");
return ret;
}
/**
* get_reserved_memory_ranges - Get reserve memory ranges. This list includes
* memory regions that should be added to the
* memory reserve map to ensure the region is
* protected from any mischief.
* @mem_ranges: Range list to add the memory ranges to.
*
* Returns 0 on success, negative errno on error.
*/
static int get_reserved_memory_ranges(struct crash_mem **mem_ranges)
{
int ret;
ret = add_rtas_mem_range(mem_ranges);
if (ret)
goto out;
ret = add_tce_mem_ranges(mem_ranges);
if (ret)
goto out;
ret = add_reserved_mem_ranges(mem_ranges);
out:
if (ret)
pr_err("Failed to setup reserved memory ranges\n");
return ret;
}
/**
* __locate_mem_hole_top_down - Looks top down for a large enough memory hole
* in the memory regions between buf_min & buf_max
* for the buffer. If found, sets kbuf->mem.
* @kbuf: Buffer contents and memory parameters.
* @buf_min: Minimum address for the buffer.
* @buf_max: Maximum address for the buffer.
*
* Returns 0 on success, negative errno on error.
*/
static int __locate_mem_hole_top_down(struct kexec_buf *kbuf,
u64 buf_min, u64 buf_max)
{
int ret = -EADDRNOTAVAIL;
phys_addr_t start, end;
u64 i;
for_each_mem_range_rev(i, &start, &end) {
/*
* memblock uses [start, end) convention while it is
* [start, end] here. Fix the off-by-one to have the
* same convention.
*/
end -= 1;
if (start > buf_max)
continue;
/* Memory hole not found */
if (end < buf_min)
break;
/* Adjust memory region based on the given range */
if (start < buf_min)
start = buf_min;
if (end > buf_max)
end = buf_max;
start = ALIGN(start, kbuf->buf_align);
if (start < end && (end - start + 1) >= kbuf->memsz) {
/* Suitable memory range found. Set kbuf->mem */
kbuf->mem = ALIGN_DOWN(end - kbuf->memsz + 1,
kbuf->buf_align);
ret = 0;
break;
}
}
return ret;
}
/**
* locate_mem_hole_top_down_ppc64 - Skip special memory regions to find a
* suitable buffer with top down approach.
* @kbuf: Buffer contents and memory parameters.
* @buf_min: Minimum address for the buffer.
* @buf_max: Maximum address for the buffer.
* @emem: Exclude memory ranges.
*
* Returns 0 on success, negative errno on error.
*/
static int locate_mem_hole_top_down_ppc64(struct kexec_buf *kbuf,
u64 buf_min, u64 buf_max,
const struct crash_mem *emem)
{
int i, ret = 0, err = -EADDRNOTAVAIL;
u64 start, end, tmin, tmax;
tmax = buf_max;
for (i = (emem->nr_ranges - 1); i >= 0; i--) {
start = emem->ranges[i].start;
end = emem->ranges[i].end;
if (start > tmax)
continue;
if (end < tmax) {
tmin = (end < buf_min ? buf_min : end + 1);
ret = __locate_mem_hole_top_down(kbuf, tmin, tmax);
if (!ret)
return 0;
}
tmax = start - 1;
if (tmax < buf_min) {
ret = err;
break;
}
ret = 0;
}
if (!ret) {
tmin = buf_min;
ret = __locate_mem_hole_top_down(kbuf, tmin, tmax);
}
return ret;
}
/**
* __locate_mem_hole_bottom_up - Looks bottom up for a large enough memory hole
* in the memory regions between buf_min & buf_max
* for the buffer. If found, sets kbuf->mem.
* @kbuf: Buffer contents and memory parameters.
* @buf_min: Minimum address for the buffer.
* @buf_max: Maximum address for the buffer.
*
* Returns 0 on success, negative errno on error.
*/
static int __locate_mem_hole_bottom_up(struct kexec_buf *kbuf,
u64 buf_min, u64 buf_max)
{
int ret = -EADDRNOTAVAIL;
phys_addr_t start, end;
u64 i;
for_each_mem_range(i, &start, &end) {
/*
* memblock uses [start, end) convention while it is
* [start, end] here. Fix the off-by-one to have the
* same convention.
*/
end -= 1;
if (end < buf_min)
continue;
/* Memory hole not found */
if (start > buf_max)
break;
/* Adjust memory region based on the given range */
if (start < buf_min)
start = buf_min;
if (end > buf_max)
end = buf_max;
start = ALIGN(start, kbuf->buf_align);
if (start < end && (end - start + 1) >= kbuf->memsz) {
/* Suitable memory range found. Set kbuf->mem */
kbuf->mem = start;
ret = 0;
break;
}
}
return ret;
}
/**
* locate_mem_hole_bottom_up_ppc64 - Skip special memory regions to find a
* suitable buffer with bottom up approach.
* @kbuf: Buffer contents and memory parameters.
* @buf_min: Minimum address for the buffer.
* @buf_max: Maximum address for the buffer.
* @emem: Exclude memory ranges.
*
* Returns 0 on success, negative errno on error.
*/
static int locate_mem_hole_bottom_up_ppc64(struct kexec_buf *kbuf,
u64 buf_min, u64 buf_max,
const struct crash_mem *emem)
{
int i, ret = 0, err = -EADDRNOTAVAIL;
u64 start, end, tmin, tmax;
tmin = buf_min;
for (i = 0; i < emem->nr_ranges; i++) {
start = emem->ranges[i].start;
end = emem->ranges[i].end;
if (end < tmin)
continue;
if (start > tmin) {
tmax = (start > buf_max ? buf_max : start - 1);
ret = __locate_mem_hole_bottom_up(kbuf, tmin, tmax);
if (!ret)
return 0;
}
tmin = end + 1;
if (tmin > buf_max) {
ret = err;
break;
}
ret = 0;
}
if (!ret) {
tmax = buf_max;
ret = __locate_mem_hole_bottom_up(kbuf, tmin, tmax);
}
return ret;
}
/**
* check_realloc_usable_mem - Reallocate buffer if it can't accommodate entries
* @um_info: Usable memory buffer and ranges info.
* @cnt: No. of entries to accommodate.
*
* Frees up the old buffer if memory reallocation fails.
*
* Returns buffer on success, NULL on error.
*/
static u64 *check_realloc_usable_mem(struct umem_info *um_info, int cnt)
{
u32 new_size;
u64 *tbuf;
if ((um_info->idx + cnt) <= um_info->max_entries)
return um_info->buf;
new_size = um_info->size + MEM_RANGE_CHUNK_SZ;
tbuf = krealloc(um_info->buf, new_size, GFP_KERNEL);
if (tbuf) {
um_info->buf = tbuf;
um_info->size = new_size;
um_info->max_entries = (um_info->size / sizeof(u64));
}
return tbuf;
}
/**
* add_usable_mem - Add the usable memory ranges within the given memory range
* to the buffer
* @um_info: Usable memory buffer and ranges info.
* @base: Base address of memory range to look for.
* @end: End address of memory range to look for.
*
* Returns 0 on success, negative errno on error.
*/
static int add_usable_mem(struct umem_info *um_info, u64 base, u64 end)
{
u64 loc_base, loc_end;
bool add;
int i;
for (i = 0; i < um_info->nr_ranges; i++) {
add = false;
loc_base = um_info->ranges[i].start;
loc_end = um_info->ranges[i].end;
if (loc_base >= base && loc_end <= end)
add = true;
else if (base < loc_end && end > loc_base) {
if (loc_base < base)
loc_base = base;
if (loc_end > end)
loc_end = end;
add = true;
}
if (add) {
if (!check_realloc_usable_mem(um_info, 2))
return -ENOMEM;
um_info->buf[um_info->idx++] = cpu_to_be64(loc_base);
um_info->buf[um_info->idx++] =
cpu_to_be64(loc_end - loc_base + 1);
}
}
return 0;
}
/**
* kdump_setup_usable_lmb - This is a callback function that gets called by
* walk_drmem_lmbs for every LMB to set its
* usable memory ranges.
* @lmb: LMB info.
* @usm: linux,drconf-usable-memory property value.
* @data: Pointer to usable memory buffer and ranges info.
*
* Returns 0 on success, negative errno on error.
*/
static int kdump_setup_usable_lmb(struct drmem_lmb *lmb, const __be32 **usm,
void *data)
{
struct umem_info *um_info;
int tmp_idx, ret;
u64 base, end;
/*
* kdump load isn't supported on kernels already booted with
* linux,drconf-usable-memory property.
*/
if (*usm) {
pr_err("linux,drconf-usable-memory property already exists!");
return -EINVAL;
}
um_info = data;
tmp_idx = um_info->idx;
if (!check_realloc_usable_mem(um_info, 1))
return -ENOMEM;
um_info->idx++;
base = lmb->base_addr;
end = base + drmem_lmb_size() - 1;
ret = add_usable_mem(um_info, base, end);
if (!ret) {
/*
* Update the no. of ranges added. Two entries (base & size)
* for every range added.
*/
um_info->buf[tmp_idx] =
cpu_to_be64((um_info->idx - tmp_idx - 1) / 2);
}
return ret;
}
#define NODE_PATH_LEN 256
/**
* add_usable_mem_property - Add usable memory property for the given
* memory node.
* @fdt: Flattened device tree for the kdump kernel.
* @dn: Memory node.
* @um_info: Usable memory buffer and ranges info.
*
* Returns 0 on success, negative errno on error.
*/
static int add_usable_mem_property(void *fdt, struct device_node *dn,
struct umem_info *um_info)
{
int n_mem_addr_cells, n_mem_size_cells, node;
char path[NODE_PATH_LEN];
int i, len, ranges, ret;
const __be32 *prop;
u64 base, end;
of_node_get(dn);
if (snprintf(path, NODE_PATH_LEN, "%pOF", dn) > (NODE_PATH_LEN - 1)) {
pr_err("Buffer (%d) too small for memory node: %pOF\n",
NODE_PATH_LEN, dn);
return -EOVERFLOW;
}
pr_debug("Memory node path: %s\n", path);
/* Now that we know the path, find its offset in kdump kernel's fdt */
node = fdt_path_offset(fdt, path);
if (node < 0) {
pr_err("Malformed device tree: error reading %s\n", path);
ret = -EINVAL;
goto out;
}
/* Get the address & size cells */
n_mem_addr_cells = of_n_addr_cells(dn);
n_mem_size_cells = of_n_size_cells(dn);
pr_debug("address cells: %d, size cells: %d\n", n_mem_addr_cells,
n_mem_size_cells);
um_info->idx = 0;
if (!check_realloc_usable_mem(um_info, 2)) {
ret = -ENOMEM;
goto out;
}
prop = of_get_property(dn, "reg", &len);
if (!prop || len <= 0) {
ret = 0;
goto out;
}
/*
* "reg" property represents sequence of (addr,size) tuples
* each representing a memory range.
*/
ranges = (len >> 2) / (n_mem_addr_cells + n_mem_size_cells);
for (i = 0; i < ranges; i++) {
base = of_read_number(prop, n_mem_addr_cells);
prop += n_mem_addr_cells;
end = base + of_read_number(prop, n_mem_size_cells) - 1;
prop += n_mem_size_cells;
ret = add_usable_mem(um_info, base, end);
if (ret)
goto out;
}
/*
* No kdump kernel usable memory found in this memory node.
* Write (0,0) tuple in linux,usable-memory property for
* this region to be ignored.
*/
if (um_info->idx == 0) {
um_info->buf[0] = 0;
um_info->buf[1] = 0;
um_info->idx = 2;
}
ret = fdt_setprop(fdt, node, "linux,usable-memory", um_info->buf,
(um_info->idx * sizeof(u64)));
out:
of_node_put(dn);
return ret;
}
/**
* update_usable_mem_fdt - Updates kdump kernel's fdt with linux,usable-memory
* and linux,drconf-usable-memory DT properties as
* appropriate to restrict its memory usage.
* @fdt: Flattened device tree for the kdump kernel.
* @usable_mem: Usable memory ranges for kdump kernel.
*
* Returns 0 on success, negative errno on error.
*/
static int update_usable_mem_fdt(void *fdt, struct crash_mem *usable_mem)
{
struct umem_info um_info;
struct device_node *dn;
int node, ret = 0;
if (!usable_mem) {
pr_err("Usable memory ranges for kdump kernel not found\n");
return -ENOENT;
}
node = fdt_path_offset(fdt, "/ibm,dynamic-reconfiguration-memory");
if (node == -FDT_ERR_NOTFOUND)
pr_debug("No dynamic reconfiguration memory found\n");
else if (node < 0) {
pr_err("Malformed device tree: error reading /ibm,dynamic-reconfiguration-memory.\n");
return -EINVAL;
}
um_info.buf = NULL;
um_info.size = 0;
um_info.max_entries = 0;
um_info.idx = 0;
/* Memory ranges to look up */
um_info.ranges = &(usable_mem->ranges[0]);
um_info.nr_ranges = usable_mem->nr_ranges;
dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
if (dn) {
ret = walk_drmem_lmbs(dn, &um_info, kdump_setup_usable_lmb);
of_node_put(dn);
if (ret) {
pr_err("Could not setup linux,drconf-usable-memory property for kdump\n");
goto out;
}
ret = fdt_setprop(fdt, node, "linux,drconf-usable-memory",
um_info.buf, (um_info.idx * sizeof(u64)));
if (ret) {
pr_err("Failed to update fdt with linux,drconf-usable-memory property: %s",
fdt_strerror(ret));
goto out;
}
}
/*
* Walk through each memory node and set linux,usable-memory property
* for the corresponding node in kdump kernel's fdt.
*/
for_each_node_by_type(dn, "memory") {
ret = add_usable_mem_property(fdt, dn, &um_info);
if (ret) {
pr_err("Failed to set linux,usable-memory property for %s node",
dn->full_name);
of_node_put(dn);
goto out;
}
}
out:
kfree(um_info.buf);
return ret;
}
/**
* load_backup_segment - Locate a memory hole to place the backup region.
* @image: Kexec image.
* @kbuf: Buffer contents and memory parameters.
*
* Returns 0 on success, negative errno on error.
*/
static int load_backup_segment(struct kimage *image, struct kexec_buf *kbuf)
{
void *buf;
int ret;
/*
* Setup a source buffer for backup segment.
*
* A source buffer has no meaning for backup region as data will
* be copied from backup source, after crash, in the purgatory.
* But as load segment code doesn't recognize such segments,
* setup a dummy source buffer to keep it happy for now.
*/
buf = vzalloc(BACKUP_SRC_SIZE);
if (!buf)
return -ENOMEM;
kbuf->buffer = buf;
kbuf->mem = KEXEC_BUF_MEM_UNKNOWN;
kbuf->bufsz = kbuf->memsz = BACKUP_SRC_SIZE;
kbuf->top_down = false;
ret = kexec_add_buffer(kbuf);
if (ret) {
vfree(buf);
return ret;
}
image->arch.backup_buf = buf;
image->arch.backup_start = kbuf->mem;
return 0;
}
/**
* update_backup_region_phdr - Update backup region's offset for the core to
* export the region appropriately.
* @image: Kexec image.
* @ehdr: ELF core header.
*
* Assumes an exclusive program header is setup for the backup region
* in the ELF headers
*
* Returns nothing.
*/
static void update_backup_region_phdr(struct kimage *image, Elf64_Ehdr *ehdr)
{
Elf64_Phdr *phdr;
unsigned int i;
phdr = (Elf64_Phdr *)(ehdr + 1);
for (i = 0; i < ehdr->e_phnum; i++) {
if (phdr->p_paddr == BACKUP_SRC_START) {
phdr->p_offset = image->arch.backup_start;
pr_debug("Backup region offset updated to 0x%lx\n",
image->arch.backup_start);
return;
}
}
}
/**
* load_elfcorehdr_segment - Setup crash memory ranges and initialize elfcorehdr
* segment needed to load kdump kernel.
* @image: Kexec image.
* @kbuf: Buffer contents and memory parameters.
*
* Returns 0 on success, negative errno on error.
*/
static int load_elfcorehdr_segment(struct kimage *image, struct kexec_buf *kbuf)
{
struct crash_mem *cmem = NULL;
unsigned long headers_sz;
void *headers = NULL;
int ret;
ret = get_crash_memory_ranges(&cmem);
if (ret)
goto out;
/* Setup elfcorehdr segment */
ret = crash_prepare_elf64_headers(cmem, false, &headers, &headers_sz);
if (ret) {
pr_err("Failed to prepare elf headers for the core\n");
goto out;
}
/* Fix the offset for backup region in the ELF header */
update_backup_region_phdr(image, headers);
kbuf->buffer = headers;
kbuf->mem = KEXEC_BUF_MEM_UNKNOWN;
kbuf->bufsz = kbuf->memsz = headers_sz;
kbuf->top_down = false;
ret = kexec_add_buffer(kbuf);
if (ret) {
vfree(headers);
goto out;
}
image->elf_load_addr = kbuf->mem;
image->elf_headers_sz = headers_sz;
image->elf_headers = headers;
out:
kfree(cmem);
return ret;
}
/**
* load_crashdump_segments_ppc64 - Initialize the additional segements needed
* to load kdump kernel.
* @image: Kexec image.
* @kbuf: Buffer contents and memory parameters.
*
* Returns 0 on success, negative errno on error.
*/
int load_crashdump_segments_ppc64(struct kimage *image,
struct kexec_buf *kbuf)
{
int ret;
/* Load backup segment - first 64K bytes of the crashing kernel */
ret = load_backup_segment(image, kbuf);
if (ret) {
pr_err("Failed to load backup segment\n");
return ret;
}
pr_debug("Loaded the backup region at 0x%lx\n", kbuf->mem);
/* Load elfcorehdr segment - to export crashing kernel's vmcore */
ret = load_elfcorehdr_segment(image, kbuf);
if (ret) {
pr_err("Failed to load elfcorehdr segment\n");
return ret;
}
pr_debug("Loaded elf core header at 0x%lx, bufsz=0x%lx memsz=0x%lx\n",
image->elf_load_addr, kbuf->bufsz, kbuf->memsz);
return 0;
}
/**
* setup_purgatory_ppc64 - initialize PPC64 specific purgatory's global
* variables and call setup_purgatory() to initialize
* common global variable.
* @image: kexec image.
* @slave_code: Slave code for the purgatory.
* @fdt: Flattened device tree for the next kernel.
* @kernel_load_addr: Address where the kernel is loaded.
* @fdt_load_addr: Address where the flattened device tree is loaded.
*
* Returns 0 on success, negative errno on error.
*/
int setup_purgatory_ppc64(struct kimage *image, const void *slave_code,
const void *fdt, unsigned long kernel_load_addr,
unsigned long fdt_load_addr)
{
struct device_node *dn = NULL;
int ret;
ret = setup_purgatory(image, slave_code, fdt, kernel_load_addr,
fdt_load_addr);
if (ret)
goto out;
if (image->type == KEXEC_TYPE_CRASH) {
u32 my_run_at_load = 1;
/*
* Tell relocatable kernel to run at load address
* via the word meant for that at 0x5c.
*/
ret = kexec_purgatory_get_set_symbol(image, "run_at_load",
&my_run_at_load,
sizeof(my_run_at_load),
false);
if (ret)
goto out;
}
/* Tell purgatory where to look for backup region */
ret = kexec_purgatory_get_set_symbol(image, "backup_start",
&image->arch.backup_start,
sizeof(image->arch.backup_start),
false);
if (ret)
goto out;
/* Setup OPAL base & entry values */
dn = of_find_node_by_path("/ibm,opal");
if (dn) {
u64 val;
of_property_read_u64(dn, "opal-base-address", &val);
ret = kexec_purgatory_get_set_symbol(image, "opal_base", &val,
sizeof(val), false);
if (ret)
goto out;
of_property_read_u64(dn, "opal-entry-address", &val);
ret = kexec_purgatory_get_set_symbol(image, "opal_entry", &val,
sizeof(val), false);
}
out:
if (ret)
pr_err("Failed to setup purgatory symbols");
of_node_put(dn);
return ret;
}
/**
* get_cpu_node_size - Compute the size of a CPU node in the FDT.
* This should be done only once and the value is stored in
* a static variable.
* Returns the max size of a CPU node in the FDT.
*/
static unsigned int cpu_node_size(void)
{
static unsigned int size;
struct device_node *dn;
struct property *pp;
/*
* Don't compute it twice, we are assuming that the per CPU node size
* doesn't change during the system's life.
*/
if (size)
return size;
dn = of_find_node_by_type(NULL, "cpu");
if (WARN_ON_ONCE(!dn)) {
// Unlikely to happen
return 0;
}
/*
* We compute the sub node size for a CPU node, assuming it
* will be the same for all.
*/
size += strlen(dn->name) + 5;
for_each_property_of_node(dn, pp) {
size += strlen(pp->name);
size += pp->length;
}
of_node_put(dn);
return size;
}
/**
* kexec_extra_fdt_size_ppc64 - Return the estimated additional size needed to
* setup FDT for kexec/kdump kernel.
* @image: kexec image being loaded.
*
* Returns the estimated extra size needed for kexec/kdump kernel FDT.
*/
unsigned int kexec_extra_fdt_size_ppc64(struct kimage *image)
{
unsigned int cpu_nodes, extra_size = 0;
struct device_node *dn;
u64 usm_entries;
// Budget some space for the password blob. There's already extra space
// for the key name
if (plpks_is_available())
extra_size += (unsigned int)plpks_get_passwordlen();
if (image->type != KEXEC_TYPE_CRASH)
return extra_size;
/*
* For kdump kernel, account for linux,usable-memory and
* linux,drconf-usable-memory properties. Get an approximate on the
* number of usable memory entries and use for FDT size estimation.
*/
if (drmem_lmb_size()) {
usm_entries = ((memory_hotplug_max() / drmem_lmb_size()) +
(2 * (resource_size(&crashk_res) / drmem_lmb_size())));
extra_size += (unsigned int)(usm_entries * sizeof(u64));
}
/*
* Get the number of CPU nodes in the current DT. This allows to
* reserve places for CPU nodes added since the boot time.
*/
cpu_nodes = 0;
for_each_node_by_type(dn, "cpu") {
cpu_nodes++;
}
if (cpu_nodes > boot_cpu_node_count)
extra_size += (cpu_nodes - boot_cpu_node_count) * cpu_node_size();
return extra_size;
}
/**
* add_node_props - Reads node properties from device node structure and add
* them to fdt.
* @fdt: Flattened device tree of the kernel
* @node_offset: offset of the node to add a property at
* @dn: device node pointer
*
* Returns 0 on success, negative errno on error.
*/
static int add_node_props(void *fdt, int node_offset, const struct device_node *dn)
{
int ret = 0;
struct property *pp;
if (!dn)
return -EINVAL;
for_each_property_of_node(dn, pp) {
ret = fdt_setprop(fdt, node_offset, pp->name, pp->value, pp->length);
if (ret < 0) {
pr_err("Unable to add %s property: %s\n", pp->name, fdt_strerror(ret));
return ret;
}
}
return ret;
}
/**
* update_cpus_node - Update cpus node of flattened device tree using of_root
* device node.
* @fdt: Flattened device tree of the kernel.
*
* Returns 0 on success, negative errno on error.
*/
static int update_cpus_node(void *fdt)
{
struct device_node *cpus_node, *dn;
int cpus_offset, cpus_subnode_offset, ret = 0;
cpus_offset = fdt_path_offset(fdt, "/cpus");
if (cpus_offset < 0 && cpus_offset != -FDT_ERR_NOTFOUND) {
pr_err("Malformed device tree: error reading /cpus node: %s\n",
fdt_strerror(cpus_offset));
return cpus_offset;
}
if (cpus_offset > 0) {
ret = fdt_del_node(fdt, cpus_offset);
if (ret < 0) {
pr_err("Error deleting /cpus node: %s\n", fdt_strerror(ret));
return -EINVAL;
}
}
/* Add cpus node to fdt */
cpus_offset = fdt_add_subnode(fdt, fdt_path_offset(fdt, "/"), "cpus");
if (cpus_offset < 0) {
pr_err("Error creating /cpus node: %s\n", fdt_strerror(cpus_offset));
return -EINVAL;
}
/* Add cpus node properties */
cpus_node = of_find_node_by_path("/cpus");
ret = add_node_props(fdt, cpus_offset, cpus_node);
of_node_put(cpus_node);
if (ret < 0)
return ret;
/* Loop through all subnodes of cpus and add them to fdt */
for_each_node_by_type(dn, "cpu") {
cpus_subnode_offset = fdt_add_subnode(fdt, cpus_offset, dn->full_name);
if (cpus_subnode_offset < 0) {
pr_err("Unable to add %s subnode: %s\n", dn->full_name,
fdt_strerror(cpus_subnode_offset));
ret = cpus_subnode_offset;
goto out;
}
ret = add_node_props(fdt, cpus_subnode_offset, dn);
if (ret < 0)
goto out;
}
out:
of_node_put(dn);
return ret;
}
static int copy_property(void *fdt, int node_offset, const struct device_node *dn,
const char *propname)
{
const void *prop, *fdtprop;
int len = 0, fdtlen = 0;
prop = of_get_property(dn, propname, &len);
fdtprop = fdt_getprop(fdt, node_offset, propname, &fdtlen);
if (fdtprop && !prop)
return fdt_delprop(fdt, node_offset, propname);
else if (prop)
return fdt_setprop(fdt, node_offset, propname, prop, len);
else
return -FDT_ERR_NOTFOUND;
}
static int update_pci_dma_nodes(void *fdt, const char *dmapropname)
{
struct device_node *dn;
int pci_offset, root_offset, ret = 0;
if (!firmware_has_feature(FW_FEATURE_LPAR))
return 0;
root_offset = fdt_path_offset(fdt, "/");
for_each_node_with_property(dn, dmapropname) {
pci_offset = fdt_subnode_offset(fdt, root_offset, of_node_full_name(dn));
if (pci_offset < 0)
continue;
ret = copy_property(fdt, pci_offset, dn, "ibm,dma-window");
if (ret < 0)
break;
ret = copy_property(fdt, pci_offset, dn, dmapropname);
if (ret < 0)
break;
}
return ret;
}
/**
* setup_new_fdt_ppc64 - Update the flattend device-tree of the kernel
* being loaded.
* @image: kexec image being loaded.
* @fdt: Flattened device tree for the next kernel.
* @initrd_load_addr: Address where the next initrd will be loaded.
* @initrd_len: Size of the next initrd, or 0 if there will be none.
* @cmdline: Command line for the next kernel, or NULL if there will
* be none.
*
* Returns 0 on success, negative errno on error.
*/
int setup_new_fdt_ppc64(const struct kimage *image, void *fdt,
unsigned long initrd_load_addr,
unsigned long initrd_len, const char *cmdline)
{
struct crash_mem *umem = NULL, *rmem = NULL;
int i, nr_ranges, ret;
/*
* Restrict memory usage for kdump kernel by setting up
* usable memory ranges and memory reserve map.
*/
if (image->type == KEXEC_TYPE_CRASH) {
ret = get_usable_memory_ranges(&umem);
if (ret)
goto out;
ret = update_usable_mem_fdt(fdt, umem);
if (ret) {
pr_err("Error setting up usable-memory property for kdump kernel\n");
goto out;
}
/*
* Ensure we don't touch crashed kernel's memory except the
* first 64K of RAM, which will be backed up.
*/
ret = fdt_add_mem_rsv(fdt, BACKUP_SRC_END + 1,
crashk_res.start - BACKUP_SRC_SIZE);
if (ret) {
pr_err("Error reserving crash memory: %s\n",
fdt_strerror(ret));
goto out;
}
/* Ensure backup region is not used by kdump/capture kernel */
ret = fdt_add_mem_rsv(fdt, image->arch.backup_start,
BACKUP_SRC_SIZE);
if (ret) {
pr_err("Error reserving memory for backup: %s\n",
fdt_strerror(ret));
goto out;
}
}
/* Update cpus nodes information to account hotplug CPUs. */
ret = update_cpus_node(fdt);
if (ret < 0)
goto out;
#define DIRECT64_PROPNAME "linux,direct64-ddr-window-info"
#define DMA64_PROPNAME "linux,dma64-ddr-window-info"
ret = update_pci_dma_nodes(fdt, DIRECT64_PROPNAME);
if (ret < 0)
goto out;
ret = update_pci_dma_nodes(fdt, DMA64_PROPNAME);
if (ret < 0)
goto out;
#undef DMA64_PROPNAME
#undef DIRECT64_PROPNAME
/* Update memory reserve map */
ret = get_reserved_memory_ranges(&rmem);
if (ret)
goto out;
nr_ranges = rmem ? rmem->nr_ranges : 0;
for (i = 0; i < nr_ranges; i++) {
u64 base, size;
base = rmem->ranges[i].start;
size = rmem->ranges[i].end - base + 1;
ret = fdt_add_mem_rsv(fdt, base, size);
if (ret) {
pr_err("Error updating memory reserve map: %s\n",
fdt_strerror(ret));
goto out;
}
}
// If we have PLPKS active, we need to provide the password to the new kernel
if (plpks_is_available())
ret = plpks_populate_fdt(fdt);
out:
kfree(rmem);
kfree(umem);
return ret;
}
/**
* arch_kexec_locate_mem_hole - Skip special memory regions like rtas, opal,
* tce-table, reserved-ranges & such (exclude
* memory ranges) as they can't be used for kexec
* segment buffer. Sets kbuf->mem when a suitable
* memory hole is found.
* @kbuf: Buffer contents and memory parameters.
*
* Assumes minimum of PAGE_SIZE alignment for kbuf->memsz & kbuf->buf_align.
*
* Returns 0 on success, negative errno on error.
*/
int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf)
{
struct crash_mem **emem;
u64 buf_min, buf_max;
int ret;
/* Look up the exclude ranges list while locating the memory hole */
emem = &(kbuf->image->arch.exclude_ranges);
if (!(*emem) || ((*emem)->nr_ranges == 0)) {
pr_warn("No exclude range list. Using the default locate mem hole method\n");
return kexec_locate_mem_hole(kbuf);
}
buf_min = kbuf->buf_min;
buf_max = kbuf->buf_max;
/* Segments for kdump kernel should be within crashkernel region */
if (kbuf->image->type == KEXEC_TYPE_CRASH) {
buf_min = (buf_min < crashk_res.start ?
crashk_res.start : buf_min);
buf_max = (buf_max > crashk_res.end ?
crashk_res.end : buf_max);
}
if (buf_min > buf_max) {
pr_err("Invalid buffer min and/or max values\n");
return -EINVAL;
}
if (kbuf->top_down)
ret = locate_mem_hole_top_down_ppc64(kbuf, buf_min, buf_max,
*emem);
else
ret = locate_mem_hole_bottom_up_ppc64(kbuf, buf_min, buf_max,
*emem);
/* Add the buffer allocated to the exclude list for the next lookup */
if (!ret) {
add_mem_range(emem, kbuf->mem, kbuf->memsz);
sort_memory_ranges(*emem, true);
} else {
pr_err("Failed to locate memory buffer of size %lu\n",
kbuf->memsz);
}
return ret;
}
/**
* arch_kexec_kernel_image_probe - Does additional handling needed to setup
* kexec segments.
* @image: kexec image being loaded.
* @buf: Buffer pointing to elf data.
* @buf_len: Length of the buffer.
*
* Returns 0 on success, negative errno on error.
*/
int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
unsigned long buf_len)
{
int ret;
/* Get exclude memory ranges needed for setting up kexec segments */
ret = get_exclude_memory_ranges(&(image->arch.exclude_ranges));
if (ret) {
pr_err("Failed to setup exclude memory ranges for buffer lookup\n");
return ret;
}
return kexec_image_probe_default(image, buf, buf_len);
}
/**
* arch_kimage_file_post_load_cleanup - Frees up all the allocations done
* while loading the image.
* @image: kexec image being loaded.
*
* Returns 0 on success, negative errno on error.
*/
int arch_kimage_file_post_load_cleanup(struct kimage *image)
{
kfree(image->arch.exclude_ranges);
image->arch.exclude_ranges = NULL;
vfree(image->arch.backup_buf);
image->arch.backup_buf = NULL;
vfree(image->elf_headers);
image->elf_headers = NULL;
image->elf_headers_sz = 0;
kvfree(image->arch.fdt);
image->arch.fdt = NULL;
return kexec_image_post_load_cleanup_default(image);
}