linux/arch/powerpc/kexec/file_load_64.c

805 lines
22 KiB
C
Raw Normal View History

// 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 <asm/drmem.h>
#include <asm/kexec_ranges.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 crash_mem_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;
}
/**
* __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, &memblock.memory, NULL, NUMA_NO_NODE,
MEMBLOCK_NONE, &start, &end, NULL) {
/*
* 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, &memblock.memory, NULL, NUMA_NO_NODE,
MEMBLOCK_NONE, &start, &end, NULL) {
/*
* 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");
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);
goto out;
}
}
out:
kfree(um_info.buf);
return ret;
}
/**
* 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)
{
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;
}
out:
if (ret)
pr_err("Failed to setup purgatory symbols");
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;
int ret;
ret = setup_new_fdt(image, fdt, initrd_load_addr, initrd_len, cmdline);
if (ret)
goto out;
/*
* Restrict memory usage for kdump kernel by setting up
* usable memory ranges.
*/
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 */
ret = fdt_add_mem_rsv(fdt, 0, crashk_res.start);
if (ret) {
pr_err("Error reserving crash memory: %s\n",
fdt_strerror(ret));
goto out;
}
}
out:
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;
/*
* Use the generic kexec_locate_mem_hole for regular
* kexec_file_load syscall
*/
if (kbuf->image->type != KEXEC_TYPE_CRASH)
return kexec_locate_mem_hole(kbuf);
/* 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);
}
/* Segments for kdump kernel should be within crashkernel region */
buf_min = (kbuf->buf_min < crashk_res.start ?
crashk_res.start : kbuf->buf_min);
buf_max = (kbuf->buf_max > crashk_res.end ?
crashk_res.end : kbuf->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)
{
if (image->type == KEXEC_TYPE_CRASH) {
int ret;
/* Get exclude memory ranges needed for setting up kdump 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 this until all changes for panic kernel are in */
return -EOPNOTSUPP;
}
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;
return kexec_image_post_load_cleanup_default(image);
}