[PATCH v17 04/10] powerpc: Use common of_kexec_alloc_and_setup_fdt()

From: Lakshmi Ramasubramanian
Date: Tue Feb 09 2021 - 15:05:24 EST

From: Rob Herring <robh@xxxxxxxxxx>

The code for setting up the /chosen node in the device tree
and updating the memory reservation for the next kernel has been
moved to of_kexec_alloc_and_setup_fdt() defined in "drivers/of/kexec.c".

Use the common of_kexec_alloc_and_setup_fdt() to setup the device tree
and update the memory reservation for kexec for powerpc.

Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Lakshmi Ramasubramanian <nramas@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/kexec.h | 1 +
arch/powerpc/kexec/elf_64.c | 29 ++++---
arch/powerpc/kexec/file_load.c | 132 +-----------------------------
arch/powerpc/kexec/file_load_64.c | 3 +
4 files changed, 25 insertions(+), 140 deletions(-)

diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index dbf09d2f36d0..bdd0ddb9ac4d 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -111,6 +111,7 @@ struct kimage_arch {
unsigned long elf_headers_mem;
unsigned long elf_headers_sz;
void *elf_headers;
+ void *fdt;

#ifdef CONFIG_IMA_KEXEC
phys_addr_t ima_buffer_addr;
diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c
index d0e459bb2f05..bfabd06f99b1 100644
--- a/arch/powerpc/kexec/elf_64.c
+++ b/arch/powerpc/kexec/elf_64.c
@@ -19,6 +19,7 @@
#include <linux/kexec.h>
#include <linux/libfdt.h>
#include <linux/module.h>
+#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/slab.h>
#include <linux/types.h>
@@ -29,7 +30,6 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
unsigned long cmdline_len)
{
int ret;
- unsigned int fdt_size;
unsigned long kernel_load_addr;
unsigned long initrd_load_addr = 0, fdt_load_addr;
void *fdt;
@@ -102,19 +102,13 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
pr_debug("Loaded initrd at 0x%lx\n", initrd_load_addr);
}

- fdt_size = fdt_totalsize(initial_boot_params) * 2;
- fdt = kmalloc(fdt_size, GFP_KERNEL);
+ fdt = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr,
+ initrd_len, cmdline);
if (!fdt) {
pr_err("Not enough memory for the device tree.\n");
ret = -ENOMEM;
goto out;
}
- ret = fdt_open_into(initial_boot_params, fdt, fdt_size);
- if (ret < 0) {
- pr_err("Error setting up the new device tree.\n");
- ret = -EINVAL;
- goto out;
- }

ret = setup_new_fdt_ppc64(image, fdt, initrd_load_addr,
initrd_len, cmdline);
@@ -124,13 +118,17 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
fdt_pack(fdt);

kbuf.buffer = fdt;
- kbuf.bufsz = kbuf.memsz = fdt_size;
+ kbuf.bufsz = kbuf.memsz = fdt_totalsize(fdt);
kbuf.buf_align = PAGE_SIZE;
kbuf.top_down = true;
kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
ret = kexec_add_buffer(&kbuf);
if (ret)
goto out;
+
+ /* FDT will be freed in arch_kimage_file_post_load_cleanup */
+ image->arch.fdt = fdt;
+
fdt_load_addr = kbuf.mem;

pr_debug("Loaded device tree at 0x%lx\n", fdt_load_addr);
@@ -145,8 +143,15 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
kfree(modified_cmdline);
kexec_free_elf_info(&elf_info);

- /* Make kimage_file_post_load_cleanup free the fdt buffer for us. */
- return ret ? ERR_PTR(ret) : fdt;
+ /*
+ * Once FDT buffer has been successfully passed to kexec_add_buffer(),
+ * the FDT buffer address is saved in image->arch.fdt. In that case,
+ * the memory cannot be freed here in case of any other error.
+ */
+ if (ret && !image->arch.fdt)
+ kvfree(fdt);
+
+ return ret ? ERR_PTR(ret) : NULL;
}

const struct kexec_file_ops kexec_elf64_ops = {
diff --git a/arch/powerpc/kexec/file_load.c b/arch/powerpc/kexec/file_load.c
index e452b11df631..d23e2969395c 100644
--- a/arch/powerpc/kexec/file_load.c
+++ b/arch/powerpc/kexec/file_load.c
@@ -156,135 +156,11 @@ int setup_new_fdt(const struct kimage *image, void *fdt,
unsigned long initrd_load_addr, unsigned long initrd_len,
const char *cmdline)
{
- int ret, chosen_node;
- const void *prop;
-
- /* Remove memory reservation for the current device tree. */
- ret = delete_fdt_mem_rsv(fdt, __pa(initial_boot_params),
- fdt_totalsize(initial_boot_params));
- if (ret == 0)
- pr_debug("Removed old device tree reservation.\n");
- else if (ret != -ENOENT)
- return ret;
-
- chosen_node = fdt_path_offset(fdt, "/chosen");
- if (chosen_node == -FDT_ERR_NOTFOUND) {
- chosen_node = fdt_add_subnode(fdt, fdt_path_offset(fdt, "/"),
- "chosen");
- if (chosen_node < 0) {
- pr_err("Error creating /chosen.\n");
- return -EINVAL;
- }
- } else if (chosen_node < 0) {
- pr_err("Malformed device tree: error reading /chosen.\n");
- return -EINVAL;
- }
-
- /* Did we boot using an initrd? */
- prop = fdt_getprop(fdt, chosen_node, "linux,initrd-start", NULL);
- if (prop) {
- uint64_t tmp_start, tmp_end, tmp_size;
-
- tmp_start = fdt64_to_cpu(*((const fdt64_t *) prop));
-
- prop = fdt_getprop(fdt, chosen_node, "linux,initrd-end", NULL);
- if (!prop) {
- pr_err("Malformed device tree.\n");
- return -EINVAL;
- }
- tmp_end = fdt64_to_cpu(*((const fdt64_t *) prop));
-
- /*
- * kexec reserves exact initrd size, while firmware may
- * reserve a multiple of PAGE_SIZE, so check for both.
- */
- tmp_size = tmp_end - tmp_start;
- ret = delete_fdt_mem_rsv(fdt, tmp_start, tmp_size);
- if (ret == -ENOENT)
- ret = delete_fdt_mem_rsv(fdt, tmp_start,
- round_up(tmp_size, PAGE_SIZE));
- if (ret == 0)
- pr_debug("Removed old initrd reservation.\n");
- else if (ret != -ENOENT)
- return ret;
-
- /* If there's no new initrd, delete the old initrd's info. */
- if (initrd_len == 0) {
- ret = fdt_delprop(fdt, chosen_node,
- "linux,initrd-start");
- if (ret) {
- pr_err("Error deleting linux,initrd-start.\n");
- return -EINVAL;
- }
-
- ret = fdt_delprop(fdt, chosen_node, "linux,initrd-end");
- if (ret) {
- pr_err("Error deleting linux,initrd-end.\n");
- return -EINVAL;
- }
- }
- }
-
- if (initrd_len) {
- ret = fdt_setprop_u64(fdt, chosen_node,
- "linux,initrd-start",
- initrd_load_addr);
- if (ret < 0)
- goto err;
-
- /* initrd-end is the first address after the initrd image. */
- ret = fdt_setprop_u64(fdt, chosen_node, "linux,initrd-end",
- initrd_load_addr + initrd_len);
- if (ret < 0)
- goto err;
-
- ret = fdt_add_mem_rsv(fdt, initrd_load_addr, initrd_len);
- if (ret) {
- pr_err("Error reserving initrd memory: %s\n",
- fdt_strerror(ret));
- return -EINVAL;
- }
- }
-
- if (cmdline != NULL) {
- ret = fdt_setprop_string(fdt, chosen_node, "bootargs", cmdline);
- if (ret < 0)
- goto err;
- } else {
- ret = fdt_delprop(fdt, chosen_node, "bootargs");
- if (ret && ret != -FDT_ERR_NOTFOUND) {
- pr_err("Error deleting bootargs.\n");
- return -EINVAL;
- }
- }
-
- if (image->type == KEXEC_TYPE_CRASH) {
- /*
- * Avoid elfcorehdr from being stomped on in kdump kernel by
- * setting up memory reserve map.
- */
- ret = fdt_add_mem_rsv(fdt, image->arch.elf_headers_mem,
- image->arch.elf_headers_sz);
- if (ret) {
- pr_err("Error reserving elfcorehdr memory: %s\n",
- fdt_strerror(ret));
- goto err;
- }
- }
-
- ret = setup_ima_buffer(image, fdt, chosen_node);
- if (ret) {
- pr_err("Error setting up the new device tree.\n");
- return ret;
- }
+ int ret;

- ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0);
+ ret = setup_ima_buffer(image, fdt, fdt_path_offset(fdt, "/chosen"));
if (ret)
- goto err;
-
- return 0;
+ pr_err("Error setting up the new device tree.\n");

-err:
- pr_err("Error setting up the new device tree.\n");
- return -EINVAL;
+ return ret;
}
diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c
index a05c19b3cc60..dac3d29c7c77 100644
--- a/arch/powerpc/kexec/file_load_64.c
+++ b/arch/powerpc/kexec/file_load_64.c
@@ -1111,5 +1111,8 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image)
image->arch.elf_headers = NULL;
image->arch.elf_headers_sz = 0;

+ kvfree(image->arch.fdt);
+ image->arch.fdt = NULL;
+
return kexec_image_post_load_cleanup_default(image);
}
--
2.30.0