The patch titled
Subject: powerpc: kexec_file: add buffer hand-over support for the next kernel
has been added to the -mm tree. Its filename is
powerpc-kexec_file-add-buffer-hand-over-support-for-the-next-kernel.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/powerpc-kexec_file-add-buffer-hand-over-support-for-the-next-kernel.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/powerpc-kexec_file-add-buffer-hand-over-support-for-the-next-kernel.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxxxxxxx>
Subject: powerpc: kexec_file: add buffer hand-over support for the next kernel
The buffer hand-over mechanism allows the currently running kernel to pass
data to kernel that will be kexec'd via a kexec segment. The second kernel
can check whether the previous kernel sent data and retrieve it.
This is the architecture-specific part.
Link: http://lkml.kernel.org/r/1472149111-30598-3-git-send-email-bauerman@xxxxxxxxxxxxxxxxxx
Signed-off-by: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxxxxxxx>
Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Dave Young <dyoung@xxxxxxxxxx>
Cc: Vivek Goyal <vgoyal@xxxxxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Stewart Smith <stewart@xxxxxxxxxxxxxxxxxx>
Cc: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
Cc: Eric Richter <erichte@xxxxxxxxxxxxxxxxxx>
Cc: Balbir Singh <bsingharora@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/kexec.h | 12 ++
arch/powerpc/kernel/kexec_elf_64.c | 2
arch/powerpc/kernel/machine_kexec_64.c | 114 +++++++++++++++++++++--
3 files changed, 120 insertions(+), 8 deletions(-)
diff -puN arch/powerpc/include/asm/kexec.h~powerpc-kexec_file-add-buffer-hand-over-support-for-the-next-kernel arch/powerpc/include/asm/kexec.h
--- a/arch/powerpc/include/asm/kexec.h~powerpc-kexec_file-add-buffer-hand-over-support-for-the-next-kernel
+++ a/arch/powerpc/include/asm/kexec.h
@@ -92,12 +92,20 @@ static inline bool kdump_in_progress(voi
}
#ifdef CONFIG_KEXEC_FILE
+#define ARCH_HAS_KIMAGE_ARCH
+
+struct kimage_arch {
+ phys_addr_t handover_buffer_addr;
+ unsigned long handover_buffer_size;
+};
+
int setup_purgatory(struct kimage *image, const void *slave_code,
const void *fdt, unsigned long kernel_load_addr,
unsigned long fdt_load_addr, unsigned long stack_top,
int debug);
-int setup_new_fdt(void *fdt, unsigned long initrd_load_addr,
- unsigned long initrd_len, const char *cmdline);
+int setup_new_fdt(const struct kimage *image, void *fdt,
+ unsigned long initrd_load_addr, unsigned long initrd_len,
+ const char *cmdline);
bool find_debug_console(const void *fdt);
#endif /* CONFIG_KEXEC_FILE */
diff -puN arch/powerpc/kernel/kexec_elf_64.c~powerpc-kexec_file-add-buffer-hand-over-support-for-the-next-kernel arch/powerpc/kernel/kexec_elf_64.c
--- a/arch/powerpc/kernel/kexec_elf_64.c~powerpc-kexec_file-add-buffer-hand-over-support-for-the-next-kernel
+++ a/arch/powerpc/kernel/kexec_elf_64.c
@@ -209,7 +209,7 @@ void *elf64_load(struct kimage *image, c
goto out;
}
- ret = setup_new_fdt(fdt, initrd_load_addr, initrd_len, cmdline);
+ ret = setup_new_fdt(image, fdt, initrd_load_addr, initrd_len, cmdline);
if (ret)
goto out;
diff -puN arch/powerpc/kernel/machine_kexec_64.c~powerpc-kexec_file-add-buffer-hand-over-support-for-the-next-kernel arch/powerpc/kernel/machine_kexec_64.c
--- a/arch/powerpc/kernel/machine_kexec_64.c~powerpc-kexec_file-add-buffer-hand-over-support-for-the-next-kernel
+++ a/arch/powerpc/kernel/machine_kexec_64.c
@@ -489,6 +489,60 @@ int arch_kimage_file_post_load_cleanup(s
return image->fops->cleanup(image->image_loader_data);
}
+bool kexec_can_hand_over_buffer(void)
+{
+ return true;
+}
+
+int arch_kexec_add_handover_buffer(struct kimage *image,
+ unsigned long load_addr, unsigned long size)
+{
+ image->arch.handover_buffer_addr = load_addr;
+ image->arch.handover_buffer_size = size;
+
+ return 0;
+}
+
+int kexec_get_handover_buffer(void **addr, unsigned long *size)
+{
+ int ret;
+ u64 start_addr, end_addr;
+
+ ret = of_property_read_u64(of_chosen,
+ "linux,kexec-handover-buffer-start",
+ &start_addr);
+ if (ret == -EINVAL)
+ return -ENOENT;
+ else if (ret)
+ return -EINVAL;
+
+ ret = of_property_read_u64(of_chosen, "linux,kexec-handover-buffer-end",
+ &end_addr);
+ if (ret == -EINVAL)
+ return -ENOENT;
+ else if (ret)
+ return -EINVAL;
+
+ *addr = __va(start_addr);
+ /* -end is the first address after the buffer. */
+ *size = end_addr - start_addr;
+
+ return 0;
+}
+
+int kexec_free_handover_buffer(void)
+{
+ int ret;
+ void *addr;
+ unsigned long size;
+
+ ret = kexec_get_handover_buffer(&addr, &size);
+ if (ret)
+ return ret;
+
+ return memblock_free((phys_addr_t) addr, size);
+}
+
/**
* arch_kexec_walk_mem() - call func(data) for each unreserved memory block
* @kbuf: Context info for the search. Also passed to @func.
@@ -686,9 +740,52 @@ int setup_purgatory(struct kimage *image
return 0;
}
-/*
- * setup_new_fdt() - modify /chosen and memory reservation for the next kernel
- * @fdt:
+/**
+ * setup_handover_buffer() - add properties and reservation for the handover buffer
+ * @image: kexec image being loaded.
+ * @fdt: Flattened device tree for the next kernel.
+ * @chosen_node: Offset to the chosen node.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+static int setup_handover_buffer(const struct kimage *image, void *fdt,
+ int chosen_node)
+{
+ int ret;
+
+ if (image->arch.handover_buffer_addr == 0)
+ return 0;
+
+ ret = fdt_setprop_u64(fdt, chosen_node,
+ "linux,kexec-handover-buffer-start",
+ image->arch.handover_buffer_addr);
+ if (ret < 0)
+ return -EINVAL;
+
+ /* -end is the first address after the buffer. */
+ ret = fdt_setprop_u64(fdt, chosen_node,
+ "linux,kexec-handover-buffer-end",
+ image->arch.handover_buffer_addr +
+ image->arch.handover_buffer_size);
+ if (ret < 0)
+ return -EINVAL;
+
+ ret = fdt_add_mem_rsv(fdt, image->arch.handover_buffer_addr,
+ image->arch.handover_buffer_size);
+ if (ret)
+ return -EINVAL;
+
+ pr_debug("kexec handover buffer at 0x%llx, size = 0x%lx\n",
+ image->arch.handover_buffer_addr,
+ image->arch.handover_buffer_size);
+
+ return 0;
+}
+
+/**
+ * setup_new_fdt() - modify /chosen and memory reservations for the next kernel
+ * @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
@@ -696,8 +793,9 @@ int setup_purgatory(struct kimage *image
*
* Return: 0 on success, or negative errno on error.
*/
-int setup_new_fdt(void *fdt, unsigned long initrd_load_addr,
- unsigned long initrd_len, const char *cmdline)
+int setup_new_fdt(const struct kimage *image, void *fdt,
+ unsigned long initrd_load_addr, unsigned long initrd_len,
+ const char *cmdline)
{
uint64_t oldfdt_addr;
int i, ret, chosen_node;
@@ -839,6 +937,12 @@ int setup_new_fdt(void *fdt, unsigned lo
}
}
+ ret = setup_handover_buffer(image, fdt, chosen_node);
+ if (ret) {
+ pr_err("Error setting up the new device tree.\n");
+ return ret;
+ }
+
ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0);
if (ret) {
pr_err("Error setting up the new device tree.\n");
_
Patches currently in -mm which might be from bauerman@xxxxxxxxxxxxxxxxxx are
kexec_file-allow-arch-specific-memory-walking-for-kexec_add_buffer.patch
kexec_file-change-kexec_add_buffer-to-take-kexec_buf-as-argument.patch
kexec_file-factor-out-kexec_locate_mem_hole-from-kexec_add_buffer.patch
powerpc-factor-out-relocation-code-from-module_64c-to-elf_util_64c.patch
powerpc-generalize-elf64_apply_relocate_add.patch
powerpc-adapt-elf64_apply_relocate_add-for-kexec_file_load.patch
powerpc-add-functions-to-read-elf-files-of-any-endianness.patch
powerpc-implement-kexec_file_load.patch
powerpc-add-code-to-work-with-device-trees-in-kexec_file_load.patch
powerpc-add-support-for-loading-elf-kernels-with-kexec_file_load.patch
powerpc-add-purgatory-for-kexec_file_load-implementation.patch
powerpc-enable-config_kexec_file-in-powerpc-server-defconfigs.patch
kexec_file-add-buffer-hand-over-support-for-the-next-kernel.patch
powerpc-kexec_file-add-buffer-hand-over-support-for-the-next-kernel.patch
kexec_file-allow-skipping-checksum-calculation-for-some-segments.patch
kexec_file-add-mechanism-to-update-kexec-segments.patch
ima-demonstration-code-for-kexec-buffer-passing.patch
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