arch_kexec_walk_mem and arch_kexec_apply_relocations_add are used by
generic kexec code, while setup_purgatory is powerpc-specific and sets
runtime variables needed by the powerpc purgatory implementation.

Signed-off-by: Josh Sklar <sk...@linux.vnet.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauer...@linux.vnet.ibm.com>
---
 arch/powerpc/Kconfig                   |  13 ++
 arch/powerpc/include/asm/kexec.h       |   7 +
 arch/powerpc/include/asm/systbl.h      |   1 +
 arch/powerpc/include/asm/unistd.h      |   2 +-
 arch/powerpc/include/uapi/asm/unistd.h |   1 +
 arch/powerpc/kernel/Makefile           |   4 +-
 arch/powerpc/kernel/machine_kexec_64.c | 252 +++++++++++++++++++++++++++++++++
 7 files changed, 278 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 140a1b84019a..41300c3a1bfe 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -460,6 +460,19 @@ config KEXEC
          interface is strongly in flux, so no good recommendation can be
          made.
 
+config KEXEC_FILE
+       bool "kexec file based system call"
+       select KEXEC_CORE
+       select BUILD_BIN2C
+       depends on PPC64
+       depends on CRYPTO=y
+       depends on CRYPTO_SHA256=y
+       help
+         This is a new version of the kexec system call. This call is
+         file based and takes in file descriptors as system call arguments
+         for kernel and initramfs as opposed to a list of segments as is the
+         case for the older kexec call.
+
 config RELOCATABLE
        bool "Build a relocatable kernel"
        depends on (PPC64 && !COMPILE_TEST) || (FLATMEM && (44x || FSL_BOOKE))
diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index eca2f975bf44..0c7e020d935a 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -91,6 +91,13 @@ static inline bool kdump_in_progress(void)
        return crashing_cpu >= 0;
 }
 
+#ifdef CONFIG_KEXEC_FILE
+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);
+#endif /* CONFIG_KEXEC_FILE */
+
 #else /* !CONFIG_KEXEC_CORE */
 static inline void crash_kexec_secondary(struct pt_regs *regs) { }
 
diff --git a/arch/powerpc/include/asm/systbl.h 
b/arch/powerpc/include/asm/systbl.h
index 2fc5d4db503c..4b369d83fe9c 100644
--- a/arch/powerpc/include/asm/systbl.h
+++ b/arch/powerpc/include/asm/systbl.h
@@ -386,3 +386,4 @@ SYSCALL(mlock2)
 SYSCALL(copy_file_range)
 COMPAT_SYS_SPU(preadv2)
 COMPAT_SYS_SPU(pwritev2)
+SYSCALL(kexec_file_load)
diff --git a/arch/powerpc/include/asm/unistd.h 
b/arch/powerpc/include/asm/unistd.h
index cf12c580f6b2..a01e97d3f305 100644
--- a/arch/powerpc/include/asm/unistd.h
+++ b/arch/powerpc/include/asm/unistd.h
@@ -12,7 +12,7 @@
 #include <uapi/asm/unistd.h>
 
 
-#define NR_syscalls            382
+#define NR_syscalls            383
 
 #define __NR__exit __NR_exit
 
diff --git a/arch/powerpc/include/uapi/asm/unistd.h 
b/arch/powerpc/include/uapi/asm/unistd.h
index e9f5f41aa55a..2f26335a3c42 100644
--- a/arch/powerpc/include/uapi/asm/unistd.h
+++ b/arch/powerpc/include/uapi/asm/unistd.h
@@ -392,5 +392,6 @@
 #define __NR_copy_file_range   379
 #define __NR_preadv2           380
 #define __NR_pwritev2          381
+#define __NR_kexec_file_load   382
 
 #endif /* _UAPI_ASM_POWERPC_UNISTD_H_ */
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index fd6b7b96d93d..fef0d730acc4 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -123,9 +123,11 @@ ifneq ($(CONFIG_PPC_INDIRECT_PIO),y)
 obj-y                          += iomap.o
 endif
 
-ifeq ($(CONFIG_MODULES)$(CONFIG_WORD_SIZE),y64)
+ifneq ($(CONFIG_MODULES)$(CONFIG_KEXEC_FILE),)
+ifeq ($(CONFIG_WORD_SIZE),64)
 obj-y                          += elf_util.o elf_util_64.o
 endif
+endif
 
 obj64-$(CONFIG_PPC_TRANSACTIONAL_MEM)  += tm.o
 
diff --git a/arch/powerpc/kernel/machine_kexec_64.c 
b/arch/powerpc/kernel/machine_kexec_64.c
index 4c780a342282..1e678dc5096a 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -18,6 +18,8 @@
 #include <linux/kernel.h>
 #include <linux/cpu.h>
 #include <linux/hardirq.h>
+#include <linux/memblock.h>
+#include <linux/libfdt.h>
 
 #include <asm/page.h>
 #include <asm/current.h>
@@ -31,6 +33,12 @@
 #include <asm/hw_breakpoint.h>
 #include <asm/asm-prototypes.h>
 
+#define SLAVE_CODE_SIZE                256
+
+#ifdef CONFIG_KEXEC_FILE
+static struct kexec_file_ops *kexec_file_loaders[] = { };
+#endif
+
 #ifdef CONFIG_PPC_BOOK3E
 int default_machine_kexec_prepare(struct kimage *image)
 {
@@ -432,3 +440,247 @@ static int __init export_htab_values(void)
 }
 late_initcall(export_htab_values);
 #endif /* CONFIG_PPC_STD_MMU_64 */
+
+#ifdef CONFIG_KEXEC_FILE
+int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
+                                 unsigned long buf_len)
+{
+       int i, ret = -ENOEXEC;
+       struct kexec_file_ops *fops;
+
+       /* We don't support crash kernels yet. */
+       if (image->type == KEXEC_TYPE_CRASH)
+               return -ENOTSUPP;
+
+       for (i = 0; i < ARRAY_SIZE(kexec_file_loaders); i++) {
+               fops = kexec_file_loaders[i];
+               if (!fops || !fops->probe)
+                       continue;
+
+               ret = fops->probe(buf, buf_len);
+               if (!ret) {
+                       image->fops = fops;
+                       return ret;
+               }
+       }
+
+       return ret;
+}
+
+void *arch_kexec_kernel_image_load(struct kimage *image)
+{
+       if (!image->fops || !image->fops->load)
+               return ERR_PTR(-ENOEXEC);
+
+       return image->fops->load(image, image->kernel_buf,
+                                image->kernel_buf_len, image->initrd_buf,
+                                image->initrd_buf_len, image->cmdline_buf,
+                                image->cmdline_buf_len);
+}
+
+int arch_kimage_file_post_load_cleanup(struct kimage *image)
+{
+       if (!image->fops || !image->fops->cleanup)
+               return 0;
+
+       return image->fops->cleanup(image->image_loader_data);
+}
+
+/**
+ * arch_kexec_walk_mem() - call func(data) for each unreserved memory block
+ * @kbuf:      Context info for the search. Also passed to @func.
+ * @func:      Function to call for each memory block.
+ *
+ * This function is used by kexec_add_buffer and kexec_locate_mem_hole
+ * to find unreserved memory to load kexec segments into.
+ *
+ * Return: The memory walk will stop when func returns a non-zero value
+ * and that value will be returned. If all free regions are visited without
+ * func returning non-zero, then zero will be returned.
+ */
+int arch_kexec_walk_mem(struct kexec_buf *kbuf, int (*func)(u64, u64, void *))
+{
+       int ret = 0;
+       u64 i;
+       phys_addr_t mstart, mend;
+
+       if (kbuf->top_down) {
+               for_each_free_mem_range_reverse(i, NUMA_NO_NODE, 0,
+                                               &mstart, &mend, NULL) {
+                       /*
+                        * In memblock, end points to the first byte after the
+                        * range while in kexec, end points to the last byte
+                        * in the range.
+                        */
+                       ret = func(mstart, mend - 1, kbuf);
+                       if (ret)
+                               break;
+               }
+       } else {
+               for_each_free_mem_range(i, NUMA_NO_NODE, 0, &mstart, &mend,
+                                       NULL) {
+                       /*
+                        * In memblock, end points to the first byte after the
+                        * range while in kexec, end points to the last byte
+                        * in the range.
+                        */
+                       ret = func(mstart, mend - 1, kbuf);
+                       if (ret)
+                               break;
+               }
+       }
+
+       return ret;
+}
+
+/**
+ * arch_kexec_apply_relocations_add() - apply purgatory relocations
+ * @ehdr:      Pointer to ELF headers.
+ * @sechdrs:   Pointer to section headers.
+ * @relsec:    Section index of SHT_RELA section.
+ *
+ * Elf64_Shdr.sh_offset has been modified to keep the pointer to the section
+ * contents, while Elf64_Shdr.sh_addr points to the final address of the
+ * section in memory.
+ */
+int arch_kexec_apply_relocations_add(const Elf64_Ehdr *ehdr,
+                                    Elf64_Shdr *sechdrs, unsigned int relsec)
+{
+       /* Section containing the relocation entries. */
+       Elf64_Shdr *rel_section = &sechdrs[relsec];
+       const Elf64_Rela *rela = (const Elf64_Rela *) rel_section->sh_offset;
+       unsigned int num_rela = rel_section->sh_size / sizeof(Elf64_Rela);
+       /* Section to which relocations apply. */
+       Elf64_Shdr *target_section = &sechdrs[rel_section->sh_info];
+       /* Associated symbol table. */
+       Elf64_Shdr *symtabsec = &sechdrs[rel_section->sh_link];
+       void *syms_base = (void *) symtabsec->sh_offset;
+       void *loc_base = (void *) target_section->sh_offset;
+       Elf64_Addr addr_base = target_section->sh_addr;
+       struct elf_info elf_info;
+       const char *strtab;
+
+       if (symtabsec->sh_link >= ehdr->e_shnum) {
+               /* Invalid strtab section number */
+               pr_err("Invalid string table section index %d\n",
+                      symtabsec->sh_link);
+               return -ENOEXEC;
+       }
+       /* String table for the associated symbol table. */
+       strtab = (const char *) sechdrs[symtabsec->sh_link].sh_offset;
+
+       elf_init_elf_info(ehdr, sechdrs, &elf_info);
+
+       return elf64_apply_relocate_add(&elf_info, strtab, rela, num_rela,
+                                       syms_base, loc_base, addr_base,
+                                       true, true, "kexec purgatory");
+}
+
+/**
+ * setup_purgatory() - setup the purgatory runtime variables
+ * @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.
+ * @stack_top:         Address where the purgatory can place its stack.
+ * @debug:             Can the purgatory print messages to the console?
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+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 ret, tree_node;
+       const void *prop;
+       unsigned long opal_base, opal_entry;
+       uint64_t toc;
+       unsigned int *slave_code_buf, master_entry;
+       struct elf_info purg_info;
+
+       slave_code_buf = kmalloc(SLAVE_CODE_SIZE, GFP_KERNEL);
+       if (!slave_code_buf)
+               return -ENOMEM;
+
+       /* Get the slave code from the new kernel and put it in purgatory. */
+       ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
+                                            slave_code_buf, SLAVE_CODE_SIZE,
+                                            true);
+       if (ret) {
+               kfree(slave_code_buf);
+               return ret;
+       }
+
+       master_entry = slave_code_buf[0];
+       memcpy(slave_code_buf, slave_code, SLAVE_CODE_SIZE);
+       slave_code_buf[0] = master_entry;
+       ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
+                                            slave_code_buf, SLAVE_CODE_SIZE,
+                                            false);
+       kfree(slave_code_buf);
+
+       ret = kexec_purgatory_get_set_symbol(image, "kernel", &kernel_load_addr,
+                                            sizeof(kernel_load_addr), false);
+       if (ret)
+               return ret;
+       ret = kexec_purgatory_get_set_symbol(image, "dt_offset", &fdt_load_addr,
+                                            sizeof(fdt_load_addr), false);
+       if (ret)
+               return ret;
+
+       tree_node = fdt_path_offset(fdt, "/ibm,opal");
+       if (tree_node >= 0) {
+               prop = fdt_getprop(fdt, tree_node, "opal-base-address", NULL);
+               if (!prop) {
+                       pr_err("OPAL address not found in the device tree.\n");
+                       return -EINVAL;
+               }
+               opal_base = fdt64_to_cpu((const fdt64_t *) prop);
+
+               prop = fdt_getprop(fdt, tree_node, "opal-entry-address", NULL);
+               if (!prop) {
+                       pr_err("OPAL address not found in the device tree.\n");
+                       return -EINVAL;
+               }
+               opal_entry = fdt64_to_cpu((const fdt64_t *) prop);
+
+               ret = kexec_purgatory_get_set_symbol(image, "opal_base",
+                                                    &opal_base,
+                                                    sizeof(opal_base), false);
+               if (ret)
+                       return ret;
+               ret = kexec_purgatory_get_set_symbol(image, "opal_entry",
+                                                    &opal_entry,
+                                                    sizeof(opal_entry), false);
+               if (ret)
+                       return ret;
+       }
+
+       ret = kexec_purgatory_get_set_symbol(image, "stack", &stack_top,
+                                            sizeof(stack_top), false);
+       if (ret)
+               return ret;
+
+       elf_init_elf_info(image->purgatory_info.ehdr,
+                         image->purgatory_info.sechdrs, &purg_info);
+       toc = my_r2(&purg_info);
+       ret = kexec_purgatory_get_set_symbol(image, "my_toc", &toc, sizeof(toc),
+                                            false);
+       if (ret)
+               return ret;
+
+       pr_debug("Purgatory TOC is at 0x%llx\n", toc);
+
+       ret = kexec_purgatory_get_set_symbol(image, "debug", &debug,
+                                            sizeof(debug), false);
+       if (ret)
+               return ret;
+       if (!debug)
+               pr_debug("Disabling purgatory output.\n");
+
+       return 0;
+}
+
+#endif /* CONFIG_KEXEC_FILE */
-- 
1.9.1

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