powerpc, kexec_file: factor out memblock-based arch_kexec_walk_mem()

Memblock list is another source for usable system memory layout.
So move powerpc's arch_kexec_walk_mem() to common code so that other
memblock-based architectures, particularly arm64, can also utilise it.
A moved function is now renamed to kexec_walk_memblock() and integrated
into kexec_locate_mem_hole(), which will now be usable for all
architectures with no need for overriding arch_kexec_walk_mem().

With this change, arch_kexec_walk_mem() need no longer be a weak function,
and was now renamed to kexec_walk_resources().

Since powerpc doesn't support kdump in its kexec_file_load(), the current
kexec_walk_memblock() won't work for kdump either in this form, this will
be fixed in the next patch.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Acked-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/arch/powerpc/kernel/machine_kexec_file_64.c b/arch/powerpc/kernel/machine_kexec_file_64.c
index c77e95e..0d20c7a 100644 (file)
--- a/arch/powerpc/kernel/machine_kexec_file_64.c
+++ b/arch/powerpc/kernel/machine_kexec_file_64.c
@@ -24,7 +24,6 @@
 
 #include <linux/slab.h>
 #include <linux/kexec.h>
-#include <linux/memblock.h>
 #include <linux/of_fdt.h>
 #include <linux/libfdt.h>
 #include <asm/ima.h>
@@ -47,59 +46,6 @@ int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
 }
 
 /**
- * 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)(struct resource *, void *))
-{
-       int ret = 0;
-       u64 i;
-       phys_addr_t mstart, mend;
-       struct resource res = { };
-
-       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.
-                        */
-                       res.start = mstart;
-                       res.end = mend - 1;
-                       ret = func(&res, 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.
-                        */
-                       res.start = mstart;
-                       res.end = mend - 1;
-                       ret = func(&res, kbuf);
-                       if (ret)
-                               break;
-               }
-       }
-
-       return ret;
-}
-
-/**
  * setup_purgatory - initialize the purgatory's global variables
  * @image:             kexec image.
  * @slave_code:                Slave code for the purgatory.

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index f378cb7..d58d1f2 100644 (file)
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -192,8 +192,6 @@ int __weak arch_kexec_apply_relocations(struct purgatory_info *pi,
                                        const Elf_Shdr *relsec,
                                        const Elf_Shdr *symtab);
 
-int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
-                              int (*func)(struct resource *, void *));
 extern int kexec_add_buffer(struct kexec_buf *kbuf);
 int kexec_locate_mem_hole(struct kexec_buf *kbuf);
 

diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 9e6529d..d03195a 100644 (file)
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -16,6 +16,7 @@
 #include <linux/file.h>
 #include <linux/slab.h>
 #include <linux/kexec.h>
+#include <linux/memblock.h>
 #include <linux/mutex.h>
 #include <linux/list.h>
 #include <linux/fs.h>
@@ -499,8 +500,57 @@ static int locate_mem_hole_callback(struct resource *res, void *arg)
        return locate_mem_hole_bottom_up(start, end, kbuf);
 }
 
+#ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
+static int kexec_walk_memblock(struct kexec_buf *kbuf,
+                              int (*func)(struct resource *, void *))
+{
+       return 0;
+}
+#else
+static int kexec_walk_memblock(struct kexec_buf *kbuf,
+                              int (*func)(struct resource *, void *))
+{
+       int ret = 0;
+       u64 i;
+       phys_addr_t mstart, mend;
+       struct resource res = { };
+
+       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.
+                        */
+                       res.start = mstart;
+                       res.end = mend - 1;
+                       ret = func(&res, 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.
+                        */
+                       res.start = mstart;
+                       res.end = mend - 1;
+                       ret = func(&res, kbuf);
+                       if (ret)
+                               break;
+               }
+       }
+
+       return ret;
+}
+#endif
+
 /**
- * arch_kexec_walk_mem - call func(data) on free memory regions
+ * kexec_walk_resources - call func(data) on free memory regions
  * @kbuf:      Context info for the search. Also passed to @func.
  * @func:      Function to call for each memory region.
  *
@@ -508,8 +558,8 @@ static int locate_mem_hole_callback(struct resource *res, void *arg)
  * and that value will be returned. If all free regions are visited without
  * func returning non-zero, then zero will be returned.
  */
-int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
-                              int (*func)(struct resource *, void *))
+static int kexec_walk_resources(struct kexec_buf *kbuf,
+                               int (*func)(struct resource *, void *))
 {
        if (kbuf->image->type == KEXEC_TYPE_CRASH)
                return walk_iomem_res_desc(crashk_res.desc,
@@ -536,7 +586,10 @@ int kexec_locate_mem_hole(struct kexec_buf *kbuf)
        if (kbuf->mem != KEXEC_BUF_MEM_UNKNOWN)
                return 0;
 
-       ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback);
+       if (IS_ENABLED(CONFIG_ARCH_DISCARD_MEMBLOCK))
+               ret = kexec_walk_resources(kbuf, locate_mem_hole_callback);
+       else
+               ret = kexec_walk_memblock(kbuf, locate_mem_hole_callback);
 
        return ret == 1 ? 0 : -EADDRNOTAVAIL;
 }