Re: [PATCH v10 2/8] powerpc: Move delete_fdt_mem_rsv() to drivers/of/kexec.c
From: Lakshmi Ramasubramanian
Date: Sun Dec 06 2020 - 20:52:47 EST
On 12/4/20 6:22 PM, Thiago Jung Bauermann wrote:
Hello Lakshmi,
Lakshmi Ramasubramanian <nramas@xxxxxxxxxxxxxxxxxxx> writes:
delete_fdt_mem_rsv() retrieves the memory reserve map entry, for
the given starting address and size, from the device tree blob, and
removes the entry from the device tree blob. This function is called
to free the resources reserved for the buffer used for carrying forward
the IMA measurement logs on kexec. This function does not have
architecture specific code, but is currently limited to powerpc.
Move delete_fdt_mem_rsv() to "drivers/of/kexec_fdt.c" so that it is
s/kexec_fdt.c/kexec.c/
Missed that in the patch description. Will fix it. Thanks.
accessible for other architectures as well.
Co-developed-by: Prakhar Srivastava <prsriva@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Prakhar Srivastava <prsriva@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Lakshmi Ramasubramanian <nramas@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/kexec.h | 1 -
arch/powerpc/kexec/file_load.c | 32 -----------------
drivers/of/Makefile | 1 +
drivers/of/kexec.c | 61 ++++++++++++++++++++++++++++++++
include/linux/kexec.h | 5 +++
5 files changed, 67 insertions(+), 33 deletions(-)
create mode 100644 drivers/of/kexec.c
diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index 55d6ede30c19..7c223031ecdd 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -126,7 +126,6 @@ int setup_purgatory(struct kimage *image, const void *slave_code,
int setup_new_fdt(const struct kimage *image, void *fdt,
unsigned long initrd_load_addr, unsigned long initrd_len,
const char *cmdline);
-int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size);
#ifdef CONFIG_PPC64
struct kexec_buf;
diff --git a/arch/powerpc/kexec/file_load.c b/arch/powerpc/kexec/file_load.c
index 9a232bc36c8f..9efc98b1e2ae 100644
--- a/arch/powerpc/kexec/file_load.c
+++ b/arch/powerpc/kexec/file_load.c
@@ -109,38 +109,6 @@ int setup_purgatory(struct kimage *image, const void *slave_code,
return 0;
}
-/**
- * delete_fdt_mem_rsv - delete memory reservation with given address and size
- *
- * Return: 0 on success, or negative errno on error.
- */
-int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size)
-{
- int i, ret, num_rsvs = fdt_num_mem_rsv(fdt);
-
- for (i = 0; i < num_rsvs; i++) {
- uint64_t rsv_start, rsv_size;
-
- ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size);
- if (ret) {
- pr_err("Malformed device tree.\n");
- return -EINVAL;
- }
-
- if (rsv_start == start && rsv_size == size) {
- ret = fdt_del_mem_rsv(fdt, i);
- if (ret) {
- pr_err("Error deleting device tree reservation.\n");
- return -EINVAL;
- }
-
- return 0;
- }
- }
-
- return -ENOENT;
-}
-
/*
* setup_new_fdt - modify /chosen and memory reservation for the next kernel
* @image: kexec image being loaded.
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index 6e1e5212f058..77d24712c0c8 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -13,5 +13,6 @@ obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o
obj-$(CONFIG_OF_RESOLVE) += resolver.o
obj-$(CONFIG_OF_OVERLAY) += overlay.o
obj-$(CONFIG_OF_NUMA) += of_numa.o
+obj-$(CONFIG_OF_FLATTREE) += kexec.o
Isn't this too broad? kexec.o will only be useful to kernel configs
which enable CONFIG_KEXEC_FILE, so perhaps do:
ifdef CONFIG_OF_FLATTREE
ifdef CONFIG_KEXEC_FILE
obj-y += kexec.o
endif
endif
What do you think?
Per Rob's feedback on v9 patch set, I have moved all the architecture
independent ima kexec functions to a single file "drivers/of/kexec.c"
Since these functions are enabled on different kernel CONFIGs, I have
used IS_ENABLED(CONFIG_XYZ) macro instead of "#ifdef" in the C file to
conditionally compile.
obj-$(CONFIG_OF_UNITTEST) += unittest-data/
diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
new file mode 100644
index 000000000000..b7d59105fcb8
--- /dev/null
+++ b/drivers/of/kexec.c
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Microsoft Corporation
+ *
+ * Author: Lakshmi Ramasubramanian (nramas@xxxxxxxxxxxxxxxxxxx)
+ *
+ * File: kexec.c
+ * Defines kexec related functions.
+ */
+
+#define pr_fmt(fmt) "OF: kexec: " fmt
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/memblock.h>
+#include <linux/kexec.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/libfdt.h>
+
+/**
+ * delete_fdt_mem_rsv - delete memory reservation with given address and size
+ *
+ * @fdt: Flattened Device Tree to update
+ * @start: Starting address of the reservation to delete
+ * @size: Size of the reservation to delete
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size)
+{
+ int i, ret, num_rsvs;
+
+ if (!IS_ENABLED(CONFIG_KEXEC_FILE))
+ return 0;
If you agree with my suggestion, then this IS_ENABLED() wouldn't be
needed.
Please see my response above.
If there is a way to keep all the ima kexec functions in a single file
and yet not use "#ifdef" in C file to conditionally compile, please let
me know. I'll update.
thanks,
-lakshmi
+
+ num_rsvs = fdt_num_mem_rsv(fdt);
+ for (i = 0; i < num_rsvs; i++) {
+ uint64_t rsv_start, rsv_size;
+
+ ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size);
+ if (ret) {
+ pr_err("Malformed device tree.\n");
+ return -EINVAL;
+ }
+
+ if (rsv_start == start && rsv_size == size) {
+ ret = fdt_del_mem_rsv(fdt, i);
+ if (ret) {
+ pr_err("Error deleting device tree reservation.\n");
+ return -EINVAL;
+ }
+
+ pr_debug("Freed reserved memory at %lu of size %lu\n",
+ start, size);
+ return 0;
+ }
+ }
+
+ return -ENOENT;
+}
The function code is unchanged apart from the addition of the
IS_ENABLED() and the pr_debug(), so that is good.
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 9e93bef52968..d0234c4815da 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -407,6 +407,11 @@ static inline int kexec_crash_loaded(void) { return 0; }
#define kexec_in_progress false
#endif /* CONFIG_KEXEC_CORE */
+#if defined(CONFIG_OF_FLATTREE)
This would also change to require CONFIG_KEXEC_FILE.
+extern int delete_fdt_mem_rsv(void *fdt, unsigned long start,
+ unsigned long size);
+#endif /* CONFIG_OF_FLATTREE */
+
#endif /* !defined(__ASSEBMLY__) */
#endif /* LINUX_KEXEC_H */