lkml.org 
[lkml]   [2018]   [Nov]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v16 06/16] lib: fdt: add a helper function for handling memory range property
Date
Added function, fdt_setprop_reg(), will be used later to handle
kexec-specific property in arm64's kexec_file implementation.
It will possibly be merged into libfdt in the future.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: devicetree@vger.kernel.org
---
include/linux/libfdt.h | 26 ++++++++++++++++++++
lib/Makefile | 2 +-
lib/fdt_addresses.c | 56 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 83 insertions(+), 1 deletion(-)
create mode 100644 lib/fdt_addresses.c

diff --git a/include/linux/libfdt.h b/include/linux/libfdt.h
index 90ed4ebfa692..47c4dc9e135c 100644
--- a/include/linux/libfdt.h
+++ b/include/linux/libfdt.h
@@ -5,4 +5,30 @@
#include <linux/libfdt_env.h>
#include "../../scripts/dtc/libfdt/libfdt.h"

+/**
+ * fdt_setprop_reg - add/set a memory region property
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node to add a property at
+ * @name: name of property
+ * @addr: physical start address
+ * @size: size of region
+ *
+ * returns:
+ * 0, on success
+ * -FDT_ERR_BADLAYOUT,
+ * -FDT_ERR_BADMAGIC,
+ * -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
+ * #address-cells property
+ * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ * -FDT_ERR_BADSTATE,
+ * -FDT_ERR_BADSTRUCTURE,
+ * -FDT_ERR_BADVERSION,
+ * -FDT_ERR_BADVALUE, addr or size doesn't fit to respective cells size
+ * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
+ * contain a new property
+ * -FDT_ERR_TRUNCATED, standard meanings
+ */
+int fdt_setprop_reg(void *fdt, int nodeoffset, const char *name,
+ u64 addr, u64 size);
+
#endif /* _INCLUDE_LIBFDT_H_ */
diff --git a/lib/Makefile b/lib/Makefile
index db06d1237898..2a96cb05e15d 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -205,7 +205,7 @@ KASAN_SANITIZE_stackdepot.o := n
KCOV_INSTRUMENT_stackdepot.o := n

libfdt_files = fdt.o fdt_ro.o fdt_wip.o fdt_rw.o fdt_sw.o fdt_strerror.o \
- fdt_empty_tree.o
+ fdt_empty_tree.o fdt_addresses.o
$(foreach file, $(libfdt_files), \
$(eval CFLAGS_$(file) = -I$(src)/../scripts/dtc/libfdt))
lib-$(CONFIG_LIBFDT) += $(libfdt_files)
diff --git a/lib/fdt_addresses.c b/lib/fdt_addresses.c
new file mode 100644
index 000000000000..97ddd5a5cc10
--- /dev/null
+++ b/lib/fdt_addresses.c
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/libfdt_env.h>
+#include <linux/types.h>
+#include "../scripts/dtc/libfdt/fdt_addresses.c"
+
+/*
+ * helper functions for arm64 kexec
+ * Those functions may be merged into libfdt in the future.
+ */
+
+/* This function assumes that cells is 1 or 2 */
+static void cpu64_to_fdt_cells(void *buf, u64 val64, int cells)
+{
+ __be32 val32;
+
+ while (cells) {
+ val32 = cpu_to_fdt32(val64 >> (32 * (--cells)));
+ memcpy(buf, &val32, sizeof(val32));
+ buf += sizeof(val32);
+ }
+}
+
+int fdt_setprop_reg(void *fdt, int nodeoffset, const char *name,
+ u64 addr, u64 size)
+{
+ int addr_cells, size_cells;
+ char buf[sizeof(__be32) * 2 * 2];
+ /* assume dt_root_[addr|size]_cells <= 2 */
+ void *prop;
+ size_t buf_size;
+
+ addr_cells = fdt_address_cells(fdt, 0);
+ if (addr_cells < 0)
+ return addr_cells;
+ size_cells = fdt_size_cells(fdt, 0);
+ if (size_cells < 0)
+ return size_cells;
+
+ /* if *_cells >= 2, cells can hold 64-bit values anyway */
+ if ((addr_cells == 1) && ((addr > U32_MAX) ||
+ ((addr + size) > U32_MAX)))
+ return -FDT_ERR_BADVALUE;
+
+ if ((size_cells == 1) && (size > U32_MAX))
+ return -FDT_ERR_BADVALUE;
+
+ buf_size = (addr_cells + size_cells) * sizeof(u32);
+ prop = buf;
+
+ cpu64_to_fdt_cells(prop, addr, addr_cells);
+ prop += addr_cells * sizeof(u32);
+
+ cpu64_to_fdt_cells(prop, size, size_cells);
+
+ return fdt_setprop(fdt, nodeoffset, name, buf, buf_size);
+}
--
2.19.0
\
 
 \ /
  Last update: 2018-11-15 06:53    [W:0.183 / U:3.576 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site