[Minios-devel] [UNIKRAFT RFC PATCH] plat/common:Add helper to simplify accessing fdt for arm

[Jianyong Wu <Jianyong.Wu@xxxxxxx>]

Wrap some reading ops on dtb like reading property
and address conversion op to simplify acquiring
device address for arm.

Signed-off-by: Wei Chen <wei.chen@xxxxxxx>
Signed-off-by: Jianyong Wu <jianyong.wu@xxxxxxx>
---
 plat/common/arm/fdt.c         | 103 ++++++++++++++++++++++++++++++++++++++++++
 plat/common/include/arm/fdt.h |  46 +++++++++++++++++++
 plat/kvm/Makefile.uk          |   1 +
 3 files changed, 150 insertions(+)
 create mode 100644 plat/common/arm/fdt.c
 create mode 100644 plat/common/include/arm/fdt.h

diff --git a/plat/common/arm/fdt.c b/plat/common/arm/fdt.c
new file mode 100644
index 0000000..172f344
--- /dev/null
+++ b/plat/common/arm/fdt.c
@@ -0,0 +1,103 @@
+/* SPDX-License-Identifier: ISC */
+/*
+ * Authors: Wei Chen <Wei.Chen@xxxxxxx>
+ * Authors: Jianyong Wu <Jianyong.Wu@xxxxxxx>
+ *
+ * Copyright (c) 2018 Arm Ltd.
+ *
+ * Permission to use, copy, modify, and/or distribute this software
+ * for any purpose with or without fee is hereby granted, provided
+ * that the above copyright notice and this permission notice appear
+ * in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+ * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
+ * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+ * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+#include <libfdt.h>
+#include <kvm/console.h>
+#include <uk/assert.h>
+#include <kvm-arm/mm.h>
+#include <arm/cpu.h>
+#include <arm/fdt.h>
+#include <uk/arch/limits.h>
+
+void *_libkvmplat_dtb;
+
+/*
+ * uk_dtb_find_device find device offset in dtb by
+ * searching device list
+ */
+int uk_dtb_find_device(const char *device_list[],
+       uint32_t size)
+{
+       uint32_t idx;
+       int device = -1;
+
+       for (idx = 0;
+               idx < size / sizeof(device_list[0]);
+               idx++) {
+               device = fdt_node_offset_by_compatible(_libkvmplat_dtb, -1,
+               device_list[idx]);
+               if (device >= 0)
+               break;
+       }
+
+       return device;
+}
+
+/*
+ * uk_dtb_read_reg read specified device address and
+ * size in reg region from dtb
+ */
+uint64_t uk_dtb_read_reg(int device, uint32_t index,
+       uint64_t *size)
+{
+       int  prop_len, prop_min_len;
+       uint32_t naddr, nsize, term_size;
+       uint64_t addr;
+       fdt32_t *regs;
+
+       UK_ASSERT(device != -1);
+       naddr = fdt_address_cells(_libkvmplat_dtb, device);
+       UK_ASSERT(naddr < FDT_MAX_NCELLS);
+
+       nsize = fdt_size_cells(_libkvmplat_dtb, device);
+       UK_ASSERT(nsize < FDT_MAX_NCELLS);
+
+       regs = fdt_getprop(_libkvmplat_dtb, device, "reg", &prop_len);
+       prop_min_len = (int)sizeof(fdt32_t) * (naddr + nsize);
+       UK_ASSERT(regs != NULL && prop_len >= prop_min_len);
+
+       term_size = nsize + naddr;
+       index = index * term_size;
+       if(sizeof(fdt32_t) * (index + 1) > prop_len)
+               UK_CRASH("too large index\n");
+
+       addr = uk_dtb_read_number(regs + index, naddr);
+
+       *size = uk_dtb_read_number(regs + index + naddr, nsize);
+
+       return addr;
+}
+
+/* this reads a number from a given dtb cell address */
+uint64_t uk_dtb_read_number(fdt32_t *regs, uint32_t size)
+{
+       uint64_t number = 0;
+       UK_ASSERT(size < 3 && size > 0);
+
+       for(uint32_t i = 0; i < size; i++)
+       {
+               number <<= 32;
+               number |= fdt32_to_cpu(*regs);
+               regs++;
+       }
+
+       return number;
+}
diff --git a/plat/common/include/arm/fdt.h b/plat/common/include/arm/fdt.h
new file mode 100644
index 0000000..a958b6f
--- /dev/null
+++ b/plat/common/include/arm/fdt.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Authors: Wei Chen <wei.chen@xxxxxxx>
+ * Authors: Jianyong Wu <Jianyong.Wu@xxxxxxx>
+ *
+ * Copyright (c) 2018, Arm Ltd. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.
+ */
+
+#ifndef __PLAT_CMN_ARM_FDT_H__
+#define __PLAT_CMN_ARM_FDT_H__
+
+extern void *_libkvmplat_dtb;
+
+int uk_dtb_find_device(const char *device_list[],
+       uint32_t size);
+uint64_t uk_dtb_read_reg(int device, uint32_t index,
+        uint64_t *size);
+uint64_t uk_dtb_read_number(fdt32_t *regs, uint32_t size);
+#endif /* __PLAT_CMN_ARM_FDT_H__ */
diff --git a/plat/kvm/Makefile.uk b/plat/kvm/Makefile.uk
index 1f9c5dc..8e481b4 100644
--- a/plat/kvm/Makefile.uk
+++ b/plat/kvm/Makefile.uk
@@ -59,6 +59,7 @@ LIBKVMPLAT_SRCS-$(CONFIG_ARCH_ARM_64) += 
$(UK_PLAT_COMMON_BASE)/arm/cache64.S|co
 LIBKVMPLAT_SRCS-$(CONFIG_ARCH_ARM_64) += 
$(UK_PLAT_COMMON_BASE)/arm/psci_arm64.S|common
 LIBKVMPLAT_SRCS-$(CONFIG_ARCH_ARM_64) += 
$(UK_PLAT_COMMON_BASE)/arm/time.c|common
 LIBKVMPLAT_SRCS-$(CONFIG_ARCH_ARM_64) += 
$(UK_PLAT_COMMON_BASE)/arm/traps.c|common
+LIBKVMPLAT_SRCS-$(CONFIG_ARCH_ARM_64) += 
$(UK_PLAT_COMMON_BASE)/arm/fdt.c|common
 LIBKVMPLAT_SRCS-$(CONFIG_ARCH_ARM_64) += $(LIBKVMPLAT_BASE)/arm/entry64.S
 LIBKVMPLAT_SRCS-$(CONFIG_ARCH_ARM_64) += $(LIBKVMPLAT_BASE)/arm/exceptions.S
 LIBKVMPLAT_SRCS-$(CONFIG_ARCH_ARM_64) += $(LIBKVMPLAT_BASE)/arm/pagetable.S
-- 
2.7.4


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