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[4/5] xen/ppc: Parse device tree for OPAL node on PowerNV

Message ID fc4011f42ea017ec9ae12c4f1a0c1a09b7bbcfc8.1690579561.git.sanastasio@raptorengineering.com (mailing list archive)
State Superseded
Headers show
Series xen/ppc: Add PowerNV bare metal support | expand

Commit Message

Shawn Anastasio July 28, 2023, 9:35 p.m. UTC
Communication with firmware boot services on PowerNV requires parsing
the fdt blob passed by the bootloader in order to obtain the firmware
entrypoint. Use Xen's libfdt to do this and store the information
required for firmware calls, to be implemented in a future patch.

The full xen/common build doesn't yet work, but libfdt and its xen/lib
dependency can be made to build by defining a few stub headers.

Signed-off-by: Shawn Anastasio <sanastasio@raptorengineering.com>
---
 xen/arch/ppc/Kconfig                 |  1 +
 xen/arch/ppc/Makefile                |  1 +
 xen/arch/ppc/arch.mk                 |  4 +--
 xen/arch/ppc/include/asm/boot.h      | 16 +++++++++-
 xen/arch/ppc/include/asm/bug.h       | 18 +++++++++++
 xen/arch/ppc/include/asm/cache.h     |  6 ++++
 xen/arch/ppc/include/asm/processor.h | 13 +++++++-
 xen/arch/ppc/include/asm/string.h    |  6 ++++
 xen/arch/ppc/include/asm/system.h    |  6 ++++
 xen/arch/ppc/opal.c                  | 48 ++++++++++++++++++++++++++++
 xen/arch/ppc/setup.c                 |  9 ++++--
 11 files changed, 122 insertions(+), 6 deletions(-)
 create mode 100644 xen/arch/ppc/include/asm/bug.h
 create mode 100644 xen/arch/ppc/include/asm/cache.h
 create mode 100644 xen/arch/ppc/include/asm/string.h
 create mode 100644 xen/arch/ppc/include/asm/system.h
 create mode 100644 xen/arch/ppc/opal.c

Comments

Jan Beulich July 31, 2023, 4:06 p.m. UTC | #1
On 28.07.2023 23:35, Shawn Anastasio wrote:
> --- a/xen/arch/ppc/arch.mk
> +++ b/xen/arch/ppc/arch.mk
> @@ -10,5 +10,5 @@ CFLAGS += -mstrict-align -mcmodel=medium -mabi=elfv2 -fPIC -mno-altivec -mno-vsx
>  LDFLAGS += -m elf64lppc
>  
>  # TODO: Drop override when more of the build is working
> -override ALL_OBJS-y = arch/$(SRCARCH)/built_in.o
> -override ALL_LIBS-y =
> +override ALL_OBJS-y = arch/$(SRCARCH)/built_in.o common/libfdt/built_in.o lib/built_in.o
> +override ALL_LIBS-y = lib/lib.a

Can't you drop the ALL_LIBS-y override right here?

Jan
Shawn Anastasio Aug. 1, 2023, 6:24 p.m. UTC | #2
On 7/31/23 11:06 AM, Jan Beulich wrote:
> On 28.07.2023 23:35, Shawn Anastasio wrote:
>> --- a/xen/arch/ppc/arch.mk
>> +++ b/xen/arch/ppc/arch.mk
>> @@ -10,5 +10,5 @@ CFLAGS += -mstrict-align -mcmodel=medium -mabi=elfv2 -fPIC -mno-altivec -mno-vsx
>>  LDFLAGS += -m elf64lppc
>>  
>>  # TODO: Drop override when more of the build is working
>> -override ALL_OBJS-y = arch/$(SRCARCH)/built_in.o
>> -override ALL_LIBS-y =
>> +override ALL_OBJS-y = arch/$(SRCARCH)/built_in.o common/libfdt/built_in.o lib/built_in.o
>> +override ALL_LIBS-y = lib/lib.a
> 
> Can't you drop the ALL_LIBS-y override right here?

Just tested this and it does indeed work. I'll drop the override in v2.

> Jan

Thanks,
Shawn
diff mbox series

Patch

diff --git a/xen/arch/ppc/Kconfig b/xen/arch/ppc/Kconfig
index a2ade2ecf4..b32dce39b8 100644
--- a/xen/arch/ppc/Kconfig
+++ b/xen/arch/ppc/Kconfig
@@ -1,5 +1,6 @@ 
 config PPC
 	def_bool y
+	select HAS_DEVICE_TREE
 
 config PPC64
 	def_bool y
diff --git a/xen/arch/ppc/Makefile b/xen/arch/ppc/Makefile
index 098a4dd0a9..0c0a7884a1 100644
--- a/xen/arch/ppc/Makefile
+++ b/xen/arch/ppc/Makefile
@@ -2,6 +2,7 @@  obj-$(CONFIG_PPC64) += ppc64/
 
 obj-y += boot-of.init.o
 obj-$(CONFIG_EARLY_PRINTK) += early_printk.init.o
+obj-y += opal.o
 obj-y += setup.o
 
 $(TARGET): $(TARGET)-syms
diff --git a/xen/arch/ppc/arch.mk b/xen/arch/ppc/arch.mk
index 0183b9ac6a..9f66f7a57b 100644
--- a/xen/arch/ppc/arch.mk
+++ b/xen/arch/ppc/arch.mk
@@ -10,5 +10,5 @@  CFLAGS += -mstrict-align -mcmodel=medium -mabi=elfv2 -fPIC -mno-altivec -mno-vsx
 LDFLAGS += -m elf64lppc
 
 # TODO: Drop override when more of the build is working
-override ALL_OBJS-y = arch/$(SRCARCH)/built_in.o
-override ALL_LIBS-y =
+override ALL_OBJS-y = arch/$(SRCARCH)/built_in.o common/libfdt/built_in.o lib/built_in.o
+override ALL_LIBS-y = lib/lib.a
diff --git a/xen/arch/ppc/include/asm/boot.h b/xen/arch/ppc/include/asm/boot.h
index 9b8a7c43c2..296539cd9e 100644
--- a/xen/arch/ppc/include/asm/boot.h
+++ b/xen/arch/ppc/include/asm/boot.h
@@ -4,7 +4,10 @@ 
 
 #include <xen/types.h>
 
-/* a collection of interfaces used during boot. */
+/*
+ * OpenFirmware boot interfaces
+ */
+
 enum {
     OF_FAILURE = -1,
     OF_SUCCESS = 0,
@@ -20,4 +23,15 @@  struct of_service {
 int enter_of(struct of_service *args, unsigned long entry);
 void boot_of_init(unsigned long vec);
 
+/*
+ * OPAL boot interfaces
+ */
+
+struct opal {
+    uint64_t base;
+    uint64_t entry;
+};
+
+void boot_opal_init(const void *fdt);
+
 #endif /* _ASM_PPC_BOOT_H */
diff --git a/xen/arch/ppc/include/asm/bug.h b/xen/arch/ppc/include/asm/bug.h
new file mode 100644
index 0000000000..e5e874b31c
--- /dev/null
+++ b/xen/arch/ppc/include/asm/bug.h
@@ -0,0 +1,18 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ASM_PPC_BUG_H
+#define _ASM_PPC_BUG_H
+
+#include <xen/stringify.h>
+
+/*
+ * Power ISA guarantees that an instruction consisting of all zeroes is
+ * illegal.
+ */
+#define BUG_OPCODE  0x00000000
+
+#define BUG_INSTR ".long " __stringify(BUG_OPCODE)
+
+#define BUG_FN_REG r0
+
+#endif /* _ASM_PPC_BUG_H */
diff --git a/xen/arch/ppc/include/asm/cache.h b/xen/arch/ppc/include/asm/cache.h
new file mode 100644
index 0000000000..8a0a6b7b17
--- /dev/null
+++ b/xen/arch/ppc/include/asm/cache.h
@@ -0,0 +1,6 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ASM_PPC_CACHE_H
+#define _ASM_PPC_CACHE_H
+
+#endif /* _ASM_PPC_CACHE_H */
diff --git a/xen/arch/ppc/include/asm/processor.h b/xen/arch/ppc/include/asm/processor.h
index 838d279508..2300640787 100644
--- a/xen/arch/ppc/include/asm/processor.h
+++ b/xen/arch/ppc/include/asm/processor.h
@@ -133,6 +133,17 @@  struct cpu_user_regs
     uint32_t entry_vector;
 };
 
-#endif
+/*
+ * panic() isn't available at the moment so an infinite loop will be
+ * used temporarily.
+ * TODO: change it to panic()
+ */
+static inline void noreturn die(void)
+{
+    for ( ; ; )
+        HMT_very_low();
+}
+
+#endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_PPC_PROCESSOR_H */
diff --git a/xen/arch/ppc/include/asm/string.h b/xen/arch/ppc/include/asm/string.h
new file mode 100644
index 0000000000..7a420e05e4
--- /dev/null
+++ b/xen/arch/ppc/include/asm/string.h
@@ -0,0 +1,6 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ASM_PPC_STRING_H
+#define _ASM_PPC_STRING_H
+
+#endif /* _ASM_PPC_STRING_H */
diff --git a/xen/arch/ppc/include/asm/system.h b/xen/arch/ppc/include/asm/system.h
new file mode 100644
index 0000000000..94091df644
--- /dev/null
+++ b/xen/arch/ppc/include/asm/system.h
@@ -0,0 +1,6 @@ 
+#ifndef _ASM_SYSTEM_H_
+#define _ASM_SYSTEM_H_
+
+#define smp_wmb() __asm__ __volatile__ ( "lwsync" : : : "memory" )
+
+#endif /* _ASM_SYSTEM_H */
diff --git a/xen/arch/ppc/opal.c b/xen/arch/ppc/opal.c
new file mode 100644
index 0000000000..251de8ac23
--- /dev/null
+++ b/xen/arch/ppc/opal.c
@@ -0,0 +1,48 @@ 
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#include <asm/boot.h>
+#include <asm/early_printk.h>
+#include <asm/opal-api.h>
+#include <asm/processor.h>
+#include <xen/types.h>
+#include <xen/libfdt/libfdt.h>
+#include <xen/init.h>
+#include <xen/lib.h>
+
+/* Global OPAL struct containing entrypoint and base */
+struct opal opal;
+
+void __init boot_opal_init(const void *fdt)
+{
+    int opal_node;
+    const __be64 *opal_base;
+    const __be64 *opal_entry;
+
+    if ( fdt_check_header(fdt) < 0 )
+    {
+        /*
+         * NOTE: This won't actually print since the early serial
+         * console isn't set up yet.
+         */
+        early_printk("Booted without valid FDT pointer in r3!\n");
+        die();
+    }
+
+    opal_node = fdt_path_offset(fdt, "/ibm,opal");
+    if ( opal_node < 0 )
+    {
+        early_printk("Unable to find ibm,opal node!\n");
+        die();
+    }
+
+    opal_base = fdt_getprop(fdt, opal_node, "opal-base-address", NULL);
+    opal_entry = fdt_getprop(fdt, opal_node, "opal-entry-address", NULL);
+    if ( !opal_base || !opal_entry )
+    {
+        early_printk("Failed to get opal-base-address/opal-entry-address "
+                     "property from DT!\n");
+        die();
+    }
+
+    opal.base = be64_to_cpu(*opal_base);
+    opal.entry = be64_to_cpu(*opal_entry);
+}
diff --git a/xen/arch/ppc/setup.c b/xen/arch/ppc/setup.c
index 7c623a49f5..bacd6d1acd 100644
--- a/xen/arch/ppc/setup.c
+++ b/xen/arch/ppc/setup.c
@@ -18,8 +18,13 @@  void __init noreturn start_xen(unsigned long r3, unsigned long r4,
     }
     else
     {
-        /* kexec boot: Unimplemented */
-        __builtin_trap();
+        /*
+         * kexec boot protocol
+         *
+         * TODO: This currently assumes an OPAL/PowerNV system, but it's also
+         * possible to be kexec'd on an OF system.
+         */
+        boot_opal_init((void *) r3);
     }
 
     early_printk("Hello, ppc64le!\n");