From 7651defa19abf480166a4d2f4d6c416bf30d0ab8 Mon Sep 17 00:00:00 2001
From: Hollis Blanchard <hollisb@us.ibm.com>
Date: Thu, 27 Jul 2006 17:44:14 -0500
Subject: [PATCH] [powerpc] implement per-cpu data areas, based on x86 code
 Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>

---
 xen/arch/powerpc/Makefile               |  3 +++
 xen/arch/powerpc/setup.c                | 36 +++++++++++++++++++++++++
 xen/arch/powerpc/{xen.lds => xen.lds.S} | 13 +++++++++
 xen/include/asm-powerpc/percpu.h        | 22 +++++++++++++++
 4 files changed, 74 insertions(+)
 rename xen/arch/powerpc/{xen.lds => xen.lds.S} (96%)
 create mode 100644 xen/include/asm-powerpc/percpu.h

diff --git a/xen/arch/powerpc/Makefile b/xen/arch/powerpc/Makefile
index 050d4d82ca..2634acbdf6 100644
--- a/xen/arch/powerpc/Makefile
+++ b/xen/arch/powerpc/Makefile
@@ -109,6 +109,9 @@ $(TARGET): boot32.o $(TARGET).bin.o
 asm-offsets.s: $(TARGET_SUBARCH)/asm-offsets.c $(HDRS)
 	$(CC) $(CFLAGS) -S -o $@ $<
 
+xen.lds: xen.lds.S $(HDRS)
+	$(CC) $(CFLAGS) -P -E $(AFLAGS) -o $@ $<
+
 dom0.bin: $(DOM0_IMAGE)
 	cp $< $@
 
diff --git a/xen/arch/powerpc/setup.c b/xen/arch/powerpc/setup.c
index 176328c827..dbb4dfe0b8 100644
--- a/xen/arch/powerpc/setup.c
+++ b/xen/arch/powerpc/setup.c
@@ -40,6 +40,7 @@
 #include <asm/cache.h>
 #include <asm/debugger.h>
 #include <asm/delay.h>
+#include <asm/percpu.h>
 #include "exceptions.h"
 #include "of-devtree.h"
 
@@ -68,6 +69,7 @@ cpumask_t cpu_online_map; /* missing ifdef in schedule.c */
 ulong isa_io_base;
 struct ns16550_defaults ns16550;
 
+extern char __per_cpu_start[], __per_cpu_data_end[], __per_cpu_end[];
 extern void idle_loop(void);
 
 /* move us to a header file */
@@ -117,6 +119,36 @@ static void hw_probe_attn(unsigned char key, struct cpu_user_regs *regs)
     asm volatile(".long 0x00000200; nop");
 }
 
+static void percpu_init_areas(void)
+{
+    unsigned int i, data_size = __per_cpu_data_end - __per_cpu_start;
+
+    BUG_ON(data_size > PERCPU_SIZE);
+
+    for ( i = 1; i < NR_CPUS; i++ )
+        memcpy(__per_cpu_start + (i << PERCPU_SHIFT),
+               __per_cpu_start,
+               data_size);
+}
+
+static void percpu_free_unused_areas(void)
+{
+    unsigned int i, first_unused;
+
+    /* Find first unused CPU number. */
+    for ( i = 0; i < NR_CPUS; i++ )
+        if ( !cpu_online(i) )
+            break;
+    first_unused = i;
+
+    /* Check that there are no holes in cpu_online_map. */
+    for ( ; i < NR_CPUS; i++ )
+        BUG_ON(cpu_online(i));
+
+    init_xenheap_pages((ulong)__per_cpu_start + (first_unused << PERCPU_SHIFT),
+                       (ulong)__per_cpu_end);
+}
+
 static void __init start_of_day(void)
 {
     struct domain *idle_domain;
@@ -135,6 +167,8 @@ static void __init start_of_day(void)
     /* for some reason we need to set our own bit in the thread map */
     cpu_set(0, cpu_sibling_map[0]);
 
+    percpu_free_unused_areas();
+
     initialize_keytable();
     /* Register another key that will allow for the the Harware Probe
      * to be contacted, this works with RiscWatch probes and should
@@ -265,6 +299,8 @@ static void __init __start_xen(multiboot_info_t *mbi)
     ofd_walk((void *)oftree, OFD_ROOT, ofd_dump_props, OFD_DUMP_ALL);
 #endif
 
+    percpu_init_areas();
+
     /* mark all memory from modules onward as unused */
     init_boot_pages(freemem, eomem);
 
diff --git a/xen/arch/powerpc/xen.lds b/xen/arch/powerpc/xen.lds.S
similarity index 96%
rename from xen/arch/powerpc/xen.lds
rename to xen/arch/powerpc/xen.lds.S
index b4ac9c48a6..9449bc9aba 100644
--- a/xen/arch/powerpc/xen.lds
+++ b/xen/arch/powerpc/xen.lds.S
@@ -1,3 +1,7 @@
+#include <asm/config.h>
+#include <asm/page.h>
+#include <asm/percpu.h>
+
 /* Script for -z combreloc: combine and sort reloc sections */
 OUTPUT_FORMAT("elf64-powerpc", "elf64-powerpc",
 	      "elf64-powerpc")
@@ -104,6 +108,7 @@ SECTIONS
   }
 
   /* Xen addition */
+
   . = ALIGN(32);
   __setup_start = .;
   .setup.init : { *(.setup.init) }
@@ -114,6 +119,14 @@ SECTIONS
   __inithcall_start = .;
   .inithcall.text : { *(.inithcall.text) }
   __inithcall_end = .;
+
+  __per_cpu_start = .;
+  .data.percpu : { *(.data.percpu) } :text
+  __per_cpu_data_end = .;
+  . = __per_cpu_start + (NR_CPUS << PERCPU_SHIFT);
+  . = ALIGN(STACK_SIZE);
+  __per_cpu_end = .;
+
   /* end Xen addition */
 
   .data1          : { *(.data1) }
diff --git a/xen/include/asm-powerpc/percpu.h b/xen/include/asm-powerpc/percpu.h
new file mode 100644
index 0000000000..59d62d64a7
--- /dev/null
+++ b/xen/include/asm-powerpc/percpu.h
@@ -0,0 +1,22 @@
+/* from xen/include/asm-x86/percpu.h */
+
+#ifndef __PPC_PERCPU_H__
+#define __PPC_PERCPU_H__
+
+#define PERCPU_SHIFT 12
+#define PERCPU_SIZE  (1UL << PERCPU_SHIFT)
+
+/* Separate out the type, so (int[3], foo) works. */
+#define DEFINE_PER_CPU(type, name)                      \
+    __attribute__((__section__(".data.percpu")))        \
+    __typeof__(type) per_cpu__##name
+
+/* var is in discarded region: offset to particular copy we want */
+#define per_cpu(var, cpu)  \
+    (*RELOC_HIDE(&per_cpu__##var, ((unsigned int)(cpu))<<PERCPU_SHIFT))
+#define __get_cpu_var(var) \
+    (per_cpu(var, smp_processor_id()))
+
+#define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu__##name
+
+#endif /* __PPC_PERCPU_H__ */
-- 
2.30.2