x86/oprofile: introduce oprofile_add_data64()

The IBS implemention writes 64 bit register values to the cpu buffer
by writing two 32 values using oprofile_add_data(). This patch
introduces oprofile_add_data64() to write a single 64 bit value to the
buffer.
Signed-off-by: Robert Richter <robert.richter@amd.com>

arch/x86/oprofile/op_model_amd.c

@@ -140,13 +140,10 @@ op_amd_handle_ibs(struct pt_regs * const regs,
 			rdmsrl(MSR_AMD64_IBSFETCHLINAD, val);
 			oprofile_write_reserve(&entry, regs, val,
 					       IBS_FETCH_CODE, IBS_FETCH_SIZE);
-			oprofile_add_data(&entry, (u32)val);
-			oprofile_add_data(&entry, (u32)(val >> 32));
-			oprofile_add_data(&entry, (u32)ctl);
-			oprofile_add_data(&entry, (u32)(ctl >> 32));
+			oprofile_add_data64(&entry, val);
+			oprofile_add_data64(&entry, ctl);
 			rdmsrl(MSR_AMD64_IBSFETCHPHYSAD, val);
-			oprofile_add_data(&entry, (u32)val);
-			oprofile_add_data(&entry, (u32)(val >> 32));
+			oprofile_add_data64(&entry, val);
 			oprofile_write_commit(&entry);
 
 			/* reenable the IRQ */
@@ -162,23 +159,17 @@ op_amd_handle_ibs(struct pt_regs * const regs,
 			rdmsrl(MSR_AMD64_IBSOPRIP, val);
 			oprofile_write_reserve(&entry, regs, val,
 					       IBS_OP_CODE, IBS_OP_SIZE);
-			oprofile_add_data(&entry, (u32)val);
-			oprofile_add_data(&entry, (u32)(val >> 32));
+			oprofile_add_data64(&entry, val);
 			rdmsrl(MSR_AMD64_IBSOPDATA, val);
-			oprofile_add_data(&entry, (u32)val);
-			oprofile_add_data(&entry, (u32)(val >> 32));
+			oprofile_add_data64(&entry, val);
 			rdmsrl(MSR_AMD64_IBSOPDATA2, val);
-			oprofile_add_data(&entry, (u32)val);
-			oprofile_add_data(&entry, (u32)(val >> 32));
+			oprofile_add_data64(&entry, val);
 			rdmsrl(MSR_AMD64_IBSOPDATA3, val);
-			oprofile_add_data(&entry, (u32)val);
-			oprofile_add_data(&entry, (u32)(val >> 32));
+			oprofile_add_data64(&entry, val);
 			rdmsrl(MSR_AMD64_IBSDCLINAD, val);
-			oprofile_add_data(&entry, (u32)val);
-			oprofile_add_data(&entry, (u32)(val >> 32));
+			oprofile_add_data64(&entry, val);
 			rdmsrl(MSR_AMD64_IBSDCPHYSAD, val);
-			oprofile_add_data(&entry, (u32)val);
-			oprofile_add_data(&entry, (u32)(val >> 32));
+			oprofile_add_data64(&entry, val);
 			oprofile_write_commit(&entry);
 
 			/* reenable the IRQ */

drivers/oprofile/cpu_buffer.c

@@ -406,6 +406,21 @@ int oprofile_add_data(struct op_entry *entry, unsigned long val)
 	return op_cpu_buffer_add_data(entry, val);
 }
 
+int oprofile_add_data64(struct op_entry *entry, u64 val)
+{
+	if (!entry->event)
+		return 0;
+	if (op_cpu_buffer_get_size(entry) < 2)
+		/*
+		 * the function returns 0 to indicate a too small
+		 * buffer, even if there is some space left
+		 */
+		return 0;
+	if (!op_cpu_buffer_add_data(entry, (u32)val))
+		return 0;
+	return op_cpu_buffer_add_data(entry, (u32)(val >> 32));
+}
+
 int oprofile_write_commit(struct op_entry *entry)
 {
 	if (!entry->event)

include/linux/oprofile.h

@@ -179,6 +179,7 @@ void oprofile_write_reserve(struct op_entry *entry,
 			    struct pt_regs * const regs,
 			    unsigned long pc, int code, int size);
 int oprofile_add_data(struct op_entry *entry, unsigned long val);
+int oprofile_add_data64(struct op_entry *entry, u64 val);
 int oprofile_write_commit(struct op_entry *entry);
 
 #endif /* OPROFILE_H */