From 9123f58bd5fdd57514b3d199308b98022685c251 Mon Sep 17 00:00:00 2001
From: Ryan Houdek <Sonicadvance1@gmail.com>
Date: Tue, 16 Jul 2013 01:22:06 -0500
Subject: [PATCH] Check for IDIVA/IDIVT correctly. Cortex-A5 parts would have
 had this set since it supports VFPv4 but not IDIVA. Qualcomm Krait/Krait 300
 still doesn't report in the kernel that it supports this.

---
 Source/Core/Common/Src/ArmCPUDetect.cpp | 57 +++++++++++++++++++++++--
 1 file changed, 53 insertions(+), 4 deletions(-)

diff --git a/Source/Core/Common/Src/ArmCPUDetect.cpp b/Source/Core/Common/Src/ArmCPUDetect.cpp
index 33eee9f05e..ca277ade02 100644
--- a/Source/Core/Common/Src/ArmCPUDetect.cpp
+++ b/Source/Core/Common/Src/ArmCPUDetect.cpp
@@ -44,6 +44,56 @@ char *GetCPUString()
 	}
 	return cpu_string;
 }
+
+unsigned char GetCPUImplementer()
+{
+	const char marker[] = "CPU implementer\t: ";
+	char *implementer_string = 0;
+	unsigned char implementer = 0;
+	char buf[1024];
+
+	File::IOFile file(procfile, "r");
+	auto const fp = file.GetHandle();
+	if (!fp)
+		return 0;
+
+	while (fgets(buf, sizeof(buf), fp))
+	{
+		if (strncmp(buf, marker, sizeof(marker) - 1))
+			continue;
+		implementer_string = buf + sizeof(marker) - 1;
+		implementer_string = strndup(implementer_string, strlen(implementer_string) - 1); // Strip the newline
+		sscanf(implementer_string, "0x%02hhx", &implementer);
+		break;
+	}
+	return implementer;
+}
+
+unsigned short GetCPUPart()
+{
+	const char marker[] = "CPU part\t: ";
+	char *part_string = 0;
+	unsigned short part = 0;
+	char buf[1024];
+
+	File::IOFile file(procfile, "r");
+	auto const fp = file.GetHandle();
+	if (!fp)
+		return 0;
+
+	while (fgets(buf, sizeof(buf), fp))
+	{
+		if (strncmp(buf, marker, sizeof(marker) - 1))
+			continue;
+		part_string = buf + sizeof(marker) - 1;
+		part_string = strndup(part_string, strlen(part_string) - 1); // Strip the newline
+		sscanf(part_string, "0x%03hx", &part);
+		break;
+	}
+	return part;
+
+}
+
 bool CheckCPUFeature(const char *feature)
 {
 	const char marker[] = "Features\t: ";
@@ -123,10 +173,9 @@ void CPUInfo::Detect()
 	bIDIVa = CheckCPUFeature("idiva");
 	bIDIVt = CheckCPUFeature("idivt");
 
-	// On some buggy kernels(Qualcomm) they show that they support VFPv4 but not IDIVa
-	// All VFPv4 CPUs will support IDIVa
-	if (bVFPv4)
-		bIDIVa = bIDIVt = true;
+	// Qualcomm Krait supports IDIVA but it doesn't report it. Check for krait.
+	if (GetCPUImplementer() == 0x51 && GetCPUPart() == 0x6F) // Krait(300) is 0x6F, Scorpion is 0x4D
+		bIDIVa = bIDIVt = true; 
 
 	// These two are ARMv8 specific.
 	bFP = CheckCPUFeature("fp");