[PATCH 2/2] soc: apple: rtkit-crashlog: Add support for AArch32 state 'CrgA' section

[Nick Chan]

Add support for CrgA section containing the AArch32 IOP CPU state, which
may appear when an AArch32 RTKit IOP crashes.

Signed-off-by: Nick Chan <towinchenmi at gmail.com>
---
 drivers/soc/apple/rtkit-crashlog.c | 96 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)

diff --git a/drivers/soc/apple/rtkit-crashlog.c b/drivers/soc/apple/rtkit-crashlog.c
index 6a8273e81e61..195b7869ce58 100644
--- a/drivers/soc/apple/rtkit-crashlog.c
+++ b/drivers/soc/apple/rtkit-crashlog.c
@@ -13,6 +13,7 @@
 #define APPLE_RTKIT_CRASHLOG_VERSION FOURCC('C', 'v', 'e', 'r')
 #define APPLE_RTKIT_CRASHLOG_MBOX FOURCC('C', 'm', 'b', 'x')
 #define APPLE_RTKIT_CRASHLOG_TIME FOURCC('C', 't', 'i', 'm')
+#define APPLE_RTKIT_CRASHLOG_AARCH32 FOURCC('C', 'r', 'g', 'A')
 #define APPLE_RTKIT_CRASHLOG_AARCH64 FOURCC('C', 'r', 'g', '8')
 
 /* For COMPILE_TEST on non-ARM64 architectures */
@@ -25,6 +26,21 @@
 #define PSR_MODE_MASK	0x0000000f
 #endif
 
+/*
+ * AArch32 mode definitions: APPLE_RTKIT depends on APPLE_MAILBOX, which
+ * depends on 64BIT, so there is no need to care about COMPILE_TEST on ARM.
+ */
+#define USR_MODE        0x00000010
+#define FIQ_MODE        0x00000011
+#define IRQ_MODE        0x00000012
+#define SVC_MODE        0x00000013
+#define MON_MODE        0x00000016
+#define ABT_MODE        0x00000017
+#define HYP_MODE        0x0000001a
+#define UND_MODE        0x0000001b
+#define SYSTEM_MODE     0x0000001f
+#define MODE_MASK_32    0x0000001f
+
 struct apple_rtkit_crashlog_header {
 	u32 fourcc;
 	u32 version;
@@ -60,6 +76,20 @@ struct apple_rtkit_crashlog_aarch64 {
 } __packed;
 static_assert(sizeof(struct apple_rtkit_crashlog_aarch64) == 0x350);
 
+struct apple_rtkit_crashlog_aarch32 {
+	u32 unk_0;
+	u32 unk_4;
+	u32 regs[16];
+	u32 psr;
+	u32 unk_x1;
+	u8 stack[0x100];
+	u32 unk_x2;
+	u32 unk_x3;
+	u32 unk_x4;
+	u32 unk_x5;
+} __packed;
+static_assert(sizeof(struct apple_rtkit_crashlog_aarch32) == 0x160);
+
 static void apple_rtkit_crashlog_dump_str(struct apple_rtkit *rtk, u8 *bfr,
 					  size_t size)
 {
@@ -123,6 +153,68 @@ static void apple_rtkit_crashlog_dump_mailbox(struct apple_rtkit *rtk, u8 *bfr,
 	}
 }
 
+static void apple_rtkit_crashlog_dump_aarch32(struct apple_rtkit *rtk, u8 *bfr,
+					      size_t size)
+{
+	struct apple_rtkit_crashlog_aarch32 *state;
+	const char *mode;
+	int i;
+
+	if (size < sizeof(*state)) {
+		dev_warn(rtk->dev, "RTKit: AArch32 section too small: 0x%zx", size);
+		return;
+	}
+
+	state = (struct apple_rtkit_crashlog_aarch32 *)bfr;
+
+	switch (state->psr & MODE_MASK_32) {
+	case USR_MODE:
+		mode = "User";
+		break;
+	case FIQ_MODE:
+		mode = "FIQ";
+		break;
+	case IRQ_MODE:
+		mode = "IRQ";
+		break;
+	case SVC_MODE:
+		mode = "Supervisor";
+		break;
+	case MON_MODE:
+		mode = "Monitor";
+		break;
+	case ABT_MODE:
+		mode = "Abort";
+		break;
+	case HYP_MODE:
+		mode = "Hypervisor";
+		break;
+	case UND_MODE:
+		mode = "Undefined";
+		break;
+	case SYSTEM_MODE:
+		mode = "System";
+		break;
+	default:
+		mode = "Unknown";
+		break;
+	}
+
+	dev_warn(rtk->dev, "RTKit: Exception dump:");
+	dev_warn(rtk->dev, "  == Exception taken from %s mode ==", mode);
+	dev_warn(rtk->dev, "  PSR    = 0x%x", state->psr);
+	dev_warn(rtk->dev, "\n");
+
+	for (i = 0; i < 16; i += 4)
+		dev_warn(rtk->dev,
+				 "  r%02d-r%02d = %08x %08x %08x %08x\n",
+				 i, i + 3,
+				 state->regs[i], state->regs[i + 1],
+				 state->regs[i + 2], state->regs[i + 3]);
+
+	dev_warn(rtk->dev, "\n");
+}
+
 static void apple_rtkit_crashlog_dump_aarch64(struct apple_rtkit *rtk, u8 *bfr,
 					      size_t size)
 {
@@ -230,6 +322,10 @@ void apple_rtkit_crashlog_dump(struct apple_rtkit *rtk, u8 *bfr, size_t size)
 			apple_rtkit_crashlog_dump_time(rtk, bfr + offset + 16,
 						       section_size);
 			break;
+		case APPLE_RTKIT_CRASHLOG_AARCH32:
+			apple_rtkit_crashlog_dump_aarch32(rtk, bfr + offset + 16,
+							  section_size);
+			break;
 		case APPLE_RTKIT_CRASHLOG_AARCH64:
 			apple_rtkit_crashlog_dump_aarch64(rtk, bfr + offset + 16,
 							  section_size);

-- 
2.55.0