2023-01-21 07:48:35

by Asahi Lina

[permalink] [raw]
Subject: [PATCH] soc: apple: rtkit: Add register dump decoding to crashlog

When the coprocessor crashes, it's useful to get a proper register dump
so we can find out what the firmware was doing. Add a decoder for this.

Originally this had ESR decoding by reusing the ARM64 arch header for
this, but that introduces some module linking and cross-arch compilation
issues, so let's leave that out for now.

Signed-off-by: Asahi Lina <[email protected]>
---
drivers/soc/apple/rtkit-crashlog.c | 83 ++++++++++++++++++++++++++++++
1 file changed, 83 insertions(+)

diff --git a/drivers/soc/apple/rtkit-crashlog.c b/drivers/soc/apple/rtkit-crashlog.c
index 732deed64660..e29ef0a80ab8 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_REGS FOURCC('C', 'r', 'g', '8')

struct apple_rtkit_crashlog_header {
u32 fourcc;
@@ -31,6 +32,24 @@ struct apple_rtkit_crashlog_mbox_entry {
};
static_assert(sizeof(struct apple_rtkit_crashlog_mbox_entry) == 0x18);

+struct apple_rtkit_crashlog_regs {
+ u32 unk_0;
+ u32 unk_4;
+ u64 regs[31];
+ u64 sp;
+ u64 pc;
+ u64 psr;
+ u64 cpacr;
+ u64 fpsr;
+ u64 fpcr;
+ u64 unk[64];
+ u64 far;
+ u64 unk_X;
+ u64 esr;
+ u64 unk_Z;
+};
+static_assert(sizeof(struct apple_rtkit_crashlog_regs) == 0x350);
+
static void apple_rtkit_crashlog_dump_str(struct apple_rtkit *rtk, u8 *bfr,
size_t size)
{
@@ -94,6 +113,66 @@ static void apple_rtkit_crashlog_dump_mailbox(struct apple_rtkit *rtk, u8 *bfr,
}
}

+static void apple_rtkit_crashlog_dump_regs(struct apple_rtkit *rtk, u8 *bfr,
+ size_t size)
+{
+ struct apple_rtkit_crashlog_regs regs;
+ const char *el;
+ int i;
+
+ if (size < sizeof(regs)) {
+ dev_warn(rtk->dev, "RTKit: Regs section too small: 0x%lx", size);
+ return;
+ }
+
+ memcpy(&regs, bfr, sizeof(regs));
+
+ switch (regs.psr & PSR_MODE_MASK) {
+ case PSR_MODE_EL0t:
+ el = "EL0t";
+ break;
+ case PSR_MODE_EL1t:
+ el = "EL1t";
+ break;
+ case PSR_MODE_EL1h:
+ el = "EL1h";
+ break;
+ case PSR_MODE_EL2t:
+ el = "EL2t";
+ break;
+ case PSR_MODE_EL2h:
+ el = "EL2h";
+ break;
+ default:
+ el = "unknown";
+ break;
+ }
+
+ dev_warn(rtk->dev, "RTKit: Exception dump:");
+ dev_warn(rtk->dev, " == Exception taken from %s ==", el);
+ dev_warn(rtk->dev, " PSR = 0x%llx", regs.psr);
+ dev_warn(rtk->dev, " PC = 0x%llx\n", regs.pc);
+ dev_warn(rtk->dev, " ESR = 0x%llx\n", regs.esr);
+ dev_warn(rtk->dev, " FAR = 0x%llx\n", regs.far);
+ dev_warn(rtk->dev, " SP = 0x%llx\n", regs.sp);
+ dev_warn(rtk->dev, "\n");
+
+ for (i = 0; i < 31; i += 4) {
+ if (i < 28)
+ dev_warn(rtk->dev,
+ " x%02d-x%02d = %016llx %016llx %016llx %016llx\n",
+ i, i + 3,
+ regs.regs[i], regs.regs[i + 1],
+ regs.regs[i + 2], regs.regs[i + 3]);
+ else
+ dev_warn(rtk->dev,
+ " x%02d-x%02d = %016llx %016llx %016llx\n", i, i + 3,
+ regs.regs[i], regs.regs[i + 1], regs.regs[i + 2]);
+ }
+
+ dev_warn(rtk->dev, "\n");
+}
+
void apple_rtkit_crashlog_dump(struct apple_rtkit *rtk, u8 *bfr, size_t size)
{
size_t offset;
@@ -140,6 +219,10 @@ 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_REGS:
+ apple_rtkit_crashlog_dump_regs(rtk, bfr + offset + 16,
+ section_size);
+ break;
default:
dev_warn(rtk->dev,
"RTKit: Unknown crashlog section: %x",
--
2.35.1


2023-01-22 10:58:07

by Sven Peter

[permalink] [raw]
Subject: Re: [PATCH] soc: apple: rtkit: Add register dump decoding to crashlog

On Sat, Jan 21, 2023, at 08:37, Asahi Lina wrote:
> When the coprocessor crashes, it's useful to get a proper register dump
> so we can find out what the firmware was doing. Add a decoder for this.
>
> Originally this had ESR decoding by reusing the ARM64 arch header for
> this, but that introduces some module linking and cross-arch compilation
> issues, so let's leave that out for now.
>
> Signed-off-by: Asahi Lina <[email protected]>
> ---

Reviewed-by: Sven Peter <[email protected]>

thanks,

Sven

2023-01-22 12:38:02

by Eric Curtin

[permalink] [raw]
Subject: Re: [PATCH] soc: apple: rtkit: Add register dump decoding to crashlog

On Sat, 21 Jan 2023 at 07:48, Asahi Lina <[email protected]> wrote:
>
> When the coprocessor crashes, it's useful to get a proper register dump
> so we can find out what the firmware was doing. Add a decoder for this.
>
> Originally this had ESR decoding by reusing the ARM64 arch header for
> this, but that introduces some module linking and cross-arch compilation
> issues, so let's leave that out for now.
>
> Signed-off-by: Asahi Lina <[email protected]>
> ---

Signed-off-by: Eric Curtin <[email protected]>

Is mise le meas/Regards,

Eric Curtin

> drivers/soc/apple/rtkit-crashlog.c | 83 ++++++++++++++++++++++++++++++
> 1 file changed, 83 insertions(+)
>
> diff --git a/drivers/soc/apple/rtkit-crashlog.c b/drivers/soc/apple/rtkit-crashlog.c
> index 732deed64660..e29ef0a80ab8 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_REGS FOURCC('C', 'r', 'g', '8')
>
> struct apple_rtkit_crashlog_header {
> u32 fourcc;
> @@ -31,6 +32,24 @@ struct apple_rtkit_crashlog_mbox_entry {
> };
> static_assert(sizeof(struct apple_rtkit_crashlog_mbox_entry) == 0x18);
>
> +struct apple_rtkit_crashlog_regs {
> + u32 unk_0;
> + u32 unk_4;
> + u64 regs[31];
> + u64 sp;
> + u64 pc;
> + u64 psr;
> + u64 cpacr;
> + u64 fpsr;
> + u64 fpcr;
> + u64 unk[64];
> + u64 far;
> + u64 unk_X;
> + u64 esr;
> + u64 unk_Z;
> +};
> +static_assert(sizeof(struct apple_rtkit_crashlog_regs) == 0x350);
> +
> static void apple_rtkit_crashlog_dump_str(struct apple_rtkit *rtk, u8 *bfr,
> size_t size)
> {
> @@ -94,6 +113,66 @@ static void apple_rtkit_crashlog_dump_mailbox(struct apple_rtkit *rtk, u8 *bfr,
> }
> }
>
> +static void apple_rtkit_crashlog_dump_regs(struct apple_rtkit *rtk, u8 *bfr,
> + size_t size)
> +{
> + struct apple_rtkit_crashlog_regs regs;
> + const char *el;
> + int i;
> +
> + if (size < sizeof(regs)) {
> + dev_warn(rtk->dev, "RTKit: Regs section too small: 0x%lx", size);
> + return;
> + }
> +
> + memcpy(&regs, bfr, sizeof(regs));
> +
> + switch (regs.psr & PSR_MODE_MASK) {
> + case PSR_MODE_EL0t:
> + el = "EL0t";
> + break;
> + case PSR_MODE_EL1t:
> + el = "EL1t";
> + break;
> + case PSR_MODE_EL1h:
> + el = "EL1h";
> + break;
> + case PSR_MODE_EL2t:
> + el = "EL2t";
> + break;
> + case PSR_MODE_EL2h:
> + el = "EL2h";
> + break;
> + default:
> + el = "unknown";
> + break;
> + }
> +
> + dev_warn(rtk->dev, "RTKit: Exception dump:");
> + dev_warn(rtk->dev, " == Exception taken from %s ==", el);
> + dev_warn(rtk->dev, " PSR = 0x%llx", regs.psr);
> + dev_warn(rtk->dev, " PC = 0x%llx\n", regs.pc);
> + dev_warn(rtk->dev, " ESR = 0x%llx\n", regs.esr);
> + dev_warn(rtk->dev, " FAR = 0x%llx\n", regs.far);
> + dev_warn(rtk->dev, " SP = 0x%llx\n", regs.sp);
> + dev_warn(rtk->dev, "\n");
> +
> + for (i = 0; i < 31; i += 4) {
> + if (i < 28)
> + dev_warn(rtk->dev,
> + " x%02d-x%02d = %016llx %016llx %016llx %016llx\n",
> + i, i + 3,
> + regs.regs[i], regs.regs[i + 1],
> + regs.regs[i + 2], regs.regs[i + 3]);
> + else
> + dev_warn(rtk->dev,
> + " x%02d-x%02d = %016llx %016llx %016llx\n", i, i + 3,
> + regs.regs[i], regs.regs[i + 1], regs.regs[i + 2]);
> + }
> +
> + dev_warn(rtk->dev, "\n");
> +}
> +
> void apple_rtkit_crashlog_dump(struct apple_rtkit *rtk, u8 *bfr, size_t size)
> {
> size_t offset;
> @@ -140,6 +219,10 @@ 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_REGS:
> + apple_rtkit_crashlog_dump_regs(rtk, bfr + offset + 16,
> + section_size);
> + break;
> default:
> dev_warn(rtk->dev,
> "RTKit: Unknown crashlog section: %x",
> --
> 2.35.1
>
>