[PATCH 1/6] powerpc: Add ppc_md.name to dump stack arch description

[PATCH 1/6] powerpc: Add ppc_md.name to dump stack arch description

[Michael Ellerman]

As soon as we know the name of the machine description we're using,
add it to the dump stack arch description, which is printed in case of
an oops.

eg: Hardware name: ... machine:pSeries

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/include/asm/setup.h   |  2 ++
 arch/powerpc/kernel/setup-common.c | 14 ++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/arch/powerpc/include/asm/setup.h b/arch/powerpc/include/asm/setup.h
index 85143849a586..e29e83f8a89c 100644
--- a/arch/powerpc/include/asm/setup.h
+++ b/arch/powerpc/include/asm/setup.h
@@ -88,6 +88,8 @@ unsigned long __init prom_init(unsigned long r3, unsigned long r4,
 			       unsigned long pp, unsigned long r6,
 			       unsigned long r7, unsigned long kbase);
 
+extern struct seq_buf ppc_hw_desc;
+
 #endif /* !__ASSEMBLY__ */
 
 #endif	/* _ASM_POWERPC_SETUP_H */
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index dd98f43bd685..42279c3f1d31 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -18,6 +18,7 @@
 #include <linux/delay.h>
 #include <linux/initrd.h>
 #include <linux/platform_device.h>
+#include <linux/printk.h>
 #include <linux/seq_file.h>
 #include <linux/ioport.h>
 #include <linux/console.h>
@@ -25,6 +26,7 @@
 #include <linux/root_dev.h>
 #include <linux/cpu.h>
 #include <linux/unistd.h>
+#include <linux/seq_buf.h>
 #include <linux/serial.h>
 #include <linux/serial_8250.h>
 #include <linux/percpu.h>
@@ -588,6 +590,15 @@ static __init int add_pcspkr(void)
 device_initcall(add_pcspkr);
 #endif	/* CONFIG_PCSPKR_PLATFORM */
 
+static char ppc_hw_desc_buf[128] __initdata;
+
+struct seq_buf ppc_hw_desc __initdata = {
+	.buffer = ppc_hw_desc_buf,
+	.size = sizeof(ppc_hw_desc_buf),
+	.len = 0,
+	.readpos = 0,
+};
+
 static __init void probe_machine(void)
 {
 	extern struct machdep_calls __machine_desc_start;
@@ -628,6 +639,9 @@ static __init void probe_machine(void)
 		for (;;);
 	}
 
+	seq_buf_printf(&ppc_hw_desc,"machine:%s ", ppc_md.name);
+	dump_stack_set_arch_desc(ppc_hw_desc.buffer);
+
 	printk(KERN_INFO "Using %s machine description\n", ppc_md.name);
 }
 
-- 
2.37.3

[PATCH 2/6] powerpc: Add PVR & CPU name to dump stack arch description

[Michael Ellerman]

Add the PVR and CPU name to the dump stack arch description, which is
printed in case of an oops.

eg: Hardware name: ... POWER8E (raw) pvr:0x4b0201

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/kernel/prom.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 2e7a04dab2f7..7987d69f1785 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -30,6 +30,7 @@
 #include <linux/libfdt.h>
 #include <linux/cpu.h>
 #include <linux/pgtable.h>
+#include <linux/seq_buf.h>
 
 #include <asm/rtas.h>
 #include <asm/page.h>
@@ -819,6 +820,10 @@ void __init early_init_devtree(void *params)
 
 	dt_cpu_ftrs_scan();
 
+	/* We can now set the CPU name & PVR for the oops output */
+	seq_buf_printf(&ppc_hw_desc, "%s pvr:0x%04lx ", cur_cpu_spec->cpu_name,
+		       mfspr(SPRN_PVR));
+
 	/* Retrieve CPU related informations from the flat tree
 	 * (altivec support, boot CPU ID, ...)
 	 */
-- 
2.37.3

[PATCH 3/6] powerpc/64: Add logical PVR to the dump stack arch description

[Michael Ellerman]

If we detect a logical PVR add that to the dump stack arch
description, which is printed in case of an oops.

eg: Hardware name: ... lpvr:0xf000004

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/kernel/prom.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 7987d69f1785..dca06ef7fcde 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -390,8 +390,10 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
 	 */
 	if (!dt_cpu_ftrs_in_use()) {
 		prop = of_get_flat_dt_prop(node, "cpu-version", NULL);
-		if (prop && (be32_to_cpup(prop) & 0xff000000) == 0x0f000000)
+		if (prop && (be32_to_cpup(prop) & 0xff000000) == 0x0f000000) {
 			identify_cpu(0, be32_to_cpup(prop));
+			seq_buf_printf(&ppc_hw_desc, "lpvr:0x%04x ", be32_to_cpup(prop));
+		}
 
 		check_cpu_feature_properties(node);
 		check_cpu_features(node, "ibm,pa-features", ibm_pa_features,
-- 
2.37.3

[PATCH 4/6] powerpc: Add device-tree model to dump stack arch description

[Michael Ellerman]

Add the model of the machine we're on to the dump stack arch
description, which is printed in case of an oops.

eg: Hardware name: model:'IBM,8247-22L'

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/kernel/prom.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index dca06ef7fcde..605e4ad8a4c2 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -715,6 +715,23 @@ static void __init tm_init(void)
 static void tm_init(void) { }
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 
+static int __init
+early_init_dt_scan_model(unsigned long node, const char *uname,
+			 int depth, void *data)
+{
+	const char *prop;
+
+	if (depth != 0)
+		return 0;
+
+	prop = of_get_flat_dt_prop(node, "model", NULL);
+	if (prop)
+		seq_buf_printf(&ppc_hw_desc, "model:'%s' ", prop);
+
+	/* break now */
+	return 1;
+}
+
 #ifdef CONFIG_PPC64
 static void __init save_fscr_to_task(void)
 {
@@ -743,6 +760,8 @@ void __init early_init_devtree(void *params)
 	if (!early_init_dt_verify(params))
 		panic("BUG: Failed verifying flat device tree, bad version?");
 
+	of_scan_flat_dt(early_init_dt_scan_model, NULL);
+
 #ifdef CONFIG_PPC_RTAS
 	/* Some machines might need RTAS info for debugging, grab it now. */
 	of_scan_flat_dt(early_init_dt_scan_rtas, NULL);
-- 
2.37.3

[PATCH 5/6] powerpc/powernv: Add opal details to dump stack arch description

[Michael Ellerman]

Add OPAL version details to the dump stack arch description, which is
printed in case of an oops.

eg: Hardware name: ... opal:v6.2

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/platforms/powernv/setup.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index dac545aa0308..fddc61ec1d5b 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -17,6 +17,7 @@
 #include <linux/console.h>
 #include <linux/delay.h>
 #include <linux/irq.h>
+#include <linux/seq_buf.h>
 #include <linux/seq_file.h>
 #include <linux/of.h>
 #include <linux/of_fdt.h>
@@ -207,8 +208,33 @@ static void __init pnv_setup_arch(void)
 	pnv_rng_init();
 }
 
+static void __init pnv_add_dump_stack_arch_desc(void)
+{
+	struct device_node *dn;
+	const char *version;
+
+	dn = of_find_node_by_path("/ibm,opal/firmware");
+	if (!dn)
+		return;
+
+	version = of_get_property(dn, "version", NULL);
+	if (!version)
+		version = of_get_property(dn, "git-id", NULL);
+
+	if (version)
+		seq_buf_printf(&ppc_hw_desc, "opal:%s", version);
+
+	version = of_get_property(dn, "mi-version", NULL);
+	if (version)
+		seq_buf_printf(&ppc_hw_desc, "mi:%s", version);
+
+	of_node_put(dn);
+}
+
 static void __init pnv_init(void)
 {
+	pnv_add_dump_stack_arch_desc();
+
 	/*
 	 * Initialize the LPC bus now so that legacy serial
 	 * ports can be found on it
-- 
2.37.3

[PATCH 6/6] powerpc/pseries: Add firmware details to dump stack arch description

[Michael Ellerman]

Add firmware version details to the dump stack arch description, which
is printed in case of an oops.

Currently /hypervisor only exists on KVM, so if we don't find that
look for something that suggests we're on phyp and if so that's
probably a good guess. The actual content of the ibm,fw-net-version
seems to be a full path so is too long to add to the description.

eg: Hardware name: ... of:'IBM,FW860.42 (SV860_138)' hv:phyp

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/platforms/pseries/setup.c | 36 ++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 5e44c65a032c..f0ce8256ebb8 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -41,6 +41,7 @@
 #include <linux/of_pci.h>
 #include <linux/memblock.h>
 #include <linux/swiotlb.h>
+#include <linux/seq_buf.h>
 
 #include <asm/mmu.h>
 #include <asm/processor.h>
@@ -1011,6 +1012,39 @@ static void __init pSeries_cmo_feature_init(void)
 	pr_debug(" <- fw_cmo_feature_init()\n");
 }
 
+static void __init pseries_add_dump_stack_arch_desc(void)
+{
+	struct device_node *dn;
+	const char *prop;
+
+	dn = of_find_node_by_path("/openprom");
+	if (dn) {
+		prop = of_get_property(dn, "model", NULL);
+		if (prop)
+			seq_buf_printf(&ppc_hw_desc, "of:'%s' ", prop);
+
+		of_node_put(dn);
+	}
+
+	dn = of_find_node_by_path("/hypervisor");
+	if (dn) {
+		prop = of_get_property(dn, "compatible", NULL);
+		if (prop)
+			seq_buf_printf(&ppc_hw_desc, "hv:%s ", prop);
+
+		of_node_put(dn);
+	} else {
+		dn = of_find_node_by_path("/");
+		if (dn) {
+			prop = of_get_property(dn, "ibm,fw-net-version", NULL);
+			if (prop)
+				seq_buf_printf(&ppc_hw_desc, "hv:phyp ");
+
+			of_node_put(dn);
+		}
+	}
+}
+
 /*
  * Early initialization.  Relocation is on but do not reference unbolted pages
  */
@@ -1018,6 +1052,8 @@ static void __init pseries_init(void)
 {
 	pr_debug(" -> pseries_init()\n");
 
+	pseries_add_dump_stack_arch_desc();
+
 #ifdef CONFIG_HVC_CONSOLE
 	if (firmware_has_feature(FW_FEATURE_LPAR))
 		hvc_vio_init_early();
-- 
2.37.3

Re: [PATCH 6/6] powerpc/pseries: Add firmware details to dump stack arch description

[Nathan Lynch]

Michael Ellerman <mpe@ellerman.id.au> writes:

> Add firmware version details to the dump stack arch description, which
> is printed in case of an oops.
>
> Currently /hypervisor only exists on KVM, so if we don't find that
> look for something that suggests we're on phyp and if so that's
> probably a good guess. The actual content of the ibm,fw-net-version
> seems to be a full path so is too long to add to the description.

My only reservation is that ibm,fw-net-version seems to be unspecified
and could disappear in future firmware versions.

/ibm,powervm-partition would be the best PAPR-specified property for
this purpose, but I don't see it on a P8/860 partition I checked,
unfortunately. I do see it on a P9. Presumably it's present in device
trees on PowerVM P9 systems and later, but it's probably too new to use
for this.

/ibm,lpar-capable "indicates that the platform is capable of supporting
logical partitioning and is only present on such systems." This one is
present on the P8.

So consider this a weak suggestion to replace the ibm,fw-net-version
check with ibm,lpar-capable. But I don't want to bikeshed it, overall
the series looks good.

>
> eg: Hardware name: ... of:'IBM,FW860.42 (SV860_138)' hv:phyp

Will this info get printed during boot as well? There are many times it
would have been useful to me when looking at logs from non-oopsed
kernels.

Re: [PATCH 6/6] powerpc/pseries: Add firmware details to dump stack arch description

[Michael Ellerman]

Nathan Lynch <nathanl@linux.ibm.com> writes:
> Michael Ellerman <mpe@ellerman.id.au> writes:
>
>> Add firmware version details to the dump stack arch description, which
>> is printed in case of an oops.
>>
>> Currently /hypervisor only exists on KVM, so if we don't find that
>> look for something that suggests we're on phyp and if so that's
>> probably a good guess. The actual content of the ibm,fw-net-version
>> seems to be a full path so is too long to add to the description.
>
> My only reservation is that ibm,fw-net-version seems to be unspecified
> and could disappear in future firmware versions.

Yeah good point.

> /ibm,powervm-partition would be the best PAPR-specified property for
> this purpose, but I don't see it on a P8/860 partition I checked,
> unfortunately. I do see it on a P9. Presumably it's present in device
> trees on PowerVM P9 systems and later, but it's probably too new to use
> for this.

I'll look for both, it's easy enough.

> /ibm,lpar-capable "indicates that the platform is capable of supporting
> logical partitioning and is only present on such systems." This one is
> present on the P8.

But conceivably qemu/KVM could provide that property, which would defeat
the purpose here which is to differentiate which actual hypervisor we're
under.

>> eg: Hardware name: ... of:'IBM,FW860.42 (SV860_138)' hv:phyp
>
> Will this info get printed during boot as well? There are many times it
> would have been useful to me when looking at logs from non-oopsed
> kernels.

No it's not. But you're right that would often be useful.

I think we can print it at the end of probe_machine().

I'll send a v2.

cheers

Re: [PATCH 1/6] powerpc: Add ppc_md.name to dump stack arch description

[Nathan Lynch]

Michael Ellerman <mpe@ellerman.id.au> writes:
> @@ -588,6 +590,15 @@ static __init int add_pcspkr(void)
>  device_initcall(add_pcspkr);
>  #endif	/* CONFIG_PCSPKR_PLATFORM */
>  
> +static char ppc_hw_desc_buf[128] __initdata;
> +
> +struct seq_buf ppc_hw_desc __initdata = {
> +	.buffer = ppc_hw_desc_buf,
> +	.size = sizeof(ppc_hw_desc_buf),
> +	.len = 0,
> +	.readpos = 0,
> +};
> +
>  static __init void probe_machine(void)
>  {
>  	extern struct machdep_calls __machine_desc_start;
> @@ -628,6 +639,9 @@ static __init void probe_machine(void)
>  		for (;;);
>  	}
>  
> +	seq_buf_printf(&ppc_hw_desc,"machine:%s ", ppc_md.name);
> +	dump_stack_set_arch_desc(ppc_hw_desc.buffer);

At first I was confused by the seemingly unnecessary use of the seq_buf,
but after reading the rest of the series I see that this is the final
addition to a temporary buffer before setting the arch description
string. Looks OK to me.