[PATCH 1/7] powerpc: Adjust CPU_FTR_SMT on all platforms

[PATCH 1/7] powerpc: Adjust CPU_FTR_SMT on all platforms

[Benjamin Herrenschmidt]

For historical reasons that code was under #ifdef CONFIG_PPC_PSERIES
but it applies equally to all 64-bit platforms.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 arch/powerpc/kernel/prom.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index d711b7e..0fc55b5 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -378,7 +378,7 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
 	check_cpu_pa_features(node);
 	check_cpu_slb_size(node);
 
-#ifdef CONFIG_PPC_PSERIES
+#ifdef CONFIG_PPC64
 	if (nthreads > 1)
 		cur_cpu_spec->cpu_features |= CPU_FTR_SMT;
 	else
-- 
1.8.3.2

[PATCH 2/7] powerpc: Make boot_cpuid common between 32 and 64-bit

[Benjamin Herrenschmidt]

Move the definition to setup-common.c and set the init value
to -1 on both 32 and 64-bit (it was 0 on 64-bit).

Additionally add a check to prom.c to garantee that the init
value has been udpated after the DT scan.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 arch/powerpc/kernel/prom.c         | 4 ++++
 arch/powerpc/kernel/setup-common.c | 3 +++
 arch/powerpc/kernel/setup_32.c     | 2 --
 arch/powerpc/kernel/setup_64.c     | 1 -
 4 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 0fc55b5..f1002b1 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -744,6 +744,10 @@ void __init early_init_devtree(void *params)
 	 * (altivec support, boot CPU ID, ...)
 	 */
 	of_scan_flat_dt(early_init_dt_scan_cpus, NULL);
+	if (boot_cpuid < 0) {
+		printk("Failed to indentify boot CPU !\n");
+		BUG();
+	}
 
 #if defined(CONFIG_SMP) && defined(CONFIG_PPC64)
 	/* We'll later wait for secondaries to check in; there are
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index bc76cc6..79b7612 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -76,6 +76,9 @@ EXPORT_SYMBOL(ppc_md);
 struct machdep_calls *machine_id;
 EXPORT_SYMBOL(machine_id);
 
+int boot_cpuid = -1;
+EXPORT_SYMBOL_GPL(boot_cpuid);
+
 unsigned long klimit = (unsigned long) _end;
 
 char cmd_line[COMMAND_LINE_SIZE];
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index 04cc4fc..ea4fda6 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -44,8 +44,6 @@
 
 extern void bootx_init(unsigned long r4, unsigned long phys);
 
-int boot_cpuid = -1;
-EXPORT_SYMBOL_GPL(boot_cpuid);
 int boot_cpuid_phys;
 EXPORT_SYMBOL_GPL(boot_cpuid_phys);
 
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 4933909..d8aabbd 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -74,7 +74,6 @@
 #define DBG(fmt...)
 #endif
 
-int boot_cpuid = 0;
 int spinning_secondaries;
 u64 ppc64_pft_size;
 
-- 
1.8.3.2

[PATCH 3/7] powerpc/prom: early_init_dt_scan_cpus() updates cpu features only once

[Benjamin Herrenschmidt]

All our cpu feature updates were done for every CPU in the device-tree,
thus overwriting the cputable bits over and over again. Instead do them
only for the boot CPU.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 arch/powerpc/kernel/prom.c | 52 +++++++++++++++++++++++-----------------------
 1 file changed, 26 insertions(+), 26 deletions(-)

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index f1002b1..7270ca1 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -346,33 +346,34 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
 #endif
 	}
 
-	if (found >= 0) {
-		DBG("boot cpu: logical %d physical %d\n", found,
-			be32_to_cpu(intserv[found_thread]));
-		boot_cpuid = found;
-		set_hard_smp_processor_id(found,
-			be32_to_cpu(intserv[found_thread]));
+	/* Not the boot CPU */
+	if (found < 0)
+		return 0;
 
-		/*
-		 * PAPR defines "logical" PVR values for cpus that
-		 * meet various levels of the architecture:
-		 * 0x0f000001	Architecture version 2.04
-		 * 0x0f000002	Architecture version 2.05
-		 * If the cpu-version property in the cpu node contains
-		 * such a value, we call identify_cpu again with the
-		 * logical PVR value in order to use the cpu feature
-		 * bits appropriate for the architecture level.
-		 *
-		 * A POWER6 partition in "POWER6 architected" mode
-		 * uses the 0x0f000002 PVR value; in POWER5+ mode
-		 * it uses 0x0f000001.
-		 */
-		prop = of_get_flat_dt_prop(node, "cpu-version", NULL);
-		if (prop && (be32_to_cpup(prop) & 0xff000000) == 0x0f000000)
-			identify_cpu(0, be32_to_cpup(prop));
+	DBG("boot cpu: logical %d physical %d\n", found,
+	    be32_to_cpu(intserv[found_thread]));
+	boot_cpuid = found;
+	set_hard_smp_processor_id(found, be32_to_cpu(intserv[found_thread]));
 
-		identical_pvr_fixup(node);
-	}
+	/*
+	 * PAPR defines "logical" PVR values for cpus that
+	 * meet various levels of the architecture:
+	 * 0x0f000001	Architecture version 2.04
+	 * 0x0f000002	Architecture version 2.05
+	 * If the cpu-version property in the cpu node contains
+	 * such a value, we call identify_cpu again with the
+	 * logical PVR value in order to use the cpu feature
+	 * bits appropriate for the architecture level.
+	 *
+	 * A POWER6 partition in "POWER6 architected" mode
+	 * uses the 0x0f000002 PVR value; in POWER5+ mode
+	 * it uses 0x0f000001.
+	 */
+	prop = of_get_flat_dt_prop(node, "cpu-version", NULL);
+	if (prop && (be32_to_cpup(prop) & 0xff000000) == 0x0f000000)
+		identify_cpu(0, be32_to_cpup(prop));
+
+	identical_pvr_fixup(node);
 
 	check_cpu_feature_properties(node);
 	check_cpu_pa_features(node);
@@ -384,7 +385,6 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
 	else
 		cur_cpu_spec->cpu_features &= ~CPU_FTR_SMT;
 #endif
-
 	return 0;
 }
 
-- 
1.8.3.2

[PATCH 4/7] powerpc/ppc64: Gracefully handle early interrupts

[Benjamin Herrenschmidt]

If we take an interrupt such as a trap caused by a BUG_ON before the
MMU has been setup, the interrupt handlers try to enable virutal mode
and cause a recursive crash, making the original problem very hard
to debug.

This fixes it by adjusting the "kernel_msr" value in the PACA so that
it only has MSR_IR and MSR_DR (translation for instruction and data)
set after the MMU has been initialized for the processor.

We may still not have a console yet but at least we don't get into
a recursive fault (and early debug console or memory dump via JTAG
of the kernel buffer *will* give us the proper error).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 arch/powerpc/kernel/paca.c     |  3 ++-
 arch/powerpc/kernel/setup_64.c | 15 +++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c
index bf0aada..ad302f8 100644
--- a/arch/powerpc/kernel/paca.c
+++ b/arch/powerpc/kernel/paca.c
@@ -152,7 +152,8 @@ void __init initialise_paca(struct paca_struct *new_paca, int cpu)
 	new_paca->paca_index = cpu;
 	new_paca->kernel_toc = kernel_toc;
 	new_paca->kernelbase = (unsigned long) _stext;
-	new_paca->kernel_msr = MSR_KERNEL;
+	/* Only set MSR:IR/DR when MMU is initialized */
+	new_paca->kernel_msr = MSR_KERNEL & ~(MSR_IR | MSR_DR);
 	new_paca->hw_cpu_id = 0xffff;
 	new_paca->kexec_state = KEXEC_STATE_NONE;
 	new_paca->__current = &init_task;
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index d8aabbd..1d33e81 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -261,6 +261,14 @@ void __init early_setup(unsigned long dt_ptr)
 	/* Initialize the hash table or TLB handling */
 	early_init_mmu();
 
+	/*
+	 * At this point, we can let interrupts switch to virtual mode
+	 * (the MMU has been setup), so adjust the MSR in the PACA to
+	 * have IR and DR set.
+	 */
+	get_paca()->kernel_msr = MSR_KERNEL;
+
+	/* Reserve large chunks of memory for use by CMA for KVM */
 	kvm_cma_reserve();
 
 	/*
@@ -293,6 +301,13 @@ void early_setup_secondary(void)
 
 	/* Initialize the hash table or TLB handling */
 	early_init_mmu_secondary();
+
+	/*
+	 * At this point, we can let interrupts switch to virtual mode
+	 * (the MMU has been setup), so adjust the MSR in the PACA to
+	 * have IR and DR set.
+	 */
+	get_paca()->kernel_msr = MSR_KERNEL;
 }
 
 #endif /* CONFIG_SMP */
-- 
1.8.3.2

[PATCH 5/7] powerpc/ppc64: Do not turn AIL (reloc-on interrupts) too early

[Benjamin Herrenschmidt]

Turn them on at the same time as we allow MSR_IR/DR in the paca
kernel MSR, ie, after the MMU has been setup enough to be able
to handle relocated access to the linear mapping.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 arch/powerpc/kernel/cpu_setup_power.S |  2 --
 arch/powerpc/kernel/setup_64.c        | 18 +++++++++++++++---
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/kernel/cpu_setup_power.S b/arch/powerpc/kernel/cpu_setup_power.S
index 37d1bb0..1557e7c 100644
--- a/arch/powerpc/kernel/cpu_setup_power.S
+++ b/arch/powerpc/kernel/cpu_setup_power.S
@@ -56,7 +56,6 @@ _GLOBAL(__setup_cpu_power8)
 	li	r0,0
 	mtspr	SPRN_LPID,r0
 	mfspr	r3,SPRN_LPCR
-	oris	r3, r3, LPCR_AIL_3@h
 	bl	__init_LPCR
 	bl	__init_HFSCR
 	bl	__init_tlb_power8
@@ -75,7 +74,6 @@ _GLOBAL(__restore_cpu_power8)
 	li	r0,0
 	mtspr	SPRN_LPID,r0
 	mfspr   r3,SPRN_LPCR
-	oris	r3, r3, LPCR_AIL_3@h
 	bl	__init_LPCR
 	bl	__init_HFSCR
 	bl	__init_tlb_power8
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 1d33e81..3d7a50a 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -195,6 +195,18 @@ static void fixup_boot_paca(void)
 	get_paca()->data_offset = 0;
 }
 
+static void cpu_ready_for_interrupts(void)
+{
+	/* Set IR and DR in PACA MSR */
+	get_paca()->kernel_msr = MSR_KERNEL;
+
+	/* Enable AIL if supported */
+	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
+		unsigned long lpcr = mfspr(SPRN_LPCR);
+		mtspr(SPRN_LPCR, lpcr | LPCR_AIL_3);
+	}
+}
+
 /*
  * Early initialization entry point. This is called by head.S
  * with MMU translation disabled. We rely on the "feature" of
@@ -264,9 +276,9 @@ void __init early_setup(unsigned long dt_ptr)
 	/*
 	 * At this point, we can let interrupts switch to virtual mode
 	 * (the MMU has been setup), so adjust the MSR in the PACA to
-	 * have IR and DR set.
+	 * have IR and DR set and enable AIL if it exists
 	 */
-	get_paca()->kernel_msr = MSR_KERNEL;
+	cpu_ready_for_interrupts();
 
 	/* Reserve large chunks of memory for use by CMA for KVM */
 	kvm_cma_reserve();
@@ -307,7 +319,7 @@ void early_setup_secondary(void)
 	 * (the MMU has been setup), so adjust the MSR in the PACA to
 	 * have IR and DR set.
 	 */
-	get_paca()->kernel_msr = MSR_KERNEL;
+	cpu_ready_for_interrupts();
 }
 
 #endif /* CONFIG_SMP */
-- 
1.8.3.2

[PATCH 6/7] powerpc/powernv: Add opal_notifier_unregister() and export to modules

[Benjamin Herrenschmidt]

opal_notifier_register() is missing a pending "unregister" variant
and should be exposed to modules.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 arch/powerpc/include/asm/opal.h       |  2 ++
 arch/powerpc/platforms/powernv/opal.c | 14 ++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index ffafab0..1dd3f9b 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -891,6 +891,8 @@ extern int early_init_dt_scan_opal(unsigned long node, const char *uname,
 				   int depth, void *data);
 
 extern int opal_notifier_register(struct notifier_block *nb);
+extern int opal_notifier_unregister(struct notifier_block *nb);
+
 extern int opal_message_notifier_register(enum OpalMessageType msg_type,
 						struct notifier_block *nb);
 extern void opal_notifier_enable(void);
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index e92f2f6..7835d5b 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -180,6 +180,20 @@ int opal_notifier_register(struct notifier_block *nb)
 	atomic_notifier_chain_register(&opal_notifier_head, nb);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(opal_notifier_register);
+
+int opal_notifier_unregister(struct notifier_block *nb)
+{
+	if (!nb) {
+		pr_warning("%s: Invalid argument (%p)\n",
+			   __func__, nb);
+		return -EINVAL;
+	}
+
+	atomic_notifier_chain_unregister(&opal_notifier_head, nb);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(opal_notifier_unregister);
 
 static void opal_do_notifier(uint64_t events)
 {
-- 
1.8.3.2

[PATCH 7/7] tty/hvc_opal: Kick the HVC thread on OPAL console events

[Benjamin Herrenschmidt]

The firmware can notify us when new input data is available, so
let's make sure we wakeup the HVC thread in that case.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 drivers/tty/hvc/hvc_opal.c | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/hvc/hvc_opal.c b/drivers/tty/hvc/hvc_opal.c
index 6496872..e4f92c1 100644
--- a/drivers/tty/hvc/hvc_opal.c
+++ b/drivers/tty/hvc/hvc_opal.c
@@ -61,6 +61,7 @@ static struct hvc_opal_priv *hvc_opal_privs[MAX_NR_HVC_CONSOLES];
 /* For early boot console */
 static struct hvc_opal_priv hvc_opal_boot_priv;
 static u32 hvc_opal_boot_termno;
+static bool hvc_opal_event_registered;
 
 static const struct hv_ops hvc_opal_raw_ops = {
 	.get_chars = opal_get_chars,
@@ -161,6 +162,18 @@ static const struct hv_ops hvc_opal_hvsi_ops = {
 	.tiocmset = hvc_opal_hvsi_tiocmset,
 };
 
+static int hvc_opal_console_event(struct notifier_block *nb,
+				  unsigned long events, void *change)
+{
+	if (events & OPAL_EVENT_CONSOLE_INPUT)
+		hvc_kick();
+	return 0;
+}
+
+static struct notifier_block hvc_opal_console_nb = {
+	.notifier_call	= hvc_opal_console_event,
+};
+
 static int hvc_opal_probe(struct platform_device *dev)
 {
 	const struct hv_ops *ops;
@@ -170,6 +183,7 @@ static int hvc_opal_probe(struct platform_device *dev)
 	unsigned int termno, boot = 0;
 	const __be32 *reg;
 
+
 	if (of_device_is_compatible(dev->dev.of_node, "ibm,opal-console-raw")) {
 		proto = HV_PROTOCOL_RAW;
 		ops = &hvc_opal_raw_ops;
@@ -213,12 +227,18 @@ static int hvc_opal_probe(struct platform_device *dev)
 		dev->dev.of_node->full_name,
 		boot ? " (boot console)" : "");
 
-	/* We don't do IRQ yet */
+	/* We don't do IRQ ... */
 	hp = hvc_alloc(termno, 0, ops, MAX_VIO_PUT_CHARS);
 	if (IS_ERR(hp))
 		return PTR_ERR(hp);
 	dev_set_drvdata(&dev->dev, hp);
 
+	/* ...  but we use OPAL event to kick the console */
+	if (!hvc_opal_event_registered) {
+		opal_notifier_register(&hvc_opal_console_nb);
+		hvc_opal_event_registered = true;
+	}
+
 	return 0;
 }
 
@@ -259,6 +279,10 @@ module_init(hvc_opal_init);
 
 static void __exit hvc_opal_exit(void)
 {
+	if (hvc_opal_event_registered)
+		opal_notifier_unregister(&hvc_opal_console_nb);
+	hvc_opal_event_registered = false;
+
 	platform_driver_unregister(&hvc_opal_driver);
 }
 module_exit(hvc_opal_exit);
-- 
1.8.3.2

Re: [PATCH 5/7] powerpc/ppc64: Do not turn AIL (reloc-on interrupts) too early

[Michael Neuling]

Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:

> Turn them on at the same time as we allow MSR_IR/DR in the paca
> kernel MSR, ie, after the MMU has been setup enough to be able
> to handle relocated access to the linear mapping.
> 
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> ---
>  arch/powerpc/kernel/cpu_setup_power.S |  2 --
>  arch/powerpc/kernel/setup_64.c        | 18 +++++++++++++++---
>  2 files changed, 15 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/cpu_setup_power.S b/arch/powerpc/kernel/cpu_setup_power.S
> index 37d1bb0..1557e7c 100644
> --- a/arch/powerpc/kernel/cpu_setup_power.S
> +++ b/arch/powerpc/kernel/cpu_setup_power.S
> @@ -56,7 +56,6 @@ _GLOBAL(__setup_cpu_power8)
>  	li	r0,0
>  	mtspr	SPRN_LPID,r0
>  	mfspr	r3,SPRN_LPCR
> -	oris	r3, r3, LPCR_AIL_3@h
>  	bl	__init_LPCR
>  	bl	__init_HFSCR
>  	bl	__init_tlb_power8
> @@ -75,7 +74,6 @@ _GLOBAL(__restore_cpu_power8)
>  	li	r0,0
>  	mtspr	SPRN_LPID,r0
>  	mfspr   r3,SPRN_LPCR
> -	oris	r3, r3, LPCR_AIL_3@h
>  	bl	__init_LPCR
>  	bl	__init_HFSCR
>  	bl	__init_tlb_power8

BTW with this we can put the   	"mfspr   r3,SPRN_LPCR" in __init_LPCR
and clean this code up bit.

Mikey

> diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
> index 1d33e81..3d7a50a 100644
> --- a/arch/powerpc/kernel/setup_64.c
> +++ b/arch/powerpc/kernel/setup_64.c
> @@ -195,6 +195,18 @@ static void fixup_boot_paca(void)
>  	get_paca()->data_offset = 0;
>  }
>  
> +static void cpu_ready_for_interrupts(void)
> +{
> +	/* Set IR and DR in PACA MSR */
> +	get_paca()->kernel_msr = MSR_KERNEL;
> +
> +	/* Enable AIL if supported */
> +	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
> +		unsigned long lpcr = mfspr(SPRN_LPCR);
> +		mtspr(SPRN_LPCR, lpcr | LPCR_AIL_3);
> +	}
> +}
> +
>  /*
>   * Early initialization entry point. This is called by head.S
>   * with MMU translation disabled. We rely on the "feature" of
> @@ -264,9 +276,9 @@ void __init early_setup(unsigned long dt_ptr)
>  	/*
>  	 * At this point, we can let interrupts switch to virtual mode
>  	 * (the MMU has been setup), so adjust the MSR in the PACA to
> -	 * have IR and DR set.
> +	 * have IR and DR set and enable AIL if it exists
>  	 */
> -	get_paca()->kernel_msr = MSR_KERNEL;
> +	cpu_ready_for_interrupts();
>  
>  	/* Reserve large chunks of memory for use by CMA for KVM */
>  	kvm_cma_reserve();
> @@ -307,7 +319,7 @@ void early_setup_secondary(void)
>  	 * (the MMU has been setup), so adjust the MSR in the PACA to
>  	 * have IR and DR set.
>  	 */
> -	get_paca()->kernel_msr = MSR_KERNEL;
> +	cpu_ready_for_interrupts();
>  }
>  
>  #endif /* CONFIG_SMP */
> -- 
> 1.8.3.2
> 
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev