Patchwork SPARC/LEON: power down instruction different of different LEONs

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Submitter Daniel Hellstrom
Date Jan. 26, 2011, 4:37 p.m.
Message ID <1296059842-22837-1-git-send-email-daniel@gaisler.com>
Download mbox | patch
Permalink /patch/80524/
State Superseded
Delegated to: David Miller
Headers show

Comments

Daniel Hellstrom - Jan. 26, 2011, 4:37 p.m.
The way a LEON is powered down is implemented differently depending
on CHIP type. The AMBA Plug&Play system ID tells revision of GRLIB
and CHIP.

This is for example needed by the GR-LEON4-ITX board and the UT699.

Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
---
 arch/sparc/include/asm/leon_amba.h |    6 +++
 arch/sparc/kernel/Makefile         |    1 +
 arch/sparc/kernel/leon_kernel.c    |    9 ++++-
 arch/sparc/kernel/leon_pmc.c       |   81 ++++++++++++++++++++++++++++++++++++
 arch/sparc/kernel/leon_smp.c       |   16 -------
 5 files changed, 96 insertions(+), 17 deletions(-)
 create mode 100644 arch/sparc/kernel/leon_pmc.c
Sam Ravnborg - Jan. 27, 2011, 5:43 a.m.
On Wed, Jan 26, 2011 at 05:37:22PM +0100, Daniel Hellstrom wrote:
> The way a LEON is powered down is implemented differently depending
> on CHIP type. The AMBA Plug&Play system ID tells revision of GRLIB
> and CHIP.
> 
> This is for example needed by the GR-LEON4-ITX board and the UT699.
> 
> Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>

It is not obvious for me how leon_pmc interact with the existing pmc.c
implmentation. I guess the latter fails during probe and is thus ignored.

Some comments below - mostly general or nitpick.

	Sam

> +
> +	/* Find System ID: GRLIB build ID and optional CHIP ID */
> +	pp = of_find_property(rootnp, "systemid", &len);
> +	if (pp)
> +		amba_system_id = *(unsigned long *)pp->value;
> +
> +	/*Find IRQMP IRQ Controller Registers base address otherwise bail out.*/

If you are going to resubmit then fix this comment (add a space)

> + * Copyright (C) 2011 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB
> + */
> +
> +#include <linux/pm.h>
> +#include <linux/init.h>
> +#include <asm/leon.h>
> +#include <asm/leon_amba.h>

For this number of includes it does not matter.
But in general we use the inverse christmas tree way.
Longer lines first. Lines with identical length sorted alphabetically.
And an empty line between the include groups.

> +/*
> + * CPU idle callback function for systems that need some extra handling
> + * See .../arch/sparc/kernel/process.c
> + */
> +void pmc_leon_idle_fixup(void)
> +{
> +	/* Prepare an address to a non-cachable region. APB is always
> +	 * none-cachable. One instruction is executed after the Sleep
> +	 * instruction, we make sure to read the bus and throw away the
> +	 * value by accessing a non-cachable area, also we make sure the
> +	 * MMU does not get a TLB miss here by using the MMU BYPASS ASI.
> +	 */
> +	register unsigned int address = (unsigned int)leon3_irqctrl_regs;
> +	__asm__ __volatile__ (
> +		"mov	%%g0, %%asr19\n"
> +		"lda	[%0] %1, %%g0\n"
> +		:
> +		: "r"(address), "i"(ASI_LEON_BYPASS));
> +}

Good to see the rasons commented!

> +
> +/* This driver is not critical to the boot process, don't care
> + * if initialized late.
> + */
> +__initcall(leon_pmc_install);

We do not use __initcall() in new code.
Use the appropriate initcall from init.h.

A patch to fix up rest of sparc is welcome :-)


	Sam
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Daniel Hellstrom - Jan. 27, 2011, 11:08 a.m.
Sam Ravnborg wrote:

>On Wed, Jan 26, 2011 at 05:37:22PM +0100, Daniel Hellstrom wrote:
>  
>
>>The way a LEON is powered down is implemented differently depending
>>on CHIP type. The AMBA Plug&Play system ID tells revision of GRLIB
>>and CHIP.
>>
>>This is for example needed by the GR-LEON4-ITX board and the UT699.
>>
>>Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
>>    
>>
>
>It is not obvious for me how leon_pmc interact with the existing pmc.c
>implmentation. I guess the latter fails during probe and is thus ignored.
>
>Some comments below - mostly general or nitpick.
>
>	Sam
>  
>
Ok, I will resend this patch.

Daniel

>  
>
>>+
>>+	/* Find System ID: GRLIB build ID and optional CHIP ID */
>>+	pp = of_find_property(rootnp, "systemid", &len);
>>+	if (pp)
>>+		amba_system_id = *(unsigned long *)pp->value;
>>+
>>+	/*Find IRQMP IRQ Controller Registers base address otherwise bail out.*/
>>    
>>
>
>If you are going to resubmit then fix this comment (add a space)
>
>  
>
>>+ * Copyright (C) 2011 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB
>>+ */
>>+
>>+#include <linux/pm.h>
>>+#include <linux/init.h>
>>+#include <asm/leon.h>
>>+#include <asm/leon_amba.h>
>>    
>>
>
>For this number of includes it does not matter.
>But in general we use the inverse christmas tree way.
>Longer lines first. Lines with identical length sorted alphabetically.
>And an empty line between the include groups.
>
>  
>
>>+/*
>>+ * CPU idle callback function for systems that need some extra handling
>>+ * See .../arch/sparc/kernel/process.c
>>+ */
>>+void pmc_leon_idle_fixup(void)
>>+{
>>+	/* Prepare an address to a non-cachable region. APB is always
>>+	 * none-cachable. One instruction is executed after the Sleep
>>+	 * instruction, we make sure to read the bus and throw away the
>>+	 * value by accessing a non-cachable area, also we make sure the
>>+	 * MMU does not get a TLB miss here by using the MMU BYPASS ASI.
>>+	 */
>>+	register unsigned int address = (unsigned int)leon3_irqctrl_regs;
>>+	__asm__ __volatile__ (
>>+		"mov	%%g0, %%asr19\n"
>>+		"lda	[%0] %1, %%g0\n"
>>+		:
>>+		: "r"(address), "i"(ASI_LEON_BYPASS));
>>+}
>>    
>>
>
>Good to see the rasons commented!
>
>  
>
>>+
>>+/* This driver is not critical to the boot process, don't care
>>+ * if initialized late.
>>+ */
>>+__initcall(leon_pmc_install);
>>    
>>
>
>We do not use __initcall() in new code.
>Use the appropriate initcall from init.h.
>
>A patch to fix up rest of sparc is welcome :-)
>
>
>	Sam
>
>
>  
>

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Daniel Hellstrom - Jan. 27, 2011, 11:33 a.m.
Daniel Hellstrom wrote:

> Sam Ravnborg wrote:
>
>> On Wed, Jan 26, 2011 at 05:37:22PM +0100, Daniel Hellstrom wrote:
>>
>>
>>> The way a LEON is powered down is implemented differently depending
>>> on CHIP type. The AMBA Plug&Play system ID tells revision of GRLIB
>>> and CHIP.
>>>
>>> This is for example needed by the GR-LEON4-ITX board and the UT699.
>>>
>>> Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
>>>
>>
>> It is not obvious for me how leon_pmc interact with the existing pmc.c
>> implmentation. I guess the latter fails during probe and is thus 
>> ignored.
>>
>> Some comments below - mostly general or nitpick.
>>
>> Sam
>>
>>
> Ok, I will resend this patch.
>
>
it is resent... See my comments below.

It does not really interact with pmc.c, it it free for anyone to set the 
function point pmc_idle, it is later used in process_32.c.

>
>>
>>
>>> +
>>> + /* Find System ID: GRLIB build ID and optional CHIP ID */
>>> + pp = of_find_property(rootnp, "systemid", &len);
>>> + if (pp)
>>> + amba_system_id = *(unsigned long *)pp->value;
>>> +
>>> + /*Find IRQMP IRQ Controller Registers base address otherwise bail 
>>> out.*/
>>>
>>
>> If you are going to resubmit then fix this comment (add a space)
>>
Fixed.

>>
>>
>>> + * Copyright (C) 2011 Daniel Hellstrom (daniel@gaisler.com) 
>>> Aeroflex Gaisler AB
>>> + */
>>> +
>>> +#include <linux/pm.h>
>>> +#include <linux/init.h>
>>> +#include <asm/leon.h>
>>> +#include <asm/leon_amba.h>
>>>
>>
>> For this number of includes it does not matter.
>> But in general we use the inverse christmas tree way.
>> Longer lines first. Lines with identical length sorted alphabetically.
>> And an empty line between the include groups.
>>
>>
Fixed.

>>
>>> +/*
>>> + * CPU idle callback function for systems that need some extra 
>>> handling
>>> + * See .../arch/sparc/kernel/process.c
>>> + */
>>> +void pmc_leon_idle_fixup(void)
>>> +{
>>> + /* Prepare an address to a non-cachable region. APB is always
>>> + * none-cachable. One instruction is executed after the Sleep
>>> + * instruction, we make sure to read the bus and throw away the
>>> + * value by accessing a non-cachable area, also we make sure the
>>> + * MMU does not get a TLB miss here by using the MMU BYPASS ASI.
>>> + */
>>> + register unsigned int address = (unsigned int)leon3_irqctrl_regs;
>>> + __asm__ __volatile__ (
>>> + "mov %%g0, %%asr19\n"
>>> + "lda [%0] %1, %%g0\n"
>>> + :
>>> + : "r"(address), "i"(ASI_LEON_BYPASS));
>>> +}
>>>
>>
>> Good to see the rasons commented!
>>
>>
>>
>>> +
>>> +/* This driver is not critical to the boot process, don't care
>>> + * if initialized late.
>>> + */
>>> +__initcall(leon_pmc_install);
>>>
>>
>> We do not use __initcall() in new code.
>> Use the appropriate initcall from init.h.
>
Now it uses late_initcall() instead.

Daniel

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Patch

diff --git a/arch/sparc/include/asm/leon_amba.h b/arch/sparc/include/asm/leon_amba.h
index 263c719..e50f326 100644
--- a/arch/sparc/include/asm/leon_amba.h
+++ b/arch/sparc/include/asm/leon_amba.h
@@ -180,6 +180,7 @@  struct amba_ahb_device {
 struct device_node;
 void _amba_init(struct device_node *dp, struct device_node ***nextp);
 
+extern unsigned long amba_system_id;
 extern struct leon3_irqctrl_regs_map *leon3_irqctrl_regs;
 extern struct leon3_gptimer_regs_map *leon3_gptimer_regs;
 extern struct amba_apb_device leon_percpu_timer_dev[16];
@@ -254,6 +255,11 @@  extern unsigned int sparc_leon_eirq;
 #define GAISLER_L2C      0xffe	/* internal device: leon2compat */
 #define GAISLER_PLUGPLAY 0xfff	/* internal device: plug & play configarea */
 
+/* Chip IDs */
+#define AEROFLEX_UT699    0x0699
+#define LEON4_NEXTREME1   0x0102
+#define GAISLER_GR712RC   0x0712
+
 #define amba_vendor(x) (((x) >> 24) & 0xff)
 
 #define amba_device(x) (((x) >> 12) & 0xfff)
diff --git a/arch/sparc/kernel/Makefile b/arch/sparc/kernel/Makefile
index 599398f..27e7f25 100644
--- a/arch/sparc/kernel/Makefile
+++ b/arch/sparc/kernel/Makefile
@@ -54,6 +54,7 @@  obj-y                   += of_device_$(BITS).o
 obj-$(CONFIG_SPARC64)   += prom_irqtrans.o
 
 obj-$(CONFIG_SPARC_LEON)+= leon_kernel.o
+obj-$(CONFIG_SPARC_LEON)+= leon_pmc.o
 
 obj-$(CONFIG_SPARC64)   += reboot.o
 obj-$(CONFIG_SPARC64)   += sysfs.o
diff --git a/arch/sparc/kernel/leon_kernel.c b/arch/sparc/kernel/leon_kernel.c
index fdab7f8..ef5edbb 100644
--- a/arch/sparc/kernel/leon_kernel.c
+++ b/arch/sparc/kernel/leon_kernel.c
@@ -30,6 +30,7 @@  struct amba_apb_device leon_percpu_timer_dev[16];
 int leondebug_irq_disable;
 int leon_debug_irqout;
 static int dummy_master_l10_counter;
+unsigned long amba_system_id;
 
 unsigned long leon3_gptimer_irq; /* interrupt controller irq number */
 unsigned long leon3_gptimer_idx; /* Timer Index (0..6) within Timer Core */
@@ -117,10 +118,16 @@  void __init leon_init_timers(irq_handler_t counter_fn)
 	master_l10_counter = (unsigned int *)&dummy_master_l10_counter;
 	dummy_master_l10_counter = 0;
 
-	/*Find IRQMP IRQ Controller Registers base address otherwise bail out.*/
 	rootnp = of_find_node_by_path("/ambapp0");
 	if (!rootnp)
 		goto bad;
+
+	/* Find System ID: GRLIB build ID and optional CHIP ID */
+	pp = of_find_property(rootnp, "systemid", &len);
+	if (pp)
+		amba_system_id = *(unsigned long *)pp->value;
+
+	/*Find IRQMP IRQ Controller Registers base address otherwise bail out.*/
 	np = of_find_node_by_name(rootnp, "GAISLER_IRQMP");
 	if (!np) {
 		np = of_find_node_by_name(rootnp, "01_00d");
diff --git a/arch/sparc/kernel/leon_pmc.c b/arch/sparc/kernel/leon_pmc.c
new file mode 100644
index 0000000..071bade
--- /dev/null
+++ b/arch/sparc/kernel/leon_pmc.c
@@ -0,0 +1,81 @@ 
+/* leon_pmc.c: LEON Power-down cpu_idle() handler
+ *
+ * Copyright (C) 2011 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB
+ */
+
+#include <linux/pm.h>
+#include <linux/init.h>
+#include <asm/leon.h>
+#include <asm/leon_amba.h>
+
+/* List of Systems that need fixup instructions around power-down instruction */
+unsigned int pmc_leon_fixup_ids[] = {
+	AEROFLEX_UT699,
+	GAISLER_GR712RC,
+	LEON4_NEXTREME1,
+	0
+};
+
+int pmc_leon_need_fixup(void)
+{
+	unsigned int systemid = amba_system_id >> 16;
+	unsigned int *id;
+
+	id = &pmc_leon_fixup_ids[0];
+	while (*id != 0) {
+		if (*id == systemid)
+			return 1;
+		id++;
+	}
+
+	return 0;
+}
+
+/*
+ * CPU idle callback function for systems that need some extra handling
+ * See .../arch/sparc/kernel/process.c
+ */
+void pmc_leon_idle_fixup(void)
+{
+	/* Prepare an address to a non-cachable region. APB is always
+	 * none-cachable. One instruction is executed after the Sleep
+	 * instruction, we make sure to read the bus and throw away the
+	 * value by accessing a non-cachable area, also we make sure the
+	 * MMU does not get a TLB miss here by using the MMU BYPASS ASI.
+	 */
+	register unsigned int address = (unsigned int)leon3_irqctrl_regs;
+	__asm__ __volatile__ (
+		"mov	%%g0, %%asr19\n"
+		"lda	[%0] %1, %%g0\n"
+		:
+		: "r"(address), "i"(ASI_LEON_BYPASS));
+}
+
+/*
+ * CPU idle callback function
+ * See .../arch/sparc/kernel/process.c
+ */
+void pmc_leon_idle(void)
+{
+	/* For systems without power-down, this will be no-op */
+	__asm__ __volatile__ ("mov	%g0, %asr19\n\t");
+}
+
+/* Install LEON Power Down function */
+static int __init leon_pmc_install(void)
+{
+	/* Assign power management IDLE handler */
+	if (pmc_leon_need_fixup())
+		pm_idle = pmc_leon_idle_fixup;
+	else
+		pm_idle = pmc_leon_idle;
+
+	printk(KERN_INFO "leon: power management initialized\n");
+
+	return 0;
+}
+
+/* This driver is not critical to the boot process, don't care
+ * if initialized late.
+ */
+__initcall(leon_pmc_install);
diff --git a/arch/sparc/kernel/leon_smp.c b/arch/sparc/kernel/leon_smp.c
index 16582d8..e9df87f 100644
--- a/arch/sparc/kernel/leon_smp.c
+++ b/arch/sparc/kernel/leon_smp.c
@@ -437,15 +437,6 @@  void __init leon_blackbox_current(unsigned *addr)
 
 }
 
-/*
- * CPU idle callback function
- * See .../arch/sparc/kernel/process.c
- */
-void pmc_leon_idle(void)
-{
-	__asm__ volatile ("mov %g0, %asr19");
-}
-
 void __init leon_init_smp(void)
 {
 	/* Patch ipi15 trap table */
@@ -456,13 +447,6 @@  void __init leon_init_smp(void)
 	BTFIXUPSET_CALL(smp_cross_call, leon_cross_call, BTFIXUPCALL_NORM);
 	BTFIXUPSET_CALL(__hard_smp_processor_id, __leon_processor_id,
 			BTFIXUPCALL_NORM);
-
-#ifndef PMC_NO_IDLE
-	/* Assign power management IDLE handler */
-	pm_idle = pmc_leon_idle;
-	printk(KERN_INFO "leon: power management initialized\n");
-#endif
-
 }
 
 #endif /* CONFIG_SPARC_LEON */