powerpc: Convert power off logic to pm_power_off

The generic Linux framework to power off the machine is a function pointer
called pm_power_off. The trick about this pointer is that device drivers can
potentially implement it rather than board files.

Today on powerpc we set pm_power_off to invoke our generic full machine power
off logic which then calls ppc_md.power_off to invoke machine specific power
off.

However, when we want to add a power off GPIO via the "gpio-poweroff" driver,
this card house falls apart. That driver only registers itself if pm_power_off
is NULL to ensure it doesn't override board specific logic. However, since we
always set pm_power_off to the generic power off logic (which will just not
power off the machine if no ppc_md.power_off call is implemented), we can't
implement power off via the generic GPIO power off driver.

To fix this up, let's get rid of the ppc_md.power_off logic and just always use
pm_power_off as was intended. Then individual drivers such as the GPIO power off
driver can implement power off logic via that function pointer.

With this patch set applied and a few patches on top of QEMU that implement a
power off GPIO on the virt e500 machine, I can successfully turn off my virtual
machine after halt.
Signed-off-by: Alexander Graf <agraf@suse.de>
[mpe: Squash into one patch and update changelog based on cover letter]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/machdep.h

@@ -142,7 +142,6 @@ struct machdep_calls {
 #endif
 
 	void		(*restart)(char *cmd);
-	void		(*power_off)(void);
 	void		(*halt)(void);
 	void		(*panic)(char *str);
 	void		(*cpu_die)(void);

arch/powerpc/kernel/setup-common.c

@@ -139,8 +139,8 @@ void machine_restart(char *cmd)
 void machine_power_off(void)
 {
 	machine_shutdown();
-	if (ppc_md.power_off)
-		ppc_md.power_off();
+	if (pm_power_off)
+		pm_power_off();
 #ifdef CONFIG_SMP
 	smp_send_stop();
 #endif
@@ -151,7 +151,7 @@ void machine_power_off(void)
 /* Used by the G5 thermal driver */
 EXPORT_SYMBOL_GPL(machine_power_off);
 
-void (*pm_power_off)(void) = machine_power_off;
+void (*pm_power_off)(void);
 EXPORT_SYMBOL_GPL(pm_power_off);
 
 void machine_halt(void)

arch/powerpc/platforms/44x/ppc476.c

@@ -94,7 +94,7 @@ static int avr_probe(struct i2c_client *client,
 {
 	avr_i2c_client = client;
 	ppc_md.restart = avr_reset_system;
-	ppc_md.power_off = avr_power_off_system;
+	pm_power_off = avr_power_off_system;
 	return 0;
 }
 

arch/powerpc/platforms/52xx/efika.c

@@ -212,6 +212,8 @@ static int __init efika_probe(void)
 	DMA_MODE_READ = 0x44;
 	DMA_MODE_WRITE = 0x48;
 
+	pm_power_off = rtas_power_off;
+
 	return 1;
 }
 
@@ -225,7 +227,6 @@ define_machine(efika)
 	.init_IRQ		= mpc52xx_init_irq,
 	.get_irq		= mpc52xx_get_irq,
 	.restart		= rtas_restart,
-	.power_off		= rtas_power_off,
 	.halt			= rtas_halt,
 	.set_rtc_time		= rtas_set_rtc_time,
 	.get_rtc_time		= rtas_get_rtc_time,

arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c

@@ -167,10 +167,10 @@ static int mcu_probe(struct i2c_client *client, const struct i2c_device_id *id)
 	if (ret)
 		goto err;
 
-	/* XXX: this is potentially racy, but there is no lock for ppc_md */
-	if (!ppc_md.power_off) {
+	/* XXX: this is potentially racy, but there is no lock for pm_power_off */
+	if (!pm_power_off) {
 		glob_mcu = mcu;
-		ppc_md.power_off = mcu_power_off;
+		pm_power_off = mcu_power_off;
 		dev_info(&client->dev, "will provide power-off service\n");
 	}
 
@@ -197,7 +197,7 @@ static int mcu_remove(struct i2c_client *client)
 	device_remove_file(&client->dev, &dev_attr_status);
 
 	if (glob_mcu == mcu) {
-		ppc_md.power_off = NULL;
+		pm_power_off = NULL;
 		glob_mcu = NULL;
 	}
 

arch/powerpc/platforms/85xx/corenet_generic.c

@@ -170,7 +170,7 @@ static int __init corenet_generic_probe(void)
 
 			ppc_md.get_irq = ehv_pic_get_irq;
 			ppc_md.restart = fsl_hv_restart;
-			ppc_md.power_off = fsl_hv_halt;
+			pm_power_off = fsl_hv_halt;
 			ppc_md.halt = fsl_hv_halt;
 #ifdef CONFIG_SMP
 			/*

arch/powerpc/platforms/85xx/sgy_cts1000.c

@@ -120,7 +120,7 @@ static int gpio_halt_probe(struct platform_device *pdev)
 
 	/* Register our halt function */
 	ppc_md.halt = gpio_halt_cb;
-	ppc_md.power_off = gpio_halt_cb;
+	pm_power_off = gpio_halt_cb;
 
 	printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d"
 	       " irq).\n", gpio, trigger, irq);
@@ -137,7 +137,7 @@ static int gpio_halt_remove(struct platform_device *pdev)
 		free_irq(irq, halt_node);
 
 		ppc_md.halt = NULL;
-		ppc_md.power_off = NULL;
+		pm_power_off = NULL;
 
 		gpio_free(gpio);
 

arch/powerpc/platforms/cell/celleb_setup.c

@@ -142,6 +142,7 @@ static int __init celleb_probe_beat(void)
 	powerpc_firmware_features |= FW_FEATURE_CELLEB_ALWAYS
 		| FW_FEATURE_BEAT | FW_FEATURE_LPAR;
 	hpte_init_beat_v3();
+	pm_power_off = beat_power_off;
 
 	return 1;
 }
@@ -190,6 +191,7 @@ static int __init celleb_probe_native(void)
 
 	powerpc_firmware_features |= FW_FEATURE_CELLEB_ALWAYS;
 	hpte_init_native();
+	pm_power_off = rtas_power_off;
 
 	return 1;
 }
@@ -204,7 +206,6 @@ define_machine(celleb_beat) {
 	.setup_arch		= celleb_setup_arch_beat,
 	.show_cpuinfo		= celleb_show_cpuinfo,
 	.restart		= beat_restart,
-	.power_off		= beat_power_off,
 	.halt			= beat_halt,
 	.get_rtc_time		= beat_get_rtc_time,
 	.set_rtc_time		= beat_set_rtc_time,
@@ -230,7 +231,6 @@ define_machine(celleb_native) {
 	.setup_arch		= celleb_setup_arch_native,
 	.show_cpuinfo		= celleb_show_cpuinfo,
 	.restart		= rtas_restart,
-	.power_off		= rtas_power_off,
 	.halt			= rtas_halt,
 	.get_boot_time		= rtas_get_boot_time,
 	.get_rtc_time		= rtas_get_rtc_time,

arch/powerpc/platforms/cell/qpace_setup.c

@@ -127,6 +127,7 @@ static int __init qpace_probe(void)
 		return 0;
 
 	hpte_init_native();
+	pm_power_off = rtas_power_off;
 
 	return 1;
 }
@@ -137,7 +138,6 @@ define_machine(qpace) {
 	.setup_arch		= qpace_setup_arch,
 	.show_cpuinfo		= qpace_show_cpuinfo,
 	.restart		= rtas_restart,
-	.power_off		= rtas_power_off,
 	.halt			= rtas_halt,
 	.get_boot_time		= rtas_get_boot_time,
 	.get_rtc_time		= rtas_get_rtc_time,

arch/powerpc/platforms/cell/setup.c

@@ -259,6 +259,7 @@ static int __init cell_probe(void)
 		return 0;
 
 	hpte_init_native();
+	pm_power_off = rtas_power_off;
 
 	return 1;
 }
@@ -269,7 +270,6 @@ define_machine(cell) {
 	.setup_arch		= cell_setup_arch,
 	.show_cpuinfo		= cell_show_cpuinfo,
 	.restart		= rtas_restart,
-	.power_off		= rtas_power_off,
 	.halt			= rtas_halt,
 	.get_boot_time		= rtas_get_boot_time,
 	.get_rtc_time		= rtas_get_rtc_time,

arch/powerpc/platforms/chrp/setup.c

@@ -585,6 +585,8 @@ static int __init chrp_probe(void)
 	DMA_MODE_READ = 0x44;
 	DMA_MODE_WRITE = 0x48;
 
+	pm_power_off = rtas_power_off;
+
 	return 1;
 }
 
@@ -597,7 +599,6 @@ define_machine(chrp) {
 	.show_cpuinfo		= chrp_show_cpuinfo,
 	.init_IRQ		= chrp_init_IRQ,
 	.restart		= rtas_restart,
-	.power_off		= rtas_power_off,
 	.halt			= rtas_halt,
 	.time_init		= chrp_time_init,
 	.set_rtc_time		= chrp_set_rtc_time,

arch/powerpc/platforms/embedded6xx/gamecube.c

@@ -67,6 +67,8 @@ static int __init gamecube_probe(void)
 	if (!of_flat_dt_is_compatible(dt_root, "nintendo,gamecube"))
 		return 0;
 
+	pm_power_off = gamecube_power_off;
+
 	return 1;
 }
 
@@ -80,7 +82,6 @@ define_machine(gamecube) {
 	.probe			= gamecube_probe,
 	.init_early		= gamecube_init_early,
 	.restart		= gamecube_restart,
-	.power_off		= gamecube_power_off,
 	.halt			= gamecube_halt,
 	.init_IRQ		= flipper_pic_probe,
 	.get_irq		= flipper_pic_get_irq,

arch/powerpc/platforms/embedded6xx/linkstation.c

@@ -147,6 +147,9 @@ static int __init linkstation_probe(void)
 
 	if (!of_flat_dt_is_compatible(root, "linkstation"))
 		return 0;
+
+	pm_power_off = linkstation_power_off;
+
 	return 1;
 }
 
@@ -158,7 +161,6 @@ define_machine(linkstation){
 	.show_cpuinfo 		= linkstation_show_cpuinfo,
 	.get_irq 		= mpic_get_irq,
 	.restart 		= linkstation_restart,
-	.power_off 		= linkstation_power_off,
 	.halt	 		= linkstation_halt,
 	.calibrate_decr 	= generic_calibrate_decr,
 };

arch/powerpc/platforms/embedded6xx/wii.c

@@ -211,6 +211,8 @@ static int __init wii_probe(void)
 	if (!of_flat_dt_is_compatible(dt_root, "nintendo,wii"))
 		return 0;
 
+	pm_power_off = wii_power_off;
+
 	return 1;
 }
 
@@ -226,7 +228,6 @@ define_machine(wii) {
 	.init_early		= wii_init_early,
 	.setup_arch		= wii_setup_arch,
 	.restart		= wii_restart,
-	.power_off		= wii_power_off,
 	.halt			= wii_halt,
 	.init_IRQ		= wii_pic_probe,
 	.get_irq		= flipper_pic_get_irq,

arch/powerpc/platforms/maple/setup.c

@@ -169,7 +169,7 @@ static void __init maple_use_rtas_reboot_and_halt_if_present(void)
 	if (rtas_service_present("system-reboot") &&
 	    rtas_service_present("power-off")) {
 		ppc_md.restart = rtas_restart;
-		ppc_md.power_off = rtas_power_off;
+		pm_power_off = rtas_power_off;
 		ppc_md.halt = rtas_halt;
 	}
 }
@@ -312,6 +312,7 @@ static int __init maple_probe(void)
 	alloc_dart_table();
 
 	hpte_init_native();
+	pm_power_off = maple_power_off;
 
 	return 1;
 }
@@ -325,7 +326,6 @@ define_machine(maple) {
 	.pci_irq_fixup		= maple_pci_irq_fixup,
 	.pci_get_legacy_ide_irq	= maple_pci_get_legacy_ide_irq,
 	.restart		= maple_restart,
-	.power_off		= maple_power_off,
 	.halt			= maple_halt,
        	.get_boot_time		= maple_get_boot_time,
        	.set_rtc_time		= maple_set_rtc_time,

arch/powerpc/platforms/powermac/setup.c

@@ -632,6 +632,8 @@ static int __init pmac_probe(void)
 	smu_cmdbuf_abs = memblock_alloc_base(4096, 4096, 0x80000000UL);
 #endif /* CONFIG_PMAC_SMU */
 
+	pm_power_off = pmac_power_off;
+
 	return 1;
 }
 
@@ -663,7 +665,6 @@ define_machine(powermac) {
 	.get_irq		= NULL,	/* changed later */
 	.pci_irq_fixup		= pmac_pci_irq_fixup,
 	.restart		= pmac_restart,
-	.power_off		= pmac_power_off,
 	.halt			= pmac_halt,
 	.time_init		= pmac_time_init,
 	.get_boot_time		= pmac_get_boot_time,

arch/powerpc/platforms/powernv/setup.c

@@ -268,7 +268,7 @@ static void __init pnv_setup_machdep_opal(void)
 	ppc_md.get_rtc_time = opal_get_rtc_time;
 	ppc_md.set_rtc_time = opal_set_rtc_time;
 	ppc_md.restart = pnv_restart;
-	ppc_md.power_off = pnv_power_off;
+	pm_power_off = pnv_power_off;
 	ppc_md.halt = pnv_halt;
 	ppc_md.machine_check_exception = opal_machine_check;
 	ppc_md.mce_check_early_recovery = opal_mce_check_early_recovery;
@@ -285,7 +285,7 @@ static void __init pnv_setup_machdep_rtas(void)
 		ppc_md.set_rtc_time = rtas_set_rtc_time;
 	}
 	ppc_md.restart = rtas_restart;
-	ppc_md.power_off = rtas_power_off;
+	pm_power_off = rtas_power_off;
 	ppc_md.halt = rtas_halt;
 }
 #endif /* CONFIG_PPC_POWERNV_RTAS */

arch/powerpc/platforms/ps3/setup.c

@@ -248,6 +248,7 @@ static int __init ps3_probe(void)
 	ps3_mm_init();
 	ps3_mm_vas_create(&htab_size);
 	ps3_hpte_init(htab_size);
+	pm_power_off = ps3_power_off;
 
 	DBG(" <- %s:%d\n", __func__, __LINE__);
 	return 1;
@@ -278,7 +279,6 @@ define_machine(ps3) {
 	.calibrate_decr			= ps3_calibrate_decr,
 	.progress			= ps3_progress,
 	.restart			= ps3_restart,
-	.power_off			= ps3_power_off,
 	.halt				= ps3_halt,
 #if defined(CONFIG_KEXEC)
 	.kexec_cpu_down			= ps3_kexec_cpu_down,

arch/powerpc/platforms/pseries/setup.c

@@ -659,6 +659,34 @@ static void __init pSeries_init_early(void)
 	pr_debug(" <- pSeries_init_early()\n");
 }
 
+/**
+ * pseries_power_off - tell firmware about how to power off the system.
+ *
+ * This function calls either the power-off rtas token in normal cases
+ * or the ibm,power-off-ups token (if present & requested) in case of
+ * a power failure. If power-off token is used, power on will only be
+ * possible with power button press. If ibm,power-off-ups token is used
+ * it will allow auto poweron after power is restored.
+ */
+static void pseries_power_off(void)
+{
+	int rc;
+	int rtas_poweroff_ups_token = rtas_token("ibm,power-off-ups");
+
+	if (rtas_flash_term_hook)
+		rtas_flash_term_hook(SYS_POWER_OFF);
+
+	if (rtas_poweron_auto == 0 ||
+		rtas_poweroff_ups_token == RTAS_UNKNOWN_SERVICE) {
+		rc = rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1);
+		printk(KERN_INFO "RTAS power-off returned %d\n", rc);
+	} else {
+		rc = rtas_call(rtas_poweroff_ups_token, 0, 1, NULL);
+		printk(KERN_INFO "RTAS ibm,power-off-ups returned %d\n", rc);
+	}
+	for (;;);
+}
+
 /*
  * Called very early, MMU is off, device-tree isn't unflattened
  */
@@ -741,6 +769,8 @@ static int __init pSeries_probe(void)
 	else
 		hpte_init_native();
 
+	pm_power_off = pseries_power_off;
+
 	pr_debug("Machine is%s LPAR !\n",
 	         (powerpc_firmware_features & FW_FEATURE_LPAR) ? "" : " not");
 
@@ -754,34 +784,6 @@ static int pSeries_pci_probe_mode(struct pci_bus *bus)
 	return PCI_PROBE_NORMAL;
 }
 
-/**
- * pSeries_power_off - tell firmware about how to power off the system.
- *
- * This function calls either the power-off rtas token in normal cases
- * or the ibm,power-off-ups token (if present & requested) in case of
- * a power failure. If power-off token is used, power on will only be
- * possible with power button press. If ibm,power-off-ups token is used
- * it will allow auto poweron after power is restored.
- */
-static void pSeries_power_off(void)
-{
-	int rc;
-	int rtas_poweroff_ups_token = rtas_token("ibm,power-off-ups");
-
-	if (rtas_flash_term_hook)
-		rtas_flash_term_hook(SYS_POWER_OFF);
-
-	if (rtas_poweron_auto == 0 ||
-		rtas_poweroff_ups_token == RTAS_UNKNOWN_SERVICE) {
-		rc = rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1);
-		printk(KERN_INFO "RTAS power-off returned %d\n", rc);
-	} else {
-		rc = rtas_call(rtas_poweroff_ups_token, 0, 1, NULL);
-		printk(KERN_INFO "RTAS ibm,power-off-ups returned %d\n", rc);
-	}
-	for (;;);
-}
-
 #ifndef CONFIG_PCI
 void pSeries_final_fixup(void) { }
 #endif
@@ -796,7 +798,6 @@ define_machine(pseries) {
 	.pcibios_fixup		= pSeries_final_fixup,
 	.pci_probe_mode		= pSeries_pci_probe_mode,
 	.restart		= rtas_restart,
-	.power_off		= pSeries_power_off,
 	.halt			= rtas_halt,
 	.panic			= rtas_os_term,
 	.get_boot_time		= rtas_get_boot_time,

arch/powerpc/sysdev/fsl_soc.c

@@ -238,7 +238,7 @@ void fsl_hv_restart(char *cmd)
 /*
  * Halt the current partition
  *
- * This function should be assigned to the ppc_md.power_off and ppc_md.halt
+ * This function should be assigned to the pm_power_off and ppc_md.halt
  * function pointers, to shut down the partition when we're running under
  * the Freescale hypervisor.
  */

arch/powerpc/xmon/xmon.c

@@ -981,7 +981,8 @@ static void bootcmds(void)
 	else if (cmd == 'h')
 		ppc_md.halt();
 	else if (cmd == 'p')
-		ppc_md.power_off();
+		if (pm_power_off)
+			pm_power_off();
 }
 
 static int cpu_cmd(void)