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powerpc: Convert power off logic to pm_power_off

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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>
This commit is contained in:
Alexander Graf
2014-10-13 16:01:09 +02:00
committed by Michael Ellerman
parent 0df1f2487d
commit 9178ba294b
21 changed files with 66 additions and 58 deletions
Download Patch File Download Diff File Expand all files Collapse all files

59
arch/powerpc/platforms/pseries/setup.c
View File

@@ -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,