| Message ID | 1397643240-13147-1-git-send-email-luis.henriques@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c index baebab2..b9cc976 100644 --- a/arch/sparc/kernel/process_64.c +++ b/arch/sparc/kernel/process_64.c @@ -57,9 +57,12 @@ void arch_cpu_idle(void) { if (tlb_type != hypervisor) { touch_nmi_watchdog(); + local_irq_enable(); } else { unsigned long pstate; + local_irq_enable(); + /* The sun4v sleeping code requires that we have PSTATE.IE cleared over * the cpu sleep hypervisor call. */ @@ -81,7 +84,6 @@ void arch_cpu_idle(void) : "=&r" (pstate) : "i" (PSTATE_IE)); } - local_irq_enable(); } #ifdef CONFIG_HOTPLUG_CPU
This is a note to let you know that I have just added a patch titled sparc64: Make sure %pil interrupts are enabled during hypervisor yield. to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.11.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 4cd897ee0372f1366684770c3d2f7b5f2cf1ae96 Mon Sep 17 00:00:00 2001 From: "David S. Miller" <davem@davemloft.net> Date: Mon, 24 Mar 2014 14:45:12 -0400 Subject: sparc64: Make sure %pil interrupts are enabled during hypervisor yield. commit cb3042d609e30e6144024801c89be3925106752b upstream. In arch_cpu_idle() we must enable %pil based interrupts before potentially invoking the hypervisor cpu yield call. As per the Hypervisor API documentation for cpu_yield: Interrupts which are blocked by some mechanism other that pstate.ie (for example %pil) are not guaranteed to cause a return from this service. It seems that only first generation Niagara chips are hit by this bug. My best guess is that later chips implement this in hardware and wake up anyways from %pil events, whereas in first generation chips the yield is implemented completely in hypervisor code and requires %pil to be enabled in order to wake properly from this call. Fixes: 87fa05aeb3a5 ("sparc: Use generic idle loop") Reported-by: Fabio M. Di Nitto <fabbione@fabbione.net> Reported-by: Jan Engelhardt <jengelh@inai.de> Tested-by: Jan Engelhardt <jengelh@inai.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- arch/sparc/kernel/process_64.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) -- 1.9.1