kernel.git/arch/s390/lib, branch linux-2.6.28.y

S390: __div64_31 broken for CONFIG_MARCH_G5

2009-03-23T21:55:24Z

commit 4fa81ed27781a12f6303b9263056635ae74e3e21 upstream. The implementation of __div64_31 for G5 machines is broken. The comments in __div64_31 are correct, only the code does not do what the comments say. The part "If the remainder has overflown subtract base and increase the quotient" is only partially realized, the base is subtracted correctly but the quotient is only increased if the dividend had the last bit set. Using the correct instruction fixes the problem. Reported-by: Frans Pop Tested-by: Frans Pop Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

[S390] Move private simple udelay function to arch/s390/lib/delay.c.

2008-10-10T19:33:58Z

Move cio's private simple udelay function to lib/delay.c and turn it into something much more readable. So we have all implementations at one place. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

[S390] nohz: Fix __udelay.

2008-10-03T19:55:54Z

This fixes a regression that came with 934b2857cc576ae53c92a66e63fce7ddcfa74691 ("[S390] nohz/sclp: disable timer on synchronous waits."). If udelay() gets called from a disabled context it sets the clock comparator to a value where it expects the next interrupt. When the interrupt happens the clock comparator gets not reset and therefore the interrupt condition doesn't get cleared. The result is an endless timer interrupt loop. In addition this patch fixes also the following: rcutorture reveals that our __udelay implementation is still buggy, since it might schedule tasklets, but prevents their execution: NOHZ: local_softirq_pending 42 NOHZ: local_softirq_pending 02 NOHZ: local_softirq_pending 142 NOHZ: local_softirq_pending 02 To fix this we make sure that only the clock comparator interrupt is enabled when the enabled wait psw is loaded. Also no code gets called anymore which might schedule tasklets. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

[S390] nohz/sclp: disable timer on synchronous waits.

2008-08-01T14:39:30Z

sclp_sync_wait wait synchronously for an sclp interrupt and disables timer interrupts. However on the irq enter paths there is an extra check if a timer interrupt would be due and calls the timer callback. This would schedule softirqs in the wrong context. So introduce local_tick_enable/disable which prevents this. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

[S390] uaccess_mvcos: #ifdef config dependent code.

2008-04-30T11:38:46Z

arch/s390/lib/uaccess_mvcos.c:166: warning: 'strnlen_user_mvcos' defined but not used arch/s390/lib/uaccess_mvcos.c:186: warning: 'strncpy_from_user_mvcos' defined but not used Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

[S390] remove -traditional

2008-04-30T11:38:44Z

Signed-off-by: Mathieu Desnoyers CC: Sam Ravnborg Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

[S390] uaccess: Always access the correct address space.

2008-04-17T05:47:06Z

The current uaccess page table walk code assumes at a few places that any access is a user space access. This is not correct if somebody has issued a set_fs(KERNEL_DS) in advance. Add code which checks which address space we are in and with this make sure we access the correct address space. This way we get also rid of the dirty if (!currrent-mm) return -EFAULT; hack in futex_atomic_cmpxchg_pt. Signed-off-by: Martin Schwidefsky Signed-off-by: Heiko Carstens

[S390] Convert s390 to GENERIC_CLOCKEVENTS.

2008-04-17T05:47:05Z

This way we get rid of s390's NO_IDLE_HZ and use the generic dynticks variant instead. In addition we get high resolution timers for free. Signed-off-by: Martin Schwidefsky Signed-off-by: Heiko Carstens

[S390] futex: let futex_atomic_cmpxchg_pt survive early functional tests.

2008-03-20T16:33:46Z

a0c1e9073ef7428a14309cba010633a6cd6719ea "futex: runtime enable pi and robust functionality" introduces a test wether futex in atomic stuff works or not. It does that by writing to address 0 of the kernel address space. This will crash on older machines where addressing mode switching is enabled but where the mvcos instruction is not available. Page table walking is done by hand and therefore the code tries to access current->mm which is NULL. Therefore add an extra check, so we survive the early test. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

[S390] Fix futex_atomic_cmpxchg_std inline assembly.

2008-02-19T14:29:35Z

Add missing exception table entry so that the kernel can handle proctection exceptions as well on the cs instruction. Currently only specification exceptions are handled correctly. The missing entry allows user space to crash the kernel. Cc: stable Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky