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s390/ctlreg: return old register contents when changing bits

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Change local_ctl_set_bit() and local_ctl_clear_bit() so they return the
previous value of the to be changed control register. This is useful if a
bit is only changed temporarily and the previous content needs to be
restored.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
This commit is contained in:
Heiko Carstens 2023-12-01 14:09:29 +01:00 committed by Alexander Gordeev
parent 207022d39d
commit f88d368453
1 changed files with 14 additions and 10 deletions
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24
arch/s390/include/asm/ctlreg.h
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@ -141,22 +141,26 @@ static __always_inline void local_ctl_store(unsigned int cr, struct ctlreg *reg)
: [cr] "i" (cr));
}
static __always_inline void local_ctl_set_bit(unsigned int cr, unsigned int bit)
static __always_inline struct ctlreg local_ctl_set_bit(unsigned int cr, unsigned int bit)
{
struct ctlreg reg;
struct ctlreg new, old;
local_ctl_store(cr, &reg);
reg.val |= 1UL << bit;
local_ctl_load(cr, &reg);
local_ctl_store(cr, &old);
new = old;
new.val |= 1UL << bit;
local_ctl_load(cr, &new);
return old;
}
static __always_inline void local_ctl_clear_bit(unsigned int cr, unsigned int bit)
static __always_inline struct ctlreg local_ctl_clear_bit(unsigned int cr, unsigned int bit)
{
struct ctlreg reg;
struct ctlreg new, old;
local_ctl_store(cr, &reg);
reg.val &= ~(1UL << bit);
local_ctl_load(cr, &reg);
local_ctl_store(cr, &old);
new = old;
new.val &= ~(1UL << bit);
local_ctl_load(cr, &new);
return old;
}
struct lowcore;