| Message ID | 1457004188-17186-1-git-send-email-thuth@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 03/03/2016 12:23, Thomas Huth wrote: > As noted by Laurent Vivier, a register that is marked with "+r" as > input and output is not required to be listed in the set of input > registers anymore. > And as noted by David Gibson, the sPAPR hypercall is also allowed to > clobber a bunch of other registers. According to the LoPAPR spec, > r0 and r3-r12, CTR, XER and CC registers are volatile, so we should > mark them in the clobber list. > > Signed-off-by: Thomas Huth <thuth@redhat.com> > --- > powerpc/spapr_hcall.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/powerpc/spapr_hcall.c b/powerpc/spapr_hcall.c > index 46731e1..dbff630 100644 > --- a/powerpc/spapr_hcall.c > +++ b/powerpc/spapr_hcall.c > @@ -96,7 +96,9 @@ static int h_random(uint64_t *val) > register uint64_t r3 asm("r3") = H_RANDOM; > register uint64_t r4 asm("r4"); > > - asm volatile (" sc 1 " : "+r"(r3), "=r"(r4) : "r"(r3)); > + asm volatile (" sc 1 " : "+r"(r3), "=r"(r4) : > + : "r0", "r5", "r6", "r7", "r8", "r9", "r10", > + "r11", "r12", "xer", "ctr", "cc"); > *val = r4; > > return r3; > Applied, thanks. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/powerpc/spapr_hcall.c b/powerpc/spapr_hcall.c index 46731e1..dbff630 100644 --- a/powerpc/spapr_hcall.c +++ b/powerpc/spapr_hcall.c @@ -96,7 +96,9 @@ static int h_random(uint64_t *val) register uint64_t r3 asm("r3") = H_RANDOM; register uint64_t r4 asm("r4"); - asm volatile (" sc 1 " : "+r"(r3), "=r"(r4) : "r"(r3)); + asm volatile (" sc 1 " : "+r"(r3), "=r"(r4) : + : "r0", "r5", "r6", "r7", "r8", "r9", "r10", + "r11", "r12", "xer", "ctr", "cc"); *val = r4; return r3;
As noted by Laurent Vivier, a register that is marked with "+r" as input and output is not required to be listed in the set of input registers anymore. And as noted by David Gibson, the sPAPR hypercall is also allowed to clobber a bunch of other registers. According to the LoPAPR spec, r0 and r3-r12, CTR, XER and CC registers are volatile, so we should mark them in the clobber list. Signed-off-by: Thomas Huth <thuth@redhat.com> --- powerpc/spapr_hcall.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)