| Message ID | 20231216134257.1743345-13-npiggin@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | powerpc: updates, P10, PNV support | expand |
On 16/12/2023 14.42, Nicholas Piggin wrote: > Storing certain values in some registers can cause asynchronous > interrupts that can crash the test case, for example decrementer > or PMU interrupts. > > Change the msleep to mdelay which does not enable MSR[EE] and so > avoids the problem. This allows removing some of the SPR special > casing. > > Signed-off-by: Nicholas Piggin <npiggin@gmail.com> > --- > powerpc/sprs.c | 14 ++------------ > 1 file changed, 2 insertions(+), 12 deletions(-) > > diff --git a/powerpc/sprs.c b/powerpc/sprs.c > index 01041912..313698e0 100644 > --- a/powerpc/sprs.c > +++ b/powerpc/sprs.c > @@ -481,12 +481,7 @@ static void set_sprs(uint64_t val) > continue; > if (sprs[i].type & SPR_HARNESS) > continue; > - if (!strcmp(sprs[i].name, "MMCR0")) { > - /* XXX: could use a comment or better abstraction! */ > - __mtspr(i, (val & 0xfffffffffbab3fffULL) | 0xfa0b2070); > - } else { > - __mtspr(i, val); > - } > + __mtspr(i, val); > } > } > > @@ -536,12 +531,7 @@ int main(int argc, char **argv) > if (pause) { > migrate_once(); > } else { > - msleep(2000); > - > - /* Taking a dec updates SRR0, SRR1, SPRG1, so don't fail. */ > - sprs[26].type |= SPR_ASYNC; > - sprs[27].type |= SPR_ASYNC; > - sprs[273].type |= SPR_ASYNC; > + mdelay(2000); > } IIRC I used the H_CEDE stuff here on purpose to increase the possibility that the guest gets rescheduled onto another CPU core on the host, and thus that it uncovers sprs that are not saved and restored on the host more easily. So I'd rather keep the msleep() here. Thomas
On Tue Dec 19, 2023 at 9:47 PM AEST, Thomas Huth wrote: > On 16/12/2023 14.42, Nicholas Piggin wrote: > > Storing certain values in some registers can cause asynchronous > > interrupts that can crash the test case, for example decrementer > > or PMU interrupts. > > > > Change the msleep to mdelay which does not enable MSR[EE] and so > > avoids the problem. This allows removing some of the SPR special > > casing. > > > > Signed-off-by: Nicholas Piggin <npiggin@gmail.com> > > --- > > powerpc/sprs.c | 14 ++------------ > > 1 file changed, 2 insertions(+), 12 deletions(-) > > > > diff --git a/powerpc/sprs.c b/powerpc/sprs.c > > index 01041912..313698e0 100644 > > --- a/powerpc/sprs.c > > +++ b/powerpc/sprs.c > > @@ -481,12 +481,7 @@ static void set_sprs(uint64_t val) > > continue; > > if (sprs[i].type & SPR_HARNESS) > > continue; > > - if (!strcmp(sprs[i].name, "MMCR0")) { > > - /* XXX: could use a comment or better abstraction! */ > > - __mtspr(i, (val & 0xfffffffffbab3fffULL) | 0xfa0b2070); > > - } else { > > - __mtspr(i, val); > > - } > > + __mtspr(i, val); > > } > > } > > > > @@ -536,12 +531,7 @@ int main(int argc, char **argv) > > if (pause) { > > migrate_once(); > > } else { > > - msleep(2000); > > - > > - /* Taking a dec updates SRR0, SRR1, SPRG1, so don't fail. */ > > - sprs[26].type |= SPR_ASYNC; > > - sprs[27].type |= SPR_ASYNC; > > - sprs[273].type |= SPR_ASYNC; > > + mdelay(2000); > > } > > IIRC I used the H_CEDE stuff here on purpose to increase the possibility > that the guest gets rescheduled onto another CPU core on the host, and thus > that it uncovers sprs that are not saved and restored on the host more > easily. So I'd rather keep the msleep() here. Ah. Not a bad idea. I'll see about making it deal with H_CEDE instead. I wonder if there would be a way to stress host CPU migration in the test harness. Instead of waiting for QEMU to exit, the script could run taskset in a loop to bounce it around. Conceptually easy, probably fiddly to wire things up nicely. I may try to take a look at adding that... but after this series so it doesn't get any bigger :/ Thanks, Nick
diff --git a/powerpc/sprs.c b/powerpc/sprs.c index 01041912..313698e0 100644 --- a/powerpc/sprs.c +++ b/powerpc/sprs.c @@ -481,12 +481,7 @@ static void set_sprs(uint64_t val) continue; if (sprs[i].type & SPR_HARNESS) continue; - if (!strcmp(sprs[i].name, "MMCR0")) { - /* XXX: could use a comment or better abstraction! */ - __mtspr(i, (val & 0xfffffffffbab3fffULL) | 0xfa0b2070); - } else { - __mtspr(i, val); - } + __mtspr(i, val); } } @@ -536,12 +531,7 @@ int main(int argc, char **argv) if (pause) { migrate_once(); } else { - msleep(2000); - - /* Taking a dec updates SRR0, SRR1, SPRG1, so don't fail. */ - sprs[26].type |= SPR_ASYNC; - sprs[27].type |= SPR_ASYNC; - sprs[273].type |= SPR_ASYNC; + mdelay(2000); } get_sprs(after);
Storing certain values in some registers can cause asynchronous interrupts that can crash the test case, for example decrementer or PMU interrupts. Change the msleep to mdelay which does not enable MSR[EE] and so avoids the problem. This allows removing some of the SPR special casing. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- powerpc/sprs.c | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-)