| Message ID | 1515150321-24894-2-git-send-email-bharata@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | powerpc: Fix memory unplug failure for radix guests | expand |
On 01/05/2018 04:35 PM, Bharata B Rao wrote: > Currently device tree nodes for memory are scanned before the > radix feature is discovered in mmu_early_init_devtree(). Move this > routine ahead of scanning memory nodes so that we know if the > guest is radix or not when scanning ibm,dynamic-reconfiguration-memory. > > Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> > --- > arch/powerpc/kernel/prom.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c > index b15bae2..079d893 100644 > --- a/arch/powerpc/kernel/prom.c > +++ b/arch/powerpc/kernel/prom.c > @@ -722,6 +722,8 @@ void __init early_init_devtree(void *params) > */ > of_scan_flat_dt(early_init_dt_scan_chosen_ppc, boot_command_line); > > + mmu_early_init_devtree(); > + > /* Scan memory nodes and rebuild MEMBLOCKs */ > of_scan_flat_dt(early_init_dt_scan_root, NULL); > of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL); > @@ -783,8 +785,6 @@ void __init early_init_devtree(void *params) > spinning_secondaries = boot_cpu_count - 1; > #endif > > - mmu_early_init_devtree(); > - > #ifdef CONFIG_PPC_POWERNV > /* Scan and build the list of machine check recoverable ranges */ > of_scan_flat_dt(early_init_dt_scan_recoverable_ranges, NULL); > I guess that will cause issues with pa-feature scanning. I don't think we finalize cpu features/mmu features that early. -aneesh
Bharata B Rao <bharata@linux.vnet.ibm.com> writes: > Currently device tree nodes for memory are scanned before the > radix feature is discovered in mmu_early_init_devtree(). Move this > routine ahead of scanning memory nodes so that we know if the > guest is radix or not when scanning ibm,dynamic-reconfiguration-memory. Sorry this doesn't work. > diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c > index b15bae2..079d893 100644 > --- a/arch/powerpc/kernel/prom.c > +++ b/arch/powerpc/kernel/prom.c > @@ -722,6 +722,8 @@ void __init early_init_devtree(void *params) > */ > of_scan_flat_dt(early_init_dt_scan_chosen_ppc, boot_command_line); > > + mmu_early_init_devtree(); > + You've moved this above parse_early_param(), but mmu_early_init_devtree() uses disable_radix, which is an early param. So this will break disable_radix handling. It will probably break other things too because the ordering of this init code is very fragile - bootstrapping is hard :) > /* Scan memory nodes and rebuild MEMBLOCKs */ > of_scan_flat_dt(early_init_dt_scan_root, NULL); > of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL); > @@ -783,8 +785,6 @@ void __init early_init_devtree(void *params) > spinning_secondaries = boot_cpu_count - 1; > #endif > > - mmu_early_init_devtree(); > - > #ifdef CONFIG_PPC_POWERNV > /* Scan and build the list of machine check recoverable ranges */ > of_scan_flat_dt(early_init_dt_scan_recoverable_ranges, NULL); cheers
On Sat, Jan 06, 2018 at 10:28:00AM +1100, Michael Ellerman wrote: > Bharata B Rao <bharata@linux.vnet.ibm.com> writes: > > > Currently device tree nodes for memory are scanned before the > > radix feature is discovered in mmu_early_init_devtree(). Move this > > routine ahead of scanning memory nodes so that we know if the > > guest is radix or not when scanning ibm,dynamic-reconfiguration-memory. > > Sorry this doesn't work. > > > diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c > > index b15bae2..079d893 100644 > > --- a/arch/powerpc/kernel/prom.c > > +++ b/arch/powerpc/kernel/prom.c > > @@ -722,6 +722,8 @@ void __init early_init_devtree(void *params) > > */ > > of_scan_flat_dt(early_init_dt_scan_chosen_ppc, boot_command_line); > > > > + mmu_early_init_devtree(); > > + > > You've moved this above parse_early_param(), but > mmu_early_init_devtree() uses disable_radix, which is an early param. So > this will break disable_radix handling. > > It will probably break other things too because the ordering of this > init code is very fragile - bootstrapping is hard :) So from your and Aneesh's reply I realize that my current approach involving upfront mapping of hotplugged memory with smaller mappings without afffecting PowerVM will not be feasible. Guess breaking the mapping appropriately during unplug would be the only real solution then. Regards, Bharata.
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c index b15bae2..079d893 100644 --- a/arch/powerpc/kernel/prom.c +++ b/arch/powerpc/kernel/prom.c @@ -722,6 +722,8 @@ void __init early_init_devtree(void *params) */ of_scan_flat_dt(early_init_dt_scan_chosen_ppc, boot_command_line); + mmu_early_init_devtree(); + /* Scan memory nodes and rebuild MEMBLOCKs */ of_scan_flat_dt(early_init_dt_scan_root, NULL); of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL); @@ -783,8 +785,6 @@ void __init early_init_devtree(void *params) spinning_secondaries = boot_cpu_count - 1; #endif - mmu_early_init_devtree(); - #ifdef CONFIG_PPC_POWERNV /* Scan and build the list of machine check recoverable ranges */ of_scan_flat_dt(early_init_dt_scan_recoverable_ranges, NULL);
Currently device tree nodes for memory are scanned before the radix feature is discovered in mmu_early_init_devtree(). Move this routine ahead of scanning memory nodes so that we know if the guest is radix or not when scanning ibm,dynamic-reconfiguration-memory. Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> --- arch/powerpc/kernel/prom.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)