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-rw-r--r--arch/powerpc/include/asm/paca.h5
-rw-r--r--arch/powerpc/kernel/asm-offsets.c1
-rw-r--r--arch/powerpc/kernel/idle_book3s.S48
-rw-r--r--arch/powerpc/platforms/powernv/idle.c30
4 files changed, 83 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index 65d0ffb2aa33..140ddb9ae5a8 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -173,6 +173,11 @@ struct paca_struct {
u8 thread_mask;
/* Mask to denote subcore sibling threads */
u8 subcore_sibling_mask;
+ /*
+ * Pointer to an array which contains pointer
+ * to the sibling threads' paca.
+ */
+ struct paca_struct **thread_sibling_pacas;
#endif
#ifdef CONFIG_PPC_BOOK3S_64
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 795505e27535..e7c8229a8812 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -728,6 +728,7 @@ int main(void)
OFFSET(PACA_THREAD_IDLE_STATE, paca_struct, thread_idle_state);
OFFSET(PACA_THREAD_MASK, paca_struct, thread_mask);
OFFSET(PACA_SUBCORE_SIBLING_MASK, paca_struct, subcore_sibling_mask);
+ OFFSET(PACA_SIBLING_PACA_PTRS, paca_struct, thread_sibling_pacas);
#endif
DEFINE(PPC_DBELL_SERVER, PPC_DBELL_SERVER);
diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S
index 995728736677..24717a73b6bb 100644
--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S
@@ -375,6 +375,46 @@ _GLOBAL(power9_idle_stop)
li r4,1
b pnv_powersave_common
/* No return */
+
+
+/*
+ * On waking up from stop 0,1,2 with ESL=1 on POWER9 DD1,
+ * HSPRG0 will be set to the HSPRG0 value of one of the
+ * threads in this core. Thus the value we have in r13
+ * may not be this thread's paca pointer.
+ *
+ * Fortunately, the TIR remains invariant. Since this thread's
+ * paca pointer is recorded in all its sibling's paca, we can
+ * correctly recover this thread's paca pointer if we
+ * know the index of this thread in the core.
+ *
+ * This index can be obtained from the TIR.
+ *
+ * i.e, thread's position in the core = TIR.
+ * If this value is i, then this thread's paca is
+ * paca->thread_sibling_pacas[i].
+ */
+power9_dd1_recover_paca:
+ mfspr r4, SPRN_TIR
+ /*
+ * Since each entry in thread_sibling_pacas is 8 bytes
+ * we need to left-shift by 3 bits. Thus r4 = i * 8
+ */
+ sldi r4, r4, 3
+ /* Get &paca->thread_sibling_pacas[0] in r5 */
+ ld r5, PACA_SIBLING_PACA_PTRS(r13)
+ /* Load paca->thread_sibling_pacas[i] into r13 */
+ ldx r13, r4, r5
+ SET_PACA(r13)
+ ld r2, PACATOC(r13)
+ /*
+ * Indicate that we have lost NVGPR state
+ * which needs to be restored from the stack.
+ */
+ li r3, 1
+ stb r0,PACA_NAPSTATELOST(r13)
+ blr
+
/*
* Called from reset vector. Check whether we have woken up with
* hypervisor state loss. If yes, restore hypervisor state and return
@@ -385,7 +425,13 @@ _GLOBAL(power9_idle_stop)
*/
_GLOBAL(pnv_restore_hyp_resource)
BEGIN_FTR_SECTION
- ld r2,PACATOC(r13);
+BEGIN_FTR_SECTION_NESTED(70)
+ mflr r6
+ bl power9_dd1_recover_paca
+ mtlr r6
+FTR_SECTION_ELSE_NESTED(70)
+ ld r2, PACATOC(r13)
+ALT_FTR_SECTION_END_NESTED_IFSET(CPU_FTR_POWER9_DD1, 70)
/*
* POWER ISA 3. Use PSSCR to determine if we
* are waking up from deep idle state
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
index 63ade787aec4..b369e39aa392 100644
--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -122,9 +122,12 @@ static void pnv_alloc_idle_core_states(void)
for (i = 0; i < nr_cores; i++) {
int first_cpu = i * threads_per_core;
int node = cpu_to_node(first_cpu);
+ size_t paca_ptr_array_size;
core_idle_state = kmalloc_node(sizeof(u32), GFP_KERNEL, node);
*core_idle_state = PNV_CORE_IDLE_THREAD_BITS;
+ paca_ptr_array_size = (threads_per_core *
+ sizeof(struct paca_struct *));
for (j = 0; j < threads_per_core; j++) {
int cpu = first_cpu + j;
@@ -132,6 +135,11 @@ static void pnv_alloc_idle_core_states(void)
paca[cpu].core_idle_state_ptr = core_idle_state;
paca[cpu].thread_idle_state = PNV_THREAD_RUNNING;
paca[cpu].thread_mask = 1 << j;
+ if (!cpu_has_feature(CPU_FTR_POWER9_DD1))
+ continue;
+ paca[cpu].thread_sibling_pacas =
+ kmalloc_node(paca_ptr_array_size,
+ GFP_KERNEL, node);
}
}
@@ -560,6 +568,28 @@ static int __init pnv_init_idle_states(void)
pnv_alloc_idle_core_states();
+ /*
+ * For each CPU, record its PACA address in each of it's
+ * sibling thread's PACA at the slot corresponding to this
+ * CPU's index in the core.
+ */
+ if (cpu_has_feature(CPU_FTR_POWER9_DD1)) {
+ int cpu;
+
+ pr_info("powernv: idle: Saving PACA pointers of all CPUs in their thread sibling PACA\n");
+ for_each_possible_cpu(cpu) {
+ int base_cpu = cpu_first_thread_sibling(cpu);
+ int idx = cpu_thread_in_core(cpu);
+ int i;
+
+ for (i = 0; i < threads_per_core; i++) {
+ int j = base_cpu + i;
+
+ paca[j].thread_sibling_pacas[idx] = &paca[cpu];
+ }
+ }
+ }
+
if (supported_cpuidle_states & OPAL_PM_NAP_ENABLED)
ppc_md.power_save = power7_idle;