+ /*
+ * We only need (or have stack space) to save this stuff if
+ * we interrupted the kernel.
+ */
+ ld r3,_MSR(r1)
+ andi. r3,r3,MSR_PR
+ bnelr
+
+ /* Copy info into temporary exception thread info */
+ ld r11,PACAKSAVE(r13)
+ CURRENT_THREAD_INFO(r11, r11)
+ CURRENT_THREAD_INFO(r12, r1)
+ ld r10,TI_FLAGS(r11)
+ std r10,TI_FLAGS(r12)
+ ld r10,TI_PREEMPT(r11)
+ std r10,TI_PREEMPT(r12)
+ ld r10,TI_TASK(r11)
+ std r10,TI_TASK(r12)
+
+ /*
+ * Advance to the next TLB exception frame for handler
+ * types that don't do it automatically.
+ */
+ LOAD_REG_ADDR(r11,extlb_level_exc)
+ lwz r12,0(r11)
+ mfspr r10,SPRN_SPRG_TLB_EXFRAME
+ add r10,r10,r12
+ mtspr SPRN_SPRG_TLB_EXFRAME,r10
+
+ /*
+ * Save registers needed to allow nesting of certain exceptions
+ * (such as TLB misses) inside special exception levels
+ */
+ mfspr r10,SPRN_SRR0
+ SPECIAL_EXC_STORE(r10,SRR0)
+ mfspr r10,SPRN_SRR1
+ SPECIAL_EXC_STORE(r10,SRR1)
+ mfspr r10,SPRN_SPRG_GEN_SCRATCH
+ SPECIAL_EXC_STORE(r10,SPRG_GEN)
+ mfspr r10,SPRN_SPRG_TLB_SCRATCH
+ SPECIAL_EXC_STORE(r10,SPRG_TLB)
+ mfspr r10,SPRN_MAS0
+ SPECIAL_EXC_STORE(r10,MAS0)
+ mfspr r10,SPRN_MAS1
+ SPECIAL_EXC_STORE(r10,MAS1)
+ mfspr r10,SPRN_MAS2
+ SPECIAL_EXC_STORE(r10,MAS2)
+ mfspr r10,SPRN_MAS3
+ SPECIAL_EXC_STORE(r10,MAS3)
+ mfspr r10,SPRN_MAS6
+ SPECIAL_EXC_STORE(r10,MAS6)
+ mfspr r10,SPRN_MAS7
+ SPECIAL_EXC_STORE(r10,MAS7)
+BEGIN_FTR_SECTION
+ mfspr r10,SPRN_MAS5
+ SPECIAL_EXC_STORE(r10,MAS5)
+ mfspr r10,SPRN_MAS8
+ SPECIAL_EXC_STORE(r10,MAS8)
+
+ /* MAS5/8 could have inappropriate values if we interrupted KVM code */
+ li r10,0
+ mtspr SPRN_MAS5,r10
+ mtspr SPRN_MAS8,r10
+END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV)
+ SPECIAL_EXC_STORE(r9,IRQHAPPENED)
+
+ mfspr r10,SPRN_DEAR
+ SPECIAL_EXC_STORE(r10,DEAR)
+ mfspr r10,SPRN_ESR
+ SPECIAL_EXC_STORE(r10,ESR)
+
+ lbz r10,PACASOFTIRQEN(r13)
+ SPECIAL_EXC_STORE(r10,SOFTE)
+ ld r10,_NIP(r1)
+ SPECIAL_EXC_STORE(r10,CSRR0)
+ ld r10,_MSR(r1)
+ SPECIAL_EXC_STORE(r10,CSRR1)
+
+ blr
+
+ret_from_level_except:
+ ld r3,_MSR(r1)
+ andi. r3,r3,MSR_PR
+ beq 1f
+ b ret_from_except
+1:
+
+ LOAD_REG_ADDR(r11,extlb_level_exc)
+ lwz r12,0(r11)
+ mfspr r10,SPRN_SPRG_TLB_EXFRAME
+ sub r10,r10,r12
+ mtspr SPRN_SPRG_TLB_EXFRAME,r10
+
+ /*
+ * It's possible that the special level exception interrupted a
+ * TLB miss handler, and inserted the same entry that the
+ * interrupted handler was about to insert. On CPUs without TLB
+ * write conditional, this can result in a duplicate TLB entry.
+ * Wipe all non-bolted entries to be safe.
+ *
+ * Note that this doesn't protect against any TLB misses
+ * we may take accessing the stack from here to the end of
+ * the special level exception. It's not clear how we can
+ * reasonably protect against that, but only CPUs with
+ * neither TLB write conditional nor bolted kernel memory
+ * are affected. Do any such CPUs even exist?
+ */
+ PPC_TLBILX_ALL(0,R0)
+
+ REST_NVGPRS(r1)
+
+ SPECIAL_EXC_LOAD(r10,SRR0)
+ mtspr SPRN_SRR0,r10
+ SPECIAL_EXC_LOAD(r10,SRR1)
+ mtspr SPRN_SRR1,r10
+ SPECIAL_EXC_LOAD(r10,SPRG_GEN)
+ mtspr SPRN_SPRG_GEN_SCRATCH,r10
+ SPECIAL_EXC_LOAD(r10,SPRG_TLB)
+ mtspr SPRN_SPRG_TLB_SCRATCH,r10
+ SPECIAL_EXC_LOAD(r10,MAS0)
+ mtspr SPRN_MAS0,r10
+ SPECIAL_EXC_LOAD(r10,MAS1)
+ mtspr SPRN_MAS1,r10
+ SPECIAL_EXC_LOAD(r10,MAS2)
+ mtspr SPRN_MAS2,r10
+ SPECIAL_EXC_LOAD(r10,MAS3)
+ mtspr SPRN_MAS3,r10
+ SPECIAL_EXC_LOAD(r10,MAS6)
+ mtspr SPRN_MAS6,r10
+ SPECIAL_EXC_LOAD(r10,MAS7)
+ mtspr SPRN_MAS7,r10
+BEGIN_FTR_SECTION
+ SPECIAL_EXC_LOAD(r10,MAS5)
+ mtspr SPRN_MAS5,r10
+ SPECIAL_EXC_LOAD(r10,MAS8)
+ mtspr SPRN_MAS8,r10
+END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV)
+
+ lbz r6,PACASOFTIRQEN(r13)
+ ld r5,SOFTE(r1)
+
+ /* Interrupts had better not already be enabled... */
+ twnei r6,0
+
+ cmpwi cr0,r5,0
+ beq 1f