Revert "convert SLB miss handlers to C" and subsequent commits

This reverts commits:
  5e46e29e6a97 ("powerpc/64s/hash: convert SLB miss handlers to C")
  8fed04d0f6ae ("powerpc/64s/hash: remove user SLB data from the paca")
  655deecf67b2 ("powerpc/64s/hash: SLB allocation status bitmaps")
  2e1626744e8d ("powerpc/64s/hash: provide arch_setup_exec hooks for hash slice setup")
  89ca4e126a3f ("powerpc/64s/hash: Add a SLB preload cache")

This series had a few bugs, and the fixes are not all trivial. So
revert most of it for now.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

7 files changed, 23 insertions, 22 deletions

diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h
index 78ed3c3f879a..1f4691ce4126 100644
--- a/arch/powerpc/include/asm/asm-prototypes.h
+++ b/arch/powerpc/include/asm/asm-prototypes.h
@@ -78,8 +78,6 @@ void kernel_bad_stack(struct pt_regs *regs);
 void system_reset_exception(struct pt_regs *regs);
 void machine_check_exception(struct pt_regs *regs);
 void emulation_assist_interrupt(struct pt_regs *regs);
-long do_slb_fault(struct pt_regs *regs, unsigned long ea);
-void do_bad_slb_fault(struct pt_regs *regs, unsigned long ea, long err);
 
 /* signals, syscalls and interrupts */
 long sys_swapcontext(struct ucontext __user *old_ctx,
diff --git a/arch/powerpc/include/asm/book3s/64/mmu-hash.h b/arch/powerpc/include/asm/book3s/64/mmu-hash.h
index bbeaf6adf93c..e0e4ce8f77d6 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu-hash.h
@@ -487,8 +487,6 @@ int htab_remove_mapping(unsigned long vstart, unsigned long vend,
 extern void pseries_add_gpage(u64 addr, u64 page_size, unsigned long number_of_pages);
 extern void demote_segment_4k(struct mm_struct *mm, unsigned long addr);
 
-extern void hash__setup_new_exec(void);
-
 #ifdef CONFIG_PPC_PSERIES
 void hpte_init_pseries(void);
 #else
@@ -503,7 +501,6 @@ struct slb_entry {
 };
 
 extern void slb_initialize(void);
-extern void core_flush_all_slbs(struct mm_struct *mm);
 extern void slb_flush_and_rebolt(void);
 void slb_flush_all_realmode(void);
 void __slb_restore_bolted_realmode(void);
diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 47578b79f0fb..a86feddddad0 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -61,6 +61,14 @@
 #define MAX_MCE_DEPTH	4
 
 /*
+ * EX_LR is only used in EXSLB and where it does not overlap with EX_DAR
+ * EX_CCR similarly with DSISR, but being 4 byte registers there is a hole
+ * in the save area so it's not necessary to overlap them. Could be used
+ * for future savings though if another 4 byte register was to be saved.
+ */
+#define EX_LR		EX_DAR
+
+/*
  * EX_R3 is only used by the bad_stack handler. bad_stack reloads and
  * saves DAR from SPRN_DAR, and EX_DAR is not used. So EX_R3 can overlap
  * with EX_DAR.
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index 6d6b3706232c..7b6e23af3808 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -113,10 +113,7 @@ struct paca_struct {
  				 * on the linear mapping */
 	/* SLB related definitions */
 	u16 vmalloc_sllp;
-	u8 slb_cache_ptr;
-	u8 stab_rr;			/* stab/slb round-robin counter */
-	u32 slb_used_bitmap;		/* Bitmaps for first 32 SLB entries. */
-	u32 slb_kern_bitmap;
+	u16 slb_cache_ptr;
 	u32 slb_cache[SLB_CACHE_ENTRIES];
 #endif /* CONFIG_PPC_BOOK3S_64 */
 
@@ -146,11 +143,24 @@ struct paca_struct {
 	struct tlb_core_data tcd;
 #endif /* CONFIG_PPC_BOOK3E */
 
+#ifdef CONFIG_PPC_BOOK3S
+	mm_context_id_t mm_ctx_id;
+#ifdef CONFIG_PPC_MM_SLICES
+	unsigned char mm_ctx_low_slices_psize[BITS_PER_LONG / BITS_PER_BYTE];
+	unsigned char mm_ctx_high_slices_psize[SLICE_ARRAY_SIZE];
+	unsigned long mm_ctx_slb_addr_limit;
+#else
+	u16 mm_ctx_user_psize;
+	u16 mm_ctx_sllp;
+#endif
+#endif
+
 	/*
 	 * then miscellaneous read-write fields
 	 */
 	struct task_struct *__current;	/* Pointer to current */
 	u64 kstack;			/* Saved Kernel stack addr */
+	u64 stab_rr;			/* stab/slb round-robin counter */
 	u64 saved_r1;			/* r1 save for RTAS calls or PM or EE=0 */
 	u64 saved_msr;			/* MSR saved here by enter_rtas */
 	u16 trap_save;			/* Used when bad stack is encountered */
@@ -248,6 +258,7 @@ struct paca_struct {
 #endif /* CONFIG_PPC_BOOK3S_64 */
 } ____cacheline_aligned;
 
+extern void copy_mm_to_paca(struct mm_struct *mm);
 extern struct paca_struct **paca_ptrs;
 extern void initialise_paca(struct paca_struct *new_paca, int cpu);
 extern void setup_paca(struct paca_struct *new_paca);
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 350c584ca179..52fadded5c1e 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -273,7 +273,6 @@ struct thread_struct {
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 	struct arch_hw_breakpoint hw_brk; /* info on the hardware breakpoint */
 	unsigned long	trap_nr;	/* last trap # on this thread */
-	u8 load_slb;			/* Ages out SLB preload cache entries */
 	u8 load_fp;
 #ifdef CONFIG_ALTIVEC
 	u8 load_vec;
diff --git a/arch/powerpc/include/asm/slice.h b/arch/powerpc/include/asm/slice.h
index a595461c9cb0..e40406cf5628 100644
--- a/arch/powerpc/include/asm/slice.h
+++ b/arch/powerpc/include/asm/slice.h
@@ -32,7 +32,6 @@ void slice_set_range_psize(struct mm_struct *mm, unsigned long start,
 			   unsigned long len, unsigned int psize);
 
 void slice_init_new_context_exec(struct mm_struct *mm);
-void slice_setup_new_exec(void);
 
 #endif /* __ASSEMBLY__ */
 
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 406eb952b808..3c0002044bc9 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -29,7 +29,6 @@
 #include <asm/page.h>
 #include <asm/accounting.h>
 
-#define SLB_PRELOAD_NR	16U
 /*
  * low level task data.
  */
@@ -45,10 +44,6 @@ struct thread_info {
 #if defined(CONFIG_VIRT_CPU_ACCOUNTING_NATIVE) && defined(CONFIG_PPC32)
 	struct cpu_accounting_data accounting;
 #endif
-	u8 slb_preload_nr;
-	u8 slb_preload_tail;
-	u32 slb_preload_esid[SLB_PRELOAD_NR];
-
 	/* low level flags - has atomic operations done on it */
 	unsigned long	flags ____cacheline_aligned_in_smp;
 };
@@ -77,12 +72,6 @@ static inline struct thread_info *current_thread_info(void)
 }
 
 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
-
-#ifdef CONFIG_PPC_BOOK3S_64
-void arch_setup_new_exec(void);
-#define arch_setup_new_exec arch_setup_new_exec
-#endif
-
 #endif /* __ASSEMBLY__ */
 
 /*