[PATCH] ppc64: Add some POWER5 specific optimisations

From: Anton Blanchard <anton@samba.org>

Add some POWER5 specific optimisations:
- icache is coherent, no need to explicitly flush
- tlbie lock no longer required

arch/ppc64/kernel/misc.S

@@ -132,7 +132,7 @@ _GLOBAL(flush_instruction_cache)
  *   flush all bytes from start through stop-1 inclusive
  */
 
-_GLOBAL(flush_icache_range)
+_GLOBAL(__flush_icache_range)
 
 /*
  * Flush the data cache to memory 

arch/ppc64/kernel/pSeries_htab.c

@@ -221,8 +221,10 @@ static long pSeries_hpte_updatepp(unsigned long slot, unsigned long newpp,
 	if ((cur_cpu_spec->cpu_features & CPU_FTR_TLBIEL) && !large && local) {
 		tlbiel(va);
 	} else {
+		if (!(cur_cpu_spec->cpu_features & CPU_FTR_LOCKLESS_TLBIE))
 			spin_lock_irqsave(&pSeries_tlbie_lock, flags);
 		tlbie(va, large);
+		if (!(cur_cpu_spec->cpu_features & CPU_FTR_LOCKLESS_TLBIE))
 			spin_unlock_irqrestore(&pSeries_tlbie_lock, flags);
 	}
 
@@ -255,8 +257,10 @@ static void pSeries_hpte_updateboltedpp(unsigned long newpp, unsigned long ea)
 	set_pp_bit(newpp, hptep);
 
 	/* Ensure it is out of the tlb too */
+	if (!(cur_cpu_spec->cpu_features & CPU_FTR_LOCKLESS_TLBIE))
 		spin_lock_irqsave(&pSeries_tlbie_lock, flags);
 	tlbie(va, 0);
+	if (!(cur_cpu_spec->cpu_features & CPU_FTR_LOCKLESS_TLBIE))
 		spin_unlock_irqrestore(&pSeries_tlbie_lock, flags);
 }
 
@@ -287,8 +291,10 @@ static void pSeries_hpte_invalidate(unsigned long slot, unsigned long va,
 	if ((cur_cpu_spec->cpu_features & CPU_FTR_TLBIEL) && !large && local) {
 		tlbiel(va);
 	} else {
+		if (!(cur_cpu_spec->cpu_features & CPU_FTR_LOCKLESS_TLBIE))
 			spin_lock_irqsave(&pSeries_tlbie_lock, flags);
 		tlbie(va, large);
+		if (!(cur_cpu_spec->cpu_features & CPU_FTR_LOCKLESS_TLBIE))
 			spin_unlock_irqrestore(&pSeries_tlbie_lock, flags);
 	}
 }
@@ -356,6 +362,7 @@ static void pSeries_flush_hash_range(unsigned long context,
 		asm volatile("ptesync":::"memory");
 	} else {
 		/* XXX double check that it is safe to take this late */
+		if (!(cur_cpu_spec->cpu_features & CPU_FTR_LOCKLESS_TLBIE))
 			spin_lock_irqsave(&pSeries_tlbie_lock, flags);
 
 		asm volatile("ptesync":::"memory");
@@ -365,6 +372,7 @@ static void pSeries_flush_hash_range(unsigned long context,
 
 		asm volatile("eieio; tlbsync; ptesync":::"memory");
 
+		if (!(cur_cpu_spec->cpu_features & CPU_FTR_LOCKLESS_TLBIE))
 			spin_unlock_irqrestore(&pSeries_tlbie_lock, flags);
 	}
 }
@@ -384,8 +392,12 @@ void hpte_init_pSeries(void)
 	root = of_find_node_by_path("/");
 	if (root) {
 		model = get_property(root, "model", NULL);
-		if (strcmp(model, "CHRP IBM,9076-N81"))
-			ppc_md.flush_hash_range = pSeries_flush_hash_range;
+		if (!strcmp(model, "CHRP IBM,9076-N81")) {
+			of_node_put(root);
+			return;
+		}
 		of_node_put(root);
 	}
+
+	ppc_md.flush_hash_range = pSeries_flush_hash_range;
 }

arch/ppc64/kernel/pSeries_lpar.c

@@ -21,6 +21,7 @@
 
 #include <linux/config.h>
 #include <linux/kernel.h>
+#include <linux/pci.h>
 #include <asm/processor.h>
 #include <asm/mmu.h>
 #include <asm/page.h>
@@ -30,13 +31,13 @@
 #include <asm/mmu_context.h>
 #include <asm/ppcdebug.h>
 #include <asm/iommu.h>
-#include <linux/pci.h>
 #include <asm/naca.h>
 #include <asm/tlbflush.h>
 #include <asm/tlb.h>
 #include <asm/hvcall.h>
 #include <asm/prom.h>
 #include <asm/abs_addr.h>
+#include <asm/cputable.h>
 
 /* in pSeries_hvCall.S */
 EXPORT_SYMBOL(plpar_hcall);
@@ -146,7 +147,7 @@ static void tce_build_pSeriesLP(struct iommu_table *tbl, long tcenum, long npage
 				   (u64)tcenum << 12, 
 				   tce.te_word );
 		
-		if(rc && printk_ratelimit()) {
+		if (rc && printk_ratelimit()) {
 			printk("tce_build_pSeriesLP: plpar_tce_put failed. rc=%ld\n", rc);
 			printk("\tindex   = 0x%lx\n", (u64)tbl->it_index);
 			printk("\ttcenum  = 0x%lx\n", (u64)tcenum);
@@ -559,11 +560,13 @@ void pSeries_lpar_flush_hash_range(unsigned long context, unsigned long number,
 	unsigned long flags;
 	struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
 
+	if (!(cur_cpu_spec->cpu_features & CPU_FTR_LOCKLESS_TLBIE))
 		spin_lock_irqsave(&pSeries_lpar_tlbie_lock, flags);
 
 	for (i = 0; i < number; i++)
 		flush_hash_page(context, batch->addr[i], batch->pte[i], local);
 
+	if (!(cur_cpu_spec->cpu_features & CPU_FTR_LOCKLESS_TLBIE))
 		spin_unlock_irqrestore(&pSeries_lpar_tlbie_lock, flags);
 }
 

arch/ppc64/mm/hash_low.S

@@ -125,11 +125,13 @@ _GLOBAL(__hash_page)
 	/* We eventually do the icache sync here (maybe inline that
 	 * code rather than call a C function...) 
 	 */
+BEGIN_FTR_SECTION
 BEGIN_FTR_SECTION
 	mr	r4,r30
 	mr	r5,r7
 	bl	.hash_page_do_lazy_icache
 END_FTR_SECTION_IFSET(CPU_FTR_NOEXECUTE)
+END_FTR_SECTION_IFCLR(CPU_FTR_COHERENT_ICACHE)
 
 	/* At this point, r3 contains new PP bits, save them in
 	 * place of "access" in the param area (sic)

arch/ppc64/mm/init.c

@@ -696,6 +696,8 @@ void __init mem_init(void)
  */
 void flush_dcache_page(struct page *page)
 {
+	if (cur_cpu_spec->cpu_features & CPU_FTR_COHERENT_ICACHE)
+		return;
 	/* avoid an atomic op if possible */
 	if (test_bit(PG_arch_1, &page->flags))
 		clear_bit(PG_arch_1, &page->flags);
@@ -705,6 +707,8 @@ void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
 {
 	clear_page(page);
 
+	if (cur_cpu_spec->cpu_features & CPU_FTR_COHERENT_ICACHE)
+		return;
 	/*
 	 * We shouldnt have to do this, but some versions of glibc
 	 * require it (ld.so assumes zero filled pages are icache clean)
@@ -736,6 +740,9 @@ void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
 		return;
 #endif
 
+	if (cur_cpu_spec->cpu_features & CPU_FTR_COHERENT_ICACHE)
+		return;
+
 	/* avoid an atomic op if possible */
 	if (test_bit(PG_arch_1, &pg->flags))
 		clear_bit(PG_arch_1, &pg->flags);
@@ -768,7 +775,8 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long ea,
 	cpumask_t tmp;
 
 	/* handle i-cache coherency */
-	if (!(cur_cpu_spec->cpu_features & CPU_FTR_NOEXECUTE)) {
+	if (!(cur_cpu_spec->cpu_features & CPU_FTR_COHERENT_ICACHE) &&
+	    !(cur_cpu_spec->cpu_features & CPU_FTR_NOEXECUTE)) {
 		unsigned long pfn = pte_pfn(pte);
 		if (pfn_valid(pfn)) {
 			struct page *page = pfn_to_page(pfn);

include/asm-ppc64/cacheflush.h

 #ifndef _PPC64_CACHEFLUSH_H
 #define _PPC64_CACHEFLUSH_H
 
-/* Keep includes the same across arches.  */
 #include <linux/mm.h>
+#include <asm/cputable.h>
 
 /*
  * No cache flushing is required when address mappings are
@@ -18,7 +18,7 @@
 #define flush_cache_vunmap(start, end)		do { } while (0)
 
 extern void flush_dcache_page(struct page *page);
-extern void flush_icache_range(unsigned long, unsigned long);
+extern void __flush_icache_range(unsigned long, unsigned long);
 extern void flush_icache_user_range(struct vm_area_struct *vma,
 				    struct page *page, unsigned long addr,
 				    int len);
@@ -35,4 +35,10 @@ do { memcpy(dst, src, len); \
 
 extern void __flush_dcache_icache(void *page_va);
 
+static inline void flush_icache_range(unsigned long start, unsigned long stop)
+{
+	if (!(cur_cpu_spec->cpu_features & CPU_FTR_COHERENT_ICACHE))
+		__flush_icache_range(start, stop);
+}
+
 #endif /* _PPC64_CACHEFLUSH_H */