From 03dd4cb26d967f9588437b0fc9cc0e8353322bb7 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Fri, 25 Mar 2016 03:53:42 -0300
Subject: Linux-libre 4.5-gnu

---
 arch/powerpc/mm/hugetlbpage-book3e.c | 59 ++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

(limited to 'arch/powerpc/mm/hugetlbpage-book3e.c')

diff --git a/arch/powerpc/mm/hugetlbpage-book3e.c b/arch/powerpc/mm/hugetlbpage-book3e.c
index ba47aaf33..83a8be791 100644
--- a/arch/powerpc/mm/hugetlbpage-book3e.c
+++ b/arch/powerpc/mm/hugetlbpage-book3e.c
@@ -8,6 +8,8 @@
 #include <linux/mm.h>
 #include <linux/hugetlb.h>
 
+#include <asm/mmu.h>
+
 #ifdef CONFIG_PPC_FSL_BOOK3E
 #ifdef CONFIG_PPC64
 static inline int tlb1_next(void)
@@ -51,6 +53,59 @@ static inline int mmu_get_tsize(int psize)
 	return mmu_psize_defs[psize].enc;
 }
 
+#if defined(CONFIG_PPC_FSL_BOOK3E) && defined(CONFIG_PPC64)
+#include <asm/paca.h>
+
+static inline void book3e_tlb_lock(void)
+{
+	struct paca_struct *paca = get_paca();
+	unsigned long tmp;
+	int token = smp_processor_id() + 1;
+
+	/*
+	 * Besides being unnecessary in the absence of SMT, this
+	 * check prevents trying to do lbarx/stbcx. on e5500 which
+	 * doesn't implement either feature.
+	 */
+	if (!cpu_has_feature(CPU_FTR_SMT))
+		return;
+
+	asm volatile("1: lbarx %0, 0, %1;"
+		     "cmpwi %0, 0;"
+		     "bne 2f;"
+		     "stbcx. %2, 0, %1;"
+		     "bne 1b;"
+		     "b 3f;"
+		     "2: lbzx %0, 0, %1;"
+		     "cmpwi %0, 0;"
+		     "bne 2b;"
+		     "b 1b;"
+		     "3:"
+		     : "=&r" (tmp)
+		     : "r" (&paca->tcd_ptr->lock), "r" (token)
+		     : "memory");
+}
+
+static inline void book3e_tlb_unlock(void)
+{
+	struct paca_struct *paca = get_paca();
+
+	if (!cpu_has_feature(CPU_FTR_SMT))
+		return;
+
+	isync();
+	paca->tcd_ptr->lock = 0;
+}
+#else
+static inline void book3e_tlb_lock(void)
+{
+}
+
+static inline void book3e_tlb_unlock(void)
+{
+}
+#endif
+
 static inline int book3e_tlb_exists(unsigned long ea, unsigned long pid)
 {
 	int found = 0;
@@ -109,7 +164,10 @@ void book3e_hugetlb_preload(struct vm_area_struct *vma, unsigned long ea,
 	 */
 	local_irq_save(flags);
 
+	book3e_tlb_lock();
+
 	if (unlikely(book3e_tlb_exists(ea, mm->context.id))) {
+		book3e_tlb_unlock();
 		local_irq_restore(flags);
 		return;
 	}
@@ -141,6 +199,7 @@ void book3e_hugetlb_preload(struct vm_area_struct *vma, unsigned long ea,
 
 	asm volatile ("tlbwe");
 
+	book3e_tlb_unlock();
 	local_irq_restore(flags);
 }
 
-- 
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