1 files changed, 190 insertions, 0 deletions
diff --git a/arch/powerpc/mm/nohash/e500_hugetlbpage.c b/arch/powerpc/mm/nohash/e500_hugetlbpage.c
new file mode 100644
index 000000000000..c7d4b317a823
--- /dev/null
+++ b/arch/powerpc/mm/nohash/e500_hugetlbpage.c
@@ -0,0 +1,190 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PPC Huge TLB Page Support for Book3E MMU
+ *
+ * Copyright (C) 2009 David Gibson, IBM Corporation.
+ * Copyright (C) 2011 Becky Bruce, Freescale Semiconductor
+ *
+ */
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+
+#include <asm/mmu.h>
+
+#ifdef CONFIG_PPC64
+#include <asm/paca.h>
+
+static inline int tlb1_next(void)
+{
+	struct paca_struct *paca = get_paca();
+	struct tlb_core_data *tcd;
+	int this, next;
+
+	tcd = paca->tcd_ptr;
+	this = tcd->esel_next;
+
+	next = this + 1;
+	if (next >= tcd->esel_max)
+		next = tcd->esel_first;
+
+	tcd->esel_next = next;
+	return this;
+}
+
+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 int tlb1_next(void)
+{
+	int index, ncams;
+
+	ncams = mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY;
+
+	index = this_cpu_read(next_tlbcam_idx);
+
+	/* Just round-robin the entries and wrap when we hit the end */
+	if (unlikely(index == ncams - 1))
+		__this_cpu_write(next_tlbcam_idx, tlbcam_index);
+	else
+		__this_cpu_inc(next_tlbcam_idx);
+
+	return index;
+}
+
+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;
+
+	mtspr(SPRN_MAS6, pid << 16);
+	asm volatile(
+		"tlbsx	0,%1\n"
+		"mfspr	%0,0x271\n"
+		"srwi	%0,%0,31\n"
+		: "=&r"(found) : "r"(ea));
+
+	return found;
+}
+
+static void
+book3e_hugetlb_preload(struct vm_area_struct *vma, unsigned long ea, pte_t pte)
+{
+	unsigned long mas1, mas2;
+	u64 mas7_3;
+	unsigned long psize, tsize, shift;
+	unsigned long flags;
+	struct mm_struct *mm;
+	int index;
+
+	if (unlikely(is_kernel_addr(ea)))
+		return;
+
+	mm = vma->vm_mm;
+
+	psize = vma_mmu_pagesize(vma);
+	shift = __ilog2(psize);
+	tsize = shift - 10;
+	/*
+	 * We can't be interrupted while we're setting up the MAS
+	 * registers or after we've confirmed that no tlb exists.
+	 */
+	local_irq_save(flags);
+
+	book3e_tlb_lock();
+
+	if (unlikely(book3e_tlb_exists(ea, mm->context.id))) {
+		book3e_tlb_unlock();
+		local_irq_restore(flags);
+		return;
+	}
+
+	/* We have to use the CAM(TLB1) on FSL parts for hugepages */
+	index = tlb1_next();
+	mtspr(SPRN_MAS0, MAS0_ESEL(index) | MAS0_TLBSEL(1));
+
+	mas1 = MAS1_VALID | MAS1_TID(mm->context.id) | MAS1_TSIZE(tsize);
+	mas2 = ea & ~((1UL << shift) - 1);
+	mas2 |= (pte_val(pte) >> PTE_WIMGE_SHIFT) & MAS2_WIMGE_MASK;
+	mas7_3 = (u64)pte_pfn(pte) << PAGE_SHIFT;
+	mas7_3 |= (pte_val(pte) >> PTE_BAP_SHIFT) & MAS3_BAP_MASK;
+	if (!pte_dirty(pte))
+		mas7_3 &= ~(MAS3_SW|MAS3_UW);
+
+	mtspr(SPRN_MAS1, mas1);
+	mtspr(SPRN_MAS2, mas2);
+
+	if (mmu_has_feature(MMU_FTR_BIG_PHYS))
+		mtspr(SPRN_MAS7, upper_32_bits(mas7_3));
+	mtspr(SPRN_MAS3, lower_32_bits(mas7_3));
+
+	asm volatile ("tlbwe");
+
+	book3e_tlb_unlock();
+	local_irq_restore(flags);
+}
+
+/*
+ * This is called at the end of handling a user page fault, when the
+ * fault has been handled by updating a PTE in the linux page tables.
+ *
+ * This must always be called with the pte lock held.
+ */
+void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
+{
+	if (is_vm_hugetlb_page(vma))
+		book3e_hugetlb_preload(vma, address, *ptep);
+}
+
+void flush_hugetlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
+{
+	struct hstate *hstate = hstate_file(vma->vm_file);
+	unsigned long tsize = huge_page_shift(hstate) - 10;
+
+	__flush_tlb_page(vma->vm_mm, vmaddr, tsize, 0);
+}