[Feature]add MT2731_MP2_MR2_SVN388 baseline version

Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/arch/powerpc/mm/slb.c b/src/kernel/linux/v4.14/arch/powerpc/mm/slb.c
new file mode 100644
index 0000000..2502fe3
--- /dev/null
+++ b/src/kernel/linux/v4.14/arch/powerpc/mm/slb.c
@@ -0,0 +1,342 @@
+/*
+ * PowerPC64 SLB support.
+ *
+ * Copyright (C) 2004 David Gibson <dwg@au.ibm.com>, IBM
+ * Based on earlier code written by:
+ * Dave Engebretsen and Mike Corrigan {engebret|mikejc}@us.ibm.com
+ *    Copyright (c) 2001 Dave Engebretsen
+ * Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM
+ *
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <asm/pgtable.h>
+#include <asm/mmu.h>
+#include <asm/mmu_context.h>
+#include <asm/paca.h>
+#include <asm/cputable.h>
+#include <asm/cacheflush.h>
+#include <asm/smp.h>
+#include <linux/compiler.h>
+#include <linux/mm_types.h>
+
+#include <asm/udbg.h>
+#include <asm/code-patching.h>
+
+enum slb_index {
+	LINEAR_INDEX	= 0, /* Kernel linear map  (0xc000000000000000) */
+	VMALLOC_INDEX	= 1, /* Kernel virtual map (0xd000000000000000) */
+	KSTACK_INDEX	= 2, /* Kernel stack map */
+};
+
+extern void slb_allocate(unsigned long ea);
+
+#define slb_esid_mask(ssize)	\
+	(((ssize) == MMU_SEGSIZE_256M)? ESID_MASK: ESID_MASK_1T)
+
+static inline unsigned long mk_esid_data(unsigned long ea, int ssize,
+					 enum slb_index index)
+{
+	return (ea & slb_esid_mask(ssize)) | SLB_ESID_V | index;
+}
+
+static inline unsigned long mk_vsid_data(unsigned long ea, int ssize,
+					 unsigned long flags)
+{
+	return (get_kernel_vsid(ea, ssize) << slb_vsid_shift(ssize)) | flags |
+		((unsigned long) ssize << SLB_VSID_SSIZE_SHIFT);
+}
+
+static inline void slb_shadow_update(unsigned long ea, int ssize,
+				     unsigned long flags,
+				     enum slb_index index)
+{
+	struct slb_shadow *p = get_slb_shadow();
+
+	/*
+	 * Clear the ESID first so the entry is not valid while we are
+	 * updating it.  No write barriers are needed here, provided
+	 * we only update the current CPU's SLB shadow buffer.
+	 */
+	WRITE_ONCE(p->save_area[index].esid, 0);
+	WRITE_ONCE(p->save_area[index].vsid, cpu_to_be64(mk_vsid_data(ea, ssize, flags)));
+	WRITE_ONCE(p->save_area[index].esid, cpu_to_be64(mk_esid_data(ea, ssize, index)));
+}
+
+static inline void slb_shadow_clear(enum slb_index index)
+{
+	WRITE_ONCE(get_slb_shadow()->save_area[index].esid, 0);
+}
+
+static inline void create_shadowed_slbe(unsigned long ea, int ssize,
+					unsigned long flags,
+					enum slb_index index)
+{
+	/*
+	 * Updating the shadow buffer before writing the SLB ensures
+	 * we don't get a stale entry here if we get preempted by PHYP
+	 * between these two statements.
+	 */
+	slb_shadow_update(ea, ssize, flags, index);
+
+	asm volatile("slbmte  %0,%1" :
+		     : "r" (mk_vsid_data(ea, ssize, flags)),
+		       "r" (mk_esid_data(ea, ssize, index))
+		     : "memory" );
+}
+
+static void __slb_flush_and_rebolt(void)
+{
+	/* If you change this make sure you change SLB_NUM_BOLTED
+	 * and PR KVM appropriately too. */
+	unsigned long linear_llp, vmalloc_llp, lflags, vflags;
+	unsigned long ksp_esid_data, ksp_vsid_data;
+
+	linear_llp = mmu_psize_defs[mmu_linear_psize].sllp;
+	vmalloc_llp = mmu_psize_defs[mmu_vmalloc_psize].sllp;
+	lflags = SLB_VSID_KERNEL | linear_llp;
+	vflags = SLB_VSID_KERNEL | vmalloc_llp;
+
+	ksp_esid_data = mk_esid_data(get_paca()->kstack, mmu_kernel_ssize, KSTACK_INDEX);
+	if ((ksp_esid_data & ~0xfffffffUL) <= PAGE_OFFSET) {
+		ksp_esid_data &= ~SLB_ESID_V;
+		ksp_vsid_data = 0;
+		slb_shadow_clear(KSTACK_INDEX);
+	} else {
+		/* Update stack entry; others don't change */
+		slb_shadow_update(get_paca()->kstack, mmu_kernel_ssize, lflags, KSTACK_INDEX);
+		ksp_vsid_data =
+			be64_to_cpu(get_slb_shadow()->save_area[KSTACK_INDEX].vsid);
+	}
+
+	/* We need to do this all in asm, so we're sure we don't touch
+	 * the stack between the slbia and rebolting it. */
+	asm volatile("isync\n"
+		     "slbia\n"
+		     /* Slot 1 - first VMALLOC segment */
+		     "slbmte	%0,%1\n"
+		     /* Slot 2 - kernel stack */
+		     "slbmte	%2,%3\n"
+		     "isync"
+		     :: "r"(mk_vsid_data(VMALLOC_START, mmu_kernel_ssize, vflags)),
+		        "r"(mk_esid_data(VMALLOC_START, mmu_kernel_ssize, VMALLOC_INDEX)),
+		        "r"(ksp_vsid_data),
+		        "r"(ksp_esid_data)
+		     : "memory");
+}
+
+void slb_flush_and_rebolt(void)
+{
+
+	WARN_ON(!irqs_disabled());
+
+	/*
+	 * We can't take a PMU exception in the following code, so hard
+	 * disable interrupts.
+	 */
+	hard_irq_disable();
+
+	__slb_flush_and_rebolt();
+	get_paca()->slb_cache_ptr = 0;
+}
+
+void slb_vmalloc_update(void)
+{
+	unsigned long vflags;
+
+	vflags = SLB_VSID_KERNEL | mmu_psize_defs[mmu_vmalloc_psize].sllp;
+	slb_shadow_update(VMALLOC_START, mmu_kernel_ssize, vflags, VMALLOC_INDEX);
+	slb_flush_and_rebolt();
+}
+
+/* Helper function to compare esids.  There are four cases to handle.
+ * 1. The system is not 1T segment size capable.  Use the GET_ESID compare.
+ * 2. The system is 1T capable, both addresses are < 1T, use the GET_ESID compare.
+ * 3. The system is 1T capable, only one of the two addresses is > 1T.  This is not a match.
+ * 4. The system is 1T capable, both addresses are > 1T, use the GET_ESID_1T macro to compare.
+ */
+static inline int esids_match(unsigned long addr1, unsigned long addr2)
+{
+	int esid_1t_count;
+
+	/* System is not 1T segment size capable. */
+	if (!mmu_has_feature(MMU_FTR_1T_SEGMENT))
+		return (GET_ESID(addr1) == GET_ESID(addr2));
+
+	esid_1t_count = (((addr1 >> SID_SHIFT_1T) != 0) +
+				((addr2 >> SID_SHIFT_1T) != 0));
+
+	/* both addresses are < 1T */
+	if (esid_1t_count == 0)
+		return (GET_ESID(addr1) == GET_ESID(addr2));
+
+	/* One address < 1T, the other > 1T.  Not a match */
+	if (esid_1t_count == 1)
+		return 0;
+
+	/* Both addresses are > 1T. */
+	return (GET_ESID_1T(addr1) == GET_ESID_1T(addr2));
+}
+
+/* Flush all user entries from the segment table of the current processor. */
+void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
+{
+	unsigned long offset;
+	unsigned long slbie_data = 0;
+	unsigned long pc = KSTK_EIP(tsk);
+	unsigned long stack = KSTK_ESP(tsk);
+	unsigned long exec_base;
+
+	/*
+	 * We need interrupts hard-disabled here, not just soft-disabled,
+	 * so that a PMU interrupt can't occur, which might try to access
+	 * user memory (to get a stack trace) and possible cause an SLB miss
+	 * which would update the slb_cache/slb_cache_ptr fields in the PACA.
+	 */
+	hard_irq_disable();
+	offset = get_paca()->slb_cache_ptr;
+	if (!mmu_has_feature(MMU_FTR_NO_SLBIE_B) &&
+	    offset <= SLB_CACHE_ENTRIES) {
+		int i;
+		asm volatile("isync" : : : "memory");
+		for (i = 0; i < offset; i++) {
+			slbie_data = (unsigned long)get_paca()->slb_cache[i]
+				<< SID_SHIFT; /* EA */
+			slbie_data |= user_segment_size(slbie_data)
+				<< SLBIE_SSIZE_SHIFT;
+			slbie_data |= SLBIE_C; /* C set for user addresses */
+			asm volatile("slbie %0" : : "r" (slbie_data));
+		}
+		asm volatile("isync" : : : "memory");
+	} else {
+		__slb_flush_and_rebolt();
+	}
+
+	/* Workaround POWER5 < DD2.1 issue */
+	if (offset == 1 || offset > SLB_CACHE_ENTRIES)
+		asm volatile("slbie %0" : : "r" (slbie_data));
+
+	get_paca()->slb_cache_ptr = 0;
+	copy_mm_to_paca(mm);
+
+	/*
+	 * preload some userspace segments into the SLB.
+	 * Almost all 32 and 64bit PowerPC executables are linked at
+	 * 0x10000000 so it makes sense to preload this segment.
+	 */
+	exec_base = 0x10000000;
+
+	if (is_kernel_addr(pc) || is_kernel_addr(stack) ||
+	    is_kernel_addr(exec_base))
+		return;
+
+	slb_allocate(pc);
+
+	if (!esids_match(pc, stack))
+		slb_allocate(stack);
+
+	if (!esids_match(pc, exec_base) &&
+	    !esids_match(stack, exec_base))
+		slb_allocate(exec_base);
+}
+
+static inline void patch_slb_encoding(unsigned int *insn_addr,
+				      unsigned int immed)
+{
+
+	/*
+	 * This function patches either an li or a cmpldi instruction with
+	 * a new immediate value. This relies on the fact that both li
+	 * (which is actually addi) and cmpldi both take a 16-bit immediate
+	 * value, and it is situated in the same location in the instruction,
+	 * ie. bits 16-31 (Big endian bit order) or the lower 16 bits.
+	 * The signedness of the immediate operand differs between the two
+	 * instructions however this code is only ever patching a small value,
+	 * much less than 1 << 15, so we can get away with it.
+	 * To patch the value we read the existing instruction, clear the
+	 * immediate value, and or in our new value, then write the instruction
+	 * back.
+	 */
+	unsigned int insn = (*insn_addr & 0xffff0000) | immed;
+	patch_instruction(insn_addr, insn);
+}
+
+extern u32 slb_miss_kernel_load_linear[];
+extern u32 slb_miss_kernel_load_io[];
+extern u32 slb_compare_rr_to_size[];
+extern u32 slb_miss_kernel_load_vmemmap[];
+
+void slb_set_size(u16 size)
+{
+	if (mmu_slb_size == size)
+		return;
+
+	mmu_slb_size = size;
+	patch_slb_encoding(slb_compare_rr_to_size, mmu_slb_size);
+}
+
+void slb_initialize(void)
+{
+	unsigned long linear_llp, vmalloc_llp, io_llp;
+	unsigned long lflags, vflags;
+	static int slb_encoding_inited;
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+	unsigned long vmemmap_llp;
+#endif
+
+	/* Prepare our SLB miss handler based on our page size */
+	linear_llp = mmu_psize_defs[mmu_linear_psize].sllp;
+	io_llp = mmu_psize_defs[mmu_io_psize].sllp;
+	vmalloc_llp = mmu_psize_defs[mmu_vmalloc_psize].sllp;
+	get_paca()->vmalloc_sllp = SLB_VSID_KERNEL | vmalloc_llp;
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+	vmemmap_llp = mmu_psize_defs[mmu_vmemmap_psize].sllp;
+#endif
+	if (!slb_encoding_inited) {
+		slb_encoding_inited = 1;
+		patch_slb_encoding(slb_miss_kernel_load_linear,
+				   SLB_VSID_KERNEL | linear_llp);
+		patch_slb_encoding(slb_miss_kernel_load_io,
+				   SLB_VSID_KERNEL | io_llp);
+		patch_slb_encoding(slb_compare_rr_to_size,
+				   mmu_slb_size);
+
+		pr_devel("SLB: linear  LLP = %04lx\n", linear_llp);
+		pr_devel("SLB: io      LLP = %04lx\n", io_llp);
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+		patch_slb_encoding(slb_miss_kernel_load_vmemmap,
+				   SLB_VSID_KERNEL | vmemmap_llp);
+		pr_devel("SLB: vmemmap LLP = %04lx\n", vmemmap_llp);
+#endif
+	}
+
+	get_paca()->stab_rr = SLB_NUM_BOLTED - 1;
+
+	lflags = SLB_VSID_KERNEL | linear_llp;
+	vflags = SLB_VSID_KERNEL | vmalloc_llp;
+
+	/* Invalidate the entire SLB (even entry 0) & all the ERATS */
+	asm volatile("isync":::"memory");
+	asm volatile("slbmte  %0,%0"::"r" (0) : "memory");
+	asm volatile("isync; slbia; isync":::"memory");
+	create_shadowed_slbe(PAGE_OFFSET, mmu_kernel_ssize, lflags, LINEAR_INDEX);
+	create_shadowed_slbe(VMALLOC_START, mmu_kernel_ssize, vflags, VMALLOC_INDEX);
+
+	/* For the boot cpu, we're running on the stack in init_thread_union,
+	 * which is in the first segment of the linear mapping, and also
+	 * get_paca()->kstack hasn't been initialized yet.
+	 * For secondary cpus, we need to bolt the kernel stack entry now.
+	 */
+	slb_shadow_clear(KSTACK_INDEX);
+	if (raw_smp_processor_id() != boot_cpuid &&
+	    (get_paca()->kstack & slb_esid_mask(mmu_kernel_ssize)) > PAGE_OFFSET)
+		create_shadowed_slbe(get_paca()->kstack,
+				     mmu_kernel_ssize, lflags, KSTACK_INDEX);
+
+	asm volatile("isync":::"memory");
+}