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+/*
+ * Copyright 2011 Tilera Corporation. All Rights Reserved.
+ *
+ *   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, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ *
+ * This routine is a helper for migrating the home of a set of pages to
+ * a new cpu.  See the documentation in homecache.c for more information.
+ */
+
+#include <linux/linkage.h>
+#include <linux/threads.h>
+#include <asm/page.h>
+#include <asm/thread_info.h>
+#include <asm/types.h>
+#include <asm/asm-offsets.h>
+#include <hv/hypervisor.h>
+
+	.text
+
+/*
+ * First, some definitions that apply to all the code in the file.
+ */
+
+/* Locals (caller-save) */
+#define r_tmp		r10
+#define r_save_sp	r11
+
+/* What we save where in the stack frame; must include all callee-saves. */
+#define FRAME_SP	8
+#define FRAME_R30	16
+#define FRAME_R31	24
+#define FRAME_R32	32
+#define FRAME_R33	40
+#define FRAME_SIZE	48
+
+
+
+
+/*
+ * On entry:
+ *
+ *   r0 the new context PA to install (moved to r_context)
+ *   r1 PTE to use for context access (moved to r_access)
+ *   r2 ASID to use for new context (moved to r_asid)
+ *   r3 pointer to cpumask with just this cpu set in it (r_my_cpumask)
+ */
+
+/* Arguments (caller-save) */
+#define r_context_in	r0
+#define r_access_in	r1
+#define r_asid_in	r2
+#define r_my_cpumask	r3
+
+/* Locals (callee-save); must not be more than FRAME_xxx above. */
+#define r_save_ics	r30
+#define r_context	r31
+#define r_access	r32
+#define r_asid		r33
+
+/*
+ * Caller-save locals and frame constants are the same as
+ * for homecache_migrate_stack_and_flush.
+ */
+
+STD_ENTRY(flush_and_install_context)
+	/*
+	 * Create a stack frame; we can't touch it once we flush the
+	 * cache until we install the new page table and flush the TLB.
+	 */
+	{
+	 move r_save_sp, sp
+	 st sp, lr
+	 addi sp, sp, -FRAME_SIZE
+	}
+	addi r_tmp, sp, FRAME_SP
+	{
+	 st r_tmp, r_save_sp
+	 addi r_tmp, sp, FRAME_R30
+	}
+	{
+	 st r_tmp, r30
+	 addi r_tmp, sp, FRAME_R31
+	}
+	{
+	 st r_tmp, r31
+	 addi r_tmp, sp, FRAME_R32
+	}
+	{
+	 st r_tmp, r32
+	 addi r_tmp, sp, FRAME_R33
+	}
+	st r_tmp, r33
+
+	/* Move some arguments to callee-save registers. */
+	{
+	 move r_context, r_context_in
+	 move r_access, r_access_in
+	}
+	move r_asid, r_asid_in
+
+	/* Disable interrupts, since we can't use our stack. */
+	{
+	 mfspr r_save_ics, INTERRUPT_CRITICAL_SECTION
+	 movei r_tmp, 1
+	}
+	mtspr INTERRUPT_CRITICAL_SECTION, r_tmp
+
+	/* First, flush our L2 cache. */
+	{
+	 move r0, zero  /* cache_pa */
+	 moveli r1, hw2_last(HV_FLUSH_EVICT_L2)  /* cache_control */
+	}
+	{
+	 shl16insli r1, r1, hw1(HV_FLUSH_EVICT_L2)
+	 move r2, r_my_cpumask  /* cache_cpumask */
+	}
+	{
+	 shl16insli r1, r1, hw0(HV_FLUSH_EVICT_L2)
+	 move r3, zero  /* tlb_va */
+	}
+	{
+	 move r4, zero  /* tlb_length */
+	 move r5, zero  /* tlb_pgsize */
+	}
+	{
+	 move r6, zero  /* tlb_cpumask */
+	 move r7, zero  /* asids */
+	}
+	{
+	 move r8, zero  /* asidcount */
+	 jal hv_flush_remote
+	}
+	bnez r0, 1f
+
+	/* Now install the new page table. */
+	{
+	 move r0, r_context
+	 move r1, r_access
+	}
+	{
+	 move r2, r_asid
+	 movei r3, HV_CTX_DIRECTIO
+	}
+	jal hv_install_context
+	bnez r0, 1f
+
+	/* Finally, flush the TLB. */
+	{
+	 movei r0, 0   /* preserve_global */
+	 jal hv_flush_all
+	}
+
+1:      /* Reset interrupts back how they were before. */
+	mtspr INTERRUPT_CRITICAL_SECTION, r_save_ics
+
+	/* Restore the callee-saved registers and return. */
+	addli lr, sp, FRAME_SIZE
+	{
+	 ld lr, lr
+	 addli r_tmp, sp, FRAME_R30
+	}
+	{
+	 ld r30, r_tmp
+	 addli r_tmp, sp, FRAME_R31
+	}
+	{
+	 ld r31, r_tmp
+	 addli r_tmp, sp, FRAME_R32
+	}
+	{
+	 ld r32, r_tmp
+	 addli r_tmp, sp, FRAME_R33
+	}
+	{
+	 ld r33, r_tmp
+	 addi sp, sp, FRAME_SIZE
+	}
+	jrp lr
+	STD_ENDPROC(flush_and_install_context)