1/*
  2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
  3 *
  4 *   This program is free software; you can redistribute it and/or
  5 *   modify it under the terms of the GNU General Public License
  6 *   as published by the Free Software Foundation, version 2.
  7 *
  8 *   This program is distributed in the hope that it will be useful, but
  9 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 10 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 11 *   NON INFRINGEMENT.  See the GNU General Public License for
 12 *   more details.
 13 *
 14 * This routine is a helper for migrating the home of a set of pages to
 15 * a new cpu.  See the documentation in homecache.c for more information.
 16 */
 17
 18#include <linux/linkage.h>
 19#include <linux/threads.h>
 20#include <asm/page.h>
 21#include <asm/thread_info.h>
 22#include <asm/types.h>
 23#include <asm/asm-offsets.h>
 24#include <hv/hypervisor.h>
 25
 26	.text
 27
 28/*
 29 * First, some definitions that apply to all the code in the file.
 30 */
 31
 32/* Locals (caller-save) */
 33#define r_tmp		r10
 34#define r_save_sp	r11
 35
 36/* What we save where in the stack frame; must include all callee-saves. */
 37#define FRAME_SP	4
 38#define FRAME_R30	8
 39#define FRAME_R31	12
 40#define FRAME_R32	16
 41#define FRAME_R33	20
 42#define FRAME_R34	24
 43#define FRAME_SIZE	28
 44
 45
 46
 47
 48/*
 49 * On entry:
 50 *
 51 *   r0 low word of the new context PA to install (moved to r_context_lo)
 52 *   r1 high word of the new context PA to install (moved to r_context_hi)
 53 *   r2 low word of PTE to use for context access (moved to r_access_lo)
 54 *   r3 high word of PTE to use for context access (moved to r_access_lo)
 55 *   r4 ASID to use for new context (moved to r_asid)
 56 *   r5 pointer to cpumask with just this cpu set in it (r_my_cpumask)
 57 */
 58
 59/* Arguments (caller-save) */
 60#define r_context_lo_in	r0
 61#define r_context_hi_in	r1
 62#define r_access_lo_in	r2
 63#define r_access_hi_in	r3
 64#define r_asid_in	r4
 65#define r_my_cpumask	r5
 66
 67/* Locals (callee-save); must not be more than FRAME_xxx above. */
 68#define r_context_lo	r30
 69#define r_context_hi	r31
 70#define r_access_lo	r32
 71#define r_access_hi	r33
 72#define r_asid		r34
 73
 74STD_ENTRY(flush_and_install_context)
 75	/*
 76	 * Create a stack frame; we can't touch it once we flush the
 77	 * cache until we install the new page table and flush the TLB.
 78	 */
 79	{
 80	 move r_save_sp, sp
 81	 sw sp, lr
 82	 addi sp, sp, -FRAME_SIZE
 83	}
 84	addi r_tmp, sp, FRAME_SP
 85	{
 86	 sw r_tmp, r_save_sp
 87	 addi r_tmp, sp, FRAME_R30
 88	}
 89	{
 90	 sw r_tmp, r30
 91	 addi r_tmp, sp, FRAME_R31
 92	}
 93	{
 94	 sw r_tmp, r31
 95	 addi r_tmp, sp, FRAME_R32
 96	}
 97	{
 98	 sw r_tmp, r32
 99	 addi r_tmp, sp, FRAME_R33
100	}
101	{
102	 sw r_tmp, r33
103	 addi r_tmp, sp, FRAME_R34
104	}
105	sw r_tmp, r34
106
107	/* Move some arguments to callee-save registers. */
108	{
109	 move r_context_lo, r_context_lo_in
110	 move r_context_hi, r_context_hi_in
111	}
112	{
113	 move r_access_lo, r_access_lo_in
114	 move r_access_hi, r_access_hi_in
115	}
116	move r_asid, r_asid_in
117
118	/* First, flush our L2 cache. */
119	{
120	 move r0, zero  /* cache_pa */
121	 move r1, zero
122	}
123	{
124	 auli r2, zero, ha16(HV_FLUSH_EVICT_L2)  /* cache_control */
125	 move r3, r_my_cpumask  /* cache_cpumask */
126	}
127	{
128	 move r4, zero  /* tlb_va */
129	 move r5, zero  /* tlb_length */
130	}
131	{
132	 move r6, zero  /* tlb_pgsize */
133	 move r7, zero  /* tlb_cpumask */
134	}
135	{
136	 move r8, zero  /* asids */
137	 move r9, zero  /* asidcount */
138	}
139	jal _hv_flush_remote
140	bnz r0, .Ldone
141
142	/* Now install the new page table. */
143	{
144	 move r0, r_context_lo
145	 move r1, r_context_hi
146	}
147	{
148	 move r2, r_access_lo
149	 move r3, r_access_hi
150	}
151	{
152	 move r4, r_asid
153	 moveli r5, HV_CTX_DIRECTIO | CTX_PAGE_FLAG
154	}
155	jal _hv_install_context
156	bnz r0, .Ldone
157
158	/* Finally, flush the TLB. */
159	{
160	 movei r0, 0   /* preserve_global */
161	 jal hv_flush_all
162	}
163
164.Ldone:
165	/* Restore the callee-saved registers and return. */
166	addli lr, sp, FRAME_SIZE
167	{
168	 lw lr, lr
169	 addli r_tmp, sp, FRAME_R30
170	}
171	{
172	 lw r30, r_tmp
173	 addli r_tmp, sp, FRAME_R31
174	}
175	{
176	 lw r31, r_tmp
177	 addli r_tmp, sp, FRAME_R32
178	}
179	{
180	 lw r32, r_tmp
181	 addli r_tmp, sp, FRAME_R33
182	}
183	{
184	 lw r33, r_tmp
185	 addli r_tmp, sp, FRAME_R34
186	}
187	{
188	 lw r34, r_tmp
189	 addi sp, sp, FRAME_SIZE
190	}
191	jrp lr
192	STD_ENDPROC(flush_and_install_context)