1/*
2 * PMU register read/write functions for TCG IBM POWER chips
3 *
4 * Copyright IBM Corp. 2021
5 *
6 * Authors:
7 *  Daniel Henrique Barboza      <danielhb413@gmail.com>
8 *
9 * This work is licensed under the terms of the GNU GPL, version 2 or later.
10 * See the COPYING file in the top-level directory.
11 */
12
13#if defined(TARGET_PPC64) && !defined(CONFIG_USER_ONLY)
14
15/*
16 * Checks whether the Group A SPR (MMCR0, MMCR2, MMCRA, and the
17 * PMCs) has problem state read access.
18 *
19 * Read acccess is granted for all PMCC values but 0b01, where a
20 * Facility Unavailable Interrupt will occur.
21 */
22static bool spr_groupA_read_allowed(DisasContext *ctx)
23{
24    if (!ctx->mmcr0_pmcc0 && ctx->mmcr0_pmcc1) {
25        gen_exception_err(ctx, POWERPC_EXCP_FU, FSCR_IC_PMU);
26        return false;
27    }
28
29    return true;
30}
31
32/*
33 * Checks whether the Group A SPR (MMCR0, MMCR2, MMCRA, and the
34 * PMCs) has problem state write access.
35 *
36 * Write acccess is granted for PMCC values 0b10 and 0b11. Userspace
37 * writing with PMCC 0b00 will generate a Hypervisor Emulation
38 * Assistance Interrupt. Userspace writing with PMCC 0b01 will
39 * generate a Facility Unavailable Interrupt.
40 */
41static bool spr_groupA_write_allowed(DisasContext *ctx)
42{
43    if (ctx->mmcr0_pmcc0) {
44        return true;
45    }
46
47    if (ctx->mmcr0_pmcc1) {
48        /* PMCC = 0b01 */
49        gen_exception_err(ctx, POWERPC_EXCP_FU, FSCR_IC_PMU);
50    } else {
51        /* PMCC = 0b00 */
52        gen_hvpriv_exception(ctx, POWERPC_EXCP_PRIV_REG);
53    }
54
55    return false;
56}
57
58/*
59 * Helper function to avoid code repetition between MMCR0 and
60 * MMCR2 problem state write functions.
61 */
62static TCGv masked_gprn_for_spr_write(int gprn, int sprn,
63                                      uint64_t spr_mask)
64{
65    TCGv ret = tcg_temp_new();
66    TCGv t0 = tcg_temp_new();
67
68    /* 'ret' starts with all mask bits cleared */
69    gen_load_spr(ret, sprn);
70    tcg_gen_andi_tl(ret, ret, ~(spr_mask));
71
72    /* Apply the mask into 'gprn' in a temp var */
73    tcg_gen_andi_tl(t0, cpu_gpr[gprn], spr_mask);
74
75    /* Add the masked gprn bits into 'ret' */
76    tcg_gen_or_tl(ret, ret, t0);
77
78    return ret;
79}
80
81void spr_read_MMCR0_ureg(DisasContext *ctx, int gprn, int sprn)
82{
83    TCGv t0;
84
85    if (!spr_groupA_read_allowed(ctx)) {
86        return;
87    }
88
89    t0 = tcg_temp_new();
90
91    /*
92     * Filter out all bits but FC, PMAO, and PMAE, according
93     * to ISA v3.1, in 10.4.4 Monitor Mode Control Register 0,
94     * fourth paragraph.
95     */
96    gen_load_spr(t0, SPR_POWER_MMCR0);
97    tcg_gen_andi_tl(t0, t0, MMCR0_UREG_MASK);
98    tcg_gen_mov_tl(cpu_gpr[gprn], t0);
99}
100
101static void write_MMCR0_common(DisasContext *ctx, TCGv val)
102{
103    /*
104     * helper_store_mmcr0 will make clock based operations that
105     * will cause 'bad icount read' errors if we do not execute
106     * gen_icount_io_start() beforehand.
107     */
108    gen_icount_io_start(ctx);
109    gen_helper_store_mmcr0(cpu_env, val);
110
111    /*
112     * End the translation block because MMCR0 writes can change
113     * ctx->pmu_insn_cnt.
114     */
115    ctx->base.is_jmp = DISAS_EXIT_UPDATE;
116}
117
118void spr_write_MMCR0_ureg(DisasContext *ctx, int sprn, int gprn)
119{
120    TCGv masked_gprn;
121
122    if (!spr_groupA_write_allowed(ctx)) {
123        return;
124    }
125
126    /*
127     * Filter out all bits but FC, PMAO, and PMAE, according
128     * to ISA v3.1, in 10.4.4 Monitor Mode Control Register 0,
129     * fourth paragraph.
130     */
131    masked_gprn = masked_gprn_for_spr_write(gprn, SPR_POWER_MMCR0,
132                                            MMCR0_UREG_MASK);
133    write_MMCR0_common(ctx, masked_gprn);
134}
135
136void spr_read_MMCR2_ureg(DisasContext *ctx, int gprn, int sprn)
137{
138    TCGv t0;
139
140    if (!spr_groupA_read_allowed(ctx)) {
141        return;
142    }
143
144    t0 = tcg_temp_new();
145
146    /*
147     * On read, filter out all bits that are not FCnP0 bits.
148     * When MMCR0[PMCC] is set to 0b10 or 0b11, providing
149     * problem state programs read/write access to MMCR2,
150     * only the FCnP0 bits can be accessed. All other bits are
151     * not changed when mtspr is executed in problem state, and
152     * all other bits return 0s when mfspr is executed in problem
153     * state, according to ISA v3.1, section 10.4.6 Monitor Mode
154     * Control Register 2, p. 1316, third paragraph.
155     */
156    gen_load_spr(t0, SPR_POWER_MMCR2);
157    tcg_gen_andi_tl(t0, t0, MMCR2_UREG_MASK);
158    tcg_gen_mov_tl(cpu_gpr[gprn], t0);
159}
160
161void spr_write_MMCR2_ureg(DisasContext *ctx, int sprn, int gprn)
162{
163    TCGv masked_gprn;
164
165    if (!spr_groupA_write_allowed(ctx)) {
166        return;
167    }
168
169    /*
170     * Filter the bits that can be written using MMCR2_UREG_MASK,
171     * similar to what is done in spr_write_MMCR0_ureg().
172     */
173    masked_gprn = masked_gprn_for_spr_write(gprn, SPR_POWER_MMCR2,
174                                            MMCR2_UREG_MASK);
175    gen_store_spr(SPR_POWER_MMCR2, masked_gprn);
176}
177
178void spr_read_PMC(DisasContext *ctx, int gprn, int sprn)
179{
180    TCGv_i32 t_sprn = tcg_const_i32(sprn);
181
182    gen_icount_io_start(ctx);
183    gen_helper_read_pmc(cpu_gpr[gprn], cpu_env, t_sprn);
184}
185
186void spr_read_PMC14_ureg(DisasContext *ctx, int gprn, int sprn)
187{
188    if (!spr_groupA_read_allowed(ctx)) {
189        return;
190    }
191
192    spr_read_PMC(ctx, gprn, sprn + 0x10);
193}
194
195void spr_read_PMC56_ureg(DisasContext *ctx, int gprn, int sprn)
196{
197    /*
198     * If PMCC = 0b11, PMC5 and PMC6 aren't included in the Performance
199     * Monitor, and a read attempt results in a Facility Unavailable
200     * Interrupt.
201     */
202    if (ctx->mmcr0_pmcc0 && ctx->mmcr0_pmcc1) {
203        gen_exception_err(ctx, POWERPC_EXCP_FU, FSCR_IC_PMU);
204        return;
205    }
206
207    /* The remaining steps are similar to PMCs 1-4 userspace read */
208    spr_read_PMC14_ureg(ctx, gprn, sprn);
209}
210
211void spr_write_PMC(DisasContext *ctx, int sprn, int gprn)
212{
213    TCGv_i32 t_sprn = tcg_const_i32(sprn);
214
215    gen_icount_io_start(ctx);
216    gen_helper_store_pmc(cpu_env, t_sprn, cpu_gpr[gprn]);
217}
218
219void spr_write_PMC14_ureg(DisasContext *ctx, int sprn, int gprn)
220{
221    if (!spr_groupA_write_allowed(ctx)) {
222        return;
223    }
224
225    spr_write_PMC(ctx, sprn + 0x10, gprn);
226}
227
228void spr_write_PMC56_ureg(DisasContext *ctx, int sprn, int gprn)
229{
230    /*
231     * If PMCC = 0b11, PMC5 and PMC6 aren't included in the Performance
232     * Monitor, and a write attempt results in a Facility Unavailable
233     * Interrupt.
234     */
235    if (ctx->mmcr0_pmcc0 && ctx->mmcr0_pmcc1) {
236        gen_exception_err(ctx, POWERPC_EXCP_FU, FSCR_IC_PMU);
237        return;
238    }
239
240    /* The remaining steps are similar to PMCs 1-4 userspace write */
241    spr_write_PMC14_ureg(ctx, sprn, gprn);
242}
243
244void spr_write_MMCR0(DisasContext *ctx, int sprn, int gprn)
245{
246    write_MMCR0_common(ctx, cpu_gpr[gprn]);
247}
248
249void spr_write_MMCR1(DisasContext *ctx, int sprn, int gprn)
250{
251    gen_icount_io_start(ctx);
252    gen_helper_store_mmcr1(cpu_env, cpu_gpr[gprn]);
253}
254#else
255void spr_read_MMCR0_ureg(DisasContext *ctx, int gprn, int sprn)
256{
257    spr_read_ureg(ctx, gprn, sprn);
258}
259
260void spr_write_MMCR0_ureg(DisasContext *ctx, int sprn, int gprn)
261{
262    spr_noaccess(ctx, gprn, sprn);
263}
264
265void spr_read_MMCR2_ureg(DisasContext *ctx, int gprn, int sprn)
266{
267    spr_read_ureg(ctx, gprn, sprn);
268}
269
270void spr_write_MMCR2_ureg(DisasContext *ctx, int sprn, int gprn)
271{
272    spr_noaccess(ctx, gprn, sprn);
273}
274
275void spr_read_PMC14_ureg(DisasContext *ctx, int gprn, int sprn)
276{
277    spr_read_ureg(ctx, gprn, sprn);
278}
279
280void spr_read_PMC56_ureg(DisasContext *ctx, int gprn, int sprn)
281{
282    spr_read_ureg(ctx, gprn, sprn);
283}
284
285void spr_write_PMC14_ureg(DisasContext *ctx, int sprn, int gprn)
286{
287    spr_noaccess(ctx, gprn, sprn);
288}
289
290void spr_write_PMC56_ureg(DisasContext *ctx, int sprn, int gprn)
291{
292    spr_noaccess(ctx, gprn, sprn);
293}
294
295void spr_write_MMCR0(DisasContext *ctx, int sprn, int gprn)
296{
297    spr_write_generic(ctx, sprn, gprn);
298}
299
300void spr_write_MMCR1(DisasContext *ctx, int sprn, int gprn)
301{
302    spr_write_generic(ctx, sprn, gprn);
303}
304
305void spr_write_PMC(DisasContext *ctx, int sprn, int gprn)
306{
307    spr_write_generic(ctx, sprn, gprn);
308}
309#endif /* defined(TARGET_PPC64) && !defined(CONFIG_USER_ONLY) */
310