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_hvpriv_exception(ctx, POWERPC_EXCP_FU);
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_hvpriv_exception(ctx, POWERPC_EXCP_FU);
50    } else {
51        /* PMCC = 0b00 */
52        gen_hvpriv_exception(ctx, POWERPC_EXCP_INVAL_SPR);
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 *
62 * 'ret' must be tcg_temp_freed() by the caller.
63 */
64static TCGv masked_gprn_for_spr_write(int gprn, int sprn,
65                                      uint64_t spr_mask)
66{
67    TCGv ret = tcg_temp_new();
68    TCGv t0 = tcg_temp_new();
69
70    /* 'ret' starts with all mask bits cleared */
71    gen_load_spr(ret, sprn);
72    tcg_gen_andi_tl(ret, ret, ~(spr_mask));
73
74    /* Apply the mask into 'gprn' in a temp var */
75    tcg_gen_andi_tl(t0, cpu_gpr[gprn], spr_mask);
76
77    /* Add the masked gprn bits into 'ret' */
78    tcg_gen_or_tl(ret, ret, t0);
79
80    tcg_temp_free(t0);
81
82    return ret;
83}
84
85void spr_read_MMCR0_ureg(DisasContext *ctx, int gprn, int sprn)
86{
87    TCGv t0;
88
89    if (!spr_groupA_read_allowed(ctx)) {
90        return;
91    }
92
93    t0 = tcg_temp_new();
94
95    /*
96     * Filter out all bits but FC, PMAO, and PMAE, according
97     * to ISA v3.1, in 10.4.4 Monitor Mode Control Register 0,
98     * fourth paragraph.
99     */
100    gen_load_spr(t0, SPR_POWER_MMCR0);
101    tcg_gen_andi_tl(t0, t0, MMCR0_UREG_MASK);
102    tcg_gen_mov_tl(cpu_gpr[gprn], t0);
103
104    tcg_temp_free(t0);
105}
106
107static void write_MMCR0_common(DisasContext *ctx, TCGv val)
108{
109    /*
110     * helper_store_mmcr0 will make clock based operations that
111     * will cause 'bad icount read' errors if we do not execute
112     * gen_icount_io_start() beforehand.
113     */
114    gen_icount_io_start(ctx);
115    gen_helper_store_mmcr0(cpu_env, val);
116
117    /*
118     * End the translation block because MMCR0 writes can change
119     * ctx->pmu_insn_cnt.
120     */
121    ctx->base.is_jmp = DISAS_EXIT_UPDATE;
122}
123
124void spr_write_MMCR0_ureg(DisasContext *ctx, int sprn, int gprn)
125{
126    TCGv masked_gprn;
127
128    if (!spr_groupA_write_allowed(ctx)) {
129        return;
130    }
131
132    /*
133     * Filter out all bits but FC, PMAO, and PMAE, according
134     * to ISA v3.1, in 10.4.4 Monitor Mode Control Register 0,
135     * fourth paragraph.
136     */
137    masked_gprn = masked_gprn_for_spr_write(gprn, SPR_POWER_MMCR0,
138                                            MMCR0_UREG_MASK);
139    write_MMCR0_common(ctx, masked_gprn);
140
141    tcg_temp_free(masked_gprn);
142}
143
144void spr_read_MMCR2_ureg(DisasContext *ctx, int gprn, int sprn)
145{
146    TCGv t0;
147
148    if (!spr_groupA_read_allowed(ctx)) {
149        return;
150    }
151
152    t0 = tcg_temp_new();
153
154    /*
155     * On read, filter out all bits that are not FCnP0 bits.
156     * When MMCR0[PMCC] is set to 0b10 or 0b11, providing
157     * problem state programs read/write access to MMCR2,
158     * only the FCnP0 bits can be accessed. All other bits are
159     * not changed when mtspr is executed in problem state, and
160     * all other bits return 0s when mfspr is executed in problem
161     * state, according to ISA v3.1, section 10.4.6 Monitor Mode
162     * Control Register 2, p. 1316, third paragraph.
163     */
164    gen_load_spr(t0, SPR_POWER_MMCR2);
165    tcg_gen_andi_tl(t0, t0, MMCR2_UREG_MASK);
166    tcg_gen_mov_tl(cpu_gpr[gprn], t0);
167
168    tcg_temp_free(t0);
169}
170
171void spr_write_MMCR2_ureg(DisasContext *ctx, int sprn, int gprn)
172{
173    TCGv masked_gprn;
174
175    if (!spr_groupA_write_allowed(ctx)) {
176        return;
177    }
178
179    /*
180     * Filter the bits that can be written using MMCR2_UREG_MASK,
181     * similar to what is done in spr_write_MMCR0_ureg().
182     */
183    masked_gprn = masked_gprn_for_spr_write(gprn, SPR_POWER_MMCR2,
184                                            MMCR2_UREG_MASK);
185    gen_store_spr(SPR_POWER_MMCR2, masked_gprn);
186
187    tcg_temp_free(masked_gprn);
188}
189
190void spr_read_PMC(DisasContext *ctx, int gprn, int sprn)
191{
192    TCGv_i32 t_sprn = tcg_const_i32(sprn);
193
194    gen_icount_io_start(ctx);
195    gen_helper_read_pmc(cpu_gpr[gprn], cpu_env, t_sprn);
196
197    tcg_temp_free_i32(t_sprn);
198}
199
200void spr_read_PMC14_ureg(DisasContext *ctx, int gprn, int sprn)
201{
202    if (!spr_groupA_read_allowed(ctx)) {
203        return;
204    }
205
206    spr_read_PMC(ctx, gprn, sprn + 0x10);
207}
208
209void spr_read_PMC56_ureg(DisasContext *ctx, int gprn, int sprn)
210{
211    /*
212     * If PMCC = 0b11, PMC5 and PMC6 aren't included in the Performance
213     * Monitor, and a read attempt results in a Facility Unavailable
214     * Interrupt.
215     */
216    if (ctx->mmcr0_pmcc0 && ctx->mmcr0_pmcc1) {
217        gen_hvpriv_exception(ctx, POWERPC_EXCP_FU);
218        return;
219    }
220
221    /* The remaining steps are similar to PMCs 1-4 userspace read */
222    spr_read_PMC14_ureg(ctx, gprn, sprn);
223}
224
225void spr_write_PMC(DisasContext *ctx, int sprn, int gprn)
226{
227    TCGv_i32 t_sprn = tcg_const_i32(sprn);
228
229    gen_icount_io_start(ctx);
230    gen_helper_store_pmc(cpu_env, t_sprn, cpu_gpr[gprn]);
231
232    tcg_temp_free_i32(t_sprn);
233}
234
235void spr_write_PMC14_ureg(DisasContext *ctx, int sprn, int gprn)
236{
237    if (!spr_groupA_write_allowed(ctx)) {
238        return;
239    }
240
241    spr_write_PMC(ctx, sprn + 0x10, gprn);
242}
243
244void spr_write_PMC56_ureg(DisasContext *ctx, int sprn, int gprn)
245{
246    /*
247     * If PMCC = 0b11, PMC5 and PMC6 aren't included in the Performance
248     * Monitor, and a write attempt results in a Facility Unavailable
249     * Interrupt.
250     */
251    if (ctx->mmcr0_pmcc0 && ctx->mmcr0_pmcc1) {
252        gen_hvpriv_exception(ctx, POWERPC_EXCP_FU);
253        return;
254    }
255
256    /* The remaining steps are similar to PMCs 1-4 userspace write */
257    spr_write_PMC14_ureg(ctx, sprn, gprn);
258}
259
260void spr_write_MMCR0(DisasContext *ctx, int sprn, int gprn)
261{
262    write_MMCR0_common(ctx, cpu_gpr[gprn]);
263}
264
265void spr_write_MMCR1(DisasContext *ctx, int sprn, int gprn)
266{
267    gen_icount_io_start(ctx);
268    gen_helper_store_mmcr1(cpu_env, cpu_gpr[gprn]);
269}
270#else
271void spr_read_MMCR0_ureg(DisasContext *ctx, int gprn, int sprn)
272{
273    spr_read_ureg(ctx, gprn, sprn);
274}
275
276void spr_write_MMCR0_ureg(DisasContext *ctx, int sprn, int gprn)
277{
278    spr_noaccess(ctx, gprn, sprn);
279}
280
281void spr_read_MMCR2_ureg(DisasContext *ctx, int gprn, int sprn)
282{
283    spr_read_ureg(ctx, gprn, sprn);
284}
285
286void spr_write_MMCR2_ureg(DisasContext *ctx, int sprn, int gprn)
287{
288    spr_noaccess(ctx, gprn, sprn);
289}
290
291void spr_read_PMC14_ureg(DisasContext *ctx, int gprn, int sprn)
292{
293    spr_read_ureg(ctx, gprn, sprn);
294}
295
296void spr_read_PMC56_ureg(DisasContext *ctx, int gprn, int sprn)
297{
298    spr_read_ureg(ctx, gprn, sprn);
299}
300
301void spr_write_PMC14_ureg(DisasContext *ctx, int sprn, int gprn)
302{
303    spr_noaccess(ctx, gprn, sprn);
304}
305
306void spr_write_PMC56_ureg(DisasContext *ctx, int sprn, int gprn)
307{
308    spr_noaccess(ctx, gprn, sprn);
309}
310
311void spr_write_MMCR0(DisasContext *ctx, int sprn, int gprn)
312{
313    spr_write_generic(ctx, sprn, gprn);
314}
315
316void spr_write_MMCR1(DisasContext *ctx, int sprn, int gprn)
317{
318    spr_write_generic(ctx, sprn, gprn);
319}
320
321void spr_write_PMC(DisasContext *ctx, int sprn, int gprn)
322{
323    spr_write_generic(ctx, sprn, gprn);
324}
325#endif /* defined(TARGET_PPC64) && !defined(CONFIG_USER_ONLY) */
326