xref: /linux/drivers/gpu/drm/i915/vlv_sideband.c (revision 3f41368fbfe1b3d5922d317fe1a0a0cab6846802)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2013-2021 Intel Corporation
4  */
5 
6 #include "i915_drv.h"
7 #include "i915_iosf_mbi.h"
8 #include "i915_reg.h"
9 #include "vlv_sideband.h"
10 
11 #include "display/intel_dpio_phy.h"
12 
13 /*
14  * IOSF sideband, see VLV2_SidebandMsg_HAS.docx and
15  * VLV_VLV2_PUNIT_HAS_0.8.docx
16  */
17 
18 /* Standard MMIO read, non-posted */
19 #define SB_MRD_NP	0x00
20 /* Standard MMIO write, non-posted */
21 #define SB_MWR_NP	0x01
22 /* Private register read, double-word addressing, non-posted */
23 #define SB_CRRDDA_NP	0x06
24 /* Private register write, double-word addressing, non-posted */
25 #define SB_CRWRDA_NP	0x07
26 
27 static void ping(void *info)
28 {
29 }
30 
31 static void __vlv_punit_get(struct drm_i915_private *i915)
32 {
33 	iosf_mbi_punit_acquire();
34 
35 	/*
36 	 * Prevent the cpu from sleeping while we use this sideband, otherwise
37 	 * the punit may cause a machine hang. The issue appears to be isolated
38 	 * with changing the power state of the CPU package while changing
39 	 * the power state via the punit, and we have only observed it
40 	 * reliably on 4-core Baytail systems suggesting the issue is in the
41 	 * power delivery mechanism and likely to be board/function
42 	 * specific. Hence we presume the workaround needs only be applied
43 	 * to the Valleyview P-unit and not all sideband communications.
44 	 */
45 	if (IS_VALLEYVIEW(i915)) {
46 		cpu_latency_qos_update_request(&i915->sb_qos, 0);
47 		on_each_cpu(ping, NULL, 1);
48 	}
49 }
50 
51 static void __vlv_punit_put(struct drm_i915_private *i915)
52 {
53 	if (IS_VALLEYVIEW(i915))
54 		cpu_latency_qos_update_request(&i915->sb_qos,
55 					       PM_QOS_DEFAULT_VALUE);
56 
57 	iosf_mbi_punit_release();
58 }
59 
60 void vlv_iosf_sb_get(struct drm_i915_private *i915, unsigned long ports)
61 {
62 	if (ports & BIT(VLV_IOSF_SB_PUNIT))
63 		__vlv_punit_get(i915);
64 
65 	mutex_lock(&i915->sb_lock);
66 }
67 
68 void vlv_iosf_sb_put(struct drm_i915_private *i915, unsigned long ports)
69 {
70 	mutex_unlock(&i915->sb_lock);
71 
72 	if (ports & BIT(VLV_IOSF_SB_PUNIT))
73 		__vlv_punit_put(i915);
74 }
75 
76 static int vlv_sideband_rw(struct drm_i915_private *i915,
77 			   u32 devfn, u32 port, u32 opcode,
78 			   u32 addr, u32 *val)
79 {
80 	struct intel_uncore *uncore = &i915->uncore;
81 	const bool is_read = (opcode == SB_MRD_NP || opcode == SB_CRRDDA_NP);
82 	int err;
83 
84 	lockdep_assert_held(&i915->sb_lock);
85 	if (port == IOSF_PORT_PUNIT)
86 		iosf_mbi_assert_punit_acquired();
87 
88 	/* Flush the previous comms, just in case it failed last time. */
89 	if (intel_wait_for_register(uncore,
90 				    VLV_IOSF_DOORBELL_REQ, IOSF_SB_BUSY, 0,
91 				    5)) {
92 		drm_dbg(&i915->drm, "IOSF sideband idle wait (%s) timed out\n",
93 			is_read ? "read" : "write");
94 		return -EAGAIN;
95 	}
96 
97 	preempt_disable();
98 
99 	intel_uncore_write_fw(uncore, VLV_IOSF_ADDR, addr);
100 	intel_uncore_write_fw(uncore, VLV_IOSF_DATA, is_read ? 0 : *val);
101 	intel_uncore_write_fw(uncore, VLV_IOSF_DOORBELL_REQ,
102 			      (devfn << IOSF_DEVFN_SHIFT) |
103 			      (opcode << IOSF_OPCODE_SHIFT) |
104 			      (port << IOSF_PORT_SHIFT) |
105 			      (0xf << IOSF_BYTE_ENABLES_SHIFT) |
106 			      (0 << IOSF_BAR_SHIFT) |
107 			      IOSF_SB_BUSY);
108 
109 	if (__intel_wait_for_register_fw(uncore,
110 					 VLV_IOSF_DOORBELL_REQ, IOSF_SB_BUSY, 0,
111 					 10000, 0, NULL) == 0) {
112 		if (is_read)
113 			*val = intel_uncore_read_fw(uncore, VLV_IOSF_DATA);
114 		err = 0;
115 	} else {
116 		drm_dbg(&i915->drm, "IOSF sideband finish wait (%s) timed out\n",
117 			is_read ? "read" : "write");
118 		err = -ETIMEDOUT;
119 	}
120 
121 	preempt_enable();
122 
123 	return err;
124 }
125 
126 u32 vlv_punit_read(struct drm_i915_private *i915, u32 addr)
127 {
128 	u32 val = 0;
129 
130 	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_PUNIT,
131 			SB_CRRDDA_NP, addr, &val);
132 
133 	return val;
134 }
135 
136 int vlv_punit_write(struct drm_i915_private *i915, u32 addr, u32 val)
137 {
138 	return vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_PUNIT,
139 			       SB_CRWRDA_NP, addr, &val);
140 }
141 
142 u32 vlv_bunit_read(struct drm_i915_private *i915, u32 reg)
143 {
144 	u32 val = 0;
145 
146 	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_BUNIT,
147 			SB_CRRDDA_NP, reg, &val);
148 
149 	return val;
150 }
151 
152 void vlv_bunit_write(struct drm_i915_private *i915, u32 reg, u32 val)
153 {
154 	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_BUNIT,
155 			SB_CRWRDA_NP, reg, &val);
156 }
157 
158 u32 vlv_nc_read(struct drm_i915_private *i915, u8 addr)
159 {
160 	u32 val = 0;
161 
162 	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_NC,
163 			SB_CRRDDA_NP, addr, &val);
164 
165 	return val;
166 }
167 
168 u32 vlv_cck_read(struct drm_i915_private *i915, u32 reg)
169 {
170 	u32 val = 0;
171 
172 	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_CCK,
173 			SB_CRRDDA_NP, reg, &val);
174 
175 	return val;
176 }
177 
178 void vlv_cck_write(struct drm_i915_private *i915, u32 reg, u32 val)
179 {
180 	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_CCK,
181 			SB_CRWRDA_NP, reg, &val);
182 }
183 
184 u32 vlv_ccu_read(struct drm_i915_private *i915, u32 reg)
185 {
186 	u32 val = 0;
187 
188 	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_CCU,
189 			SB_CRRDDA_NP, reg, &val);
190 
191 	return val;
192 }
193 
194 void vlv_ccu_write(struct drm_i915_private *i915, u32 reg, u32 val)
195 {
196 	vlv_sideband_rw(i915, PCI_DEVFN(0, 0), IOSF_PORT_CCU,
197 			SB_CRWRDA_NP, reg, &val);
198 }
199 
200 static u32 vlv_dpio_phy_iosf_port(struct drm_i915_private *i915, enum dpio_phy phy)
201 {
202 	/*
203 	 * IOSF_PORT_DPIO: VLV x2 PHY (DP/HDMI B and C), CHV x1 PHY (DP/HDMI D)
204 	 * IOSF_PORT_DPIO_2: CHV x2 PHY (DP/HDMI B and C)
205 	 */
206 	if (IS_CHERRYVIEW(i915))
207 		return phy == DPIO_PHY0 ? IOSF_PORT_DPIO_2 : IOSF_PORT_DPIO;
208 	else
209 		return IOSF_PORT_DPIO;
210 }
211 
212 u32 vlv_dpio_read(struct drm_i915_private *i915, enum dpio_phy phy, int reg)
213 {
214 	u32 port = vlv_dpio_phy_iosf_port(i915, phy);
215 	u32 val = 0;
216 
217 	vlv_sideband_rw(i915, DPIO_DEVFN, port, SB_MRD_NP, reg, &val);
218 
219 	/*
220 	 * FIXME: There might be some registers where all 1's is a valid value,
221 	 * so ideally we should check the register offset instead...
222 	 */
223 	drm_WARN(&i915->drm, val == 0xffffffff,
224 		 "DPIO PHY%d read reg 0x%x == 0x%x\n",
225 		 phy, reg, val);
226 
227 	return val;
228 }
229 
230 void vlv_dpio_write(struct drm_i915_private *i915,
231 		    enum dpio_phy phy, int reg, u32 val)
232 {
233 	u32 port = vlv_dpio_phy_iosf_port(i915, phy);
234 
235 	vlv_sideband_rw(i915, DPIO_DEVFN, port, SB_MWR_NP, reg, &val);
236 }
237 
238 u32 vlv_flisdsi_read(struct drm_i915_private *i915, u32 reg)
239 {
240 	u32 val = 0;
241 
242 	vlv_sideband_rw(i915, DPIO_DEVFN, IOSF_PORT_FLISDSI, SB_CRRDDA_NP,
243 			reg, &val);
244 	return val;
245 }
246 
247 void vlv_flisdsi_write(struct drm_i915_private *i915, u32 reg, u32 val)
248 {
249 	vlv_sideband_rw(i915, DPIO_DEVFN, IOSF_PORT_FLISDSI, SB_CRWRDA_NP,
250 			reg, &val);
251 }
252