1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * IBM/AMCC PPC4xx SoC setup code
4 *
5 * Copyright 2008 DENX Software Engineering, Stefan Roese <sr@denx.de>
6 *
7 * L2 cache routines cloned from arch/ppc/syslib/ibm440gx_common.c which is:
8 * Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
9 * Copyright (c) 2003 - 2006 Zultys Technologies
10 */
11
12 #include <linux/stddef.h>
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/errno.h>
16 #include <linux/interrupt.h>
17 #include <linux/irq.h>
18 #include <linux/of.h>
19 #include <linux/of_irq.h>
20
21 #include <asm/dcr.h>
22 #include <asm/dcr-regs.h>
23 #include <asm/reg.h>
24 #include <asm/ppc4xx.h>
25
26 static u32 dcrbase_l2c;
27
28 /*
29 * L2-cache
30 */
31
32 /* Issue L2C diagnostic command */
33 static inline u32 l2c_diag(u32 addr)
34 {
35 mtdcr(dcrbase_l2c + DCRN_L2C0_ADDR, addr);
36 mtdcr(dcrbase_l2c + DCRN_L2C0_CMD, L2C_CMD_DIAG);
37 while (!(mfdcr(dcrbase_l2c + DCRN_L2C0_SR) & L2C_SR_CC))
38 ;
39
40 return mfdcr(dcrbase_l2c + DCRN_L2C0_DATA);
41 }
42
43 static irqreturn_t l2c_error_handler(int irq, void *dev)
44 {
45 u32 sr = mfdcr(dcrbase_l2c + DCRN_L2C0_SR);
46
47 if (sr & L2C_SR_CPE) {
48 /* Read cache trapped address */
49 u32 addr = l2c_diag(0x42000000);
50 printk(KERN_EMERG "L2C: Cache Parity Error, addr[16:26] = 0x%08x\n",
51 addr);
52 }
53 if (sr & L2C_SR_TPE) {
54 /* Read tag trapped address */
55 u32 addr = l2c_diag(0x82000000) >> 16;
56 printk(KERN_EMERG "L2C: Tag Parity Error, addr[16:26] = 0x%08x\n",
57 addr);
58 }
59
60 /* Clear parity errors */
61 if (sr & (L2C_SR_CPE | L2C_SR_TPE)){
62 mtdcr(dcrbase_l2c + DCRN_L2C0_ADDR, 0);
63 mtdcr(dcrbase_l2c + DCRN_L2C0_CMD, L2C_CMD_CCP | L2C_CMD_CTE);
64 } else {
65 printk(KERN_EMERG "L2C: LRU error\n");
66 }
67
68 return IRQ_HANDLED;
69 }
70
71 static int __init ppc4xx_l2c_probe(void)
72 {
73 struct device_node *np;
74 u32 r;
75 unsigned long flags;
76 int irq;
77 const u32 *dcrreg;
78 u32 dcrbase_isram;
79 int len;
80 const u32 *prop;
81 u32 l2_size;
82
83 np = of_find_compatible_node(NULL, NULL, "ibm,l2-cache");
84 if (!np)
85 return 0;
86
87 /* Get l2 cache size */
88 prop = of_get_property(np, "cache-size", NULL);
89 if (prop == NULL) {
90 printk(KERN_ERR "%pOF: Can't get cache-size!\n", np);
91 of_node_put(np);
92 return -ENODEV;
93 }
94 l2_size = prop[0];
95
96 /* Map DCRs */
97 dcrreg = of_get_property(np, "dcr-reg", &len);
98 if (!dcrreg || (len != 4 * sizeof(u32))) {
99 printk(KERN_ERR "%pOF: Can't get DCR register base !", np);
100 of_node_put(np);
101 return -ENODEV;
102 }
103 dcrbase_isram = dcrreg[0];
104 dcrbase_l2c = dcrreg[2];
105
106 /* Get and map irq number from device tree */
107 irq = irq_of_parse_and_map(np, 0);
108 if (!irq) {
109 printk(KERN_ERR "irq_of_parse_and_map failed\n");
110 of_node_put(np);
111 return -ENODEV;
112 }
113
114 /* Install error handler */
115 if (request_irq(irq, l2c_error_handler, 0, "L2C", NULL) < 0) {
116 printk(KERN_ERR "Cannot install L2C error handler"
117 ", cache is not enabled\n");
118 of_node_put(np);
119 return -ENODEV;
120 }
121
122 local_irq_save(flags);
123 asm volatile ("sync" ::: "memory");
124
125 /* Disable SRAM */
126 mtdcr(dcrbase_isram + DCRN_SRAM0_DPC,
127 mfdcr(dcrbase_isram + DCRN_SRAM0_DPC) & ~SRAM_DPC_ENABLE);
128 mtdcr(dcrbase_isram + DCRN_SRAM0_SB0CR,
129 mfdcr(dcrbase_isram + DCRN_SRAM0_SB0CR) & ~SRAM_SBCR_BU_MASK);
130 mtdcr(dcrbase_isram + DCRN_SRAM0_SB1CR,
131 mfdcr(dcrbase_isram + DCRN_SRAM0_SB1CR) & ~SRAM_SBCR_BU_MASK);
132 mtdcr(dcrbase_isram + DCRN_SRAM0_SB2CR,
133 mfdcr(dcrbase_isram + DCRN_SRAM0_SB2CR) & ~SRAM_SBCR_BU_MASK);
134 mtdcr(dcrbase_isram + DCRN_SRAM0_SB3CR,
135 mfdcr(dcrbase_isram + DCRN_SRAM0_SB3CR) & ~SRAM_SBCR_BU_MASK);
136
137 /* Enable L2_MODE without ICU/DCU */
138 r = mfdcr(dcrbase_l2c + DCRN_L2C0_CFG) &
139 ~(L2C_CFG_ICU | L2C_CFG_DCU | L2C_CFG_SS_MASK);
140 r |= L2C_CFG_L2M | L2C_CFG_SS_256;
141 mtdcr(dcrbase_l2c + DCRN_L2C0_CFG, r);
142
143 mtdcr(dcrbase_l2c + DCRN_L2C0_ADDR, 0);
144
145 /* Hardware Clear Command */
146 mtdcr(dcrbase_l2c + DCRN_L2C0_CMD, L2C_CMD_HCC);
147 while (!(mfdcr(dcrbase_l2c + DCRN_L2C0_SR) & L2C_SR_CC))
148 ;
149
150 /* Clear Cache Parity and Tag Errors */
151 mtdcr(dcrbase_l2c + DCRN_L2C0_CMD, L2C_CMD_CCP | L2C_CMD_CTE);
152
153 /* Enable 64G snoop region starting at 0 */
154 r = mfdcr(dcrbase_l2c + DCRN_L2C0_SNP0) &
155 ~(L2C_SNP_BA_MASK | L2C_SNP_SSR_MASK);
156 r |= L2C_SNP_SSR_32G | L2C_SNP_ESR;
157 mtdcr(dcrbase_l2c + DCRN_L2C0_SNP0, r);
158
159 r = mfdcr(dcrbase_l2c + DCRN_L2C0_SNP1) &
160 ~(L2C_SNP_BA_MASK | L2C_SNP_SSR_MASK);
161 r |= 0x80000000 | L2C_SNP_SSR_32G | L2C_SNP_ESR;
162 mtdcr(dcrbase_l2c + DCRN_L2C0_SNP1, r);
163
164 asm volatile ("sync" ::: "memory");
165
166 /* Enable ICU/DCU ports */
167 r = mfdcr(dcrbase_l2c + DCRN_L2C0_CFG);
168 r &= ~(L2C_CFG_DCW_MASK | L2C_CFG_PMUX_MASK | L2C_CFG_PMIM
169 | L2C_CFG_TPEI | L2C_CFG_CPEI | L2C_CFG_NAM | L2C_CFG_NBRM);
170 r |= L2C_CFG_ICU | L2C_CFG_DCU | L2C_CFG_TPC | L2C_CFG_CPC | L2C_CFG_FRAN
171 | L2C_CFG_CPIM | L2C_CFG_TPIM | L2C_CFG_LIM | L2C_CFG_SMCM;
172
173 /* Check for 460EX/GT special handling */
174 if (of_device_is_compatible(np, "ibm,l2-cache-460ex") ||
175 of_device_is_compatible(np, "ibm,l2-cache-460gt"))
176 r |= L2C_CFG_RDBW;
177
178 mtdcr(dcrbase_l2c + DCRN_L2C0_CFG, r);
179
180 asm volatile ("sync; isync" ::: "memory");
181 local_irq_restore(flags);
182
183 printk(KERN_INFO "%dk L2-cache enabled\n", l2_size >> 10);
184
185 of_node_put(np);
186 return 0;
187 }
188 arch_initcall(ppc4xx_l2c_probe);
189
190 /*
191 * Apply a system reset. Alternatively a board specific value may be
192 * provided via the "reset-type" property in the cpu node.
193 */
194 void ppc4xx_reset_system(char *cmd)
195 {
196 struct device_node *np;
197 u32 reset_type = DBCR0_RST_SYSTEM;
198 const u32 *prop;
199
200 np = of_get_cpu_node(0, NULL);
201 if (np) {
202 prop = of_get_property(np, "reset-type", NULL);
203
204 /*
205 * Check if property exists and if it is in range:
206 * 1 - PPC4xx core reset
207 * 2 - PPC4xx chip reset
208 * 3 - PPC4xx system reset (default)
209 */
210 if ((prop) && ((prop[0] >= 1) && (prop[0] <= 3)))
211 reset_type = prop[0] << 28;
212 }
213
214 mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | reset_type);
215
216 while (1)
217 ; /* Just in case the reset doesn't work */
218 }
219
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