1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2017 Andes Technology Corporation
4  * Rick Chen, Andes Technology Corporation <rick@andestech.com>
5  */
6 
7 /* CPU specific code */
8 #include <common.h>
9 #include <cpu_func.h>
10 #include <irq_func.h>
11 #include <asm/cache.h>
12 #include <asm/csr.h>
13 
14 #define CSR_MCACHE_CTL	0x7ca
15 #define CSR_MMISC_CTL	0x7d0
16 #define CSR_MARCHID		0xf12
17 
18 #define V5_MCACHE_CTL_IC_EN_OFFSET      0
19 #define V5_MCACHE_CTL_DC_EN_OFFSET      1
20 #define V5_MCACHE_CTL_DC_COHEN_OFFSET	19
21 #define V5_MCACHE_CTL_DC_COHSTA_OFFSET	20
22 
23 #define V5_MCACHE_CTL_IC_EN		BIT(V5_MCACHE_CTL_IC_EN_OFFSET)
24 #define V5_MCACHE_CTL_DC_EN				BIT(V5_MCACHE_CTL_DC_EN_OFFSET)
25 #define V5_MCACHE_CTL_DC_COHEN_EN       BIT(V5_MCACHE_CTL_DC_COHEN_OFFSET)
26 #define V5_MCACHE_CTL_DC_COHSTA_EN      BIT(V5_MCACHE_CTL_DC_COHSTA_OFFSET)
27 
28 
29 /*
30  * cleanup_before_linux() is called just before we call linux
31  * it prepares the processor for linux
32  *
33  * we disable interrupt and caches.
34  */
cleanup_before_linux(void)35 int cleanup_before_linux(void)
36 {
37 	disable_interrupts();
38 
39 	/* turn off I/D-cache */
40 	cache_flush();
41 	icache_disable();
42 	dcache_disable();
43 
44 	return 0;
45 }
46 
harts_early_init(void)47 void harts_early_init(void)
48 {
49 	if (CONFIG_IS_ENABLED(RISCV_MMODE)) {
50 		unsigned long long mcache_ctl_val = csr_read(CSR_MCACHE_CTL);
51 
52 		if (!(mcache_ctl_val & V5_MCACHE_CTL_DC_COHEN_EN))
53 			mcache_ctl_val |= V5_MCACHE_CTL_DC_COHEN_EN;
54 		if (!(mcache_ctl_val & V5_MCACHE_CTL_IC_EN))
55 			mcache_ctl_val |= V5_MCACHE_CTL_IC_EN;
56 		if (!(mcache_ctl_val & V5_MCACHE_CTL_DC_EN))
57 			mcache_ctl_val |= V5_MCACHE_CTL_DC_EN;
58 		csr_write(CSR_MCACHE_CTL, mcache_ctl_val);
59 
60 		/*
61 		 * Check DC_COHEN_EN, if cannot write to mcache_ctl,
62 		 * we assume this bitmap not support L2 CM
63 		 */
64 		mcache_ctl_val = csr_read(CSR_MCACHE_CTL);
65 		if ((mcache_ctl_val & V5_MCACHE_CTL_DC_COHEN_EN)) {
66 		/* Wait for DC_COHSTA bit be set */
67 			while (!(mcache_ctl_val & V5_MCACHE_CTL_DC_COHSTA_EN))
68 				mcache_ctl_val = csr_read(CSR_MCACHE_CTL);
69 		}
70 	}
71 }
72