1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 1997, 2001 Ralf Baechle (ralf@gnu.org), 4 * derived from r4xx0.c by David S. Miller (davem@davemloft.net). 5 */ 6 #include <linux/init.h> 7 #include <linux/kernel.h> 8 #include <linux/sched.h> 9 #include <linux/mm.h> 10 11 #include <asm/mipsregs.h> 12 #include <asm/bcache.h> 13 #include <asm/cacheops.h> 14 #include <asm/page.h> 15 #include <asm/pgtable.h> 16 #include <asm/mmu_context.h> 17 #include <asm/r4kcache.h> 18 19 /* Secondary cache size in bytes, if present. */ 20 static unsigned long scache_size; 21 22 #define SC_LINE 32 23 #define SC_PAGE (128*SC_LINE) 24 25 static inline void blast_r5000_scache(void) 26 { 27 unsigned long start = INDEX_BASE; 28 unsigned long end = start + scache_size; 29 30 while(start < end) { 31 cache_op(R5K_Page_Invalidate_S, start); 32 start += SC_PAGE; 33 } 34 } 35 36 static void r5k_dma_cache_inv_sc(unsigned long addr, unsigned long size) 37 { 38 unsigned long end, a; 39 40 /* Catch bad driver code */ 41 BUG_ON(size == 0); 42 43 if (size >= scache_size) { 44 blast_r5000_scache(); 45 return; 46 } 47 48 /* On the R5000 secondary cache we cannot 49 * invalidate less than a page at a time. 50 * The secondary cache is physically indexed, write-through. 51 */ 52 a = addr & ~(SC_PAGE - 1); 53 end = (addr + size - 1) & ~(SC_PAGE - 1); 54 while (a <= end) { 55 cache_op(R5K_Page_Invalidate_S, a); 56 a += SC_PAGE; 57 } 58 } 59 60 static void r5k_sc_enable(void) 61 { 62 unsigned long flags; 63 64 local_irq_save(flags); 65 set_c0_config(R5K_CONF_SE); 66 blast_r5000_scache(); 67 local_irq_restore(flags); 68 } 69 70 static void r5k_sc_disable(void) 71 { 72 unsigned long flags; 73 74 local_irq_save(flags); 75 blast_r5000_scache(); 76 clear_c0_config(R5K_CONF_SE); 77 local_irq_restore(flags); 78 } 79 80 static inline int __init r5k_sc_probe(void) 81 { 82 unsigned long config = read_c0_config(); 83 84 if (config & CONF_SC) 85 return 0; 86 87 scache_size = (512 * 1024) << ((config & R5K_CONF_SS) >> 20); 88 89 printk("R5000 SCACHE size %ldkB, linesize 32 bytes.\n", 90 scache_size >> 10); 91 92 return 1; 93 } 94 95 static struct bcache_ops r5k_sc_ops = { 96 .bc_enable = r5k_sc_enable, 97 .bc_disable = r5k_sc_disable, 98 .bc_wback_inv = r5k_dma_cache_inv_sc, 99 .bc_inv = r5k_dma_cache_inv_sc 100 }; 101 102 void r5k_sc_init(void) 103 { 104 if (r5k_sc_probe()) { 105 r5k_sc_enable(); 106 bcops = &r5k_sc_ops; 107 } 108 } 109