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