2 * arch/arm/mm/cache-tauros2.c - Tauros2 L2 cache controller support
4 * Copyright (C) 2008 Marvell Semiconductor
6 * This file is licensed under the terms of the GNU General Public
7 * License version 2. This program is licensed "as is" without any
8 * warranty of any kind, whether express or implied.
11 * - PJ1 CPU Core Datasheet,
12 * Document ID MV-S104837-01, Rev 0.7, January 24 2008.
13 * - PJ4 CPU Core Datasheet,
14 * Document ID MV-S105190-00, Rev 0.7, March 14 2008.
17 #include <linux/init.h>
19 #include <linux/of_address.h>
20 #include <asm/cacheflush.h>
22 #include <asm/cputype.h>
23 #include <asm/hardware/cache-tauros2.h>
25 /* CP15 PJ4 Control configuration register */
26 #define CCR_L2C_PREFETCH_DISABLE BIT(24)
27 #define CCR_L2C_ECC_ENABLE BIT(23)
28 #define CCR_L2C_WAY7_4_DISABLE BIT(21)
29 #define CCR_L2C_BURST8_ENABLE BIT(20)
32 * When Tauros2 is used on a CPU that supports the v7 hierarchical
33 * cache operations, the cache handling code in proc-v7.S takes care
34 * of everything, including handling DMA coherency.
36 * So, we only need to register outer cache operations here if we're
37 * being used on a pre-v7 CPU, and we only need to build support for
38 * outer cache operations into the kernel image if the kernel has been
39 * configured to support a pre-v7 CPU.
41 #ifdef CONFIG_CPU_32v5
43 * Low-level cache maintenance operations.
45 static inline void tauros2_clean_pa(unsigned long addr
)
47 __asm__("mcr p15, 1, %0, c7, c11, 3" : : "r" (addr
));
50 static inline void tauros2_clean_inv_pa(unsigned long addr
)
52 __asm__("mcr p15, 1, %0, c7, c15, 3" : : "r" (addr
));
55 static inline void tauros2_inv_pa(unsigned long addr
)
57 __asm__("mcr p15, 1, %0, c7, c7, 3" : : "r" (addr
));
64 * Note that the end addresses passed to Linux primitives are
67 #define CACHE_LINE_SIZE 32
69 static void tauros2_inv_range(unsigned long start
, unsigned long end
)
72 * Clean and invalidate partial first cache line.
74 if (start
& (CACHE_LINE_SIZE
- 1)) {
75 tauros2_clean_inv_pa(start
& ~(CACHE_LINE_SIZE
- 1));
76 start
= (start
| (CACHE_LINE_SIZE
- 1)) + 1;
80 * Clean and invalidate partial last cache line.
82 if (end
& (CACHE_LINE_SIZE
- 1)) {
83 tauros2_clean_inv_pa(end
& ~(CACHE_LINE_SIZE
- 1));
84 end
&= ~(CACHE_LINE_SIZE
- 1);
88 * Invalidate all full cache lines between 'start' and 'end'.
91 tauros2_inv_pa(start
);
92 start
+= CACHE_LINE_SIZE
;
98 static void tauros2_clean_range(unsigned long start
, unsigned long end
)
100 start
&= ~(CACHE_LINE_SIZE
- 1);
101 while (start
< end
) {
102 tauros2_clean_pa(start
);
103 start
+= CACHE_LINE_SIZE
;
109 static void tauros2_flush_range(unsigned long start
, unsigned long end
)
111 start
&= ~(CACHE_LINE_SIZE
- 1);
112 while (start
< end
) {
113 tauros2_clean_inv_pa(start
);
114 start
+= CACHE_LINE_SIZE
;
120 static void tauros2_disable(void)
122 __asm__
__volatile__ (
123 "mcr p15, 1, %0, c7, c11, 0 @L2 Cache Clean All\n\t"
124 "mrc p15, 0, %0, c1, c0, 0\n\t"
125 "bic %0, %0, #(1 << 26)\n\t"
126 "mcr p15, 0, %0, c1, c0, 0 @Disable L2 Cache\n\t"
130 static void tauros2_resume(void)
132 __asm__
__volatile__ (
133 "mcr p15, 1, %0, c7, c7, 0 @L2 Cache Invalidate All\n\t"
134 "mrc p15, 0, %0, c1, c0, 0\n\t"
135 "orr %0, %0, #(1 << 26)\n\t"
136 "mcr p15, 0, %0, c1, c0, 0 @Enable L2 Cache\n\t"
141 static inline u32 __init
read_extra_features(void)
145 __asm__("mrc p15, 1, %0, c15, c1, 0" : "=r" (u
));
150 static inline void __init
write_extra_features(u32 u
)
152 __asm__("mcr p15, 1, %0, c15, c1, 0" : : "r" (u
));
155 static inline int __init
cpuid_scheme(void)
157 return !!((processor_id
& 0x000f0000) == 0x000f0000);
160 static inline u32 __init
read_mmfr3(void)
164 __asm__("mrc p15, 0, %0, c0, c1, 7\n" : "=r" (mmfr3
));
169 static inline u32 __init
read_actlr(void)
173 __asm__("mrc p15, 0, %0, c1, c0, 1\n" : "=r" (actlr
));
178 static inline void __init
write_actlr(u32 actlr
)
180 __asm__("mcr p15, 0, %0, c1, c0, 1\n" : : "r" (actlr
));
183 static void enable_extra_feature(unsigned int features
)
187 u
= read_extra_features();
189 if (features
& CACHE_TAUROS2_PREFETCH_ON
)
190 u
&= ~CCR_L2C_PREFETCH_DISABLE
;
192 u
|= CCR_L2C_PREFETCH_DISABLE
;
193 pr_info("Tauros2: %s L2 prefetch.\n",
194 (features
& CACHE_TAUROS2_PREFETCH_ON
)
195 ? "Enabling" : "Disabling");
197 if (features
& CACHE_TAUROS2_LINEFILL_BURST8
)
198 u
|= CCR_L2C_BURST8_ENABLE
;
200 u
&= ~CCR_L2C_BURST8_ENABLE
;
201 pr_info("Tauros2: %s burst8 line fill.\n",
202 (features
& CACHE_TAUROS2_LINEFILL_BURST8
)
203 ? "Enabling" : "Disabling");
205 write_extra_features(u
);
208 static void __init
tauros2_internal_init(unsigned int features
)
212 enable_extra_feature(features
);
214 #ifdef CONFIG_CPU_32v5
215 if ((processor_id
& 0xff0f0000) == 0x56050000) {
219 * v5 CPUs with Tauros2 have the L2 cache enable bit
220 * located in the CPU Extra Features register.
222 feat
= read_extra_features();
223 if (!(feat
& 0x00400000)) {
224 pr_info("Tauros2: Enabling L2 cache.\n");
225 write_extra_features(feat
| 0x00400000);
229 outer_cache
.inv_range
= tauros2_inv_range
;
230 outer_cache
.clean_range
= tauros2_clean_range
;
231 outer_cache
.flush_range
= tauros2_flush_range
;
232 outer_cache
.disable
= tauros2_disable
;
233 outer_cache
.resume
= tauros2_resume
;
237 #ifdef CONFIG_CPU_32v7
239 * Check whether this CPU has support for the v7 hierarchical
240 * cache ops. (PJ4 is in its v7 personality mode if the MMFR3
241 * register indicates support for the v7 hierarchical cache
244 * (Although strictly speaking there may exist CPUs that
245 * implement the v7 cache ops but are only ARMv6 CPUs (due to
246 * not complying with all of the other ARMv7 requirements),
247 * there are no real-life examples of Tauros2 being used on
248 * such CPUs as of yet.)
250 if (cpuid_scheme() && (read_mmfr3() & 0xf) == 1) {
254 * When Tauros2 is used in an ARMv7 system, the L2
255 * enable bit is located in the Auxiliary System Control
256 * Register (which is the only register allowed by the
257 * ARMv7 spec to contain fine-grained cache control bits).
259 actlr
= read_actlr();
260 if (!(actlr
& 0x00000002)) {
261 pr_info("Tauros2: Enabling L2 cache.\n");
262 write_actlr(actlr
| 0x00000002);
270 pr_crit("Tauros2: Unable to detect CPU mode.\n");
274 pr_info("Tauros2: L2 cache support initialised "
275 "in %s mode.\n", mode
);
279 static const struct of_device_id tauros2_ids
[] __initconst
= {
280 { .compatible
= "marvell,tauros2-cache"},
285 void __init
tauros2_init(unsigned int features
)
288 struct device_node
*node
;
292 node
= of_find_matching_node(NULL
, tauros2_ids
);
294 pr_info("Not found marvell,tauros2-cache, disable it\n");
296 ret
= of_property_read_u32(node
, "marvell,tauros2-cache-features", &f
);
298 pr_info("Not found marvell,tauros-cache-features property, "
299 "disable extra features\n");
305 tauros2_internal_init(features
);