ARCv2: SLC: Allow boot time disable

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index 25e7077d4c049b523caa5cca0bcc8ea202851135..7c424e3f980de300f590bae41b0f6a57fca9392b 100644 (file)
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -23,6 +23,7 @@
 
 static int l2_line_sz;
 int ioc_exists;
+volatile int slc_enable = 1;
 
 void (*_cache_line_loop_ic_fn)(unsigned long paddr, unsigned long vaddr,
                               unsigned long sz, const int cacheop);
@@ -36,6 +37,7 @@ char *arc_cache_mumbojumbo(int c, char *buf, int len)
        int n = 0;
        struct cpuinfo_arc_cache *p;
 
+#define IS_USED_RUN(v)         ((v) ? "" : "(disabled) ")
 #define PR_CACHE(p, cfg, str)                                          \
        if (!(p)->ver)                                                  \
                n += scnprintf(buf + n, len - n, str"\t\t: N/A\n");     \
@@ -53,7 +55,8 @@ char *arc_cache_mumbojumbo(int c, char *buf, int len)
        p = &cpuinfo_arc700[c].slc;
        if (p->ver)
                n += scnprintf(buf + n, len - n,
-                       "SLC\t\t: %uK, %uB Line\n", p->sz_k, p->line_len);
+                              "SLC\t\t: %uK, %uB Line%s\n",
+                              p->sz_k, p->line_len, IS_USED_RUN(slc_enable));
 
        if (ioc_exists)
                n += scnprintf(buf + n, len - n, "IOC\t\t: exists\n");
@@ -908,6 +911,20 @@ void arc_cache_init(void)
                }
        }
 
+       if (is_isa_arcv2() && l2_line_sz && !slc_enable) {
+
+               /* IM set : flush before invalidate */
+               write_aux_reg(ARC_REG_SLC_CTRL,
+                       read_aux_reg(ARC_REG_SLC_CTRL) | SLC_CTRL_IM);
+
+               write_aux_reg(ARC_REG_SLC_INVALIDATE, 1);
+
+               /* Important to wait for flush to complete */
+               while (read_aux_reg(ARC_REG_SLC_CTRL) & SLC_CTRL_BUSY);
+               write_aux_reg(ARC_REG_SLC_CTRL,
+                       read_aux_reg(ARC_REG_SLC_CTRL) | SLC_CTRL_DISABLE);
+       }
+
        if (is_isa_arcv2() && ioc_exists) {
                /* IO coherency base - 0x8z */
                write_aux_reg(ARC_REG_IO_COH_AP0_BASE, 0x80000);
@@ -921,7 +938,7 @@ void arc_cache_init(void)
                __dma_cache_wback_inv = __dma_cache_wback_inv_ioc;
                __dma_cache_inv = __dma_cache_inv_ioc;
                __dma_cache_wback = __dma_cache_wback_ioc;
-       } else if (is_isa_arcv2() && l2_line_sz) {
+       } else if (is_isa_arcv2() && l2_line_sz && slc_enable) {
                __dma_cache_wback_inv = __dma_cache_wback_inv_slc;
                __dma_cache_inv = __dma_cache_inv_slc;
                __dma_cache_wback = __dma_cache_wback_slc;