ARCv2: mm: Implement cache region flush operations

These are more efficient than the per-line ops

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

2 files changed, 74 insertions, 0 deletions

diff --git a/arch/arc/include/asm/cache.h b/arch/arc/include/asm/cache.h
index 5008021fba98..16e457706129 100644
--- a/arch/arc/include/asm/cache.h
+++ b/arch/arc/include/asm/cache.h
@@ -62,6 +62,8 @@ extern unsigned long perip_base, perip_end;
 #define ARC_REG_IC_BCR          0x77    /* Build Config reg */
 #define ARC_REG_IC_IVIC         0x10
 #define ARC_REG_IC_CTRL         0x11
+#define ARC_REG_IC_IVIR         0x16
+#define ARC_REG_IC_ENDR         0x17
 #define ARC_REG_IC_IVIL         0x19
 #define ARC_REG_IC_PTAG         0x1E
 #define ARC_REG_IC_PTAG_HI      0x1F
@@ -76,6 +78,8 @@ extern unsigned long perip_base, perip_end;
 #define ARC_REG_DC_IVDL         0x4A
 #define ARC_REG_DC_FLSH         0x4B
 #define ARC_REG_DC_FLDL         0x4C
+#define ARC_REG_DC_STARTR       0x4D
+#define ARC_REG_DC_ENDR         0x4E
 #define ARC_REG_DC_PTAG         0x5C
 #define ARC_REG_DC_PTAG_HI      0x5F
 
@@ -83,6 +87,8 @@ extern unsigned long perip_base, perip_end;
 #define DC_CTRL_DIS             0x001
 #define DC_CTRL_INV_MODE_FLUSH  0x040
 #define DC_CTRL_FLUSH_STATUS    0x100
+#define DC_CTRL_RGN_OP_INV      0x200
+#define DC_CTRL_RGN_OP_MSK      0xE00
 
 /*System-level cache (L2 cache) related Auxiliary registers */
 #define ARC_REG_SLC_CFG         0x901
diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index 18132eb56150..8401fcb75d19 100644
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -21,6 +21,10 @@
 #include <asm/cachectl.h>
 #include <asm/setup.h>
 
+#ifdef CONFIG_ISA_ARCV2
+#define USE_RGN_FLSH    1
+#endif
+
 static int l2_line_sz;
 static int ioc_exists;
 int slc_enable = 1, ioc_enable = 1;
@@ -332,6 +336,8 @@ void __cache_line_loop_v3(phys_addr_t paddr, unsigned long vaddr,
         }
 }
 
+#ifndef USE_RGN_FLSH
+
 /*
  * In HS38x (MMU v4), I-cache is VIPT (can alias), D-cache is PIPT
  * Here's how cache ops are implemented
@@ -394,6 +400,68 @@ void __cache_line_loop_v4(phys_addr_t paddr, unsigned long vaddr,
         }
 }
 
+#else
+
+/*
+ * optimized flush operation which takes a region as opposed to iterating per line
+ */
+static inline
+void __cache_line_loop_v4(phys_addr_t paddr, unsigned long vaddr,
+                          unsigned long sz, const int op, const int full_page)
+{
+        const unsigned int ctl = ARC_REG_DC_CTRL;
+        unsigned int s, e, val;
+
+        /* Only for Non aliasing I-cache in HS38 */
+        if (op == OP_INV_IC) {
+                s = ARC_REG_IC_IVIR;
+                e = ARC_REG_IC_ENDR;
+        } else {
+                s = ARC_REG_DC_STARTR;
+                e = ARC_REG_DC_ENDR;
+        }
+
+        if (!full_page) {
+                /* for any leading gap between @paddr and start of cache line */
+                sz += paddr & ~CACHE_LINE_MASK;
+                paddr &= CACHE_LINE_MASK;
+
+                /*
+                 *  account for any trailing gap to end of cache line
+                 *  this is equivalent to DIV_ROUND_UP() in line ops above
+                 */
+                sz += L1_CACHE_BYTES - 1;
+        }
+
+        if (is_pae40_enabled()) {
+                /* TBD: check if crossing 4TB boundary */
+                if (op == OP_INV_IC)
+                        write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32);
+                else
+                        write_aux_reg(ARC_REG_DC_PTAG_HI, (u64)paddr >> 32);
+        }
+
+        /*
+         * Flush / Invalidate is provided by DC_CTRL.RNG_OP 0 or 1
+         * Flush-n-invalidate additionally uses setting DC_CTRL.IM = 1
+         * just as for line ops which is handled in __before_dc_op()
+         */
+        val = read_aux_reg(ctl) & ~DC_CTRL_RGN_OP_MSK;
+
+        if (op & OP_INV)
+                val |= DC_CTRL_RGN_OP_INV;
+
+        write_aux_reg(ctl, val);
+
+        /* ENDR needs to be set ahead of START */
+        write_aux_reg(e, paddr + sz);   /* ENDR is exclusive */
+        write_aux_reg(s, paddr);
+
+        /* caller waits on DC_CTRL.FS */
+}
+
+#endif
+
 #if (CONFIG_ARC_MMU_VER < 3)
 #define __cache_line_loop       __cache_line_loop_v2
 #elif (CONFIG_ARC_MMU_VER == 3)