[U-Boot] [PATCH 1/4] ARC: read pae_exist bit from MMU BCR

[Eugeniy Paltsev]

ARC_AUX_SLC_RGN_START1 and ARC_AUX_SLC_RGN_END1 register exist
only if PAE exists in current HW. So we had to check pae_exist bit
before using them.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev at synopsys.com>
---
 arch/arc/include/asm/arcregs.h |  3 +++
 arch/arc/lib/cache.c           | 28 ++++++++++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/arch/arc/include/asm/arcregs.h b/arch/arc/include/asm/arcregs.h
index ba1f7ba..53e83c7 100644
--- a/arch/arc/include/asm/arcregs.h
+++ b/arch/arc/include/asm/arcregs.h
@@ -65,6 +65,9 @@
 #define ARC_AUX_SLC_FLDL	0x912
 #define ARC_BCR_CLUSTER		0xcf
 
+/* MMU Management regs */
+#define ARC_AUX_MMU_BCR		0x06f
+
 /* IO coherency related auxiliary registers */
 #define ARC_AUX_IO_COH_ENABLE	0x500
 #define ARC_AUX_IO_COH_PARTIAL	0x501
diff --git a/arch/arc/lib/cache.c b/arch/arc/lib/cache.c
index 1073e15..0a41dc4 100644
--- a/arch/arc/lib/cache.c
+++ b/arch/arc/lib/cache.c
@@ -41,6 +41,32 @@ bool icache_exists __section(".data") = false;
 int slc_line_sz __section(".data");
 bool slc_exists __section(".data") = false;
 bool ioc_exists __section(".data") = false;
+bool pae_exists __section(".data") = false;
+
+void read_decode_mmu_bcr(void)
+{
+	/* TODO: should we compare mmu version from BCR and from CONFIG? */
+#if (CONFIG_ARC_MMU_VER >= 4)
+	u32 tmp;
+
+	tmp = read_aux_reg(ARC_AUX_MMU_BCR);
+
+	struct bcr_mmu_4 {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+	unsigned int ver:8, sasid:1, sz1:4, sz0:4, res:2, pae:1,
+		     n_ways:2, n_entry:2, n_super:2, u_itlb:3, u_dtlb:3;
+#else
+	/*           DTLB      ITLB      JES        JE         JA      */
+	unsigned int u_dtlb:3, u_itlb:3, n_super:2, n_entry:2, n_ways:2,
+		     pae:1, res:2, sz0:4, sz1:4, sasid:1, ver:8;
+#endif /* CONFIG_CPU_BIG_ENDIAN */
+	} *mmu4;
+
+	mmu4 = (struct bcr_mmu_4 *)&tmp;
+
+	pae_exists = !!mmu4->pae;
+#endif /* (CONFIG_ARC_MMU_VER >= 4) */
+}
 
 static unsigned int __before_slc_op(const int op)
 {
@@ -244,6 +270,8 @@ void cache_init(void)
 		write_aux_reg(ARC_AUX_IO_COH_ENABLE, 1);
 
 	}
+
+	read_decode_mmu_bcr();
 #endif
 }
 
-- 
2.9.3