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Diffstat (limited to 'arch/mips/kernel/mips-cm.c')
-rw-r--r--arch/mips/kernel/mips-cm.c121
1 files changed, 121 insertions, 0 deletions
diff --git a/arch/mips/kernel/mips-cm.c b/arch/mips/kernel/mips-cm.c
new file mode 100644
index 000000000000..f76f7a08412d
--- /dev/null
+++ b/arch/mips/kernel/mips-cm.c
@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) 2013 Imagination Technologies
+ * Author: Paul Burton <paul.burton@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/errno.h>
+
+#include <asm/mips-cm.h>
+#include <asm/mipsregs.h>
+
+void __iomem *mips_cm_base;
+void __iomem *mips_cm_l2sync_base;
+
+phys_t __mips_cm_phys_base(void)
+{
+ u32 config3 = read_c0_config3();
+ u32 cmgcr;
+
+ /* Check the CMGCRBase register is implemented */
+ if (!(config3 & MIPS_CONF3_CMGCR))
+ return 0;
+
+ /* Read the address from CMGCRBase */
+ cmgcr = read_c0_cmgcrbase();
+ return (cmgcr & MIPS_CMGCRF_BASE) << (36 - 32);
+}
+
+phys_t mips_cm_phys_base(void)
+ __attribute__((weak, alias("__mips_cm_phys_base")));
+
+phys_t __mips_cm_l2sync_phys_base(void)
+{
+ u32 base_reg;
+
+ /*
+ * If the L2-only sync region is already enabled then leave it at it's
+ * current location.
+ */
+ base_reg = read_gcr_l2_only_sync_base();
+ if (base_reg & CM_GCR_L2_ONLY_SYNC_BASE_SYNCEN_MSK)
+ return base_reg & CM_GCR_L2_ONLY_SYNC_BASE_SYNCBASE_MSK;
+
+ /* Default to following the CM */
+ return mips_cm_phys_base() + MIPS_CM_GCR_SIZE;
+}
+
+phys_t mips_cm_l2sync_phys_base(void)
+ __attribute__((weak, alias("__mips_cm_l2sync_phys_base")));
+
+static void mips_cm_probe_l2sync(void)
+{
+ unsigned major_rev;
+ phys_t addr;
+
+ /* L2-only sync was introduced with CM major revision 6 */
+ major_rev = (read_gcr_rev() & CM_GCR_REV_MAJOR_MSK) >>
+ CM_GCR_REV_MAJOR_SHF;
+ if (major_rev < 6)
+ return;
+
+ /* Find a location for the L2 sync region */
+ addr = mips_cm_l2sync_phys_base();
+ BUG_ON((addr & CM_GCR_L2_ONLY_SYNC_BASE_SYNCBASE_MSK) != addr);
+ if (!addr)
+ return;
+
+ /* Set the region base address & enable it */
+ write_gcr_l2_only_sync_base(addr | CM_GCR_L2_ONLY_SYNC_BASE_SYNCEN_MSK);
+
+ /* Map the region */
+ mips_cm_l2sync_base = ioremap_nocache(addr, MIPS_CM_L2SYNC_SIZE);
+}
+
+int mips_cm_probe(void)
+{
+ phys_t addr;
+ u32 base_reg;
+
+ addr = mips_cm_phys_base();
+ BUG_ON((addr & CM_GCR_BASE_GCRBASE_MSK) != addr);
+ if (!addr)
+ return -ENODEV;
+
+ mips_cm_base = ioremap_nocache(addr, MIPS_CM_GCR_SIZE);
+ if (!mips_cm_base)
+ return -ENXIO;
+
+ /* sanity check that we're looking at a CM */
+ base_reg = read_gcr_base();
+ if ((base_reg & CM_GCR_BASE_GCRBASE_MSK) != addr) {
+ pr_err("GCRs appear to have been moved (expected them at 0x%08lx)!\n",
+ (unsigned long)addr);
+ mips_cm_base = NULL;
+ return -ENODEV;
+ }
+
+ /* set default target to memory */
+ base_reg &= ~CM_GCR_BASE_CMDEFTGT_MSK;
+ base_reg |= CM_GCR_BASE_CMDEFTGT_MEM;
+ write_gcr_base(base_reg);
+
+ /* disable CM regions */
+ write_gcr_reg0_base(CM_GCR_REGn_BASE_BASEADDR_MSK);
+ write_gcr_reg0_mask(CM_GCR_REGn_MASK_ADDRMASK_MSK);
+ write_gcr_reg1_base(CM_GCR_REGn_BASE_BASEADDR_MSK);
+ write_gcr_reg1_mask(CM_GCR_REGn_MASK_ADDRMASK_MSK);
+ write_gcr_reg2_base(CM_GCR_REGn_BASE_BASEADDR_MSK);
+ write_gcr_reg2_mask(CM_GCR_REGn_MASK_ADDRMASK_MSK);
+ write_gcr_reg3_base(CM_GCR_REGn_BASE_BASEADDR_MSK);
+ write_gcr_reg3_mask(CM_GCR_REGn_MASK_ADDRMASK_MSK);
+
+ /* probe for an L2-only sync region */
+ mips_cm_probe_l2sync();
+
+ return 0;
+}