diff options
Diffstat (limited to 'arch/mips/kernel/mips-cm.c')
| -rw-r--r-- | arch/mips/kernel/mips-cm.c | 121 |
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 000000000..85bbe9b96 --- /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_addr_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_addr_t mips_cm_phys_base(void) + __attribute__((weak, alias("__mips_cm_phys_base"))); + +phys_addr_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_addr_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_addr_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_addr_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; +} |