diff options
Diffstat (limited to 'cpu/ppc4xx/tlb.c')
| -rw-r--r-- | cpu/ppc4xx/tlb.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/cpu/ppc4xx/tlb.c b/cpu/ppc4xx/tlb.c new file mode 100644 index 0000000..e26e6d4 --- /dev/null +++ b/cpu/ppc4xx/tlb.c @@ -0,0 +1,184 @@ +/* + * (C) Copyright 2007 + * Stefan Roese, DENX Software Engineering, sr@denx.de. + * + * See file CREDITS for list of people who contributed to this + * project. + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> + +#if defined(CONFIG_440) + +#include <ppc4xx.h> +#include <ppc440.h> +#include <asm/io.h> +#include <asm/mmu.h> + +typedef struct region { + unsigned long base; + unsigned long size; + unsigned long tlb_word2_i_value; +} region_t; + +static int add_tlb_entry(unsigned long base_addr, + unsigned long tlb_word0_size_value, + unsigned long tlb_word2_i_value) +{ + int i; + unsigned long tlb_word0_value; + unsigned long tlb_word1_value; + unsigned long tlb_word2_value; + + /* First, find the index of a TLB entry not being used */ + for (i=0; i<PPC4XX_TLB_SIZE; i++) { + tlb_word0_value = mftlb1(i); + if ((tlb_word0_value & TLB_WORD0_V_MASK) == TLB_WORD0_V_DISABLE) + break; + } + if (i >= PPC4XX_TLB_SIZE) + return -1; + + /* Second, create the TLB entry */ + tlb_word0_value = TLB_WORD0_EPN_ENCODE(base_addr) | TLB_WORD0_V_ENABLE | + TLB_WORD0_TS_0 | tlb_word0_size_value; + tlb_word1_value = TLB_WORD1_RPN_ENCODE(base_addr) | TLB_WORD1_ERPN_ENCODE(0); + tlb_word2_value = TLB_WORD2_U0_DISABLE | TLB_WORD2_U1_DISABLE | + TLB_WORD2_U2_DISABLE | TLB_WORD2_U3_DISABLE | + TLB_WORD2_W_DISABLE | tlb_word2_i_value | + TLB_WORD2_M_DISABLE | TLB_WORD2_G_DISABLE | + TLB_WORD2_E_DISABLE | TLB_WORD2_UX_ENABLE | + TLB_WORD2_UW_ENABLE | TLB_WORD2_UR_ENABLE | + TLB_WORD2_SX_ENABLE | TLB_WORD2_SW_ENABLE | + TLB_WORD2_SR_ENABLE; + + /* Wait for all memory accesses to complete */ + sync(); + + /* Third, add the TLB entries */ + mttlb1(i, tlb_word0_value); + mttlb2(i, tlb_word1_value); + mttlb3(i, tlb_word2_value); + + /* Execute an ISYNC instruction so that the new TLB entry takes effect */ + asm("isync"); + + return 0; +} + +static void program_tlb_addr(unsigned long base_addr, unsigned long mem_size, + unsigned long tlb_word2_i_value) +{ + int rc; + int tlb_i; + + tlb_i = tlb_word2_i_value; + while (mem_size != 0) { + rc = 0; + /* Add the TLB entries in to map the region. */ + if (((base_addr & TLB_256MB_ALIGN_MASK) == base_addr) && + (mem_size >= TLB_256MB_SIZE)) { + /* Add a 256MB TLB entry */ + if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_256MB, tlb_i)) == 0) { + mem_size -= TLB_256MB_SIZE; + base_addr += TLB_256MB_SIZE; + } + } else if (((base_addr & TLB_16MB_ALIGN_MASK) == base_addr) && + (mem_size >= TLB_16MB_SIZE)) { + /* Add a 16MB TLB entry */ + if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_16MB, tlb_i)) == 0) { + mem_size -= TLB_16MB_SIZE; + base_addr += TLB_16MB_SIZE; + } + } else if (((base_addr & TLB_1MB_ALIGN_MASK) == base_addr) && + (mem_size >= TLB_1MB_SIZE)) { + /* Add a 1MB TLB entry */ + if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_1MB, tlb_i)) == 0) { + mem_size -= TLB_1MB_SIZE; + base_addr += TLB_1MB_SIZE; + } + } else if (((base_addr & TLB_256KB_ALIGN_MASK) == base_addr) && + (mem_size >= TLB_256KB_SIZE)) { + /* Add a 256KB TLB entry */ + if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_256KB, tlb_i)) == 0) { + mem_size -= TLB_256KB_SIZE; + base_addr += TLB_256KB_SIZE; + } + } else if (((base_addr & TLB_64KB_ALIGN_MASK) == base_addr) && + (mem_size >= TLB_64KB_SIZE)) { + /* Add a 64KB TLB entry */ + if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_64KB, tlb_i)) == 0) { + mem_size -= TLB_64KB_SIZE; + base_addr += TLB_64KB_SIZE; + } + } else if (((base_addr & TLB_16KB_ALIGN_MASK) == base_addr) && + (mem_size >= TLB_16KB_SIZE)) { + /* Add a 16KB TLB entry */ + if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_16KB, tlb_i)) == 0) { + mem_size -= TLB_16KB_SIZE; + base_addr += TLB_16KB_SIZE; + } + } else if (((base_addr & TLB_4KB_ALIGN_MASK) == base_addr) && + (mem_size >= TLB_4KB_SIZE)) { + /* Add a 4KB TLB entry */ + if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_4KB, tlb_i)) == 0) { + mem_size -= TLB_4KB_SIZE; + base_addr += TLB_4KB_SIZE; + } + } else if (((base_addr & TLB_1KB_ALIGN_MASK) == base_addr) && + (mem_size >= TLB_1KB_SIZE)) { + /* Add a 1KB TLB entry */ + if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_1KB, tlb_i)) == 0) { + mem_size -= TLB_1KB_SIZE; + base_addr += TLB_1KB_SIZE; + } + } else { + printf("ERROR: no TLB size exists for the base address 0x%0X.\n", + base_addr); + } + + if (rc != 0) + printf("ERROR: no TLB entries available for the base addr 0x%0X.\n", + base_addr); + } + + return; +} + +/* + * Program one (or multiple) TLB entries for one memory region + * + * Common usage for boards with SDRAM DIMM modules to dynamically + * configure the TLB's for the SDRAM + */ +void program_tlb(u32 start, u32 size) +{ + region_t region_array; + + region_array.base = start; + region_array.size = size; + region_array.tlb_word2_i_value = TLB_WORD2_I_ENABLE; /* disable cache (for now) */ + + /* Call the routine to add in the tlb entries for the memory regions */ + program_tlb_addr(region_array.base, region_array.size, + region_array.tlb_word2_i_value); + + return; +} + +#endif /* CONFIG_440 */ |