summaryrefslogtreecommitdiff
path: root/cpu/ppc4xx/tlb.c
diff options
context:
space:
mode:
Diffstat (limited to 'cpu/ppc4xx/tlb.c')
-rw-r--r--cpu/ppc4xx/tlb.c184
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 */