/* * mmuAsm.S * * $Id$ * * Copyright (C) 1999 Eric Valette (valette@crf.canon.fr) * * This file contains the low-level support for various MMU * features. * * The license and distribution terms for this file may be * found in found in the file LICENSE in this distribution or at * http://www.OARcorp.com/rtems/license.html. * */ #include #include #include #include "asm.h" .globl asm_setdbat1 .type asm_setdbat1,@function asm_setdbat1: mtspr DBAT1U, r3 mtspr DBAT1L, r4 SYNC blr .globl asm_setdbat2 .type asm_setdbat2,@function asm_setdbat2: mtspr DBAT2U, r3 mtspr DBAT2L, r4 SYNC blr .globl asm_setdbat3 .type asm_setdbat3,@function asm_setdbat3: mtspr DBAT3U, r3 mtspr DBAT3L, r4 SYNC blr .globl L1_caches_enables .type L1_caches_enables, @function L1_caches_enables: /* * Enable caches and 604-specific features if necessary. */ mfspr r9,PVR rlwinm r9,r9,16,16,31 cmpi 0,r9,1 beq 4f /* not needed for 601 */ mfspr r11,HID0 andi. r0,r11,HID0_DCE ori r11,r11,HID0_ICE|HID0_DCE ori r8,r11,HID0_ICFI bne 3f /* don't invalidate the D-cache */ ori r8,r8,HID0_DCI /* unless it wasn't enabled */ 3: sync mtspr HID0,r8 /* enable and invalidate caches */ sync mtspr HID0,r11 /* enable caches */ sync isync cmpi 0,r9,4 /* check for 604 */ cmpi 1,r9,9 /* or 604e */ cmpi 2,r9,10 /* or mach5 */ cror 2,2,6 cror 2,2,10 bne 4f ori r11,r11,HID0_SIED|HID0_BHTE /* for 604[e], enable */ bne 2,5f ori r11,r11,HID0_BTCD 5: mtspr HID0,r11 /* superscalar exec & br history tbl */ 4: blr .globl get_L2CR .type get_L2CR, @function get_L2CR: /* Make sure this is a 750 chip */ mfspr r3,PVR rlwinm r3,r3,16,16,31 cmplwi r3,0x0008 li r3,0 bnelr /* Return the L2CR contents */ mfspr r3,L2CR blr .globl set_L2CR .type set_L2CR, @function set_L2CR: /* Usage: * When setting the L2CR register, you must do a few special things. * If you are enabling the cache, you must perform a global invalidate. * If you are disabling the cache, you must flush the cache contents first. * This routine takes care of doing these things. When first * enabling the cache, make sure you pass in the L2CR you want, as well as * passing in the global invalidate bit set. A global invalidate will * only be performed if the L2I bit is set in applyThis. When enabling * the cache, you should also set the L2E bit in applyThis. If you * want to modify the L2CR contents after the cache has been enabled, * the recommended procedure is to first call __setL2CR(0) to disable * the cache and then call it again with the new values for L2CR. Examples: * * _setL2CR(0) - disables the cache * _setL2CR(0xb9A14000) - enables my G3 MCP750 card: * - L2E set to turn on the cache * - L2SIZ set to 1MB * - L2CLK set to %2 * - L2RAM set to pipelined syncronous late-write * - L2I set to perform a global invalidation * - L2OH set to 1 nS * * A similar call should work for your card. You need to know the correct * setting for your card and then place them in the fields I have outlined * above. Other fields support optional features, such as L2DO which caches * only data, or L2TS which causes cache pushes from the L1 cache to go to *the L2 cache instead of to main memory. */ /* Make sure this is a 750 chip */ mfspr r4,PVR rlwinm r4,r4,16,16,31 cmplwi r4,0x0008 beq thisIs750 li r3,-1 blr thisIs750: /* Get the current enable bit of the L2CR into r4 */ mfspr r4,L2CR rlwinm r4,r4,0,0,0 /* See if we want to perform a global inval this time. */ rlwinm r6,r3,0,10,10 /* r6 contains the new invalidate bit */ rlwinm. r5,r3,0,0,0 /* r5 contains the new enable bit */ rlwinm r3,r3,0,11,9 /* Turn off the invalidate bit */ rlwinm r3,r3,0,1,31 /* Turn off the enable bit */ or r3,r3,r4 /* Keep the enable bit the same as it was for now. */ bne dontDisableCache /* Only disable the cache if L2CRApply has the enable bit off */ disableCache: /* Disable the cache. First, we turn off data relocation. */ mfmsr r7 rlwinm r4,r7,0,28,26 /* Turn off DR bit */ rlwinm r4,r4,0,17,15 /* Turn off EE bit - an external exception while we are flushing the cache is fatal (comment this line and see!) */ sync mtmsr r4 sync /* Now, read the first 2MB of memory to put new data in the cache. (Actually we only need the size of the L2 cache plus the size of the L1 cache, but 2MB will cover everything just to be safe). */ lis r4,0x0001 mtctr r4 li r4,0 loadLoop: lwzx r0,r0,r4 addi r4,r4,0x0020 /* Go to start of next cache line */ bdnz loadLoop /* Now, flush the first 2MB of memory */ lis r4,0x0001 mtctr r4 li r4,0 sync flushLoop: dcbf r0,r4 addi r4,r4,0x0020 /* Go to start of next cache line */ bdnz flushLoop /* Turn off the L2CR enable bit. */ rlwinm r3,r3,0,1,31 /* Reenable data relocation. */ sync mtmsr r7 sync dontDisableCache: /* Set up the L2CR configuration bits */ sync mtspr L2CR,r3 sync cmplwi r6,0 beq noInval /* Perform a global invalidation */ oris r3,r3,0x0020 sync mtspr 1017,r3 sync invalCompleteLoop: /* Wait for the invalidation to complete */ mfspr r3,1017 rlwinm. r4,r3,0,31,31 bne invalCompleteLoop rlwinm r3,r3,0,11,9; /* Turn off the L2I bit */ sync mtspr L2CR,r3 sync noInval: /* See if we need to enable the cache */ cmplwi r5,0 beqlr enableCache: /* Enable the cache */ oris r3,r3,0x8000 mtspr L2CR,r3 sync blr