| /* |
| * Useful bootup functions, which are more easily done in asm than C. |
| * |
| * NOTE: Be very very careful about the registers you use here. |
| * We don't follow any ABI calling convention among the |
| * assembler functions that call each other, especially early |
| * in the initialization. Please preserve at least r3 and r4 |
| * for these early functions, as they often contain information |
| * passed from boot roms into the C decompress function. |
| * |
| * Author: Tom Rini |
| * trini@mvista.com |
| * Derived from arch/ppc/boot/prep/head.S (Cort Dougan, many others). |
| * |
| * 2001-2004 (c) MontaVista, Software, Inc. This file is licensed under |
| * the terms of the GNU General Public License version 2. This program |
| * is licensed "as is" without any warranty of any kind, whether express |
| * or implied. |
| */ |
| |
| #include <asm/processor.h> |
| #include <asm/cache.h> |
| #include <asm/ppc_asm.h> |
| |
| |
| .text |
| |
| #ifdef CONFIG_6xx |
| .globl disable_6xx_mmu |
| disable_6xx_mmu: |
| /* Establish default MSR value, exception prefix 0xFFF. |
| * If necessary, this function must fix up the LR if we |
| * return to a different address space once the MMU is |
| * disabled. |
| */ |
| li r8,MSR_IP|MSR_FP |
| mtmsr r8 |
| isync |
| |
| /* Test for a 601 */ |
| mfpvr r10 |
| srwi r10,r10,16 |
| cmpwi 0,r10,1 /* 601 ? */ |
| beq .clearbats_601 |
| |
| /* Clear BATs */ |
| li r8,0 |
| mtspr SPRN_DBAT0U,r8 |
| mtspr SPRN_DBAT0L,r8 |
| mtspr SPRN_DBAT1U,r8 |
| mtspr SPRN_DBAT1L,r8 |
| mtspr SPRN_DBAT2U,r8 |
| mtspr SPRN_DBAT2L,r8 |
| mtspr SPRN_DBAT3U,r8 |
| mtspr SPRN_DBAT3L,r8 |
| .clearbats_601: |
| mtspr SPRN_IBAT0U,r8 |
| mtspr SPRN_IBAT0L,r8 |
| mtspr SPRN_IBAT1U,r8 |
| mtspr SPRN_IBAT1L,r8 |
| mtspr SPRN_IBAT2U,r8 |
| mtspr SPRN_IBAT2L,r8 |
| mtspr SPRN_IBAT3U,r8 |
| mtspr SPRN_IBAT3L,r8 |
| isync |
| sync |
| sync |
| |
| /* Set segment registers */ |
| li r8,16 /* load up segment register values */ |
| mtctr r8 /* for context 0 */ |
| lis r8,0x2000 /* Ku = 1, VSID = 0 */ |
| li r10,0 |
| 3: mtsrin r8,r10 |
| addi r8,r8,0x111 /* increment VSID */ |
| addis r10,r10,0x1000 /* address of next segment */ |
| bdnz 3b |
| blr |
| |
| .globl disable_6xx_l1cache |
| disable_6xx_l1cache: |
| /* Enable, invalidate and then disable the L1 icache/dcache. */ |
| li r8,0 |
| ori r8,r8,(HID0_ICE|HID0_DCE|HID0_ICFI|HID0_DCI) |
| mfspr r11,SPRN_HID0 |
| or r11,r11,r8 |
| andc r10,r11,r8 |
| isync |
| mtspr SPRN_HID0,r8 |
| sync |
| isync |
| mtspr SPRN_HID0,r10 |
| sync |
| isync |
| blr |
| #endif |
| |
| .globl _setup_L2CR |
| _setup_L2CR: |
| /* |
| * We should be skipping this section on CPUs where this results in an |
| * illegal instruction. If not, please send trini@kernel.crashing.org |
| * the PVR of your CPU. |
| */ |
| /* Invalidate/disable L2 cache */ |
| sync |
| isync |
| mfspr r8,SPRN_L2CR |
| rlwinm r8,r8,0,1,31 |
| oris r8,r8,L2CR_L2I@h |
| sync |
| isync |
| mtspr SPRN_L2CR,r8 |
| sync |
| isync |
| |
| /* Wait for the invalidation to complete */ |
| mfspr r8,SPRN_PVR |
| srwi r8,r8,16 |
| cmplwi cr0,r8,0x8000 /* 7450 */ |
| cmplwi cr1,r8,0x8001 /* 7455 */ |
| cmplwi cr2,r8,0x8002 /* 7457 */ |
| cror 4*cr0+eq,4*cr0+eq,4*cr1+eq /* Now test if any are true. */ |
| cror 4*cr0+eq,4*cr0+eq,4*cr2+eq |
| bne 2f |
| |
| 1: mfspr r8,SPRN_L2CR /* On 745x, poll L2I bit (bit 10) */ |
| rlwinm. r9,r8,0,10,10 |
| bne 1b |
| b 3f |
| |
| 2: mfspr r8,SPRN_L2CR /* On 75x & 74[01]0, poll L2IP bit (bit 31) */ |
| rlwinm. r9,r8,0,31,31 |
| bne 2b |
| |
| 3: rlwinm r8,r8,0,11,9 /* Turn off L2I bit */ |
| sync |
| isync |
| mtspr SPRN_L2CR,r8 |
| sync |
| isync |
| blr |
| |
| .globl _setup_L3CR |
| _setup_L3CR: |
| /* Invalidate/disable L3 cache */ |
| sync |
| isync |
| mfspr r8,SPRN_L3CR |
| rlwinm r8,r8,0,1,31 |
| ori r8,r8,L3CR_L3I@l |
| sync |
| isync |
| mtspr SPRN_L3CR,r8 |
| sync |
| isync |
| |
| /* Wait for the invalidation to complete */ |
| 1: mfspr r8,SPRN_L3CR |
| rlwinm. r9,r8,0,21,21 |
| bne 1b |
| |
| rlwinm r8,r8,0,22,20 /* Turn off L3I bit */ |
| sync |
| isync |
| mtspr SPRN_L3CR,r8 |
| sync |
| isync |
| blr |
| |
| |
| /* udelay (on non-601 processors) needs to know the period of the |
| * timebase in nanoseconds. This used to be hardcoded to be 60ns |
| * (period of 66MHz/4). Now a variable is used that is initialized to |
| * 60 for backward compatibility, but it can be overridden as necessary |
| * with code something like this: |
| * extern unsigned long timebase_period_ns; |
| * timebase_period_ns = 1000000000 / bd->bi_tbfreq; |
| */ |
| .data |
| .globl timebase_period_ns |
| timebase_period_ns: |
| .long 60 |
| |
| .text |
| /* |
| * Delay for a number of microseconds |
| */ |
| .globl udelay |
| udelay: |
| mfspr r4,SPRN_PVR |
| srwi r4,r4,16 |
| cmpwi 0,r4,1 /* 601 ? */ |
| bne .udelay_not_601 |
| 00: li r0,86 /* Instructions / microsecond? */ |
| mtctr r0 |
| 10: addi r0,r0,0 /* NOP */ |
| bdnz 10b |
| subic. r3,r3,1 |
| bne 00b |
| blr |
| |
| .udelay_not_601: |
| mulli r4,r3,1000 /* nanoseconds */ |
| /* Change r4 to be the number of ticks using: |
| * (nanoseconds + (timebase_period_ns - 1 )) / timebase_period_ns |
| * timebase_period_ns defaults to 60 (16.6MHz) */ |
| lis r5,timebase_period_ns@ha |
| lwz r5,timebase_period_ns@l(r5) |
| add r4,r4,r5 |
| addi r4,r4,-1 |
| divw r4,r4,r5 /* BUS ticks */ |
| 1: mftbu r5 |
| mftb r6 |
| mftbu r7 |
| cmpw 0,r5,r7 |
| bne 1b /* Get [synced] base time */ |
| addc r9,r6,r4 /* Compute end time */ |
| addze r8,r5 |
| 2: mftbu r5 |
| cmpw 0,r5,r8 |
| blt 2b |
| bgt 3f |
| mftb r6 |
| cmpw 0,r6,r9 |
| blt 2b |
| 3: blr |
| |
| .section ".relocate_code","xa" |
| /* |
| * Flush and enable instruction cache |
| * First, flush the data cache in case it was enabled and may be |
| * holding instructions for copy back. |
| */ |
| .globl flush_instruction_cache |
| flush_instruction_cache: |
| mflr r6 |
| bl flush_data_cache |
| |
| #ifdef CONFIG_8xx |
| lis r3, IDC_INVALL@h |
| mtspr SPRN_IC_CST, r3 |
| lis r3, IDC_ENABLE@h |
| mtspr SPRN_IC_CST, r3 |
| lis r3, IDC_DISABLE@h |
| mtspr SPRN_DC_CST, r3 |
| #elif CONFIG_4xx |
| lis r3,start@h # r9 = &_start |
| lis r4,_etext@ha |
| addi r4,r4,_etext@l # r8 = &_etext |
| 1: dcbf r0,r3 # Flush the data cache |
| icbi r0,r3 # Invalidate the instruction cache |
| addi r3,r3,0x10 # Increment by one cache line |
| cmplw cr0,r3,r4 # Are we at the end yet? |
| blt 1b # No, keep flushing and invalidating |
| #else |
| /* Enable, invalidate and then disable the L1 icache/dcache. */ |
| li r3,0 |
| ori r3,r3,(HID0_ICE|HID0_DCE|HID0_ICFI|HID0_DCI) |
| mfspr r4,SPRN_HID0 |
| or r5,r4,r3 |
| isync |
| mtspr SPRN_HID0,r5 |
| sync |
| isync |
| ori r5,r4,HID0_ICE /* Enable cache */ |
| mtspr SPRN_HID0,r5 |
| sync |
| isync |
| #endif |
| mtlr r6 |
| blr |
| |
| #define NUM_CACHE_LINES 128*8 |
| #define cache_flush_buffer 0x1000 |
| |
| /* |
| * Flush data cache |
| * Do this by just reading lots of stuff into the cache. |
| */ |
| .globl flush_data_cache |
| flush_data_cache: |
| lis r3,cache_flush_buffer@h |
| ori r3,r3,cache_flush_buffer@l |
| li r4,NUM_CACHE_LINES |
| mtctr r4 |
| 00: lwz r4,0(r3) |
| addi r3,r3,L1_CACHE_BYTES /* Next line, please */ |
| bdnz 00b |
| 10: blr |
| |
| .previous |
| |
