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-rw-r--r--arch/ppc/boot/common/util.S293
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+/*
+ * arch/ppc/boot/common/util.S
+ *
+ * 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.
+ */
+_GLOBAL(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
+ cmplwi 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.
+ */
+_GLOBAL(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
+