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authorDave Kleikamp <shaggy@linux.vnet.ibm.com>2010-03-05 10:43:12 +0000
committerJosh Boyer <jwboyer@linux.vnet.ibm.com>2010-05-05 09:11:10 -0400
commite7f75ad01d590243904c2d95ab47e6b2e9ef6dad (patch)
tree454cf065417973e9c2fcd75542351c2534b9a4b9 /arch/powerpc/kernel/head_44x.S
parent795033c344d88dc6aa5106d0cc358656f29bd722 (diff)
powerpc/47x: Base ppc476 support
This patch adds the base support for the 476 processor. The code was primarily written by Ben Herrenschmidt and Torez Smith, but I've been maintaining it for a while. The goal is to have a single binary that will run on 44x and 47x, but we still have some details to work out. The biggest is that the L1 cache line size differs on the two platforms, but it's currently a compile-time option. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Torez Smith <lnxtorez@linux.vnet.ibm.com> Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Diffstat (limited to 'arch/powerpc/kernel/head_44x.S')
-rw-r--r--arch/powerpc/kernel/head_44x.S502
1 files changed, 486 insertions, 16 deletions
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index 39be049a785..1acd175428c 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -37,6 +37,7 @@
#include <asm/thread_info.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
+#include <asm/synch.h>
#include "head_booke.h"
@@ -191,7 +192,7 @@ interrupt_base:
#endif
/* Data TLB Error Interrupt */
- START_EXCEPTION(DataTLBError)
+ START_EXCEPTION(DataTLBError44x)
mtspr SPRN_SPRG_WSCRATCH0, r10 /* Save some working registers */
mtspr SPRN_SPRG_WSCRATCH1, r11
mtspr SPRN_SPRG_WSCRATCH2, r12
@@ -282,7 +283,7 @@ tlb_44x_patch_hwater_D:
mfspr r10,SPRN_DEAR
/* Jump to common tlb load */
- b finish_tlb_load
+ b finish_tlb_load_44x
2:
/* The bailout. Restore registers to pre-exception conditions
@@ -302,7 +303,7 @@ tlb_44x_patch_hwater_D:
* information from different registers and bailout
* to a different point.
*/
- START_EXCEPTION(InstructionTLBError)
+ START_EXCEPTION(InstructionTLBError44x)
mtspr SPRN_SPRG_WSCRATCH0, r10 /* Save some working registers */
mtspr SPRN_SPRG_WSCRATCH1, r11
mtspr SPRN_SPRG_WSCRATCH2, r12
@@ -378,7 +379,7 @@ tlb_44x_patch_hwater_I:
mfspr r10,SPRN_SRR0
/* Jump to common TLB load point */
- b finish_tlb_load
+ b finish_tlb_load_44x
2:
/* The bailout. Restore registers to pre-exception conditions
@@ -392,15 +393,7 @@ tlb_44x_patch_hwater_I:
mfspr r10, SPRN_SPRG_RSCRATCH0
b InstructionStorage
- /* Debug Interrupt */
- DEBUG_CRIT_EXCEPTION
-
-/*
- * Local functions
- */
-
/*
-
* Both the instruction and data TLB miss get to this
* point to load the TLB.
* r10 - EA of fault
@@ -410,7 +403,7 @@ tlb_44x_patch_hwater_I:
* MMUCR - loaded with proper value when we get here
* Upon exit, we reload everything and RFI.
*/
-finish_tlb_load:
+finish_tlb_load_44x:
/* Combine RPN & ERPN an write WS 0 */
rlwimi r11,r12,0,0,31-PAGE_SHIFT
tlbwe r11,r13,PPC44x_TLB_XLAT
@@ -443,6 +436,227 @@ finish_tlb_load:
mfspr r10, SPRN_SPRG_RSCRATCH0
rfi /* Force context change */
+/* TLB error interrupts for 476
+ */
+#ifdef CONFIG_PPC_47x
+ START_EXCEPTION(DataTLBError47x)
+ mtspr SPRN_SPRG_WSCRATCH0,r10 /* Save some working registers */
+ mtspr SPRN_SPRG_WSCRATCH1,r11
+ mtspr SPRN_SPRG_WSCRATCH2,r12
+ mtspr SPRN_SPRG_WSCRATCH3,r13
+ mfcr r11
+ mtspr SPRN_SPRG_WSCRATCH4,r11
+ mfspr r10,SPRN_DEAR /* Get faulting address */
+
+ /* If we are faulting a kernel address, we have to use the
+ * kernel page tables.
+ */
+ lis r11,PAGE_OFFSET@h
+ cmplw cr0,r10,r11
+ blt+ 3f
+ lis r11,swapper_pg_dir@h
+ ori r11,r11, swapper_pg_dir@l
+ li r12,0 /* MMUCR = 0 */
+ b 4f
+
+ /* Get the PGD for the current thread and setup MMUCR */
+3: mfspr r11,SPRN_SPRG3
+ lwz r11,PGDIR(r11)
+ mfspr r12,SPRN_PID /* Get PID */
+4: mtspr SPRN_MMUCR,r12 /* Set MMUCR */
+
+ /* Mask of required permission bits. Note that while we
+ * do copy ESR:ST to _PAGE_RW position as trying to write
+ * to an RO page is pretty common, we don't do it with
+ * _PAGE_DIRTY. We could do it, but it's a fairly rare
+ * event so I'd rather take the overhead when it happens
+ * rather than adding an instruction here. We should measure
+ * whether the whole thing is worth it in the first place
+ * as we could avoid loading SPRN_ESR completely in the first
+ * place...
+ *
+ * TODO: Is it worth doing that mfspr & rlwimi in the first
+ * place or can we save a couple of instructions here ?
+ */
+ mfspr r12,SPRN_ESR
+ li r13,_PAGE_PRESENT|_PAGE_ACCESSED
+ rlwimi r13,r12,10,30,30
+
+ /* Load the PTE */
+ /* Compute pgdir/pmd offset */
+ rlwinm r12,r10,PPC44x_PGD_OFF_SHIFT,PPC44x_PGD_OFF_MASK_BIT,29
+ lwzx r11,r12,r11 /* Get pgd/pmd entry */
+
+ /* Word 0 is EPN,V,TS,DSIZ */
+ li r12,PPC47x_TLB0_VALID | PPC47x_TLBE_SIZE
+ rlwimi r10,r12,0,32-PAGE_SHIFT,31 /* Insert valid and page size*/
+ li r12,0
+ tlbwe r10,r12,0
+
+ /* XXX can we do better ? Need to make sure tlbwe has established
+ * latch V bit in MMUCR0 before the PTE is loaded further down */
+#ifdef CONFIG_SMP
+ isync
+#endif
+
+ rlwinm. r12,r11,0,0,20 /* Extract pt base address */
+ /* Compute pte address */
+ rlwimi r12,r10,PPC44x_PTE_ADD_SHIFT,PPC44x_PTE_ADD_MASK_BIT,28
+ beq 2f /* Bail if no table */
+ lwz r11,0(r12) /* Get high word of pte entry */
+
+ /* XXX can we do better ? maybe insert a known 0 bit from r11 into the
+ * bottom of r12 to create a data dependency... We can also use r10
+ * as destination nowadays
+ */
+#ifdef CONFIG_SMP
+ lwsync
+#endif
+ lwz r12,4(r12) /* Get low word of pte entry */
+
+ andc. r13,r13,r12 /* Check permission */
+
+ /* Jump to common tlb load */
+ beq finish_tlb_load_47x
+
+2: /* The bailout. Restore registers to pre-exception conditions
+ * and call the heavyweights to help us out.
+ */
+ mfspr r11,SPRN_SPRG_RSCRATCH4
+ mtcr r11
+ mfspr r13,SPRN_SPRG_RSCRATCH3
+ mfspr r12,SPRN_SPRG_RSCRATCH2
+ mfspr r11,SPRN_SPRG_RSCRATCH1
+ mfspr r10,SPRN_SPRG_RSCRATCH0
+ b DataStorage
+
+ /* Instruction TLB Error Interrupt */
+ /*
+ * Nearly the same as above, except we get our
+ * information from different registers and bailout
+ * to a different point.
+ */
+ START_EXCEPTION(InstructionTLBError47x)
+ mtspr SPRN_SPRG_WSCRATCH0,r10 /* Save some working registers */
+ mtspr SPRN_SPRG_WSCRATCH1,r11
+ mtspr SPRN_SPRG_WSCRATCH2,r12
+ mtspr SPRN_SPRG_WSCRATCH3,r13
+ mfcr r11
+ mtspr SPRN_SPRG_WSCRATCH4,r11
+ mfspr r10,SPRN_SRR0 /* Get faulting address */
+
+ /* If we are faulting a kernel address, we have to use the
+ * kernel page tables.
+ */
+ lis r11,PAGE_OFFSET@h
+ cmplw cr0,r10,r11
+ blt+ 3f
+ lis r11,swapper_pg_dir@h
+ ori r11,r11, swapper_pg_dir@l
+ li r12,0 /* MMUCR = 0 */
+ b 4f
+
+ /* Get the PGD for the current thread and setup MMUCR */
+3: mfspr r11,SPRN_SPRG_THREAD
+ lwz r11,PGDIR(r11)
+ mfspr r12,SPRN_PID /* Get PID */
+4: mtspr SPRN_MMUCR,r12 /* Set MMUCR */
+
+ /* Make up the required permissions */
+ li r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
+
+ /* Load PTE */
+ /* Compute pgdir/pmd offset */
+ rlwinm r12,r10,PPC44x_PGD_OFF_SHIFT,PPC44x_PGD_OFF_MASK_BIT,29
+ lwzx r11,r12,r11 /* Get pgd/pmd entry */
+
+ /* Word 0 is EPN,V,TS,DSIZ */
+ li r12,PPC47x_TLB0_VALID | PPC47x_TLBE_SIZE
+ rlwimi r10,r12,0,32-PAGE_SHIFT,31 /* Insert valid and page size*/
+ li r12,0
+ tlbwe r10,r12,0
+
+ /* XXX can we do better ? Need to make sure tlbwe has established
+ * latch V bit in MMUCR0 before the PTE is loaded further down */
+#ifdef CONFIG_SMP
+ isync
+#endif
+
+ rlwinm. r12,r11,0,0,20 /* Extract pt base address */
+ /* Compute pte address */
+ rlwimi r12,r10,PPC44x_PTE_ADD_SHIFT,PPC44x_PTE_ADD_MASK_BIT,28
+ beq 2f /* Bail if no table */
+
+ lwz r11,0(r12) /* Get high word of pte entry */
+ /* XXX can we do better ? maybe insert a known 0 bit from r11 into the
+ * bottom of r12 to create a data dependency... We can also use r10
+ * as destination nowadays
+ */
+#ifdef CONFIG_SMP
+ lwsync
+#endif
+ lwz r12,4(r12) /* Get low word of pte entry */
+
+ andc. r13,r13,r12 /* Check permission */
+
+ /* Jump to common TLB load point */
+ beq finish_tlb_load_47x
+
+2: /* The bailout. Restore registers to pre-exception conditions
+ * and call the heavyweights to help us out.
+ */
+ mfspr r11, SPRN_SPRG_RSCRATCH4
+ mtcr r11
+ mfspr r13, SPRN_SPRG_RSCRATCH3
+ mfspr r12, SPRN_SPRG_RSCRATCH2
+ mfspr r11, SPRN_SPRG_RSCRATCH1
+ mfspr r10, SPRN_SPRG_RSCRATCH0
+ b InstructionStorage
+
+/*
+ * Both the instruction and data TLB miss get to this
+ * point to load the TLB.
+ * r10 - free to use
+ * r11 - PTE high word value
+ * r12 - PTE low word value
+ * r13 - free to use
+ * MMUCR - loaded with proper value when we get here
+ * Upon exit, we reload everything and RFI.
+ */
+finish_tlb_load_47x:
+ /* Combine RPN & ERPN an write WS 1 */
+ rlwimi r11,r12,0,0,31-PAGE_SHIFT
+ tlbwe r11,r13,1
+
+ /* And make up word 2 */
+ li r10,0xf85 /* Mask to apply from PTE */
+ rlwimi r10,r12,29,30,30 /* DIRTY -> SW position */
+ and r11,r12,r10 /* Mask PTE bits to keep */
+ andi. r10,r12,_PAGE_USER /* User page ? */
+ beq 1f /* nope, leave U bits empty */
+ rlwimi r11,r11,3,26,28 /* yes, copy S bits to U */
+1: tlbwe r11,r13,2
+
+ /* Done...restore registers and get out of here.
+ */
+ mfspr r11, SPRN_SPRG_RSCRATCH4
+ mtcr r11
+ mfspr r13, SPRN_SPRG_RSCRATCH3
+ mfspr r12, SPRN_SPRG_RSCRATCH2
+ mfspr r11, SPRN_SPRG_RSCRATCH1
+ mfspr r10, SPRN_SPRG_RSCRATCH0
+ rfi
+
+#endif /* CONFIG_PPC_47x */
+
+ /* Debug Interrupt */
+ /*
+ * This statement needs to exist at the end of the IVPR
+ * definition just in case you end up taking a debug
+ * exception within another exception.
+ */
+ DEBUG_CRIT_EXCEPTION
+
/*
* Global functions
*/
@@ -491,9 +705,18 @@ _GLOBAL(set_context)
/*
* Init CPU state. This is called at boot time or for secondary CPUs
* to setup initial TLB entries, setup IVORs, etc...
+ *
*/
_GLOBAL(init_cpu_state)
mflr r22
+#ifdef CONFIG_PPC_47x
+ /* We use the PVR to differenciate 44x cores from 476 */
+ mfspr r3,SPRN_PVR
+ srwi r3,r3,16
+ cmplwi cr0,r3,PVR_476@h
+ beq head_start_47x
+#endif /* CONFIG_PPC_47x */
+
/*
* In case the firmware didn't do it, we apply some workarounds
* that are good for all 440 core variants here
@@ -506,7 +729,7 @@ _GLOBAL(init_cpu_state)
sync
/*
- * Set up the initial MMU state
+ * Set up the initial MMU state for 44x
*
* We are still executing code at the virtual address
* mappings set by the firmware for the base of RAM.
@@ -646,16 +869,257 @@ skpinv: addi r4,r4,1 /* Increment */
SET_IVOR(10, Decrementer);
SET_IVOR(11, FixedIntervalTimer);
SET_IVOR(12, WatchdogTimer);
- SET_IVOR(13, DataTLBError);
- SET_IVOR(14, InstructionTLBError);
+ SET_IVOR(13, DataTLBError44x);
+ SET_IVOR(14, InstructionTLBError44x);
SET_IVOR(15, DebugCrit);
+ b head_start_common
+
+
+#ifdef CONFIG_PPC_47x
+
+#ifdef CONFIG_SMP
+
+/* Entry point for secondary 47x processors */
+_GLOBAL(start_secondary_47x)
+ mr r24,r3 /* CPU number */
+
+ bl init_cpu_state
+
+ /* Now we need to bolt the rest of kernel memory which
+ * is done in C code. We must be careful because our task
+ * struct or our stack can (and will probably) be out
+ * of reach of the initial 256M TLB entry, so we use a
+ * small temporary stack in .bss for that. This works
+ * because only one CPU at a time can be in this code
+ */
+ lis r1,temp_boot_stack@h
+ ori r1,r1,temp_boot_stack@l
+ addi r1,r1,1024-STACK_FRAME_OVERHEAD
+ li r0,0
+ stw r0,0(r1)
+ bl mmu_init_secondary
+
+ /* Now we can get our task struct and real stack pointer */
+
+ /* Get current_thread_info and current */
+ lis r1,secondary_ti@ha
+ lwz r1,secondary_ti@l(r1)
+ lwz r2,TI_TASK(r1)
+
+ /* Current stack pointer */
+ addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
+ li r0,0
+ stw r0,0(r1)
+
+ /* Kernel stack for exception entry in SPRG3 */
+ addi r4,r2,THREAD /* init task's THREAD */
+ mtspr SPRN_SPRG3,r4
+
+ b start_secondary
+
+#endif /* CONFIG_SMP */
+
+/*
+ * Set up the initial MMU state for 44x
+ *
+ * We are still executing code at the virtual address
+ * mappings set by the firmware for the base of RAM.
+ */
+
+head_start_47x:
+ /* Load our current PID->MMUCR TID and MSR IS->MMUCR STS */
+ mfspr r3,SPRN_PID /* Get PID */
+ mfmsr r4 /* Get MSR */
+ andi. r4,r4,MSR_IS@l /* TS=1? */
+ beq 1f /* If not, leave STS=0 */
+ oris r3,r3,PPC47x_MMUCR_STS@h /* Set STS=1 */
+1: mtspr SPRN_MMUCR,r3 /* Put MMUCR */
+ sync
+
+ /* Find the entry we are running from */
+ bl 1f
+1: mflr r23
+ tlbsx r23,0,r23
+ tlbre r24,r23,0
+ tlbre r25,r23,1
+ tlbre r26,r23,2
+
+/*
+ * Cleanup time
+ */
+
+ /* Initialize MMUCR */
+ li r5,0
+ mtspr SPRN_MMUCR,r5
+ sync
+
+clear_all_utlb_entries:
+
+ #; Set initial values.
+
+ addis r3,0,0x8000
+ addi r4,0,0
+ addi r5,0,0
+ b clear_utlb_entry
+
+ #; Align the loop to speed things up.
+
+ .align 6
+
+clear_utlb_entry:
+
+ tlbwe r4,r3,0
+ tlbwe r5,r3,1
+ tlbwe r5,r3,2
+ addis r3,r3,0x2000
+ cmpwi r3,0
+ bne clear_utlb_entry
+ addis r3,0,0x8000
+ addis r4,r4,0x100
+ cmpwi r4,0
+ bne clear_utlb_entry
+
+ #; Restore original entry.
+
+ oris r23,r23,0x8000 /* specify the way */
+ tlbwe r24,r23,0
+ tlbwe r25,r23,1
+ tlbwe r26,r23,2
+
+/*
+ * Configure and load pinned entry into TLB for the kernel core
+ */
+
+ lis r3,PAGE_OFFSET@h
+ ori r3,r3,PAGE_OFFSET@l
+
+ /* Kernel is at the base of RAM */
+ li r4, 0 /* Load the kernel physical address */
+
+ /* Load the kernel PID = 0 */
+ li r0,0
+ mtspr SPRN_PID,r0
+ sync
+
+ /* Word 0 */
+ clrrwi r3,r3,12 /* Mask off the effective page number */
+ ori r3,r3,PPC47x_TLB0_VALID | PPC47x_TLB0_256M
+
+ /* Word 1 */
+ clrrwi r4,r4,12 /* Mask off the real page number */
+ /* ERPN is 0 for first 4GB page */
+ /* Word 2 */
+ li r5,0
+ ori r5,r5,PPC47x_TLB2_S_RWX
+#ifdef CONFIG_SMP
+ ori r5,r5,PPC47x_TLB2_M
+#endif
+
+ /* We write to way 0 and bolted 0 */
+ lis r0,0x8800
+ tlbwe r3,r0,0
+ tlbwe r4,r0,1
+ tlbwe r5,r0,2
+
+/*
+ * Configure SSPCR, ISPCR and USPCR for now to search everything, we can fix
+ * them up later
+ */
+ LOAD_REG_IMMEDIATE(r3, 0x9abcdef0)
+ mtspr SPRN_SSPCR,r3
+ mtspr SPRN_USPCR,r3
+ LOAD_REG_IMMEDIATE(r3, 0x12345670)
+ mtspr SPRN_ISPCR,r3
+
+ /* Force context change */
+ mfmsr r0
+ mtspr SPRN_SRR1, r0
+ lis r0,3f@h
+ ori r0,r0,3f@l
+ mtspr SPRN_SRR0,r0
+ sync
+ rfi
+
+ /* Invalidate original entry we used */
+3:
+ rlwinm r24,r24,0,21,19 /* clear the "valid" bit */
+ tlbwe r24,r23,0
+ addi r24,0,0
+ tlbwe r24,r23,1
+ tlbwe r24,r23,2
+ isync /* Clear out the shadow TLB entries */
+
+#ifdef CONFIG_PPC_EARLY_DEBUG_44x
+ /* Add UART mapping for early debug. */
+
+ /* Word 0 */
+ lis r3,PPC44x_EARLY_DEBUG_VIRTADDR@h
+ ori r3,r3,PPC47x_TLB0_VALID | PPC47x_TLB0_TS | PPC47x_TLB0_1M
+
+ /* Word 1 */
+ lis r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSLOW@h
+ ori r4,r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSHIGH
+
+ /* Word 2 */
+ li r5,(PPC47x_TLB2_S_RW | PPC47x_TLB2_IMG)
+
+ /* Bolted in way 0, bolt slot 5, we -hope- we don't hit the same
+ * congruence class as the kernel, we need to make sure of it at
+ * some point
+ */
+ lis r0,0x8d00
+ tlbwe r3,r0,0
+ tlbwe r4,r0,1
+ tlbwe r5,r0,2
+
+ /* Force context change */
+ isync
+#endif /* CONFIG_PPC_EARLY_DEBUG_44x */
+
+ /* Establish the interrupt vector offsets */
+ SET_IVOR(0, CriticalInput);
+ SET_IVOR(1, MachineCheckA);
+ SET_IVOR(2, DataStorage);
+ SET_IVOR(3, InstructionStorage);
+ SET_IVOR(4, ExternalInput);
+ SET_IVOR(5, Alignment);
+ SET_IVOR(6, Program);
+ SET_IVOR(7, FloatingPointUnavailable);
+ SET_IVOR(8, SystemCall);
+ SET_IVOR(9, AuxillaryProcessorUnavailable);
+ SET_IVOR(10, Decrementer);
+ SET_IVOR(11, FixedIntervalTimer);
+ SET_IVOR(12, WatchdogTimer);
+ SET_IVOR(13, DataTLBError47x);
+ SET_IVOR(14, InstructionTLBError47x);
+ SET_IVOR(15, DebugCrit);
+
+ /* We configure icbi to invalidate 128 bytes at a time since the
+ * current 32-bit kernel code isn't too happy with icache != dcache
+ * block size
+ */
+ mfspr r3,SPRN_CCR0
+ oris r3,r3,0x0020
+ mtspr SPRN_CCR0,r3
+ isync
+
+#endif /* CONFIG_PPC_47x */
+
+/*
+ * Here we are back to code that is common between 44x and 47x
+ *
+ * We proceed to further kernel initialization and return to the
+ * main kernel entry
+ */
+head_start_common:
/* Establish the interrupt vector base */
lis r4,interrupt_base@h /* IVPR only uses the high 16-bits */
mtspr SPRN_IVPR,r4
addis r22,r22,KERNELBASE@h
mtlr r22
+ isync
blr
/*
@@ -683,3 +1147,9 @@ swapper_pg_dir:
*/
abatron_pteptrs:
.space 8
+
+#ifdef CONFIG_SMP
+ .align 12
+temp_boot_stack:
+ .space 1024
+#endif /* CONFIG_SMP */