/* As with the other PowerPC ports, it is expected that when code * execution begins here, the following registers contain valid, yet * optional, information: * * r3 - Board info structure pointer (DRAM, frequency, MAC address, etc.) * r4 - Starting address of the init RAM disk * r5 - Ending address of the init RAM disk * r6 - Start of kernel command line string (e.g. "mem=128") * r7 - End of kernel command line string *
*/
__HEAD
_GLOBAL(_stext);
_GLOBAL(_start); /* * Reserve a word at a fixed location to store the address * of abatron_pteptrs
*/
nop
/* Translate device tree address to physical, save in r30/r31 */
bl get_phys_addr
mr r30,r3
mr r31,r4
li r25,0 /* phys kernel start (low) */
li r24,0 /* CPU number */
li r23,0 /* phys kernel start (high) */
#ifdef CONFIG_RELOCATABLE
LOAD_REG_ADDR_PIC(r3, _stext) /* Get our current runtime base */
/* Translate _stext address to physical, save in r23/r25 */
bl get_phys_addr
mr r23,r3
mr r25,r4
/* Check if this is the second relocation. */
cmpwi r19,1
bne 1f
/* * For the second relocation, we already get the real memstart_addr * from device tree. So we will map PAGE_OFFSET to memstart_addr, * then the virtual address of start kernel should be: * PAGE_OFFSET + (kernstart_addr - memstart_addr) * Since the offset between kernstart_addr and memstart_addr should * never be beyond 1G, so we can just use the lower 32bit of them * for the calculation.
*/
lis r3,PAGE_OFFSET@h
1: /* * We have the runtime (virtual) address of our base. * We calculate our shift of offset from a 64M page. * We could map the 64M page we belong to at PAGE_OFFSET and * get going from there.
*/
lis r4,KERNELBASE@h
ori r4,r4,KERNELBASE@l
rlwinm r6,r25,0,0x3ffffff /* r6 = PHYS_START % 64M */
rlwinm r5,r4,0,0x3ffffff /* r5 = KERNELBASE % 64M */
subf r3,r5,r6 /* r3 = r6 - r5 */
add r3,r4,r3 /* Required Virtual Address */
2: bl relocate
/* * For the second relocation, we already set the right tlb entries * for the kernel space, so skip the code in 85xx_entry_mapping.S
*/
cmpwi r19,1
beq set_ivor
#endif
/* We try to not make any assumptions about how the boot loader * setup or used the TLBs. We invalidate all mappings from the * boot loader and load a single entry in TLB1[0] to map the * first 64M of kernel memory. Any boot info passed from the * bootloader needs to live in this first 64M. * * Requirement on bootloader: * - The page we're executing in needs to reside in TLB1 and * have IPROT=1. If not an invalidate broadcast could * evict the entry we're currently executing in. * * r3 = Index of TLB1 were executing in * r4 = Current MSR[IS] * r5 = Index of TLB1 temp mapping * * Later in mapin_ram we will correctly map lowmem, and resize TLB1[0] * if needed
*/
/* Establish the interrupt vector base */
lis r4,interrupt_base@h /* IVPR only uses the high 16-bits */
mtspr SPRN_IVPR,r4
/* Setup the defaults for TLB entries */
li r2,(MAS4_TSIZED(BOOK3E_PAGESZ_4K))@l
mtspr SPRN_MAS4, r2
#if !defined(CONFIG_BDI_SWITCH) /* * The Abatron BDI JTAG debugger does not tolerate others * mucking with the debug registers.
*/
lis r2,DBCR0_IDM@h
mtspr SPRN_DBCR0,r2
isync /* clear any residual debug events */
li r2,-1
mtspr SPRN_DBSR,r2
#endif
#ifdef CONFIG_SMP /* Check to see if we're the second processor, and jump * to the secondary_start code if so
*/
LOAD_REG_ADDR_PIC(r24, boot_cpuid)
lwz r24, 0(r24)
cmpwi r24, -1
mfspr r24,SPRN_PIR
bne __secondary_start
#endif
/* * This is where the main kernel code starts.
*/
/* ptr to current */
lis r2,init_task@h
ori r2,r2,init_task@l
/* ptr to current thread */
addi r4,r2,THREAD /* init task's THREAD */
mtspr SPRN_SPRG_THREAD,r4
/* stack */
lis r1,init_thread_union@h
ori r1,r1,init_thread_union@l
li r0,0
stwu r0,THREAD_SIZE-STACK_FRAME_MIN_SIZE(r1)
/* * Decide what sort of machine this is and initialize the MMU.
*/
mr r3,r30
mr r4,r31
bl machine_init
bl MMU_init
/* Setup PTE pointers for the Abatron bdiGDB */
lis r6, swapper_pg_dir@h
ori r6, r6, swapper_pg_dir@l
lis r5, abatron_pteptrs@h
ori r5, r5, abatron_pteptrs@l
lis r3, kernstart_virt_addr@ha
lwz r4, kernstart_virt_addr@l(r3)
stw r5, 0(r4) /* Save abatron_pteptrs at a fixed location */
stw r6, 0(r5)
/* Let's move on */
lis r4,start_kernel@h
ori r4,r4,start_kernel@l
lis r3,MSR_KERNEL@h
ori r3,r3,MSR_KERNEL@l
mtspr SPRN_SRR0,r4
mtspr SPRN_SRR1,r3
rfi /* change context and jump to start_kernel */
/* Macros to hide the PTE size differences * * FIND_PTE -- walks the page tables given EA & pgdir pointer * r10 -- free * r11 -- PGDIR pointer * r12 -- free * r13 -- EA of fault * label 2: is the bailout case * * if we find the pte (fall through): * r11 is low pte word * r12 is pointer to the pte * r10 is the pshift from the PGD, if we're a hugepage
*/
#ifdef CONFIG_PTE_64BIT
#ifdef CONFIG_HUGETLB_PAGE
#define FIND_PTE \
rlwinm r12, r13, 14, 18, 28; /* Compute pgdir/pmd offset */ \
add r12, r11, r12; \
lwz r11, 4(r12); /* Get pgd/pmd entry */ \
rlwinm. r10, r11, 32 - _PAGE_PSIZE_SHIFT, 0x1e; /* get tsize*/ \
bne 1000f; /* Huge page (leaf entry) */ \
rlwinm. r12, r11, 0, 0, 20; /* Extract pt base address */ \
beq 2f; /* Bail if no table */ \
rlwimi r12, r13, 23, 20, 28; /* Compute pte address */ \
li r10, 0; /* clear r10 */ \
lwz r11, 4(r12); /* Get pte entry */ \
1000:
#else
#define FIND_PTE \
rlwinm r12, r13, 14, 18, 28; /* Compute pgdir/pmd offset */ \
add r12, r11, r12; \
lwz r11, 4(r12); /* Get pgd/pmd entry */ \
rlwinm. r12, r11, 0, 0, 20; /* Extract pt base address */ \
beq 2f; /* Bail if no table */ \
rlwimi r12, r13, 23, 20, 28; /* Compute pte address */ \
lwz r11, 4(r12); /* Get pte entry */
#endif /* HUGEPAGE */
#else /* !PTE_64BIT */
#define FIND_PTE \
rlwimi r11, r13, 12, 20, 29; /* Create L1 (pgdir/pmd) address */ \
lwz r11, 0(r11); /* Get L1 entry */ \
rlwinm. r12, r11, 0, 0, 19; /* Extract L2 (pte) base address */ \
beq 2f; /* Bail if no table */ \
rlwimi r12, r13, 22, 20, 29; /* Compute PTE address */ \
lwz r11, 0(r12); /* Get Linux PTE */
#endif
/* * Interrupt vector entry code * * The Book E MMUs are always on so we don't need to handle * interrupts in real mode as with previous PPC processors. In * this case we handle interrupts in the kernel virtual address * space. * * Interrupt vectors are dynamically placed relative to the * interrupt prefix as determined by the address of interrupt_base. * The interrupt vectors offsets are programmed using the labels * for each interrupt vector entry. * * Interrupt vectors must be aligned on a 16 byte boundary. * We align on a 32 byte cache line boundary for good measure.
*/
/* If we are faulting a kernel address, we have to use the * kernel page tables.
*/
lis r11, PAGE_OFFSET@h
cmplw 5, r13, r11
blt 5, 3f
lis r11, swapper_pg_dir@h
ori r11, r11, swapper_pg_dir@l
mfspr r12,SPRN_MAS1 /* Set TID to 0 */
rlwinm r12,r12,0,16,1
mtspr SPRN_MAS1,r12
b 4f
/* Get the PGD for the current thread */
3:
mfspr r11,SPRN_SPRG_THREAD
lwz r11,PGDIR(r11)
#ifdef CONFIG_PTE_64BIT
li r13,_PAGE_PRESENT|_PAGE_BAP_SR
oris r13,r13,_PAGE_ACCESSED@h
#else
li r13,_PAGE_PRESENT|_PAGE_READ|_PAGE_ACCESSED
#endif
andc. r13,r13,r11 /* Check permission */
#ifdef CONFIG_PTE_64BIT
#ifdef CONFIG_SMP
subf r13,r11,r12 /* create false data dep */
lwzx r13,r11,r13 /* Get upper pte bits */
#else
lwz r13,0(r12) /* Get upper pte bits */
#endif
#endif
bne 2f /* Bail if permission/valid mismatch */
/* Jump to common tlb load */
b finish_tlb_load
2: /* The bailout. Restore registers to pre-exception conditions * and call the heavyweights to help us out.
*/
mfspr r10, SPRN_SPRG_THREAD
lwz r11, THREAD_NORMSAVE(3)(r10)
mtcr r11
lwz r13, THREAD_NORMSAVE(2)(r10)
lwz r12, THREAD_NORMSAVE(1)(r10)
lwz r11, THREAD_NORMSAVE(0)(r10)
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(InstructionTLBError)
mtspr SPRN_SPRG_WSCRATCH0, r10 /* Save some working registers */
mfspr r10, SPRN_SPRG_THREAD
stw r11, THREAD_NORMSAVE(0)(r10)
#ifdef CONFIG_KVM_BOOKE_HV
BEGIN_FTR_SECTION
mfspr r11, SPRN_SRR1
END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV)
#endif
stw r12, THREAD_NORMSAVE(1)(r10)
stw r13, THREAD_NORMSAVE(2)(r10)
mfcr r13
stw r13, THREAD_NORMSAVE(3)(r10)
DO_KVM BOOKE_INTERRUPT_ITLB_MISS SPRN_SRR1
START_BTB_FLUSH_SECTION
mfspr r11, SPRN_SRR1
andi. r10,r11,MSR_PR
beq 1f
BTB_FLUSH(r10)
1:
END_BTB_FLUSH_SECTION
mfspr r13, 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 5, r13, r11
blt 5, 3f
lis r11, swapper_pg_dir@h
ori r11, r11, swapper_pg_dir@l
mfspr r12,SPRN_MAS1 /* Set TID to 0 */
rlwinm r12,r12,0,16,1
mtspr SPRN_MAS1,r12
FIND_PTE /* Make up the required permissions for kernel code */
#ifdef CONFIG_PTE_64BIT
li r13,_PAGE_PRESENT | _PAGE_BAP_SX
oris r13,r13,_PAGE_ACCESSED@h
#else
li r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
#endif
b 4f
/* Get the PGD for the current thread */
3:
mfspr r11,SPRN_SPRG_THREAD
lwz r11,PGDIR(r11)
FIND_PTE /* Make up the required permissions for user code */
#ifdef CONFIG_PTE_64BIT
li r13,_PAGE_PRESENT | _PAGE_BAP_UX
oris r13,r13,_PAGE_ACCESSED@h
#else
li r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
#endif
4:
andc. r13,r13,r11 /* Check permission */
#ifdef CONFIG_PTE_64BIT
#ifdef CONFIG_SMP
subf r13,r11,r12 /* create false data dep */
lwzx r13,r11,r13 /* Get upper pte bits */
#else
lwz r13,0(r12) /* Get upper pte bits */
#endif
#endif
bne 2f /* Bail if permission mismatch */
/* Jump to common TLB load point */
b finish_tlb_load
2: /* The bailout. Restore registers to pre-exception conditions * and call the heavyweights to help us out.
*/
mfspr r10, SPRN_SPRG_THREAD
lwz r11, THREAD_NORMSAVE(3)(r10)
mtcr r11
lwz r13, THREAD_NORMSAVE(2)(r10)
lwz r12, THREAD_NORMSAVE(1)(r10)
lwz r11, THREAD_NORMSAVE(0)(r10)
mfspr r10, SPRN_SPRG_RSCRATCH0
b InstructionStorage
/* * Both the instruction and data TLB miss get to this * point to load the TLB. * r10 - tsize encoding (if HUGETLB_PAGE) or available to use * r11 - TLB (info from Linux PTE) * r12 - available to use * r13 - upper bits of PTE (if PTE_64BIT) or available to use * CR5 - results of addr >= PAGE_OFFSET * MAS0, MAS1 - loaded with proper value when we get here * MAS2, MAS3 - will need additional info from Linux PTE * Upon exit, we reload everything and RFI.
*/
finish_tlb_load:
#ifdef CONFIG_HUGETLB_PAGE
cmpwi 6, r10, 0 /* check for huge page */
beq 6, finish_tlb_load_cont /* !huge */
/* Alas, we need more scratch registers for hugepages */
mfspr r12, SPRN_SPRG_THREAD
stw r14, THREAD_NORMSAVE(4)(r12)
stw r15, THREAD_NORMSAVE(5)(r12)
stw r16, THREAD_NORMSAVE(6)(r12)
stw r17, THREAD_NORMSAVE(7)(r12)
/* Get the next_tlbcam_idx percpu var */
#ifdef CONFIG_SMP
lwz r15, TASK_CPU-THREAD(r12)
lis r14, __per_cpu_offset@h
ori r14, r14, __per_cpu_offset@l
rlwinm r15, r15, 2, 0, 29
lwzx r16, r14, r15
#else
li r16, 0
#endif
lis r17, next_tlbcam_idx@h
ori r17, r17, next_tlbcam_idx@l
add r17, r17, r16 /* r17 = *next_tlbcam_idx */
lwz r15, 0(r17) /* r15 = next_tlbcam_idx */
#ifdef CONFIG_SPE /* Note that the SPE support is closely modeled after the AltiVec * support. Changes to one are likely to be applicable to the
* other! */
_GLOBAL(load_up_spe) /* * Disable SPE for the task which had SPE previously, * and save its SPE registers in its thread_struct. * Enables SPE for use in the kernel on return. * On SMP we know the SPE units are free, since we give it up every * switch. -- Kumar
*/
mfmsr r5
oris r5,r5,MSR_SPE@h
mtmsr r5 /* enable use of SPE now */
isync /* enable use of SPE after return */
oris r9,r9,MSR_SPE@h
mfspr r5,SPRN_SPRG_THREAD /* current task's THREAD (phys) */
li r4,1
li r10,THREAD_ACC
stw r4,THREAD_USED_SPE(r5)
evlddx evr4,r10,r5
evmra evr4,evr4
REST_32EVRS(0,r10,r5,THREAD_EVR0)
blr
/* * SPE unavailable trap from kernel - print a message, but let * the task use SPE in the kernel until it returns to user mode.
*/
SYM_FUNC_START_LOCAL(KernelSPE)
lwz r3,_MSR(r1)
oris r3,r3,MSR_SPE@h
stw r3,_MSR(r1) /* enable use of SPE after return */
#ifdef CONFIG_PRINTK
lis r3,87f@h
ori r3,r3,87f@l
mr r4,r2 /* current */
lwz r5,_NIP(r1)
bl _printk
#endif
b interrupt_return
#ifdef CONFIG_PRINTK
87: .string "SPE used in kernel (task=%p, pc=%x) \n"
#endif
.align 4,0
SYM_FUNC_END(KernelSPE)
#endif /* CONFIG_SPE */
/* * Translate the effec addr in r3 to phys addr. The phys addr will be put * into r3(higher 32bit) and r4(lower 32bit)
*/
SYM_FUNC_START_LOCAL(get_phys_addr)
mfmsr r8
mfspr r9,SPRN_PID
rlwinm r9,r9,16,0x3fff0000 /* turn PID into MAS6[SPID] */
rlwimi r9,r8,28,0x00000001 /* turn MSR[DS] into MAS6[SAS] */
mtspr SPRN_MAS6,r9
#ifdef CONFIG_PPC_E500
#ifndef CONFIG_PPC_E500MC /* Adjust or setup IVORs for e500v1/v2 */
_GLOBAL(__setup_e500_ivors)
li r3,DebugCrit@l
mtspr SPRN_IVOR15,r3
li r3,SPEUnavailable@l
mtspr SPRN_IVOR32,r3
li r3,SPEFloatingPointData@l
mtspr SPRN_IVOR33,r3
li r3,SPEFloatingPointRound@l
mtspr SPRN_IVOR34,r3
li r3,PerformanceMonitor@l
mtspr SPRN_IVOR35,r3
sync
blr
#else /* Adjust or setup IVORs for e500mc */
_GLOBAL(__setup_e500mc_ivors)
li r3,DebugDebug@l
mtspr SPRN_IVOR15,r3
li r3,PerformanceMonitor@l
mtspr SPRN_IVOR35,r3
li r3,Doorbell@l
mtspr SPRN_IVOR36,r3
li r3,CriticalDoorbell@l
mtspr SPRN_IVOR37,r3
sync
blr
/* setup ehv ivors for */
_GLOBAL(__setup_ehv_ivors)
li r3,GuestDoorbell@l
mtspr SPRN_IVOR38,r3
li r3,CriticalGuestDoorbell@l
mtspr SPRN_IVOR39,r3
li r3,Hypercall@l
mtspr SPRN_IVOR40,r3
li r3,Ehvpriv@l
mtspr SPRN_IVOR41,r3
sync
blr
#endif /* CONFIG_PPC_E500MC */
#endif /* CONFIG_PPC_E500 */
/* * extern void abort(void) * * At present, this routine just applies a system reset.
*/
_GLOBAL(abort)
li r13,0
mtspr SPRN_DBCR0,r13 /* disable all debug events */
isync
mfmsr r13
ori r13,r13,MSR_DE@l /* Enable Debug Events */
mtmsr r13
isync
mfspr r13,SPRN_DBCR0
lis r13,(DBCR0_IDM|DBCR0_RST_CHIP)@h
mtspr SPRN_DBCR0,r13
isync
#ifdef CONFIG_SMP /* When we get here, r24 needs to hold the CPU # */
.globl __secondary_start
__secondary_start:
LOAD_REG_ADDR_PIC(r3, tlbcam_index)
lwz r3,0(r3)
mtctr r3
li r26,0 /* r26 safe? */
bl switch_to_as1
mr r27,r3 /* tlb entry */ /* Load each CAM entry */
1: mr r3,r26
bl loadcam_entry
addi r26,r26,1
bdnz 1b
mr r3,r27 /* tlb entry */
LOAD_REG_ADDR_PIC(r4, memstart_addr)
lwz r4,0(r4)
mr r5,r25 /* phys kernel start */
rlwinm r5,r5,0,~0x3ffffff /* aligned 64M */
subf r4,r5,r4 /* memstart_addr - phys kernel start */
lis r7,KERNELBASE@h
ori r7,r7,KERNELBASE@l
cmpw r20,r7 /* if kernstart_virt_addr != KERNELBASE, randomized */
beq 2f
li r4,0
2: li r5,0 /* no device tree */
li r6,0 /* not boot cpu */
bl restore_to_as0
lis r3,__secondary_hold_acknowledge@h
ori r3,r3,__secondary_hold_acknowledge@l
stw r24,0(r3)
li r3,0
mr r4,r24 /* Why? */
bl call_setup_cpu
/* get current's stack and current */
lis r2,secondary_current@ha
lwz r2,secondary_current@l(r2)
lwz r1,TASK_STACK(r2)
/* stack */
addi r1,r1,THREAD_SIZE-STACK_FRAME_MIN_SIZE
li r0,0
stw r0,0(r1)
/* ptr to current thread */
addi r4,r2,THREAD /* address of our thread_struct */
mtspr SPRN_SPRG_THREAD,r4
/* Setup the defaults for TLB entries */
li r4,(MAS4_TSIZED(BOOK3E_PAGESZ_4K))@l
mtspr SPRN_MAS4,r4
/* Jump to start_secondary */
lis r4,MSR_KERNEL@h
ori r4,r4,MSR_KERNEL@l
lis r3,start_secondary@h
ori r3,r3,start_secondary@l
mtspr SPRN_SRR0,r3
mtspr SPRN_SRR1,r4
sync
rfi
sync
lis r3,(MAS1_VALID|MAS1_IPROT)@h
ori r3,r3,(MAS1_TSIZE(BOOK3E_PAGESZ_64M))@l
mtspr SPRN_MAS1,r3 /* Write MAS1 */
lis r3,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@h
ori r3,r3,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@l
and r3,r3,r4
ori r3,r3,MAS2_M_IF_NEEDED@l
mtspr SPRN_MAS2,r3 /* Write MAS2(EPN) */
/* * Return to the start of the relocated kernel and run again * r3 - virtual address of fdt * r4 - entry of the kernel
*/
_GLOBAL(reloc_kernel_entry)
mfmsr r7
rlwinm r7, r7, 0, ~(MSR_IS | MSR_DS)
mtspr SPRN_SRR0,r4
mtspr SPRN_SRR1,r7
rfi
/* * Create a tlb entry with the same effective and physical address as * the tlb entry used by the current running code. But set the TS to 1. * Then switch to the address space 1. It will return with the r3 set to * the ESEL of the new created tlb.
*/
_GLOBAL(switch_to_as1)
mflr r5
/* * Restore to the address space 0 and also invalidate the tlb entry created * by switch_to_as1. * r3 - the tlb entry which should be invalidated * r4 - __pa(PAGE_OFFSET in AS1) - __pa(PAGE_OFFSET in AS0) * r5 - device tree virtual address. If r4 is 0, r5 is ignored. * r6 - boot cpu
*/
_GLOBAL(restore_to_as0)
mflr r0
bcl 20,31,$+4
0: mflr r9
addi r9,r9,1f - 0b
/* * We may map the PAGE_OFFSET in AS0 to a different physical address, * so we need calculate the right jump and device tree address based * on the offset passed by r4.
*/
add r9,r9,r4
add r5,r5,r4
add r0,r0,r4
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