diff options
Diffstat (limited to 'arch/avr32/cpu')
| -rw-r--r-- | arch/avr32/cpu/at32ap700x/Makefile | 2 | ||||
| -rw-r--r-- | arch/avr32/cpu/at32ap700x/mmu.c | 78 | ||||
| -rw-r--r-- | arch/avr32/cpu/start.S | 19 |
3 files changed, 92 insertions, 7 deletions
diff --git a/arch/avr32/cpu/at32ap700x/Makefile b/arch/avr32/cpu/at32ap700x/Makefile index 46e6ef6..30ea925 100644 --- a/arch/avr32/cpu/at32ap700x/Makefile +++ b/arch/avr32/cpu/at32ap700x/Makefile @@ -24,7 +24,7 @@ include $(TOPDIR)/config.mk LIB := $(obj)lib$(SOC).a -COBJS := portmux.o clk.o +COBJS := portmux.o clk.o mmu.o SRCS := $(SOBJS:.o=.S) $(COBJS:.o=.c) OBJS := $(addprefix $(obj),$(SOBJS) $(COBJS)) diff --git a/arch/avr32/cpu/at32ap700x/mmu.c b/arch/avr32/cpu/at32ap700x/mmu.c new file mode 100644 index 0000000..c3a1b93 --- /dev/null +++ b/arch/avr32/cpu/at32ap700x/mmu.c @@ -0,0 +1,78 @@ +#include <common.h> +#include <asm/arch/mmu.h> +#include <asm/sysreg.h> + +void mmu_init_r(unsigned long dest_addr) +{ + uintptr_t vmr_table_addr; + + /* Round monitor address down to the nearest page boundary */ + dest_addr &= PAGE_ADDR_MASK; + + /* Initialize TLB entry 0 to cover the monitor, and lock it */ + sysreg_write(TLBEHI, dest_addr | SYSREG_BIT(TLBEHI_V)); + sysreg_write(TLBELO, dest_addr | MMU_VMR_CACHE_WRBACK); + sysreg_write(MMUCR, SYSREG_BF(DRP, 0) | SYSREG_BF(DLA, 1) + | SYSREG_BIT(MMUCR_S) | SYSREG_BIT(M)); + __builtin_tlbw(); + + /* + * Calculate the address of the VM range table in a PC-relative + * manner to make sure we hit the SDRAM and not the flash. + */ + vmr_table_addr = (uintptr_t)&mmu_vmr_table; + sysreg_write(PTBR, vmr_table_addr); + printf("VMR table @ 0x%08x\n", vmr_table_addr); + + /* Enable paging */ + sysreg_write(MMUCR, SYSREG_BF(DRP, 1) | SYSREG_BF(DLA, 1) + | SYSREG_BIT(MMUCR_S) | SYSREG_BIT(M) | SYSREG_BIT(E)); +} + +int mmu_handle_tlb_miss(void) +{ + const struct mmu_vm_range *vmr_table; + const struct mmu_vm_range *vmr; + unsigned int fault_pgno; + int first, last; + + fault_pgno = sysreg_read(TLBEAR) >> PAGE_SHIFT; + vmr_table = (const struct mmu_vm_range *)sysreg_read(PTBR); + + /* Do a binary search through the VM ranges */ + first = 0; + last = CONFIG_SYS_NR_VM_REGIONS; + while (first < last) { + unsigned int start; + int middle; + + /* Pick the entry in the middle of the remaining range */ + middle = (first + last) >> 1; + vmr = &vmr_table[middle]; + start = vmr->virt_pgno; + + /* Do the bisection thing */ + if (fault_pgno < start) { + last = middle; + } else if (fault_pgno >= (start + vmr->nr_pages)) { + first = middle + 1; + } else { + /* Got it; let's slam it into the TLB */ + uint32_t tlbelo; + + tlbelo = vmr->phys & ~PAGE_ADDR_MASK; + tlbelo |= fault_pgno << PAGE_SHIFT; + sysreg_write(TLBELO, tlbelo); + __builtin_tlbw(); + + /* Zero means success */ + return 0; + } + } + + /* + * Didn't find any matching entries. Return a nonzero value to + * indicate that this should be treated as a fatal exception. + */ + return -1; +} diff --git a/arch/avr32/cpu/start.S b/arch/avr32/cpu/start.S index 99c9e06..06bf4c6 100644 --- a/arch/avr32/cpu/start.S +++ b/arch/avr32/cpu/start.S @@ -82,12 +82,19 @@ _evba: .org 0x44 rjmp unknown_exception /* DTLB Modified */ - .org 0x50 - rjmp unknown_exception /* ITLB Miss */ - .org 0x60 - rjmp unknown_exception /* DTLB Miss (read) */ - .org 0x70 - rjmp unknown_exception /* DTLB Miss (write) */ + .org 0x50 /* ITLB Miss */ + pushm r8-r12,lr + rjmp 1f + .org 0x60 /* DTLB Miss (read) */ + pushm r8-r12,lr + rjmp 1f + .org 0x70 /* DTLB Miss (write) */ + pushm r8-r12,lr +1: mov r12, sp + rcall mmu_handle_tlb_miss + popm r8-r12,lr + brne unknown_exception + rete .size _evba, . - _evba |