diff options
Diffstat (limited to 'arch/cris/arch-v10/mm/init.c')
| -rw-r--r-- | arch/cris/arch-v10/mm/init.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/arch/cris/arch-v10/mm/init.c b/arch/cris/arch-v10/mm/init.c new file mode 100644 index 0000000..a9f975a --- /dev/null +++ b/arch/cris/arch-v10/mm/init.c @@ -0,0 +1,264 @@ +/* + * linux/arch/cris/arch-v10/mm/init.c + * + */ +#include <linux/config.h> +#include <linux/mmzone.h> +#include <linux/init.h> +#include <linux/bootmem.h> +#include <linux/mm.h> +#include <asm/pgtable.h> +#include <asm/page.h> +#include <asm/types.h> +#include <asm/mmu.h> +#include <asm/io.h> +#include <asm/mmu_context.h> +#include <asm/arch/svinto.h> + +extern void tlb_init(void); + +/* + * The kernel is already mapped with a kernel segment at kseg_c so + * we don't need to map it with a page table. However head.S also + * temporarily mapped it at kseg_4 so we should set up the ksegs again, + * clear the TLB and do some other paging setup stuff. + */ + +void __init +paging_init(void) +{ + int i; + unsigned long zones_size[MAX_NR_ZONES]; + + printk("Setting up paging and the MMU.\n"); + + /* clear out the init_mm.pgd that will contain the kernel's mappings */ + + for(i = 0; i < PTRS_PER_PGD; i++) + swapper_pg_dir[i] = __pgd(0); + + /* make sure the current pgd table points to something sane + * (even if it is most probably not used until the next + * switch_mm) + */ + + current_pgd = init_mm.pgd; + + /* initialise the TLB (tlb.c) */ + + tlb_init(); + + /* see README.mm for details on the KSEG setup */ + +#ifdef CONFIG_CRIS_LOW_MAP + /* Etrax-100 LX version 1 has a bug so that we cannot map anything + * across the 0x80000000 boundary, so we need to shrink the user-virtual + * area to 0x50000000 instead of 0xb0000000 and map things slightly + * different. The unused areas are marked as paged so that we can catch + * freak kernel accesses there. + * + * The ARTPEC chip is mapped at 0xa so we pass that segment straight + * through. We cannot vremap it because the vmalloc area is below 0x8 + * and Juliette needs an uncached area above 0x8. + * + * Same thing with 0xc and 0x9, which is memory-mapped I/O on some boards. + * We map them straight over in LOW_MAP, but use vremap in LX version 2. + */ + +#define CACHED_BOOTROM (KSEG_F | 0x08000000UL) + + *R_MMU_KSEG = ( IO_STATE(R_MMU_KSEG, seg_f, seg ) | /* bootrom */ + IO_STATE(R_MMU_KSEG, seg_e, page ) | + IO_STATE(R_MMU_KSEG, seg_d, page ) | + IO_STATE(R_MMU_KSEG, seg_c, page ) | + IO_STATE(R_MMU_KSEG, seg_b, seg ) | /* kernel reg area */ +#ifdef CONFIG_JULIETTE + IO_STATE(R_MMU_KSEG, seg_a, seg ) | /* ARTPEC etc. */ +#else + IO_STATE(R_MMU_KSEG, seg_a, page ) | +#endif + IO_STATE(R_MMU_KSEG, seg_9, seg ) | /* LED's on some boards */ + IO_STATE(R_MMU_KSEG, seg_8, seg ) | /* CSE0/1, flash and I/O */ + IO_STATE(R_MMU_KSEG, seg_7, page ) | /* kernel vmalloc area */ + IO_STATE(R_MMU_KSEG, seg_6, seg ) | /* kernel DRAM area */ + IO_STATE(R_MMU_KSEG, seg_5, seg ) | /* cached flash */ + IO_STATE(R_MMU_KSEG, seg_4, page ) | /* user area */ + IO_STATE(R_MMU_KSEG, seg_3, page ) | /* user area */ + IO_STATE(R_MMU_KSEG, seg_2, page ) | /* user area */ + IO_STATE(R_MMU_KSEG, seg_1, page ) | /* user area */ + IO_STATE(R_MMU_KSEG, seg_0, page ) ); /* user area */ + + *R_MMU_KBASE_HI = ( IO_FIELD(R_MMU_KBASE_HI, base_f, 0x3 ) | + IO_FIELD(R_MMU_KBASE_HI, base_e, 0x0 ) | + IO_FIELD(R_MMU_KBASE_HI, base_d, 0x0 ) | + IO_FIELD(R_MMU_KBASE_HI, base_c, 0x0 ) | + IO_FIELD(R_MMU_KBASE_HI, base_b, 0xb ) | +#ifdef CONFIG_JULIETTE + IO_FIELD(R_MMU_KBASE_HI, base_a, 0xa ) | +#else + IO_FIELD(R_MMU_KBASE_HI, base_a, 0x0 ) | +#endif + IO_FIELD(R_MMU_KBASE_HI, base_9, 0x9 ) | + IO_FIELD(R_MMU_KBASE_HI, base_8, 0x8 ) ); + + *R_MMU_KBASE_LO = ( IO_FIELD(R_MMU_KBASE_LO, base_7, 0x0 ) | + IO_FIELD(R_MMU_KBASE_LO, base_6, 0x4 ) | + IO_FIELD(R_MMU_KBASE_LO, base_5, 0x0 ) | + IO_FIELD(R_MMU_KBASE_LO, base_4, 0x0 ) | + IO_FIELD(R_MMU_KBASE_LO, base_3, 0x0 ) | + IO_FIELD(R_MMU_KBASE_LO, base_2, 0x0 ) | + IO_FIELD(R_MMU_KBASE_LO, base_1, 0x0 ) | + IO_FIELD(R_MMU_KBASE_LO, base_0, 0x0 ) ); +#else + /* This code is for the corrected Etrax-100 LX version 2... */ + +#define CACHED_BOOTROM (KSEG_A | 0x08000000UL) + + *R_MMU_KSEG = ( IO_STATE(R_MMU_KSEG, seg_f, seg ) | /* cached flash */ + IO_STATE(R_MMU_KSEG, seg_e, seg ) | /* uncached flash */ + IO_STATE(R_MMU_KSEG, seg_d, page ) | /* vmalloc area */ + IO_STATE(R_MMU_KSEG, seg_c, seg ) | /* kernel area */ + IO_STATE(R_MMU_KSEG, seg_b, seg ) | /* kernel reg area */ + IO_STATE(R_MMU_KSEG, seg_a, seg ) | /* bootrom */ + IO_STATE(R_MMU_KSEG, seg_9, page ) | /* user area */ + IO_STATE(R_MMU_KSEG, seg_8, page ) | + IO_STATE(R_MMU_KSEG, seg_7, page ) | + IO_STATE(R_MMU_KSEG, seg_6, page ) | + IO_STATE(R_MMU_KSEG, seg_5, page ) | + IO_STATE(R_MMU_KSEG, seg_4, page ) | + IO_STATE(R_MMU_KSEG, seg_3, page ) | + IO_STATE(R_MMU_KSEG, seg_2, page ) | + IO_STATE(R_MMU_KSEG, seg_1, page ) | + IO_STATE(R_MMU_KSEG, seg_0, page ) ); + + *R_MMU_KBASE_HI = ( IO_FIELD(R_MMU_KBASE_HI, base_f, 0x0 ) | + IO_FIELD(R_MMU_KBASE_HI, base_e, 0x8 ) | + IO_FIELD(R_MMU_KBASE_HI, base_d, 0x0 ) | + IO_FIELD(R_MMU_KBASE_HI, base_c, 0x4 ) | + IO_FIELD(R_MMU_KBASE_HI, base_b, 0xb ) | + IO_FIELD(R_MMU_KBASE_HI, base_a, 0x3 ) | + IO_FIELD(R_MMU_KBASE_HI, base_9, 0x0 ) | + IO_FIELD(R_MMU_KBASE_HI, base_8, 0x0 ) ); + + *R_MMU_KBASE_LO = ( IO_FIELD(R_MMU_KBASE_LO, base_7, 0x0 ) | + IO_FIELD(R_MMU_KBASE_LO, base_6, 0x0 ) | + IO_FIELD(R_MMU_KBASE_LO, base_5, 0x0 ) | + IO_FIELD(R_MMU_KBASE_LO, base_4, 0x0 ) | + IO_FIELD(R_MMU_KBASE_LO, base_3, 0x0 ) | + IO_FIELD(R_MMU_KBASE_LO, base_2, 0x0 ) | + IO_FIELD(R_MMU_KBASE_LO, base_1, 0x0 ) | + IO_FIELD(R_MMU_KBASE_LO, base_0, 0x0 ) ); +#endif + + *R_MMU_CONTEXT = ( IO_FIELD(R_MMU_CONTEXT, page_id, 0 ) ); + + /* The MMU has been enabled ever since head.S but just to make + * it totally obvious we do it here as well. + */ + + *R_MMU_CTRL = ( IO_STATE(R_MMU_CTRL, inv_excp, enable ) | + IO_STATE(R_MMU_CTRL, acc_excp, enable ) | + IO_STATE(R_MMU_CTRL, we_excp, enable ) ); + + *R_MMU_ENABLE = IO_STATE(R_MMU_ENABLE, mmu_enable, enable); + + /* + * initialize the bad page table and bad page to point + * to a couple of allocated pages + */ + + empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE); + memset((void *)empty_zero_page, 0, PAGE_SIZE); + + /* All pages are DMA'able in Etrax, so put all in the DMA'able zone */ + + zones_size[0] = ((unsigned long)high_memory - PAGE_OFFSET) >> PAGE_SHIFT; + + for (i = 1; i < MAX_NR_ZONES; i++) + zones_size[i] = 0; + + /* Use free_area_init_node instead of free_area_init, because the former + * is designed for systems where the DRAM starts at an address substantially + * higher than 0, like us (we start at PAGE_OFFSET). This saves space in the + * mem_map page array. + */ + + free_area_init_node(0, &contig_page_data, zones_size, PAGE_OFFSET >> PAGE_SHIFT, 0); +} + +/* Initialize remaps of some I/O-ports. It is important that this + * is called before any driver is initialized. + */ + +static int +__init init_ioremap(void) +{ + + /* Give the external I/O-port addresses their values */ + +#ifdef CONFIG_CRIS_LOW_MAP + /* Simply a linear map (see the KSEG map above in paging_init) */ + port_cse1_addr = (volatile unsigned long *)(MEM_CSE1_START | + MEM_NON_CACHEABLE); + port_csp0_addr = (volatile unsigned long *)(MEM_CSP0_START | + MEM_NON_CACHEABLE); + port_csp4_addr = (volatile unsigned long *)(MEM_CSP4_START | + MEM_NON_CACHEABLE); +#else + /* Note that nothing blows up just because we do this remapping + * it's ok even if the ports are not used or connected + * to anything (or connected to a non-I/O thing) */ + port_cse1_addr = (volatile unsigned long *) + ioremap((unsigned long)(MEM_CSE1_START | MEM_NON_CACHEABLE), 16); + port_csp0_addr = (volatile unsigned long *) + ioremap((unsigned long)(MEM_CSP0_START | MEM_NON_CACHEABLE), 16); + port_csp4_addr = (volatile unsigned long *) + ioremap((unsigned long)(MEM_CSP4_START | MEM_NON_CACHEABLE), 16); +#endif + return 0; +} + +__initcall(init_ioremap); + +/* Helper function for the two below */ + +static inline void +flush_etrax_cacherange(void *startadr, int length) +{ + /* CACHED_BOOTROM is mapped to the boot-rom area (cached) which + * we can use to get fast dummy-reads of cachelines + */ + + volatile short *flushadr = (volatile short *)(((unsigned long)startadr & ~PAGE_MASK) | + CACHED_BOOTROM); + + length = length > 8192 ? 8192 : length; /* No need to flush more than cache size */ + + while(length > 0) { + *flushadr; /* dummy read to flush */ + flushadr += (32/sizeof(short)); /* a cacheline is 32 bytes */ + length -= 32; + } +} + +/* Due to a bug in Etrax100(LX) all versions, receiving DMA buffers + * will occationally corrupt certain CPU writes if the DMA buffers + * happen to be hot in the cache. + * + * As a workaround, we have to flush the relevant parts of the cache + * before (re) inserting any receiving descriptor into the DMA HW. + */ + +void +prepare_rx_descriptor(struct etrax_dma_descr *desc) +{ + flush_etrax_cacherange((void *)desc->buf, desc->sw_len ? desc->sw_len : 65536); +} + +/* Do the same thing but flush the entire cache */ + +void +flush_etrax_cache(void) +{ + flush_etrax_cacherange(0, 8192); +} |