- 根目录:
- arch
- cris
- arch-v10
- mm
- init.c
/*
* linux/arch/cris/arch-v10/mm/init.c
*
*/
#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 <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)
*/
per_cpu(current_pgd, smp_processor_id()) = 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, 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 occasionally 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);
}