Commit e5083a63 authored by Johannes Weiner's avatar Johannes Weiner Committed by Chris Zankel
Browse files

xtensa: nommu support



Add support for !CONFIG_MMU setups.

Signed-off-by: default avatarJohannes Weiner <jw@emlix.com>
Signed-off-by: default avatarChris Zankel <chris@zankel.net>
parent 7789f89a
......@@ -65,13 +65,17 @@ extern void __flush_invalidate_dcache_range(unsigned long, unsigned long);
# define __flush_invalidate_dcache_range(p,s) __invalidate_dcache_range(p,s)
#endif
#if (DCACHE_WAY_SIZE > PAGE_SIZE)
#if defined(CONFIG_MMU) && (DCACHE_WAY_SIZE > PAGE_SIZE)
extern void __flush_invalidate_dcache_page_alias(unsigned long, unsigned long);
#else
static inline void __flush_invalidate_dcache_page_alias(unsigned long virt,
unsigned long phys) { }
#endif
#if (ICACHE_WAY_SIZE > PAGE_SIZE)
#if defined(CONFIG_MMU) && (ICACHE_WAY_SIZE > PAGE_SIZE)
extern void __invalidate_icache_page_alias(unsigned long, unsigned long);
#else
# define __invalidate_icache_page_alias(v,p) do { } while(0)
static inline void __invalidate_icache_page_alias(unsigned long virt,
unsigned long phys) { }
#endif
/*
......
......@@ -44,8 +44,9 @@
* the value desired).
*/
#ifndef MAX_DMA_ADDRESS
#define MAX_DMA_ADDRESS (PAGE_OFFSET + XCHAL_KIO_SIZE - 1)
#endif
/* Reserve and release a DMA channel */
extern int request_dma(unsigned int dmanr, const char * device_id);
......
......@@ -69,21 +69,28 @@ static inline void * phys_to_virt(unsigned long address)
static inline void *ioremap(unsigned long offset, unsigned long size)
{
#ifdef CONFIG_MMU
if (offset >= XCHAL_KIO_PADDR
&& offset < XCHAL_KIO_PADDR + XCHAL_KIO_SIZE)
return (void*)(offset-XCHAL_KIO_PADDR+XCHAL_KIO_BYPASS_VADDR);
else
BUG();
#else
return (void *)offset;
#endif
}
static inline void *ioremap_nocache(unsigned long offset, unsigned long size)
{
#ifdef CONFIG_MMU
if (offset >= XCHAL_KIO_PADDR
&& offset < XCHAL_KIO_PADDR + XCHAL_KIO_SIZE)
return (void*)(offset-XCHAL_KIO_PADDR+XCHAL_KIO_CACHED_VADDR);
else
BUG();
#else
return (void *)offset;
#endif
}
static inline void iounmap(void *addr)
......
......@@ -11,7 +11,12 @@
#ifndef _XTENSA_MMU_H
#define _XTENSA_MMU_H
#ifndef CONFIG_MMU
#include <asm/nommu.h>
#else
/* Default "unsigned long" context */
typedef unsigned long mm_context_t;
#endif /* CONFIG_MMU */
#endif /* _XTENSA_MMU_H */
......@@ -13,6 +13,10 @@
#ifndef _XTENSA_MMU_CONTEXT_H
#define _XTENSA_MMU_CONTEXT_H
#ifndef CONFIG_MMU
#include <asm/nommu_context.h>
#else
#include <linux/stringify.h>
#include <linux/sched.h>
......@@ -133,4 +137,5 @@ static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
}
#endif /* CONFIG_MMU */
#endif /* _XTENSA_MMU_CONTEXT_H */
typedef struct {
unsigned long end_brk;
} mm_context_t;
static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
}
static inline int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
{
return 0;
}
static inline void destroy_context(struct mm_struct *mm)
{
}
static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
{
}
static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk)
{
}
static inline void deactivate_mm(struct task_struct *tsk, struct mm_struct *mm)
{
}
......@@ -33,8 +33,14 @@
#define PAGE_SIZE (__XTENSA_UL_CONST(1) << PAGE_SHIFT)
#define PAGE_MASK (~(PAGE_SIZE-1))
#ifdef CONFIG_MMU
#define PAGE_OFFSET XCHAL_KSEG_CACHED_VADDR
#define MAX_MEM_PFN XCHAL_KSEG_SIZE
#else
#define PAGE_OFFSET 0
#define MAX_MEM_PFN (PLATFORM_DEFAULT_MEM_START + PLATFORM_DEFAULT_MEM_SIZE)
#endif
#define PGTABLE_START 0x80000000
/*
......@@ -165,8 +171,9 @@ extern void copy_user_page(void*, void*, unsigned long, struct page*);
#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
#define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT)
#ifdef CONFIG_MMU
#define WANT_PAGE_VIRTUAL
#endif
#endif /* __ASSEMBLY__ */
......
......@@ -183,7 +183,15 @@ extern unsigned long empty_zero_page[1024];
#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
#ifdef CONFIG_MMU
extern pgd_t swapper_pg_dir[PAGE_SIZE/sizeof(pgd_t)];
extern void paging_init(void);
extern void pgtable_cache_init(void);
#else
# define swapper_pg_dir NULL
static inline void paging_init(void) { }
static inline void pgtable_cache_init(void) { }
#endif
/*
* The pmd contains the kernel virtual address of the pte page.
......@@ -383,8 +391,6 @@ ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
#else
extern void paging_init(void);
#define kern_addr_valid(addr) (1)
extern void update_mmu_cache(struct vm_area_struct * vma,
......@@ -398,9 +404,6 @@ extern void update_mmu_cache(struct vm_area_struct * vma,
#define io_remap_pfn_range(vma,from,pfn,size,prot) \
remap_pfn_range(vma, from, pfn, size, prot)
extern void pgtable_cache_init(void);
typedef pte_t *pte_addr_t;
#endif /* !defined (__ASSEMBLY__) */
......
......@@ -13,6 +13,7 @@
#include <variant/core.h>
#include <asm/coprocessor.h>
#include <platform/hardware.h>
#include <linux/compiler.h>
#include <asm/ptrace.h>
......@@ -35,7 +36,12 @@
* the 1 GB requirement applies to the stack as well.
*/
#ifdef CONFIG_MMU
#define TASK_SIZE __XTENSA_UL_CONST(0x40000000)
#else
#define TASK_SIZE (PLATFORM_DEFAULT_MEM_START + PLATFORM_DEFAULT_MEM_SIZE)
#endif
#define STACK_TOP TASK_SIZE
#define STACK_TOP_MAX STACK_TOP
......
......@@ -1463,6 +1463,7 @@ ENTRY(_spill_registers)
callx0 a0 # should not return
1: j 1b
#ifdef CONFIG_MMU
/*
* We should never get here. Bail out!
*/
......@@ -1775,7 +1776,7 @@ ENTRY(fast_store_prohibited)
bbsi.l a2, PS_UM_BIT, 1f
j _kernel_exception
1: j _user_exception
#endif /* CONFIG_MMU */
/*
* System Calls.
......
......@@ -235,8 +235,9 @@ should_never_return:
*/
.section ".bss.page_aligned", "w"
#ifdef CONFIG_MMU
ENTRY(swapper_pg_dir)
.fill PAGE_SIZE, 1, 0
#endif
ENTRY(empty_zero_page)
.fill PAGE_SIZE, 1, 0
......@@ -84,7 +84,13 @@ sysmem_info_t __initdata sysmem;
int initrd_is_mapped;
#endif
#ifdef CONFIG_MMU
extern void init_mmu(void);
#else
static inline void init_mmu(void) { }
#endif
extern void zones_init(void);
/*
* Boot parameter parsing.
......@@ -286,6 +292,7 @@ void __init setup_arch(char **cmdline_p)
paging_init();
zones_init();
#ifdef CONFIG_VT
# if defined(CONFIG_VGA_CONSOLE)
......
......@@ -104,6 +104,7 @@ static dispatch_init_table_t __initdata dispatch_init_table[] = {
#endif
{ EXCCAUSE_UNALIGNED, KRNL, fast_unaligned },
#endif
#ifdef CONFIG_MMU
{ EXCCAUSE_ITLB_MISS, 0, do_page_fault },
{ EXCCAUSE_ITLB_MISS, USER|KRNL, fast_second_level_miss},
{ EXCCAUSE_ITLB_MULTIHIT, 0, do_multihit },
......@@ -118,6 +119,7 @@ static dispatch_init_table_t __initdata dispatch_init_table[] = {
{ EXCCAUSE_STORE_CACHE_ATTRIBUTE, USER|KRNL, fast_store_prohibited },
{ EXCCAUSE_STORE_CACHE_ATTRIBUTE, 0, do_page_fault },
{ EXCCAUSE_LOAD_CACHE_ATTRIBUTE, 0, do_page_fault },
#endif /* CONFIG_MMU */
/* XCCHAL_EXCCAUSE_FLOATING_POINT unhandled */
#if XTENSA_HAVE_COPROCESSOR(0)
COPROCESSOR(0),
......
......@@ -309,6 +309,7 @@ ENTRY(_DoubleExceptionVector)
* All other exceptions are unexpected and thus unrecoverable!
*/
#ifdef CONFIG_MMU
.extern fast_second_level_miss_double_kernel
.Lksp: /* a0: a0, a1: a1, a2: a2, a3: trashed, depc: depc, excsave: a3 */
......@@ -319,6 +320,9 @@ ENTRY(_DoubleExceptionVector)
bnez a3, .Lunrecoverable
1: movi a3, fast_second_level_miss_double_kernel
jx a3
#else
.equ .Lksp, .Lunrecoverable
#endif
/* Critical! We can't handle this situation. PANIC! */
......
......@@ -2,4 +2,5 @@
# Makefile for the Linux/Xtensa-specific parts of the memory manager.
#
obj-y := init.o fault.o tlb.o misc.o cache.o
obj-y := init.o cache.o misc.o
obj-$(CONFIG_MMU) += fault.o mmu.o tlb.o
......@@ -24,15 +24,8 @@
#include <linux/mm.h>
#include <linux/slab.h>
#include <asm/pgtable.h>
#include <asm/bootparam.h>
#include <asm/mmu_context.h>
#include <asm/tlb.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
/* References to section boundaries */
......@@ -160,7 +153,7 @@ void __init bootmem_init(void)
}
void __init paging_init(void)
void __init zones_init(void)
{
unsigned long zones_size[MAX_NR_ZONES];
int i;
......@@ -175,42 +168,9 @@ void __init paging_init(void)
zones_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn;
#endif
/* Initialize the kernel's page tables. */
memset(swapper_pg_dir, 0, PAGE_SIZE);
free_area_init_node(0, zones_size, ARCH_PFN_OFFSET, NULL);
}
/*
* Flush the mmu and reset associated register to default values.
*/
void __init init_mmu (void)
{
/* Writing zeros to the <t>TLBCFG special registers ensure
* that valid values exist in the register. For existing
* PGSZID<w> fields, zero selects the first element of the
* page-size array. For nonexistent PGSZID<w> fields, zero is
* the best value to write. Also, when changing PGSZID<w>
* fields, the corresponding TLB must be flushed.
*/
set_itlbcfg_register (0);
set_dtlbcfg_register (0);
flush_tlb_all ();
/* Set rasid register to a known value. */
set_rasid_register (ASID_USER_FIRST);
/* Set PTEVADDR special register to the start of the page
* table, which is in kernel mappable space (ie. not
* statically mapped). This register's value is undefined on
* reset.
*/
set_ptevaddr_register (PGTABLE_START);
}
/*
* Initialize memory pages.
*/
......@@ -281,23 +241,3 @@ void free_initmem(void)
printk("Freeing unused kernel memory: %dk freed\n",
(&__init_end - &__init_begin) >> 10);
}
struct kmem_cache *pgtable_cache __read_mostly;
static void pgd_ctor(void* addr)
{
pte_t* ptep = (pte_t*)addr;
int i;
for (i = 0; i < 1024; i++, ptep++)
pte_clear(NULL, 0, ptep);
}
void __init pgtable_cache_init(void)
{
pgtable_cache = kmem_cache_create("pgd",
PAGE_SIZE, PAGE_SIZE,
SLAB_HWCACHE_ALIGN,
pgd_ctor);
}
......@@ -84,6 +84,7 @@ ENTRY(copy_page)
retw
#ifdef CONFIG_MMU
/*
* If we have to deal with cache aliasing, we use temporary memory mappings
* to ensure that the source and destination pages have the same color as
......@@ -311,6 +312,7 @@ ENTRY(__invalidate_icache_page_alias)
/* End of special treatment in tlb miss exception */
ENTRY(__tlbtemp_mapping_end)
#endif /* CONFIG_MMU
/*
* void __invalidate_icache_page(ulong start)
......
/*
* xtensa mmu stuff
*
* Extracted from init.c
*/
#include <linux/percpu.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/cache.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
#include <asm/page.h>
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
void __init paging_init(void)
{
memset(swapper_pg_dir, 0, PAGE_SIZE);
}
/*
* Flush the mmu and reset associated register to default values.
*/
void __init init_mmu(void)
{
/* Writing zeros to the <t>TLBCFG special registers ensure
* that valid values exist in the register. For existing
* PGSZID<w> fields, zero selects the first element of the
* page-size array. For nonexistent PGSZID<w> fields, zero is
* the best value to write. Also, when changing PGSZID<w>
* fields, the corresponding TLB must be flushed.
*/
set_itlbcfg_register(0);
set_dtlbcfg_register(0);
flush_tlb_all();
/* Set rasid register to a known value. */
set_rasid_register(ASID_USER_FIRST);
/* Set PTEVADDR special register to the start of the page
* table, which is in kernel mappable space (ie. not
* statically mapped). This register's value is undefined on
* reset.
*/
set_ptevaddr_register(PGTABLE_START);
}
struct kmem_cache *pgtable_cache __read_mostly;
static void pgd_ctor(void *addr)
{
pte_t *ptep = (pte_t *)addr;
int i;
for (i = 0; i < 1024; i++, ptep++)
pte_clear(NULL, 0, ptep);
}
void __init pgtable_cache_init(void)
{
pgtable_cache = kmem_cache_create("pgd",
PAGE_SIZE, PAGE_SIZE,
SLAB_HWCACHE_ALIGN,
pgd_ctor);
}
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