Commit 6e4662ff authored by Stuart Menefy's avatar Stuart Menefy Committed by Paul Mundt

sh: Use MMU.TTB register as pointer to current pgd.

Add TTB accessor functions and give it a sensible default
value. We will use this later for optimizing the fault
path.
Signed-off-by: default avatarStuart Menefy <stuart.menefy@st.com>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent b5a1bcbe
...@@ -155,9 +155,6 @@ extern char __init_begin, __init_end; ...@@ -155,9 +155,6 @@ extern char __init_begin, __init_end;
/* /*
* paging_init() sets up the page tables * paging_init() sets up the page tables
*
* This routines also unmaps the page at virtual kernel address 0, so
* that we can trap those pesky NULL-reference errors in the kernel.
*/ */
void __init paging_init(void) void __init paging_init(void)
{ {
...@@ -180,14 +177,11 @@ void __init paging_init(void) ...@@ -180,14 +177,11 @@ void __init paging_init(void)
*/ */
{ {
unsigned long max_dma, low, start_pfn; unsigned long max_dma, low, start_pfn;
pgd_t *pg_dir;
int i;
/* We don't need kernel mapping as hardware support that. */
pg_dir = swapper_pg_dir;
for (i = 0; i < PTRS_PER_PGD; i++) /* We don't need to map the kernel through the TLB, as
pgd_val(pg_dir[i]) = 0; * it is permanatly mapped using P1. So clear the
* entire pgd. */
memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
/* Turn on the MMU */ /* Turn on the MMU */
enable_mmu(); enable_mmu();
...@@ -206,6 +200,10 @@ void __init paging_init(void) ...@@ -206,6 +200,10 @@ void __init paging_init(void)
} }
} }
/* Set an initial value for the MMU.TTB so we don't have to
* check for a null value. */
set_TTB(swapper_pg_dir);
#elif defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4) #elif defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4)
/* /*
* If we don't have CONFIG_MMU set and the processor in question * If we don't have CONFIG_MMU set and the processor in question
......
...@@ -10,7 +10,6 @@ ...@@ -10,7 +10,6 @@
#include <asm/cpu/mmu_context.h> #include <asm/cpu/mmu_context.h>
#include <asm/tlbflush.h> #include <asm/tlbflush.h>
#include <asm/pgalloc.h>
#include <asm/uaccess.h> #include <asm/uaccess.h>
#include <asm/io.h> #include <asm/io.h>
...@@ -42,10 +41,8 @@ extern unsigned long mmu_context_cache; ...@@ -42,10 +41,8 @@ extern unsigned long mmu_context_cache;
/* /*
* Get MMU context if needed. * Get MMU context if needed.
*/ */
static __inline__ void static inline void get_mmu_context(struct mm_struct *mm)
get_mmu_context(struct mm_struct *mm)
{ {
extern void flush_tlb_all(void);
unsigned long mc = mmu_context_cache; unsigned long mc = mmu_context_cache;
/* Check if we have old version of context. */ /* Check if we have old version of context. */
...@@ -61,6 +58,7 @@ get_mmu_context(struct mm_struct *mm) ...@@ -61,6 +58,7 @@ get_mmu_context(struct mm_struct *mm)
* Flush all TLB and start new cycle. * Flush all TLB and start new cycle.
*/ */
flush_tlb_all(); flush_tlb_all();
/* /*
* Fix version; Note that we avoid version #0 * Fix version; Note that we avoid version #0
* to distingush NO_CONTEXT. * to distingush NO_CONTEXT.
...@@ -75,11 +73,10 @@ get_mmu_context(struct mm_struct *mm) ...@@ -75,11 +73,10 @@ get_mmu_context(struct mm_struct *mm)
* Initialize the context related info for a new mm_struct * Initialize the context related info for a new mm_struct
* instance. * instance.
*/ */
static __inline__ int init_new_context(struct task_struct *tsk, static inline int init_new_context(struct task_struct *tsk,
struct mm_struct *mm) struct mm_struct *mm)
{ {
mm->context.id = NO_CONTEXT; mm->context.id = NO_CONTEXT;
return 0; return 0;
} }
...@@ -87,12 +84,12 @@ static __inline__ int init_new_context(struct task_struct *tsk, ...@@ -87,12 +84,12 @@ static __inline__ int init_new_context(struct task_struct *tsk,
* Destroy context related info for an mm_struct that is about * Destroy context related info for an mm_struct that is about
* to be put to rest. * to be put to rest.
*/ */
static __inline__ void destroy_context(struct mm_struct *mm) static inline void destroy_context(struct mm_struct *mm)
{ {
/* Do nothing */ /* Do nothing */
} }
static __inline__ void set_asid(unsigned long asid) static inline void set_asid(unsigned long asid)
{ {
unsigned long __dummy; unsigned long __dummy;
...@@ -105,7 +102,7 @@ static __inline__ void set_asid(unsigned long asid) ...@@ -105,7 +102,7 @@ static __inline__ void set_asid(unsigned long asid)
"r" (0xffffff00)); "r" (0xffffff00));
} }
static __inline__ unsigned long get_asid(void) static inline unsigned long get_asid(void)
{ {
unsigned long asid; unsigned long asid;
...@@ -120,24 +117,29 @@ static __inline__ unsigned long get_asid(void) ...@@ -120,24 +117,29 @@ static __inline__ unsigned long get_asid(void)
* After we have set current->mm to a new value, this activates * After we have set current->mm to a new value, this activates
* the context for the new mm so we see the new mappings. * the context for the new mm so we see the new mappings.
*/ */
static __inline__ void activate_context(struct mm_struct *mm) static inline void activate_context(struct mm_struct *mm)
{ {
get_mmu_context(mm); get_mmu_context(mm);
set_asid(mm->context.id & MMU_CONTEXT_ASID_MASK); set_asid(mm->context.id & MMU_CONTEXT_ASID_MASK);
} }
/* MMU_TTB can be used for optimizing the fault handling. /* MMU_TTB is used for optimizing the fault handling. */
(Currently not used) */ static inline void set_TTB(pgd_t *pgd)
static __inline__ void switch_mm(struct mm_struct *prev, {
ctrl_outl((unsigned long)pgd, MMU_TTB);
}
static inline pgd_t *get_TTB(void)
{
return (pgd_t *)ctrl_inl(MMU_TTB);
}
static inline void switch_mm(struct mm_struct *prev,
struct mm_struct *next, struct mm_struct *next,
struct task_struct *tsk) struct task_struct *tsk)
{ {
if (likely(prev != next)) { if (likely(prev != next)) {
unsigned long __pgdir = (unsigned long)next->pgd; set_TTB(next->pgd);
__asm__ __volatile__("mov.l %0, %1"
: /* no output */
: "r" (__pgdir), "m" (__m(MMU_TTB)));
activate_context(next); activate_context(next);
} }
} }
...@@ -147,7 +149,7 @@ static __inline__ void switch_mm(struct mm_struct *prev, ...@@ -147,7 +149,7 @@ static __inline__ void switch_mm(struct mm_struct *prev,
#define activate_mm(prev, next) \ #define activate_mm(prev, next) \
switch_mm((prev),(next),NULL) switch_mm((prev),(next),NULL)
static __inline__ void static inline void
enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{ {
} }
......
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