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ARC: MMUv4 preps/3 - Abstract out TLB Insert/Delete 

This reorganizes the current TLB operations into psuedo-ops to better
pair with MMUv4's native Insert/Delete operations

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This commit is contained in:
Vineet Gupta 2013-07-01 18:12:28 +05:30
parent d091fcb97f
commit 483e9bcb01
2 changed files with 57 additions and 41 deletions
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2
arch/arc/include/asm/mmu.h
View File

@ -32,6 +32,8 @@
/* Error code if probe fails */
#define TLB_LKUP_ERR 0x80000000
#define TLB_DUP_ERR (TLB_LKUP_ERR | 0x00000001)
/* TLB Commands */
#define TLBWrite 0x1
#define TLBRead 0x2

96
arch/arc/mm/tlb.c
View File

@ -52,6 +52,7 @@
*/
#include <linux/module.h>
#include <linux/bug.h>
#include <asm/arcregs.h>
#include <asm/setup.h>
#include <asm/mmu_context.h>
@ -109,38 +110,41 @@ struct mm_struct *asid_mm_map[NUM_ASID + 1];
/*
* Utility Routine to erase a J-TLB entry
* The procedure is to look it up in the MMU. If found, ERASE it by
* issuing a TlbWrite CMD with PD0 = PD1 = 0
* Caller needs to setup Index Reg (manually or via getIndex)
*/
static void __tlb_entry_erase(void)
static inline void __tlb_entry_erase(void)
{
write_aux_reg(ARC_REG_TLBPD1, 0);
write_aux_reg(ARC_REG_TLBPD0, 0);
write_aux_reg(ARC_REG_TLBCOMMAND, TLBWrite);
}
static inline unsigned int tlb_entry_lkup(unsigned long vaddr_n_asid)
{
unsigned int idx;
write_aux_reg(ARC_REG_TLBPD0, vaddr_n_asid);
write_aux_reg(ARC_REG_TLBCOMMAND, TLBProbe);
idx = read_aux_reg(ARC_REG_TLBINDEX);
return idx;
}
static void tlb_entry_erase(unsigned int vaddr_n_asid)
{
unsigned int idx;
/* Locate the TLB entry for this vaddr + ASID */
write_aux_reg(ARC_REG_TLBPD0, vaddr_n_asid);
write_aux_reg(ARC_REG_TLBCOMMAND, TLBProbe);
idx = read_aux_reg(ARC_REG_TLBINDEX);
idx = tlb_entry_lkup(vaddr_n_asid);
/* No error means entry found, zero it out */
if (likely(!(idx & TLB_LKUP_ERR))) {
__tlb_entry_erase();
} else { /* Some sort of Error */
} else {
/* Duplicate entry error */
if (idx & 0x1) {
/* TODO we need to handle this case too */
pr_emerg("unhandled Duplicate flush for %x\n",
vaddr_n_asid);
}
/* else entry not found so nothing to do */
WARN(idx == TLB_DUP_ERR, "Probe returned Dup PD for %x\n",
vaddr_n_asid);
}
}
@ -159,7 +163,7 @@ static void utlb_invalidate(void)
{
#if (CONFIG_ARC_MMU_VER >= 2)
#if (CONFIG_ARC_MMU_VER < 3)
#if (CONFIG_ARC_MMU_VER == 2)
/* MMU v2 introduced the uTLB Flush command.
* There was however an obscure hardware bug, where uTLB flush would
* fail when a prior probe for J-TLB (both totally unrelated) would
@ -182,6 +186,36 @@ static void utlb_invalidate(void)
}
static void tlb_entry_insert(unsigned int pd0, unsigned int pd1)
{
unsigned int idx;
/*
* First verify if entry for this vaddr+ASID already exists
* This also sets up PD0 (vaddr, ASID..) for final commit
*/
idx = tlb_entry_lkup(pd0);
/*
* If Not already present get a free slot from MMU.
* Otherwise, Probe would have located the entry and set INDEX Reg
* with existing location. This will cause Write CMD to over-write
* existing entry with new PD0 and PD1
*/
if (likely(idx & TLB_LKUP_ERR))
write_aux_reg(ARC_REG_TLBCOMMAND, TLBGetIndex);
/* setup the other half of TLB entry (pfn, rwx..) */
write_aux_reg(ARC_REG_TLBPD1, pd1);
/*
* Commit the Entry to MMU
* It doesnt sound safe to use the TLBWriteNI cmd here
* which doesn't flush uTLBs. I'd rather be safe than sorry.
*/
write_aux_reg(ARC_REG_TLBCOMMAND, TLBWrite);
}
/*
* Un-conditionally (without lookup) erase the entire MMU contents
*/
@ -341,7 +375,8 @@ void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
void create_tlb(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
{
unsigned long flags;
unsigned int idx, asid_or_sasid, rwx;
unsigned int asid_or_sasid, rwx;
unsigned long pd0, pd1;
/*
* create_tlb() assumes that current->mm == vma->mm, since
@ -385,8 +420,7 @@ void create_tlb(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
/* ASID for this task */
asid_or_sasid = read_aux_reg(ARC_REG_PID) & 0xff;
write_aux_reg(ARC_REG_TLBPD0, address | asid_or_sasid |
(pte_val(*ptep) & PTE_BITS_IN_PD0));
pd0 = address | asid_or_sasid | (pte_val(*ptep) & PTE_BITS_IN_PD0);
/*
* ARC MMU provides fully orthogonal access bits for K/U mode,
@ -402,29 +436,9 @@ void create_tlb(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
else
rwx |= (rwx << 3); /* r w x => Kr Kw Kx Ur Uw Ux */
/* Load remaining info in PD1 (Page Frame Addr and Kx/Kw/Kr Flags) */
write_aux_reg(ARC_REG_TLBPD1,
rwx | (pte_val(*ptep) & PTE_BITS_NON_RWX_IN_PD1));
pd1 = rwx | (pte_val(*ptep) & PTE_BITS_NON_RWX_IN_PD1);
/* First verify if entry for this vaddr+ASID already exists */
write_aux_reg(ARC_REG_TLBCOMMAND, TLBProbe);
idx = read_aux_reg(ARC_REG_TLBINDEX);
/*
* If Not already present get a free slot from MMU.
* Otherwise, Probe would have located the entry and set INDEX Reg
* with existing location. This will cause Write CMD to over-write
* existing entry with new PD0 and PD1
*/
if (likely(idx & TLB_LKUP_ERR))
write_aux_reg(ARC_REG_TLBCOMMAND, TLBGetIndex);
/*
* Commit the Entry to MMU
* It doesnt sound safe to use the TLBWriteNI cmd here
* which doesn't flush uTLBs. I'd rather be safe than sorry.
*/
write_aux_reg(ARC_REG_TLBCOMMAND, TLBWrite);
tlb_entry_insert(pd0, pd1);
local_irq_restore(flags);
}