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linux/arch/mips/mm/tlbex.c
David Daney bf28607fbe MIPS: Close races in TLB modify handlers. 
Page table entries are made invalid by writing a zero into the the PTE
slot in a page table.  This creates a race condition with the TLB
modify handlers when they are updating the PTE.

CPU0                              CPU1

Test for _PAGE_PRESENT
.                                 set to not _PAGE_PRESENT (zero)
Set to _PAGE_VALID

So now the page not present value (zero) is suddenly valid and user
space programs have access to physical page zero.

We close the race by putting the test for _PAGE_PRESENT and setting of
_PAGE_VALID into an atomic LL/SC section.  This requires more registers
than just K0 and K1 in the handlers, so we need to save some registers
to a save area and then restore them when we are done.

The save area is an array of cacheline aligned structures that should
not suffer cache line bouncing as they are CPU private.

[ralf@linux-mips.org: Fix !defined(CONFIG_MIPS_PGD_C0_CONTEXT) build error.]

Signed-off-by: David Daney <david.daney@cavium.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2577/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-07-26 06:47:47 +01:00

2160 lines
57 KiB
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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Synthesize TLB refill handlers at runtime.
*
* Copyright (C) 2004, 2005, 2006, 2008 Thiemo Seufer
* Copyright (C) 2005, 2007, 2008, 2009 Maciej W. Rozycki
* Copyright (C) 2006 Ralf Baechle (ralf@linux-mips.org)
* Copyright (C) 2008, 2009 Cavium Networks, Inc.
*
* ... and the days got worse and worse and now you see
* I've gone completly out of my mind.
*
* They're coming to take me a away haha
* they're coming to take me a away hoho hihi haha
* to the funny farm where code is beautiful all the time ...
*
* (Condolences to Napoleon XIV)
*/
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/smp.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/cache.h>
#include <asm/cacheflush.h>
#include <asm/pgtable.h>
#include <asm/war.h>
#include <asm/uasm.h>
/*
* TLB load/store/modify handlers.
*
* Only the fastpath gets synthesized at runtime, the slowpath for
* do_page_fault remains normal asm.
*/
extern void tlb_do_page_fault_0(void);
extern void tlb_do_page_fault_1(void);
struct work_registers {
int r1;
int r2;
int r3;
};
struct tlb_reg_save {
unsigned long a;
unsigned long b;
} ____cacheline_aligned_in_smp;
static struct tlb_reg_save handler_reg_save[NR_CPUS];
static inline int r45k_bvahwbug(void)
{
/* XXX: We should probe for the presence of this bug, but we don't. */
return 0;
}
static inline int r4k_250MHZhwbug(void)
{
/* XXX: We should probe for the presence of this bug, but we don't. */
return 0;
}
static inline int __maybe_unused bcm1250_m3_war(void)
{
return BCM1250_M3_WAR;
}
static inline int __maybe_unused r10000_llsc_war(void)
{
return R10000_LLSC_WAR;
}
static int use_bbit_insns(void)
{
switch (current_cpu_type()) {
case CPU_CAVIUM_OCTEON:
case CPU_CAVIUM_OCTEON_PLUS:
case CPU_CAVIUM_OCTEON2:
return 1;
default:
return 0;
}
}
static int use_lwx_insns(void)
{
switch (current_cpu_type()) {
case CPU_CAVIUM_OCTEON2:
return 1;
default:
return 0;
}
}
#if defined(CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE) && \
CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE > 0
static bool scratchpad_available(void)
{
return true;
}
static int scratchpad_offset(int i)
{
/*
* CVMSEG starts at address -32768 and extends for
* CAVIUM_OCTEON_CVMSEG_SIZE 128 byte cache lines.
*/
i += 1; /* Kernel use starts at the top and works down. */
return CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE * 128 - (8 * i) - 32768;
}
#else
static bool scratchpad_available(void)
{
return false;
}
static int scratchpad_offset(int i)
{
BUG();
/* Really unreachable, but evidently some GCC want this. */
return 0;
}
#endif
/*
* Found by experiment: At least some revisions of the 4kc throw under
* some circumstances a machine check exception, triggered by invalid
* values in the index register. Delaying the tlbp instruction until
* after the next branch, plus adding an additional nop in front of
* tlbwi/tlbwr avoids the invalid index register values. Nobody knows
* why; it's not an issue caused by the core RTL.
*
*/
static int __cpuinit m4kc_tlbp_war(void)
{
return (current_cpu_data.processor_id & 0xffff00) ==
(PRID_COMP_MIPS | PRID_IMP_4KC);
}
/* Handle labels (which must be positive integers). */
enum label_id {
label_second_part = 1,
label_leave,
label_vmalloc,
label_vmalloc_done,
label_tlbw_hazard,
label_split,
label_tlbl_goaround1,
label_tlbl_goaround2,
label_nopage_tlbl,
label_nopage_tlbs,
label_nopage_tlbm,
label_smp_pgtable_change,
label_r3000_write_probe_fail,
label_large_segbits_fault,
#ifdef CONFIG_HUGETLB_PAGE
label_tlb_huge_update,
#endif
};
UASM_L_LA(_second_part)
UASM_L_LA(_leave)
UASM_L_LA(_vmalloc)
UASM_L_LA(_vmalloc_done)
UASM_L_LA(_tlbw_hazard)
UASM_L_LA(_split)
UASM_L_LA(_tlbl_goaround1)
UASM_L_LA(_tlbl_goaround2)
UASM_L_LA(_nopage_tlbl)
UASM_L_LA(_nopage_tlbs)
UASM_L_LA(_nopage_tlbm)
UASM_L_LA(_smp_pgtable_change)
UASM_L_LA(_r3000_write_probe_fail)
UASM_L_LA(_large_segbits_fault)
#ifdef CONFIG_HUGETLB_PAGE
UASM_L_LA(_tlb_huge_update)
#endif
/*
* For debug purposes.
*/
static inline void dump_handler(const u32 *handler, int count)
{
int i;
pr_debug("\t.set push\n");
pr_debug("\t.set noreorder\n");
for (i = 0; i < count; i++)
pr_debug("\t%p\t.word 0x%08x\n", &handler[i], handler[i]);
pr_debug("\t.set pop\n");
}
/* The only general purpose registers allowed in TLB handlers. */
#define K0 26
#define K1 27
/* Some CP0 registers */
#define C0_INDEX 0, 0
#define C0_ENTRYLO0 2, 0
#define C0_TCBIND 2, 2
#define C0_ENTRYLO1 3, 0
#define C0_CONTEXT 4, 0
#define C0_PAGEMASK 5, 0
#define C0_BADVADDR 8, 0
#define C0_ENTRYHI 10, 0
#define C0_EPC 14, 0
#define C0_XCONTEXT 20, 0
#ifdef CONFIG_64BIT
# define GET_CONTEXT(buf, reg) UASM_i_MFC0(buf, reg, C0_XCONTEXT)
#else
# define GET_CONTEXT(buf, reg) UASM_i_MFC0(buf, reg, C0_CONTEXT)
#endif
/* The worst case length of the handler is around 18 instructions for
* R3000-style TLBs and up to 63 instructions for R4000-style TLBs.
* Maximum space available is 32 instructions for R3000 and 64
* instructions for R4000.
*
* We deliberately chose a buffer size of 128, so we won't scribble
* over anything important on overflow before we panic.
*/
static u32 tlb_handler[128] __cpuinitdata;
/* simply assume worst case size for labels and relocs */
static struct uasm_label labels[128] __cpuinitdata;
static struct uasm_reloc relocs[128] __cpuinitdata;
#ifdef CONFIG_64BIT
static int check_for_high_segbits __cpuinitdata;
#endif
static int check_for_high_segbits __cpuinitdata;
static unsigned int kscratch_used_mask __cpuinitdata;
static int __cpuinit allocate_kscratch(void)
{
int r;
unsigned int a = cpu_data[0].kscratch_mask & ~kscratch_used_mask;
r = ffs(a);
if (r == 0)
return -1;
r--; /* make it zero based */
kscratch_used_mask |= (1 << r);
return r;
}
static int scratch_reg __cpuinitdata;
static int pgd_reg __cpuinitdata;
enum vmalloc64_mode {not_refill, refill_scratch, refill_noscratch};
static struct work_registers __cpuinit build_get_work_registers(u32 **p)
{
struct work_registers r;
int smp_processor_id_reg;
int smp_processor_id_sel;
int smp_processor_id_shift;
if (scratch_reg > 0) {
/* Save in CPU local C0_KScratch? */
UASM_i_MTC0(p, 1, 31, scratch_reg);
r.r1 = K0;
r.r2 = K1;
r.r3 = 1;
return r;
}
if (num_possible_cpus() > 1) {
#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
smp_processor_id_shift = 51;
smp_processor_id_reg = 20; /* XContext */
smp_processor_id_sel = 0;
#else
# ifdef CONFIG_32BIT
smp_processor_id_shift = 25;
smp_processor_id_reg = 4; /* Context */
smp_processor_id_sel = 0;
# endif
# ifdef CONFIG_64BIT
smp_processor_id_shift = 26;
smp_processor_id_reg = 4; /* Context */
smp_processor_id_sel = 0;
# endif
#endif
/* Get smp_processor_id */
UASM_i_MFC0(p, K0, smp_processor_id_reg, smp_processor_id_sel);
UASM_i_SRL_SAFE(p, K0, K0, smp_processor_id_shift);
/* handler_reg_save index in K0 */
UASM_i_SLL(p, K0, K0, ilog2(sizeof(struct tlb_reg_save)));
UASM_i_LA(p, K1, (long)&handler_reg_save);
UASM_i_ADDU(p, K0, K0, K1);
} else {
UASM_i_LA(p, K0, (long)&handler_reg_save);
}
/* K0 now points to save area, save $1 and $2 */
UASM_i_SW(p, 1, offsetof(struct tlb_reg_save, a), K0);
UASM_i_SW(p, 2, offsetof(struct tlb_reg_save, b), K0);
r.r1 = K1;
r.r2 = 1;
r.r3 = 2;
return r;
}
static void __cpuinit build_restore_work_registers(u32 **p)
{
if (scratch_reg > 0) {
UASM_i_MFC0(p, 1, 31, scratch_reg);
return;
}
/* K0 already points to save area, restore $1 and $2 */
UASM_i_LW(p, 1, offsetof(struct tlb_reg_save, a), K0);
UASM_i_LW(p, 2, offsetof(struct tlb_reg_save, b), K0);
}
#ifndef CONFIG_MIPS_PGD_C0_CONTEXT
/*
* CONFIG_MIPS_PGD_C0_CONTEXT implies 64 bit and lack of pgd_current,
* we cannot do r3000 under these circumstances.
*
* Declare pgd_current here instead of including mmu_context.h to avoid type
* conflicts for tlbmiss_handler_setup_pgd
*/
extern unsigned long pgd_current[];
/*
* The R3000 TLB handler is simple.
*/
static void __cpuinit build_r3000_tlb_refill_handler(void)
{
long pgdc = (long)pgd_current;
u32 *p;
memset(tlb_handler, 0, sizeof(tlb_handler));
p = tlb_handler;
uasm_i_mfc0(&p, K0, C0_BADVADDR);
uasm_i_lui(&p, K1, uasm_rel_hi(pgdc)); /* cp0 delay */
uasm_i_lw(&p, K1, uasm_rel_lo(pgdc), K1);
uasm_i_srl(&p, K0, K0, 22); /* load delay */
uasm_i_sll(&p, K0, K0, 2);
uasm_i_addu(&p, K1, K1, K0);
uasm_i_mfc0(&p, K0, C0_CONTEXT);
uasm_i_lw(&p, K1, 0, K1); /* cp0 delay */
uasm_i_andi(&p, K0, K0, 0xffc); /* load delay */
uasm_i_addu(&p, K1, K1, K0);
uasm_i_lw(&p, K0, 0, K1);
uasm_i_nop(&p); /* load delay */
uasm_i_mtc0(&p, K0, C0_ENTRYLO0);
uasm_i_mfc0(&p, K1, C0_EPC); /* cp0 delay */
uasm_i_tlbwr(&p); /* cp0 delay */
uasm_i_jr(&p, K1);
uasm_i_rfe(&p); /* branch delay */
if (p > tlb_handler + 32)
panic("TLB refill handler space exceeded");
pr_debug("Wrote TLB refill handler (%u instructions).\n",
(unsigned int)(p - tlb_handler));
memcpy((void *)ebase, tlb_handler, 0x80);
dump_handler((u32 *)ebase, 32);
}
#endif /* CONFIG_MIPS_PGD_C0_CONTEXT */
/*
* The R4000 TLB handler is much more complicated. We have two
* consecutive handler areas with 32 instructions space each.
* Since they aren't used at the same time, we can overflow in the
* other one.To keep things simple, we first assume linear space,
* then we relocate it to the final handler layout as needed.
*/
static u32 final_handler[64] __cpuinitdata;
/*
* Hazards
*
* From the IDT errata for the QED RM5230 (Nevada), processor revision 1.0:
* 2. A timing hazard exists for the TLBP instruction.
*
* stalling_instruction
* TLBP
*
* The JTLB is being read for the TLBP throughout the stall generated by the
* previous instruction. This is not really correct as the stalling instruction
* can modify the address used to access the JTLB. The failure symptom is that
* the TLBP instruction will use an address created for the stalling instruction
* and not the address held in C0_ENHI and thus report the wrong results.
*
* The software work-around is to not allow the instruction preceding the TLBP
* to stall - make it an NOP or some other instruction guaranteed not to stall.
*
* Errata 2 will not be fixed. This errata is also on the R5000.
*
* As if we MIPS hackers wouldn't know how to nop pipelines happy ...
*/
static void __cpuinit __maybe_unused build_tlb_probe_entry(u32 **p)
{
switch (current_cpu_type()) {
/* Found by experiment: R4600 v2.0/R4700 needs this, too. */
case CPU_R4600:
case CPU_R4700:
case CPU_R5000:
case CPU_R5000A:
case CPU_NEVADA:
uasm_i_nop(p);
uasm_i_tlbp(p);
break;
default:
uasm_i_tlbp(p);
break;
}
}
/*
* Write random or indexed TLB entry, and care about the hazards from
* the preceding mtc0 and for the following eret.
*/
enum tlb_write_entry { tlb_random, tlb_indexed };
static void __cpuinit build_tlb_write_entry(u32 **p, struct uasm_label **l,
struct uasm_reloc **r,
enum tlb_write_entry wmode)
{
void(*tlbw)(u32 **) = NULL;
switch (wmode) {
case tlb_random: tlbw = uasm_i_tlbwr; break;
case tlb_indexed: tlbw = uasm_i_tlbwi; break;
}
if (cpu_has_mips_r2) {
if (cpu_has_mips_r2_exec_hazard)
uasm_i_ehb(p);
tlbw(p);
return;
}
switch (current_cpu_type()) {
case CPU_R4000PC:
case CPU_R4000SC:
case CPU_R4000MC:
case CPU_R4400PC:
case CPU_R4400SC:
case CPU_R4400MC:
/*
* This branch uses up a mtc0 hazard nop slot and saves
* two nops after the tlbw instruction.
*/
uasm_il_bgezl(p, r, 0, label_tlbw_hazard);
tlbw(p);
uasm_l_tlbw_hazard(l, *p);
uasm_i_nop(p);
break;
case CPU_R4600:
case CPU_R4700:
case CPU_R5000:
case CPU_R5000A:
uasm_i_nop(p);
tlbw(p);
uasm_i_nop(p);
break;
case CPU_R4300:
case CPU_5KC:
case CPU_TX49XX:
case CPU_PR4450:
case CPU_XLR:
uasm_i_nop(p);
tlbw(p);
break;
case CPU_R10000:
case CPU_R12000:
case CPU_R14000:
case CPU_4KC:
case CPU_4KEC:
case CPU_SB1:
case CPU_SB1A:
case CPU_4KSC:
case CPU_20KC:
case CPU_25KF:
case CPU_BMIPS32:
case CPU_BMIPS3300:
case CPU_BMIPS4350:
case CPU_BMIPS4380:
case CPU_BMIPS5000:
case CPU_LOONGSON2:
case CPU_R5500:
if (m4kc_tlbp_war())
uasm_i_nop(p);
case CPU_ALCHEMY:
tlbw(p);
break;
case CPU_NEVADA:
uasm_i_nop(p); /* QED specifies 2 nops hazard */
/*
* This branch uses up a mtc0 hazard nop slot and saves
* a nop after the tlbw instruction.
*/
uasm_il_bgezl(p, r, 0, label_tlbw_hazard);
tlbw(p);
uasm_l_tlbw_hazard(l, *p);
break;
case CPU_RM7000:
uasm_i_nop(p);
uasm_i_nop(p);
uasm_i_nop(p);
uasm_i_nop(p);
tlbw(p);
break;
case CPU_RM9000:
/*
* When the JTLB is updated by tlbwi or tlbwr, a subsequent
* use of the JTLB for instructions should not occur for 4
* cpu cycles and use for data translations should not occur
* for 3 cpu cycles.
*/
uasm_i_ssnop(p);
uasm_i_ssnop(p);
uasm_i_ssnop(p);
uasm_i_ssnop(p);
tlbw(p);
uasm_i_ssnop(p);
uasm_i_ssnop(p);
uasm_i_ssnop(p);
uasm_i_ssnop(p);
break;
case CPU_VR4111:
case CPU_VR4121:
case CPU_VR4122:
case CPU_VR4181:
case CPU_VR4181A:
uasm_i_nop(p);
uasm_i_nop(p);
tlbw(p);
uasm_i_nop(p);
uasm_i_nop(p);
break;
case CPU_VR4131:
case CPU_VR4133:
case CPU_R5432:
uasm_i_nop(p);
uasm_i_nop(p);
tlbw(p);
break;
case CPU_JZRISC:
tlbw(p);
uasm_i_nop(p);
break;
default:
panic("No TLB refill handler yet (CPU type: %d)",
current_cpu_data.cputype);
break;
}
}
static __cpuinit __maybe_unused void build_convert_pte_to_entrylo(u32 **p,
unsigned int reg)
{
if (kernel_uses_smartmips_rixi) {
UASM_i_SRL(p, reg, reg, ilog2(_PAGE_NO_EXEC));
UASM_i_ROTR(p, reg, reg, ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC));
} else {
#ifdef CONFIG_64BIT_PHYS_ADDR
uasm_i_dsrl_safe(p, reg, reg, ilog2(_PAGE_GLOBAL));
#else
UASM_i_SRL(p, reg, reg, ilog2(_PAGE_GLOBAL));
#endif
}
}
#ifdef CONFIG_HUGETLB_PAGE
static __cpuinit void build_restore_pagemask(u32 **p,
struct uasm_reloc **r,
unsigned int tmp,
enum label_id lid,
int restore_scratch)
{
if (restore_scratch) {
/* Reset default page size */
if (PM_DEFAULT_MASK >> 16) {
uasm_i_lui(p, tmp, PM_DEFAULT_MASK >> 16);
uasm_i_ori(p, tmp, tmp, PM_DEFAULT_MASK & 0xffff);
uasm_i_mtc0(p, tmp, C0_PAGEMASK);
uasm_il_b(p, r, lid);
} else if (PM_DEFAULT_MASK) {
uasm_i_ori(p, tmp, 0, PM_DEFAULT_MASK);
uasm_i_mtc0(p, tmp, C0_PAGEMASK);
uasm_il_b(p, r, lid);
} else {
uasm_i_mtc0(p, 0, C0_PAGEMASK);
uasm_il_b(p, r, lid);
}
if (scratch_reg > 0)
UASM_i_MFC0(p, 1, 31, scratch_reg);
else
UASM_i_LW(p, 1, scratchpad_offset(0), 0);
} else {
/* Reset default page size */
if (PM_DEFAULT_MASK >> 16) {
uasm_i_lui(p, tmp, PM_DEFAULT_MASK >> 16);
uasm_i_ori(p, tmp, tmp, PM_DEFAULT_MASK & 0xffff);
uasm_il_b(p, r, lid);
uasm_i_mtc0(p, tmp, C0_PAGEMASK);
} else if (PM_DEFAULT_MASK) {
uasm_i_ori(p, tmp, 0, PM_DEFAULT_MASK);
uasm_il_b(p, r, lid);
uasm_i_mtc0(p, tmp, C0_PAGEMASK);
} else {
uasm_il_b(p, r, lid);
uasm_i_mtc0(p, 0, C0_PAGEMASK);
}
}
}
static __cpuinit void build_huge_tlb_write_entry(u32 **p,
struct uasm_label **l,
struct uasm_reloc **r,
unsigned int tmp,
enum tlb_write_entry wmode,
int restore_scratch)
{
/* Set huge page tlb entry size */
uasm_i_lui(p, tmp, PM_HUGE_MASK >> 16);
uasm_i_ori(p, tmp, tmp, PM_HUGE_MASK & 0xffff);
uasm_i_mtc0(p, tmp, C0_PAGEMASK);
build_tlb_write_entry(p, l, r, wmode);
build_restore_pagemask(p, r, tmp, label_leave, restore_scratch);
}
/*
* Check if Huge PTE is present, if so then jump to LABEL.
*/
static void __cpuinit
build_is_huge_pte(u32 **p, struct uasm_reloc **r, unsigned int tmp,
unsigned int pmd, int lid)
{
UASM_i_LW(p, tmp, 0, pmd);
if (use_bbit_insns()) {
uasm_il_bbit1(p, r, tmp, ilog2(_PAGE_HUGE), lid);
} else {
uasm_i_andi(p, tmp, tmp, _PAGE_HUGE);
uasm_il_bnez(p, r, tmp, lid);
}
}
static __cpuinit void build_huge_update_entries(u32 **p,
unsigned int pte,
unsigned int tmp)
{
int small_sequence;
/*
* A huge PTE describes an area the size of the
* configured huge page size. This is twice the
* of the large TLB entry size we intend to use.
* A TLB entry half the size of the configured
* huge page size is configured into entrylo0
* and entrylo1 to cover the contiguous huge PTE
* address space.
*/
small_sequence = (HPAGE_SIZE >> 7) < 0x10000;
/* We can clobber tmp. It isn't used after this.*/
if (!small_sequence)
uasm_i_lui(p, tmp, HPAGE_SIZE >> (7 + 16));
build_convert_pte_to_entrylo(p, pte);
UASM_i_MTC0(p, pte, C0_ENTRYLO0); /* load it */
/* convert to entrylo1 */
if (small_sequence)
UASM_i_ADDIU(p, pte, pte, HPAGE_SIZE >> 7);
else
UASM_i_ADDU(p, pte, pte, tmp);
UASM_i_MTC0(p, pte, C0_ENTRYLO1); /* load it */
}
static __cpuinit void build_huge_handler_tail(u32 **p,
struct uasm_reloc **r,
struct uasm_label **l,
unsigned int pte,
unsigned int ptr)
{
#ifdef CONFIG_SMP
UASM_i_SC(p, pte, 0, ptr);
uasm_il_beqz(p, r, pte, label_tlb_huge_update);
UASM_i_LW(p, pte, 0, ptr); /* Needed because SC killed our PTE */
#else
UASM_i_SW(p, pte, 0, ptr);
#endif
build_huge_update_entries(p, pte, ptr);
build_huge_tlb_write_entry(p, l, r, pte, tlb_indexed, 0);
}
#endif /* CONFIG_HUGETLB_PAGE */
#ifdef CONFIG_64BIT
/*
* TMP and PTR are scratch.
* TMP will be clobbered, PTR will hold the pmd entry.
*/
static void __cpuinit
build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
unsigned int tmp, unsigned int ptr)
{
#ifndef CONFIG_MIPS_PGD_C0_CONTEXT
long pgdc = (long)pgd_current;
#endif
/*
* The vmalloc handling is not in the hotpath.
*/
uasm_i_dmfc0(p, tmp, C0_BADVADDR);
if (check_for_high_segbits) {
/*
* The kernel currently implicitely assumes that the
* MIPS SEGBITS parameter for the processor is
* (PGDIR_SHIFT+PGDIR_BITS) or less, and will never
* allocate virtual addresses outside the maximum
* range for SEGBITS = (PGDIR_SHIFT+PGDIR_BITS). But
* that doesn't prevent user code from accessing the
* higher xuseg addresses. Here, we make sure that
* everything but the lower xuseg addresses goes down
* the module_alloc/vmalloc path.
*/
uasm_i_dsrl_safe(p, ptr, tmp, PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3);
uasm_il_bnez(p, r, ptr, label_vmalloc);
} else {
uasm_il_bltz(p, r, tmp, label_vmalloc);
}
/* No uasm_i_nop needed here, since the next insn doesn't touch TMP. */
#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
if (pgd_reg != -1) {
/* pgd is in pgd_reg */
UASM_i_MFC0(p, ptr, 31, pgd_reg);
} else {
/*
* &pgd << 11 stored in CONTEXT [23..63].
*/
UASM_i_MFC0(p, ptr, C0_CONTEXT);
/* Clear lower 23 bits of context. */
uasm_i_dins(p, ptr, 0, 0, 23);
/* 1 0 1 0 1 << 6 xkphys cached */
uasm_i_ori(p, ptr, ptr, 0x540);
uasm_i_drotr(p, ptr, ptr, 11);
}
#elif defined(CONFIG_SMP)
# ifdef CONFIG_MIPS_MT_SMTC
/*
* SMTC uses TCBind value as "CPU" index
*/
uasm_i_mfc0(p, ptr, C0_TCBIND);
uasm_i_dsrl_safe(p, ptr, ptr, 19);
# else
/*
* 64 bit SMP running in XKPHYS has smp_processor_id() << 3
* stored in CONTEXT.
*/
uasm_i_dmfc0(p, ptr, C0_CONTEXT);
uasm_i_dsrl_safe(p, ptr, ptr, 23);
# endif
UASM_i_LA_mostly(p, tmp, pgdc);
uasm_i_daddu(p, ptr, ptr, tmp);
uasm_i_dmfc0(p, tmp, C0_BADVADDR);
uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr);
#else
UASM_i_LA_mostly(p, ptr, pgdc);
uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr);
#endif
uasm_l_vmalloc_done(l, *p);
/* get pgd offset in bytes */
uasm_i_dsrl_safe(p, tmp, tmp, PGDIR_SHIFT - 3);
uasm_i_andi(p, tmp, tmp, (PTRS_PER_PGD - 1)<<3);
uasm_i_daddu(p, ptr, ptr, tmp); /* add in pgd offset */
#ifndef __PAGETABLE_PMD_FOLDED
uasm_i_dmfc0(p, tmp, C0_BADVADDR); /* get faulting address */
uasm_i_ld(p, ptr, 0, ptr); /* get pmd pointer */
uasm_i_dsrl_safe(p, tmp, tmp, PMD_SHIFT-3); /* get pmd offset in bytes */
uasm_i_andi(p, tmp, tmp, (PTRS_PER_PMD - 1)<<3);
uasm_i_daddu(p, ptr, ptr, tmp); /* add in pmd offset */
#endif
}
/*
* BVADDR is the faulting address, PTR is scratch.
* PTR will hold the pgd for vmalloc.
*/
static void __cpuinit
build_get_pgd_vmalloc64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
unsigned int bvaddr, unsigned int ptr,
enum vmalloc64_mode mode)
{
long swpd = (long)swapper_pg_dir;
int single_insn_swpd;
int did_vmalloc_branch = 0;
single_insn_swpd = uasm_in_compat_space_p(swpd) && !uasm_rel_lo(swpd);
uasm_l_vmalloc(l, *p);
if (mode != not_refill && check_for_high_segbits) {
if (single_insn_swpd) {
uasm_il_bltz(p, r, bvaddr, label_vmalloc_done);
uasm_i_lui(p, ptr, uasm_rel_hi(swpd));
did_vmalloc_branch = 1;
/* fall through */
} else {
uasm_il_bgez(p, r, bvaddr, label_large_segbits_fault);
}
}
if (!did_vmalloc_branch) {
if (uasm_in_compat_space_p(swpd) && !uasm_rel_lo(swpd)) {
uasm_il_b(p, r, label_vmalloc_done);
uasm_i_lui(p, ptr, uasm_rel_hi(swpd));
} else {
UASM_i_LA_mostly(p, ptr, swpd);
uasm_il_b(p, r, label_vmalloc_done);
if (uasm_in_compat_space_p(swpd))
uasm_i_addiu(p, ptr, ptr, uasm_rel_lo(swpd));
else
uasm_i_daddiu(p, ptr, ptr, uasm_rel_lo(swpd));
}
}
if (mode != not_refill && check_for_high_segbits) {
uasm_l_large_segbits_fault(l, *p);
/*
* We get here if we are an xsseg address, or if we are
* an xuseg address above (PGDIR_SHIFT+PGDIR_BITS) boundary.
*
* Ignoring xsseg (assume disabled so would generate
* (address errors?), the only remaining possibility
* is the upper xuseg addresses. On processors with
* TLB_SEGBITS <= PGDIR_SHIFT+PGDIR_BITS, these
* addresses would have taken an address error. We try
* to mimic that here by taking a load/istream page
* fault.
*/
UASM_i_LA(p, ptr, (unsigned long)tlb_do_page_fault_0);
uasm_i_jr(p, ptr);
if (mode == refill_scratch) {
if (scratch_reg > 0)
UASM_i_MFC0(p, 1, 31, scratch_reg);
else
UASM_i_LW(p, 1, scratchpad_offset(0), 0);
} else {
uasm_i_nop(p);
}
}
}
#else /* !CONFIG_64BIT */
/*
* TMP and PTR are scratch.
* TMP will be clobbered, PTR will hold the pgd entry.
*/
static void __cpuinit __maybe_unused
build_get_pgde32(u32 **p, unsigned int tmp, unsigned int ptr)
{
long pgdc = (long)pgd_current;
/* 32 bit SMP has smp_processor_id() stored in CONTEXT. */
#ifdef CONFIG_SMP
#ifdef CONFIG_MIPS_MT_SMTC
/*
* SMTC uses TCBind value as "CPU" index
*/
uasm_i_mfc0(p, ptr, C0_TCBIND);
UASM_i_LA_mostly(p, tmp, pgdc);
uasm_i_srl(p, ptr, ptr, 19);
#else
/*
* smp_processor_id() << 3 is stored in CONTEXT.
*/
uasm_i_mfc0(p, ptr, C0_CONTEXT);
UASM_i_LA_mostly(p, tmp, pgdc);
uasm_i_srl(p, ptr, ptr, 23);
#endif
uasm_i_addu(p, ptr, tmp, ptr);
#else
UASM_i_LA_mostly(p, ptr, pgdc);
#endif
uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */
uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr);
uasm_i_srl(p, tmp, tmp, PGDIR_SHIFT); /* get pgd only bits */
uasm_i_sll(p, tmp, tmp, PGD_T_LOG2);
uasm_i_addu(p, ptr, ptr, tmp); /* add in pgd offset */
}
#endif /* !CONFIG_64BIT */
static void __cpuinit build_adjust_context(u32 **p, unsigned int ctx)
{
unsigned int shift = 4 - (PTE_T_LOG2 + 1) + PAGE_SHIFT - 12;
unsigned int mask = (PTRS_PER_PTE / 2 - 1) << (PTE_T_LOG2 + 1);
switch (current_cpu_type()) {
case CPU_VR41XX:
case CPU_VR4111:
case CPU_VR4121:
case CPU_VR4122:
case CPU_VR4131:
case CPU_VR4181:
case CPU_VR4181A:
case CPU_VR4133:
shift += 2;
break;
default:
break;
}
if (shift)
UASM_i_SRL(p, ctx, ctx, shift);
uasm_i_andi(p, ctx, ctx, mask);
}
static void __cpuinit build_get_ptep(u32 **p, unsigned int tmp, unsigned int ptr)
{
/*
* Bug workaround for the Nevada. It seems as if under certain
* circumstances the move from cp0_context might produce a
* bogus result when the mfc0 instruction and its consumer are
* in a different cacheline or a load instruction, probably any
* memory reference, is between them.
*/
switch (current_cpu_type()) {
case CPU_NEVADA:
UASM_i_LW(p, ptr, 0, ptr);
GET_CONTEXT(p, tmp); /* get context reg */
break;
default:
GET_CONTEXT(p, tmp); /* get context reg */
UASM_i_LW(p, ptr, 0, ptr);
break;
}
build_adjust_context(p, tmp);
UASM_i_ADDU(p, ptr, ptr, tmp); /* add in offset */
}
static void __cpuinit build_update_entries(u32 **p, unsigned int tmp,
unsigned int ptep)
{
/*
* 64bit address support (36bit on a 32bit CPU) in a 32bit
* Kernel is a special case. Only a few CPUs use it.
*/
#ifdef CONFIG_64BIT_PHYS_ADDR
if (cpu_has_64bits) {
uasm_i_ld(p, tmp, 0, ptep); /* get even pte */
uasm_i_ld(p, ptep, sizeof(pte_t), ptep); /* get odd pte */
if (kernel_uses_smartmips_rixi) {
UASM_i_SRL(p, tmp, tmp, ilog2(_PAGE_NO_EXEC));
UASM_i_SRL(p, ptep, ptep, ilog2(_PAGE_NO_EXEC));
UASM_i_ROTR(p, tmp, tmp, ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC));
UASM_i_MTC0(p, tmp, C0_ENTRYLO0); /* load it */
UASM_i_ROTR(p, ptep, ptep, ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC));
} else {
uasm_i_dsrl_safe(p, tmp, tmp, ilog2(_PAGE_GLOBAL)); /* convert to entrylo0 */
UASM_i_MTC0(p, tmp, C0_ENTRYLO0); /* load it */
uasm_i_dsrl_safe(p, ptep, ptep, ilog2(_PAGE_GLOBAL)); /* convert to entrylo1 */
}
UASM_i_MTC0(p, ptep, C0_ENTRYLO1); /* load it */
} else {
int pte_off_even = sizeof(pte_t) / 2;
int pte_off_odd = pte_off_even + sizeof(pte_t);
/* The pte entries are pre-shifted */
uasm_i_lw(p, tmp, pte_off_even, ptep); /* get even pte */
UASM_i_MTC0(p, tmp, C0_ENTRYLO0); /* load it */
uasm_i_lw(p, ptep, pte_off_odd, ptep); /* get odd pte */
UASM_i_MTC0(p, ptep, C0_ENTRYLO1); /* load it */
}
#else
UASM_i_LW(p, tmp, 0, ptep); /* get even pte */
UASM_i_LW(p, ptep, sizeof(pte_t), ptep); /* get odd pte */
if (r45k_bvahwbug())
build_tlb_probe_entry(p);
if (kernel_uses_smartmips_rixi) {
UASM_i_SRL(p, tmp, tmp, ilog2(_PAGE_NO_EXEC));
UASM_i_SRL(p, ptep, ptep, ilog2(_PAGE_NO_EXEC));
UASM_i_ROTR(p, tmp, tmp, ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC));
if (r4k_250MHZhwbug())
UASM_i_MTC0(p, 0, C0_ENTRYLO0);
UASM_i_MTC0(p, tmp, C0_ENTRYLO0); /* load it */
UASM_i_ROTR(p, ptep, ptep, ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC));
} else {
UASM_i_SRL(p, tmp, tmp, ilog2(_PAGE_GLOBAL)); /* convert to entrylo0 */
if (r4k_250MHZhwbug())
UASM_i_MTC0(p, 0, C0_ENTRYLO0);
UASM_i_MTC0(p, tmp, C0_ENTRYLO0); /* load it */
UASM_i_SRL(p, ptep, ptep, ilog2(_PAGE_GLOBAL)); /* convert to entrylo1 */
if (r45k_bvahwbug())
uasm_i_mfc0(p, tmp, C0_INDEX);
}
if (r4k_250MHZhwbug())
UASM_i_MTC0(p, 0, C0_ENTRYLO1);
UASM_i_MTC0(p, ptep, C0_ENTRYLO1); /* load it */
#endif
}
struct mips_huge_tlb_info {
int huge_pte;
int restore_scratch;
};
static struct mips_huge_tlb_info __cpuinit
build_fast_tlb_refill_handler (u32 **p, struct uasm_label **l,
struct uasm_reloc **r, unsigned int tmp,
unsigned int ptr, int c0_scratch)
{
struct mips_huge_tlb_info rv;
unsigned int even, odd;
int vmalloc_branch_delay_filled = 0;
const int scratch = 1; /* Our extra working register */
rv.huge_pte = scratch;
rv.restore_scratch = 0;
if (check_for_high_segbits) {
UASM_i_MFC0(p, tmp, C0_BADVADDR);
if (pgd_reg != -1)
UASM_i_MFC0(p, ptr, 31, pgd_reg);
else
UASM_i_MFC0(p, ptr, C0_CONTEXT);
if (c0_scratch >= 0)
UASM_i_MTC0(p, scratch, 31, c0_scratch);
else
UASM_i_SW(p, scratch, scratchpad_offset(0), 0);
uasm_i_dsrl_safe(p, scratch, tmp,
PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3);
uasm_il_bnez(p, r, scratch, label_vmalloc);
if (pgd_reg == -1) {
vmalloc_branch_delay_filled = 1;
/* Clear lower 23 bits of context. */
uasm_i_dins(p, ptr, 0, 0, 23);
}
} else {
if (pgd_reg != -1)
UASM_i_MFC0(p, ptr, 31, pgd_reg);
else
UASM_i_MFC0(p, ptr, C0_CONTEXT);
UASM_i_MFC0(p, tmp, C0_BADVADDR);
if (c0_scratch >= 0)
UASM_i_MTC0(p, scratch, 31, c0_scratch);
else
UASM_i_SW(p, scratch, scratchpad_offset(0), 0);
if (pgd_reg == -1)
/* Clear lower 23 bits of context. */
uasm_i_dins(p, ptr, 0, 0, 23);
uasm_il_bltz(p, r, tmp, label_vmalloc);
}
if (pgd_reg == -1) {
vmalloc_branch_delay_filled = 1;
/* 1 0 1 0 1 << 6 xkphys cached */
uasm_i_ori(p, ptr, ptr, 0x540);
uasm_i_drotr(p, ptr, ptr, 11);
}
#ifdef __PAGETABLE_PMD_FOLDED
#define LOC_PTEP scratch
#else
#define LOC_PTEP ptr
#endif
if (!vmalloc_branch_delay_filled)
/* get pgd offset in bytes */
uasm_i_dsrl_safe(p, scratch, tmp, PGDIR_SHIFT - 3);
uasm_l_vmalloc_done(l, *p);
/*
* tmp ptr
* fall-through case = badvaddr *pgd_current
* vmalloc case = badvaddr swapper_pg_dir
*/
if (vmalloc_branch_delay_filled)
/* get pgd offset in bytes */
uasm_i_dsrl_safe(p, scratch, tmp, PGDIR_SHIFT - 3);
#ifdef __PAGETABLE_PMD_FOLDED
GET_CONTEXT(p, tmp); /* get context reg */
#endif
uasm_i_andi(p, scratch, scratch, (PTRS_PER_PGD - 1) << 3);
if (use_lwx_insns()) {
UASM_i_LWX(p, LOC_PTEP, scratch, ptr);
} else {
uasm_i_daddu(p, ptr, ptr, scratch); /* add in pgd offset */
uasm_i_ld(p, LOC_PTEP, 0, ptr); /* get pmd pointer */
}
#ifndef __PAGETABLE_PMD_FOLDED
/* get pmd offset in bytes */
uasm_i_dsrl_safe(p, scratch, tmp, PMD_SHIFT - 3);
uasm_i_andi(p, scratch, scratch, (PTRS_PER_PMD - 1) << 3);
GET_CONTEXT(p, tmp); /* get context reg */
if (use_lwx_insns()) {
UASM_i_LWX(p, scratch, scratch, ptr);
} else {
uasm_i_daddu(p, ptr, ptr, scratch); /* add in pmd offset */
UASM_i_LW(p, scratch, 0, ptr);
}
#endif
/* Adjust the context during the load latency. */
build_adjust_context(p, tmp);
#ifdef CONFIG_HUGETLB_PAGE
uasm_il_bbit1(p, r, scratch, ilog2(_PAGE_HUGE), label_tlb_huge_update);
/*
* The in the LWX case we don't want to do the load in the
* delay slot. It cannot issue in the same cycle and may be
* speculative and unneeded.
*/
if (use_lwx_insns())
uasm_i_nop(p);
#endif /* CONFIG_HUGETLB_PAGE */
/* build_update_entries */
if (use_lwx_insns()) {
even = ptr;
odd = tmp;
UASM_i_LWX(p, even, scratch, tmp);
UASM_i_ADDIU(p, tmp, tmp, sizeof(pte_t));
UASM_i_LWX(p, odd, scratch, tmp);
} else {
UASM_i_ADDU(p, ptr, scratch, tmp); /* add in offset */
even = tmp;
odd = ptr;
UASM_i_LW(p, even, 0, ptr); /* get even pte */
UASM_i_LW(p, odd, sizeof(pte_t), ptr); /* get odd pte */
}
if (kernel_uses_smartmips_rixi) {
uasm_i_dsrl_safe(p, even, even, ilog2(_PAGE_NO_EXEC));
uasm_i_dsrl_safe(p, odd, odd, ilog2(_PAGE_NO_EXEC));
uasm_i_drotr(p, even, even,
ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC));
UASM_i_MTC0(p, even, C0_ENTRYLO0); /* load it */
uasm_i_drotr(p, odd, odd,
ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC));
} else {
uasm_i_dsrl_safe(p, even, even, ilog2(_PAGE_GLOBAL));
UASM_i_MTC0(p, even, C0_ENTRYLO0); /* load it */
uasm_i_dsrl_safe(p, odd, odd, ilog2(_PAGE_GLOBAL));
}
UASM_i_MTC0(p, odd, C0_ENTRYLO1); /* load it */
if (c0_scratch >= 0) {
UASM_i_MFC0(p, scratch, 31, c0_scratch);
build_tlb_write_entry(p, l, r, tlb_random);
uasm_l_leave(l, *p);
rv.restore_scratch = 1;
} else if (PAGE_SHIFT == 14 || PAGE_SHIFT == 13) {
build_tlb_write_entry(p, l, r, tlb_random);
uasm_l_leave(l, *p);
UASM_i_LW(p, scratch, scratchpad_offset(0), 0);
} else {
UASM_i_LW(p, scratch, scratchpad_offset(0), 0);
build_tlb_write_entry(p, l, r, tlb_random);
uasm_l_leave(l, *p);
rv.restore_scratch = 1;
}
uasm_i_eret(p); /* return from trap */
return rv;
}
/*
* For a 64-bit kernel, we are using the 64-bit XTLB refill exception
* because EXL == 0. If we wrap, we can also use the 32 instruction
* slots before the XTLB refill exception handler which belong to the
* unused TLB refill exception.
*/
#define MIPS64_REFILL_INSNS 32
static void __cpuinit build_r4000_tlb_refill_handler(void)
{
u32 *p = tlb_handler;
struct uasm_label *l = labels;
struct uasm_reloc *r = relocs;
u32 *f;
unsigned int final_len;
struct mips_huge_tlb_info htlb_info __maybe_unused;
enum vmalloc64_mode vmalloc_mode __maybe_unused;
memset(tlb_handler, 0, sizeof(tlb_handler));
memset(labels, 0, sizeof(labels));
memset(relocs, 0, sizeof(relocs));
memset(final_handler, 0, sizeof(final_handler));
if ((scratch_reg > 0 || scratchpad_available()) && use_bbit_insns()) {
htlb_info = build_fast_tlb_refill_handler(&p, &l, &r, K0, K1,
scratch_reg);
vmalloc_mode = refill_scratch;
} else {
htlb_info.huge_pte = K0;
htlb_info.restore_scratch = 0;
vmalloc_mode = refill_noscratch;
/*
* create the plain linear handler
*/
if (bcm1250_m3_war()) {
unsigned int segbits = 44;
uasm_i_dmfc0(&p, K0, C0_BADVADDR);
uasm_i_dmfc0(&p, K1, C0_ENTRYHI);
uasm_i_xor(&p, K0, K0, K1);
uasm_i_dsrl_safe(&p, K1, K0, 62);
uasm_i_dsrl_safe(&p, K0, K0, 12 + 1);
uasm_i_dsll_safe(&p, K0, K0, 64 + 12 + 1 - segbits);
uasm_i_or(&p, K0, K0, K1);
uasm_il_bnez(&p, &r, K0, label_leave);
/* No need for uasm_i_nop */
}
#ifdef CONFIG_64BIT
build_get_pmde64(&p, &l, &r, K0, K1); /* get pmd in K1 */
#else
build_get_pgde32(&p, K0, K1); /* get pgd in K1 */
#endif
#ifdef CONFIG_HUGETLB_PAGE
build_is_huge_pte(&p, &r, K0, K1, label_tlb_huge_update);
#endif
build_get_ptep(&p, K0, K1);
build_update_entries(&p, K0, K1);
build_tlb_write_entry(&p, &l, &r, tlb_random);
uasm_l_leave(&l, p);
uasm_i_eret(&p); /* return from trap */
}
#ifdef CONFIG_HUGETLB_PAGE
uasm_l_tlb_huge_update(&l, p);
build_huge_update_entries(&p, htlb_info.huge_pte, K1);
build_huge_tlb_write_entry(&p, &l, &r, K0, tlb_random,
htlb_info.restore_scratch);
#endif
#ifdef CONFIG_64BIT
build_get_pgd_vmalloc64(&p, &l, &r, K0, K1, vmalloc_mode);
#endif
/*
* Overflow check: For the 64bit handler, we need at least one
* free instruction slot for the wrap-around branch. In worst
* case, if the intended insertion point is a delay slot, we
* need three, with the second nop'ed and the third being
* unused.
*/
/* Loongson2 ebase is different than r4k, we have more space */
#if defined(CONFIG_32BIT) || defined(CONFIG_CPU_LOONGSON2)
if ((p - tlb_handler) > 64)
panic("TLB refill handler space exceeded");
#else
if (((p - tlb_handler) > (MIPS64_REFILL_INSNS * 2) - 1)
|| (((p - tlb_handler) > (MIPS64_REFILL_INSNS * 2) - 3)
&& uasm_insn_has_bdelay(relocs,
tlb_handler + MIPS64_REFILL_INSNS - 3)))
panic("TLB refill handler space exceeded");
#endif
/*
* Now fold the handler in the TLB refill handler space.
*/
#if defined(CONFIG_32BIT) || defined(CONFIG_CPU_LOONGSON2)
f = final_handler;
/* Simplest case, just copy the handler. */
uasm_copy_handler(relocs, labels, tlb_handler, p, f);
final_len = p - tlb_handler;
#else /* CONFIG_64BIT */
f = final_handler + MIPS64_REFILL_INSNS;
if ((p - tlb_handler) <= MIPS64_REFILL_INSNS) {
/* Just copy the handler. */
uasm_copy_handler(relocs, labels, tlb_handler, p, f);
final_len = p - tlb_handler;
} else {
#if defined(CONFIG_HUGETLB_PAGE)
const enum label_id ls = label_tlb_huge_update;
#else
const enum label_id ls = label_vmalloc;
#endif
u32 *split;
int ov = 0;
int i;
for (i = 0; i < ARRAY_SIZE(labels) && labels[i].lab != ls; i++)
;
BUG_ON(i == ARRAY_SIZE(labels));
split = labels[i].addr;
/*
* See if we have overflown one way or the other.
*/
if (split > tlb_handler + MIPS64_REFILL_INSNS ||
split < p - MIPS64_REFILL_INSNS)
ov = 1;
if (ov) {
/*
* Split two instructions before the end. One
* for the branch and one for the instruction
* in the delay slot.
*/
split = tlb_handler + MIPS64_REFILL_INSNS - 2;
/*
* If the branch would fall in a delay slot,
* we must back up an additional instruction
* so that it is no longer in a delay slot.
*/
if (uasm_insn_has_bdelay(relocs, split - 1))
split--;
}
/* Copy first part of the handler. */
uasm_copy_handler(relocs, labels, tlb_handler, split, f);
f += split - tlb_handler;
if (ov) {
/* Insert branch. */
uasm_l_split(&l, final_handler);
uasm_il_b(&f, &r, label_split);
if (uasm_insn_has_bdelay(relocs, split))
uasm_i_nop(&f);
else {
uasm_copy_handler(relocs, labels,
split, split + 1, f);
uasm_move_labels(labels, f, f + 1, -1);
f++;
split++;
}
}
/* Copy the rest of the handler. */
uasm_copy_handler(relocs, labels, split, p, final_handler);
final_len = (f - (final_handler + MIPS64_REFILL_INSNS)) +
(p - split);
}
#endif /* CONFIG_64BIT */
uasm_resolve_relocs(relocs, labels);
pr_debug("Wrote TLB refill handler (%u instructions).\n",
final_len);
memcpy((void *)ebase, final_handler, 0x100);
dump_handler((u32 *)ebase, 64);
}
/*
* 128 instructions for the fastpath handler is generous and should
* never be exceeded.
*/
#define FASTPATH_SIZE 128
u32 handle_tlbl[FASTPATH_SIZE] __cacheline_aligned;
u32 handle_tlbs[FASTPATH_SIZE] __cacheline_aligned;
u32 handle_tlbm[FASTPATH_SIZE] __cacheline_aligned;
#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
u32 tlbmiss_handler_setup_pgd[16] __cacheline_aligned;
static void __cpuinit build_r4000_setup_pgd(void)
{
const int a0 = 4;
const int a1 = 5;
u32 *p = tlbmiss_handler_setup_pgd;
struct uasm_label *l = labels;
struct uasm_reloc *r = relocs;
memset(tlbmiss_handler_setup_pgd, 0, sizeof(tlbmiss_handler_setup_pgd));
memset(labels, 0, sizeof(labels));
memset(relocs, 0, sizeof(relocs));
pgd_reg = allocate_kscratch();
if (pgd_reg == -1) {
/* PGD << 11 in c0_Context */
/*
* If it is a ckseg0 address, convert to a physical
* address. Shifting right by 29 and adding 4 will
* result in zero for these addresses.
*
*/
UASM_i_SRA(&p, a1, a0, 29);
UASM_i_ADDIU(&p, a1, a1, 4);
uasm_il_bnez(&p, &r, a1, label_tlbl_goaround1);
uasm_i_nop(&p);
uasm_i_dinsm(&p, a0, 0, 29, 64 - 29);
uasm_l_tlbl_goaround1(&l, p);
UASM_i_SLL(&p, a0, a0, 11);
uasm_i_jr(&p, 31);
UASM_i_MTC0(&p, a0, C0_CONTEXT);
} else {
/* PGD in c0_KScratch */
uasm_i_jr(&p, 31);
UASM_i_MTC0(&p, a0, 31, pgd_reg);
}
if (p - tlbmiss_handler_setup_pgd > ARRAY_SIZE(tlbmiss_handler_setup_pgd))
panic("tlbmiss_handler_setup_pgd space exceeded");
uasm_resolve_relocs(relocs, labels);
pr_debug("Wrote tlbmiss_handler_setup_pgd (%u instructions).\n",
(unsigned int)(p - tlbmiss_handler_setup_pgd));
dump_handler(tlbmiss_handler_setup_pgd,
ARRAY_SIZE(tlbmiss_handler_setup_pgd));
}
#endif
static void __cpuinit
iPTE_LW(u32 **p, unsigned int pte, unsigned int ptr)
{
#ifdef CONFIG_SMP
# ifdef CONFIG_64BIT_PHYS_ADDR
if (cpu_has_64bits)
uasm_i_lld(p, pte, 0, ptr);
else
# endif
UASM_i_LL(p, pte, 0, ptr);
#else
# ifdef CONFIG_64BIT_PHYS_ADDR
if (cpu_has_64bits)
uasm_i_ld(p, pte, 0, ptr);
else
# endif
UASM_i_LW(p, pte, 0, ptr);
#endif
}
static void __cpuinit
iPTE_SW(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr,
unsigned int mode)
{
#ifdef CONFIG_64BIT_PHYS_ADDR
unsigned int hwmode = mode & (_PAGE_VALID | _PAGE_DIRTY);
#endif
uasm_i_ori(p, pte, pte, mode);
#ifdef CONFIG_SMP
# ifdef CONFIG_64BIT_PHYS_ADDR
if (cpu_has_64bits)
uasm_i_scd(p, pte, 0, ptr);
else
# endif
UASM_i_SC(p, pte, 0, ptr);
if (r10000_llsc_war())
uasm_il_beqzl(p, r, pte, label_smp_pgtable_change);
else
uasm_il_beqz(p, r, pte, label_smp_pgtable_change);
# ifdef CONFIG_64BIT_PHYS_ADDR
if (!cpu_has_64bits) {
/* no uasm_i_nop needed */
uasm_i_ll(p, pte, sizeof(pte_t) / 2, ptr);
uasm_i_ori(p, pte, pte, hwmode);
uasm_i_sc(p, pte, sizeof(pte_t) / 2, ptr);
uasm_il_beqz(p, r, pte, label_smp_pgtable_change);
/* no uasm_i_nop needed */
uasm_i_lw(p, pte, 0, ptr);
} else
uasm_i_nop(p);
# else
uasm_i_nop(p);
# endif
#else
# ifdef CONFIG_64BIT_PHYS_ADDR
if (cpu_has_64bits)
uasm_i_sd(p, pte, 0, ptr);
else
# endif
UASM_i_SW(p, pte, 0, ptr);
# ifdef CONFIG_64BIT_PHYS_ADDR
if (!cpu_has_64bits) {
uasm_i_lw(p, pte, sizeof(pte_t) / 2, ptr);
uasm_i_ori(p, pte, pte, hwmode);
uasm_i_sw(p, pte, sizeof(pte_t) / 2, ptr);
uasm_i_lw(p, pte, 0, ptr);
}
# endif
#endif
}
/*
* Check if PTE is present, if not then jump to LABEL. PTR points to
* the page table where this PTE is located, PTE will be re-loaded
* with it's original value.
*/
static void __cpuinit
build_pte_present(u32 **p, struct uasm_reloc **r,
int pte, int ptr, int scratch, enum label_id lid)
{
int t = scratch >= 0 ? scratch : pte;
if (kernel_uses_smartmips_rixi) {
if (use_bbit_insns()) {
uasm_il_bbit0(p, r, pte, ilog2(_PAGE_PRESENT), lid);
uasm_i_nop(p);
} else {
uasm_i_andi(p, t, pte, _PAGE_PRESENT);
uasm_il_beqz(p, r, t, lid);
if (pte == t)
/* You lose the SMP race :-(*/
iPTE_LW(p, pte, ptr);
}
} else {
uasm_i_andi(p, t, pte, _PAGE_PRESENT | _PAGE_READ);
uasm_i_xori(p, t, t, _PAGE_PRESENT | _PAGE_READ);
uasm_il_bnez(p, r, t, lid);
if (pte == t)
/* You lose the SMP race :-(*/
iPTE_LW(p, pte, ptr);
}
}
/* Make PTE valid, store result in PTR. */
static void __cpuinit
build_make_valid(u32 **p, struct uasm_reloc **r, unsigned int pte,
unsigned int ptr)
{
unsigned int mode = _PAGE_VALID | _PAGE_ACCESSED;
iPTE_SW(p, r, pte, ptr, mode);
}
/*
* Check if PTE can be written to, if not branch to LABEL. Regardless
* restore PTE with value from PTR when done.
*/
static void __cpuinit
build_pte_writable(u32 **p, struct uasm_reloc **r,
unsigned int pte, unsigned int ptr, int scratch,
enum label_id lid)
{
int t = scratch >= 0 ? scratch : pte;
uasm_i_andi(p, t, pte, _PAGE_PRESENT | _PAGE_WRITE);
uasm_i_xori(p, t, t, _PAGE_PRESENT | _PAGE_WRITE);
uasm_il_bnez(p, r, t, lid);
if (pte == t)
/* You lose the SMP race :-(*/
iPTE_LW(p, pte, ptr);
else
uasm_i_nop(p);
}
/* Make PTE writable, update software status bits as well, then store
* at PTR.
*/
static void __cpuinit
build_make_write(u32 **p, struct uasm_reloc **r, unsigned int pte,
unsigned int ptr)
{
unsigned int mode = (_PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID
| _PAGE_DIRTY);
iPTE_SW(p, r, pte, ptr, mode);
}
/*
* Check if PTE can be modified, if not branch to LABEL. Regardless
* restore PTE with value from PTR when done.
*/
static void __cpuinit
build_pte_modifiable(u32 **p, struct uasm_reloc **r,
unsigned int pte, unsigned int ptr, int scratch,
enum label_id lid)
{
if (use_bbit_insns()) {
uasm_il_bbit0(p, r, pte, ilog2(_PAGE_WRITE), lid);
uasm_i_nop(p);
} else {
int t = scratch >= 0 ? scratch : pte;
uasm_i_andi(p, t, pte, _PAGE_WRITE);
uasm_il_beqz(p, r, t, lid);
if (pte == t)
/* You lose the SMP race :-(*/
iPTE_LW(p, pte, ptr);
}
}
#ifndef CONFIG_MIPS_PGD_C0_CONTEXT
/*
* R3000 style TLB load/store/modify handlers.
*/
/*
* This places the pte into ENTRYLO0 and writes it with tlbwi.
* Then it returns.
*/
static void __cpuinit
build_r3000_pte_reload_tlbwi(u32 **p, unsigned int pte, unsigned int tmp)
{
uasm_i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */
uasm_i_mfc0(p, tmp, C0_EPC); /* cp0 delay */
uasm_i_tlbwi(p);
uasm_i_jr(p, tmp);
uasm_i_rfe(p); /* branch delay */
}
/*
* This places the pte into ENTRYLO0 and writes it with tlbwi
* or tlbwr as appropriate. This is because the index register
* may have the probe fail bit set as a result of a trap on a
* kseg2 access, i.e. without refill. Then it returns.
*/
static void __cpuinit
build_r3000_tlb_reload_write(u32 **p, struct uasm_label **l,
struct uasm_reloc **r, unsigned int pte,
unsigned int tmp)
{
uasm_i_mfc0(p, tmp, C0_INDEX);
uasm_i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */
uasm_il_bltz(p, r, tmp, label_r3000_write_probe_fail); /* cp0 delay */
uasm_i_mfc0(p, tmp, C0_EPC); /* branch delay */
uasm_i_tlbwi(p); /* cp0 delay */
uasm_i_jr(p, tmp);
uasm_i_rfe(p); /* branch delay */
uasm_l_r3000_write_probe_fail(l, *p);
uasm_i_tlbwr(p); /* cp0 delay */
uasm_i_jr(p, tmp);
uasm_i_rfe(p); /* branch delay */
}
static void __cpuinit
build_r3000_tlbchange_handler_head(u32 **p, unsigned int pte,
unsigned int ptr)
{
long pgdc = (long)pgd_current;
uasm_i_mfc0(p, pte, C0_BADVADDR);
uasm_i_lui(p, ptr, uasm_rel_hi(pgdc)); /* cp0 delay */
uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr);
uasm_i_srl(p, pte, pte, 22); /* load delay */
uasm_i_sll(p, pte, pte, 2);
uasm_i_addu(p, ptr, ptr, pte);
uasm_i_mfc0(p, pte, C0_CONTEXT);
uasm_i_lw(p, ptr, 0, ptr); /* cp0 delay */
uasm_i_andi(p, pte, pte, 0xffc); /* load delay */
uasm_i_addu(p, ptr, ptr, pte);
uasm_i_lw(p, pte, 0, ptr);
uasm_i_tlbp(p); /* load delay */
}
static void __cpuinit build_r3000_tlb_load_handler(void)
{
u32 *p = handle_tlbl;
struct uasm_label *l = labels;
struct uasm_reloc *r = relocs;
memset(handle_tlbl, 0, sizeof(handle_tlbl));
memset(labels, 0, sizeof(labels));
memset(relocs, 0, sizeof(relocs));
build_r3000_tlbchange_handler_head(&p, K0, K1);
build_pte_present(&p, &r, K0, K1, -1, label_nopage_tlbl);
uasm_i_nop(&p); /* load delay */
build_make_valid(&p, &r, K0, K1);
build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);
uasm_l_nopage_tlbl(&l, p);
uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
uasm_i_nop(&p);
if ((p - handle_tlbl) > FASTPATH_SIZE)
panic("TLB load handler fastpath space exceeded");
uasm_resolve_relocs(relocs, labels);
pr_debug("Wrote TLB load handler fastpath (%u instructions).\n",
(unsigned int)(p - handle_tlbl));
dump_handler(handle_tlbl, ARRAY_SIZE(handle_tlbl));
}
static void __cpuinit build_r3000_tlb_store_handler(void)
{
u32 *p = handle_tlbs;
struct uasm_label *l = labels;
struct uasm_reloc *r = relocs;
memset(handle_tlbs, 0, sizeof(handle_tlbs));
memset(labels, 0, sizeof(labels));
memset(relocs, 0, sizeof(relocs));
build_r3000_tlbchange_handler_head(&p, K0, K1);
build_pte_writable(&p, &r, K0, K1, -1, label_nopage_tlbs);
uasm_i_nop(&p); /* load delay */
build_make_write(&p, &r, K0, K1);
build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);
uasm_l_nopage_tlbs(&l, p);
uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
uasm_i_nop(&p);
if ((p - handle_tlbs) > FASTPATH_SIZE)
panic("TLB store handler fastpath space exceeded");
uasm_resolve_relocs(relocs, labels);
pr_debug("Wrote TLB store handler fastpath (%u instructions).\n",
(unsigned int)(p - handle_tlbs));
dump_handler(handle_tlbs, ARRAY_SIZE(handle_tlbs));
}
static void __cpuinit build_r3000_tlb_modify_handler(void)
{
u32 *p = handle_tlbm;
struct uasm_label *l = labels;
struct uasm_reloc *r = relocs;
struct work_registers wr;
memset(handle_tlbm, 0, sizeof(handle_tlbm));
memset(labels, 0, sizeof(labels));
memset(relocs, 0, sizeof(relocs));
build_r3000_tlbchange_handler_head(&p, K0, K1);
build_pte_modifiable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbm);
uasm_i_nop(&p); /* load delay */
build_make_write(&p, &r, K0, K1);
build_r3000_pte_reload_tlbwi(&p, K0, K1);
uasm_l_nopage_tlbm(&l, p);
uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
uasm_i_nop(&p);
if ((p - handle_tlbm) > FASTPATH_SIZE)
panic("TLB modify handler fastpath space exceeded");
uasm_resolve_relocs(relocs, labels);
pr_debug("Wrote TLB modify handler fastpath (%u instructions).\n",
(unsigned int)(p - handle_tlbm));
dump_handler(handle_tlbm, ARRAY_SIZE(handle_tlbm));
}
#endif /* CONFIG_MIPS_PGD_C0_CONTEXT */
/*
* R4000 style TLB load/store/modify handlers.
*/
static struct work_registers __cpuinit
build_r4000_tlbchange_handler_head(u32 **p, struct uasm_label **l,
struct uasm_reloc **r)
{
struct work_registers wr = build_get_work_registers(p);
#ifdef CONFIG_64BIT
build_get_pmde64(p, l, r, wr.r1, wr.r2); /* get pmd in ptr */
#else
build_get_pgde32(p, wr.r1, wr.r2); /* get pgd in ptr */
#endif
#ifdef CONFIG_HUGETLB_PAGE
/*
* For huge tlb entries, pmd doesn't contain an address but
* instead contains the tlb pte. Check the PAGE_HUGE bit and
* see if we need to jump to huge tlb processing.
*/
build_is_huge_pte(p, r, wr.r1, wr.r2, label_tlb_huge_update);
#endif
UASM_i_MFC0(p, wr.r1, C0_BADVADDR);
UASM_i_LW(p, wr.r2, 0, wr.r2);
UASM_i_SRL(p, wr.r1, wr.r1, PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2);
uasm_i_andi(p, wr.r1, wr.r1, (PTRS_PER_PTE - 1) << PTE_T_LOG2);
UASM_i_ADDU(p, wr.r2, wr.r2, wr.r1);
#ifdef CONFIG_SMP
uasm_l_smp_pgtable_change(l, *p);
#endif
iPTE_LW(p, wr.r1, wr.r2); /* get even pte */
if (!m4kc_tlbp_war())
build_tlb_probe_entry(p);
return wr;
}
static void __cpuinit
build_r4000_tlbchange_handler_tail(u32 **p, struct uasm_label **l,
struct uasm_reloc **r, unsigned int tmp,
unsigned int ptr)
{
uasm_i_ori(p, ptr, ptr, sizeof(pte_t));
uasm_i_xori(p, ptr, ptr, sizeof(pte_t));
build_update_entries(p, tmp, ptr);
build_tlb_write_entry(p, l, r, tlb_indexed);
uasm_l_leave(l, *p);
build_restore_work_registers(p);
uasm_i_eret(p); /* return from trap */
#ifdef CONFIG_64BIT
build_get_pgd_vmalloc64(p, l, r, tmp, ptr, not_refill);
#endif
}
static void __cpuinit build_r4000_tlb_load_handler(void)
{
u32 *p = handle_tlbl;
struct uasm_label *l = labels;
struct uasm_reloc *r = relocs;
struct work_registers wr;
memset(handle_tlbl, 0, sizeof(handle_tlbl));
memset(labels, 0, sizeof(labels));
memset(relocs, 0, sizeof(relocs));
if (bcm1250_m3_war()) {
unsigned int segbits = 44;
uasm_i_dmfc0(&p, K0, C0_BADVADDR);
uasm_i_dmfc0(&p, K1, C0_ENTRYHI);
uasm_i_xor(&p, K0, K0, K1);
uasm_i_dsrl_safe(&p, K1, K0, 62);
uasm_i_dsrl_safe(&p, K0, K0, 12 + 1);
uasm_i_dsll_safe(&p, K0, K0, 64 + 12 + 1 - segbits);
uasm_i_or(&p, K0, K0, K1);
uasm_il_bnez(&p, &r, K0, label_leave);
/* No need for uasm_i_nop */
}
wr = build_r4000_tlbchange_handler_head(&p, &l, &r);
build_pte_present(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbl);
if (m4kc_tlbp_war())
build_tlb_probe_entry(&p);
if (kernel_uses_smartmips_rixi) {
/*
* If the page is not _PAGE_VALID, RI or XI could not
* have triggered it. Skip the expensive test..
*/
if (use_bbit_insns()) {
uasm_il_bbit0(&p, &r, wr.r1, ilog2(_PAGE_VALID),
label_tlbl_goaround1);
} else {
uasm_i_andi(&p, wr.r3, wr.r1, _PAGE_VALID);
uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround1);
}
uasm_i_nop(&p);
uasm_i_tlbr(&p);
/* Examine entrylo 0 or 1 based on ptr. */
if (use_bbit_insns()) {
uasm_i_bbit0(&p, wr.r2, ilog2(sizeof(pte_t)), 8);
} else {
uasm_i_andi(&p, wr.r3, wr.r2, sizeof(pte_t));
uasm_i_beqz(&p, wr.r3, 8);
}
/* load it in the delay slot*/
UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO0);
/* load it if ptr is odd */
UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO1);
/*
* If the entryLo (now in wr.r3) is valid (bit 1), RI or
* XI must have triggered it.
*/
if (use_bbit_insns()) {
uasm_il_bbit1(&p, &r, wr.r3, 1, label_nopage_tlbl);
uasm_i_nop(&p);
uasm_l_tlbl_goaround1(&l, p);
} else {
uasm_i_andi(&p, wr.r3, wr.r3, 2);
uasm_il_bnez(&p, &r, wr.r3, label_nopage_tlbl);
uasm_i_nop(&p);
}
uasm_l_tlbl_goaround1(&l, p);
}
build_make_valid(&p, &r, wr.r1, wr.r2);
build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);
#ifdef CONFIG_HUGETLB_PAGE
/*
* This is the entry point when build_r4000_tlbchange_handler_head
* spots a huge page.
*/
uasm_l_tlb_huge_update(&l, p);
iPTE_LW(&p, wr.r1, wr.r2);
build_pte_present(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbl);
build_tlb_probe_entry(&p);
if (kernel_uses_smartmips_rixi) {
/*
* If the page is not _PAGE_VALID, RI or XI could not
* have triggered it. Skip the expensive test..
*/
if (use_bbit_insns()) {
uasm_il_bbit0(&p, &r, wr.r1, ilog2(_PAGE_VALID),
label_tlbl_goaround2);
} else {
uasm_i_andi(&p, wr.r3, wr.r1, _PAGE_VALID);
uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround2);
}
uasm_i_nop(&p);
uasm_i_tlbr(&p);
/* Examine entrylo 0 or 1 based on ptr. */
if (use_bbit_insns()) {
uasm_i_bbit0(&p, wr.r2, ilog2(sizeof(pte_t)), 8);
} else {
uasm_i_andi(&p, wr.r3, wr.r2, sizeof(pte_t));
uasm_i_beqz(&p, wr.r3, 8);
}
/* load it in the delay slot*/
UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO0);
/* load it if ptr is odd */
UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO1);
/*
* If the entryLo (now in wr.r3) is valid (bit 1), RI or
* XI must have triggered it.
*/
if (use_bbit_insns()) {
uasm_il_bbit0(&p, &r, wr.r3, 1, label_tlbl_goaround2);
} else {
uasm_i_andi(&p, wr.r3, wr.r3, 2);
uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround2);
}
/*
* We clobbered C0_PAGEMASK, restore it. On the other branch
* it is restored in build_huge_tlb_write_entry.
*/
build_restore_pagemask(&p, &r, wr.r3, label_nopage_tlbl, 0);
uasm_l_tlbl_goaround2(&l, p);
}
uasm_i_ori(&p, wr.r1, wr.r1, (_PAGE_ACCESSED | _PAGE_VALID));
build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2);
#endif
uasm_l_nopage_tlbl(&l, p);
build_restore_work_registers(&p);
uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
uasm_i_nop(&p);
if ((p - handle_tlbl) > FASTPATH_SIZE)
panic("TLB load handler fastpath space exceeded");
uasm_resolve_relocs(relocs, labels);
pr_debug("Wrote TLB load handler fastpath (%u instructions).\n",
(unsigned int)(p - handle_tlbl));
dump_handler(handle_tlbl, ARRAY_SIZE(handle_tlbl));
}
static void __cpuinit build_r4000_tlb_store_handler(void)
{
u32 *p = handle_tlbs;
struct uasm_label *l = labels;
struct uasm_reloc *r = relocs;
struct work_registers wr;
memset(handle_tlbs, 0, sizeof(handle_tlbs));
memset(labels, 0, sizeof(labels));
memset(relocs, 0, sizeof(relocs));
wr = build_r4000_tlbchange_handler_head(&p, &l, &r);
build_pte_writable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbs);
if (m4kc_tlbp_war())
build_tlb_probe_entry(&p);
build_make_write(&p, &r, wr.r1, wr.r2);
build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);
#ifdef CONFIG_HUGETLB_PAGE
/*
* This is the entry point when
* build_r4000_tlbchange_handler_head spots a huge page.
*/
uasm_l_tlb_huge_update(&l, p);
iPTE_LW(&p, wr.r1, wr.r2);
build_pte_writable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbs);
build_tlb_probe_entry(&p);
uasm_i_ori(&p, wr.r1, wr.r1,
_PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY);
build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2);
#endif
uasm_l_nopage_tlbs(&l, p);
build_restore_work_registers(&p);
uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
uasm_i_nop(&p);
if ((p - handle_tlbs) > FASTPATH_SIZE)
panic("TLB store handler fastpath space exceeded");
uasm_resolve_relocs(relocs, labels);
pr_debug("Wrote TLB store handler fastpath (%u instructions).\n",
(unsigned int)(p - handle_tlbs));
dump_handler(handle_tlbs, ARRAY_SIZE(handle_tlbs));
}
static void __cpuinit build_r4000_tlb_modify_handler(void)
{
u32 *p = handle_tlbm;
struct uasm_label *l = labels;
struct uasm_reloc *r = relocs;
struct work_registers wr;
memset(handle_tlbm, 0, sizeof(handle_tlbm));
memset(labels, 0, sizeof(labels));
memset(relocs, 0, sizeof(relocs));
wr = build_r4000_tlbchange_handler_head(&p, &l, &r);
build_pte_modifiable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbm);
if (m4kc_tlbp_war())
build_tlb_probe_entry(&p);
/* Present and writable bits set, set accessed and dirty bits. */
build_make_write(&p, &r, wr.r1, wr.r2);
build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);
#ifdef CONFIG_HUGETLB_PAGE
/*
* This is the entry point when
* build_r4000_tlbchange_handler_head spots a huge page.
*/
uasm_l_tlb_huge_update(&l, p);
iPTE_LW(&p, wr.r1, wr.r2);
build_pte_modifiable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbm);
build_tlb_probe_entry(&p);
uasm_i_ori(&p, wr.r1, wr.r1,
_PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY);
build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2);
#endif
uasm_l_nopage_tlbm(&l, p);
build_restore_work_registers(&p);
uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
uasm_i_nop(&p);
if ((p - handle_tlbm) > FASTPATH_SIZE)
panic("TLB modify handler fastpath space exceeded");
uasm_resolve_relocs(relocs, labels);
pr_debug("Wrote TLB modify handler fastpath (%u instructions).\n",
(unsigned int)(p - handle_tlbm));
dump_handler(handle_tlbm, ARRAY_SIZE(handle_tlbm));
}
void __cpuinit build_tlb_refill_handler(void)
{
/*
* The refill handler is generated per-CPU, multi-node systems
* may have local storage for it. The other handlers are only
* needed once.
*/
static int run_once = 0;
#ifdef CONFIG_64BIT
check_for_high_segbits = current_cpu_data.vmbits > (PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3);
#endif
switch (current_cpu_type()) {
case CPU_R2000:
case CPU_R3000:
case CPU_R3000A:
case CPU_R3081E:
case CPU_TX3912:
case CPU_TX3922:
case CPU_TX3927:
#ifndef CONFIG_MIPS_PGD_C0_CONTEXT
build_r3000_tlb_refill_handler();
if (!run_once) {
build_r3000_tlb_load_handler();
build_r3000_tlb_store_handler();
build_r3000_tlb_modify_handler();
run_once++;
}
#else
panic("No R3000 TLB refill handler");
#endif
break;
case CPU_R6000:
case CPU_R6000A:
panic("No R6000 TLB refill handler yet");
break;
case CPU_R8000:
panic("No R8000 TLB refill handler yet");
break;
default:
if (!run_once) {
scratch_reg = allocate_kscratch();
#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
build_r4000_setup_pgd();
#endif
build_r4000_tlb_load_handler();
build_r4000_tlb_store_handler();
build_r4000_tlb_modify_handler();
run_once++;
}
build_r4000_tlb_refill_handler();
}
}
void __cpuinit flush_tlb_handlers(void)
{
local_flush_icache_range((unsigned long)handle_tlbl,
(unsigned long)handle_tlbl + sizeof(handle_tlbl));
local_flush_icache_range((unsigned long)handle_tlbs,
(unsigned long)handle_tlbs + sizeof(handle_tlbs));
local_flush_icache_range((unsigned long)handle_tlbm,
(unsigned long)handle_tlbm + sizeof(handle_tlbm));
#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
local_flush_icache_range((unsigned long)tlbmiss_handler_setup_pgd,
(unsigned long)tlbmiss_handler_setup_pgd + sizeof(handle_tlbm));
#endif
}
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