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linux/arch/mips/mm/tlbex.c
Huacai Chen e02e07e312
MIPS: Loongson: Introduce and use loongson_llsc_mb() 
On the Loongson-2G/2H/3A/3B there is a hardware flaw that ll/sc and
lld/scd is very weak ordering. We should add sync instructions "before
each ll/lld" and "at the branch-target between ll/sc" to workaround.
Otherwise, this flaw will cause deadlock occasionally (e.g. when doing
heavy load test with LTP).

Below is the explaination of CPU designer:

"For Loongson 3 family, when a memory access instruction (load, store,
or prefetch)'s executing occurs between the execution of LL and SC, the
success or failure of SC is not predictable. Although programmer would
not insert memory access instructions between LL and SC, the memory
instructions before LL in program-order, may dynamically executed
between the execution of LL/SC, so a memory fence (SYNC) is needed
before LL/LLD to avoid this situation.

Since Loongson-3A R2 (3A2000), we have improved our hardware design to
handle this case. But we later deduce a rarely circumstance that some
speculatively executed memory instructions due to branch misprediction
between LL/SC still fall into the above case, so a memory fence (SYNC)
at branch-target (if its target is not between LL/SC) is needed for
Loongson 3A1000, 3B1500, 3A2000 and 3A3000.

Our processor is continually evolving and we aim to to remove all these
workaround-SYNCs around LL/SC for new-come processor."

Here is an example:

Both cpu1 and cpu2 simutaneously run atomic_add by 1 on same atomic var,
this bug cause both 'sc' run by two cpus (in atomic_add) succeed at same
time('sc' return 1), and the variable is only *added by 1*, sometimes,
which is wrong and unacceptable(it should be added by 2).

Why disable fix-loongson3-llsc in compiler?
Because compiler fix will cause problems in kernel's __ex_table section.

This patch fix all the cases in kernel, but:

+. the fix at the end of futex_atomic_cmpxchg_inatomic is for branch-target
of 'bne', there other cases which smp_mb__before_llsc() and smp_llsc_mb() fix
the ll and branch-target coincidently such as atomic_sub_if_positive/
cmpxchg/xchg, just like this one.

+. Loongson 3 does support CONFIG_EDAC_ATOMIC_SCRUB, so no need to touch
edac.h

+. local_ops and cmpxchg_local should not be affected by this bug since
only the owner can write.

+. mips_atomic_set for syscall.c is deprecated and rarely used, just let
it go

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Huang Pei <huangpei@loongson.cn>
[paul.burton@mips.com:
  - Simplify the addition of -mno-fix-loongson3-llsc to cflags, and add
    a comment describing why it's there.
  - Make loongson_llsc_mb() a no-op when
    CONFIG_CPU_LOONGSON3_WORKAROUNDS=n, rather than a compiler memory
    barrier.
  - Add a comment describing the bug & how loongson_llsc_mb() helps
    in asm/barrier.h.]
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: ambrosehua@gmail.com
Cc: Steven J . Hill <Steven.Hill@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: Li Xuefeng <lixuefeng@loongson.cn>
Cc: Xu Chenghua <xuchenghua@loongson.cn>
2019-02-04 10:53:34 -08:00

2656 lines
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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.
* Copyright (C) 2011 MIPS Technologies, Inc.
*
* ... and the days got worse and worse and now you see
* I've gone completely 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/export.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/smp.h>
#include <linux/string.h>
#include <linux/cache.h>
#include <asm/cacheflush.h>
#include <asm/cpu-type.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/war.h>
#include <asm/uasm.h>
#include <asm/setup.h>
#include <asm/tlbex.h>
static int mips_xpa_disabled;
static int __init xpa_disable(char *s)
{
mips_xpa_disabled = 1;
return 1;
}
__setup("noxpa", xpa_disable);
/*
* 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:
case CPU_CAVIUM_OCTEON3:
return 1;
default:
return 0;
}
}
static int use_lwx_insns(void)
{
switch (current_cpu_type()) {
case CPU_CAVIUM_OCTEON2:
case CPU_CAVIUM_OCTEON3:
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 m4kc_tlbp_war(void)
{
return current_cpu_type() == CPU_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_0,
label_split = label_tlbw_hazard_0 + 8,
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_MIPS_HUGE_TLB_SUPPORT
label_tlb_huge_update,
#endif
};
UASM_L_LA(_second_part)
UASM_L_LA(_leave)
UASM_L_LA(_vmalloc)
UASM_L_LA(_vmalloc_done)
/* _tlbw_hazard_x is handled differently. */
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_MIPS_HUGE_TLB_SUPPORT
UASM_L_LA(_tlb_huge_update)
#endif
static int hazard_instance;
static void uasm_bgezl_hazard(u32 **p, struct uasm_reloc **r, int instance)
{
switch (instance) {
case 0 ... 7:
uasm_il_bgezl(p, r, 0, label_tlbw_hazard_0 + instance);
return;
default:
BUG();
}
}
static void uasm_bgezl_label(struct uasm_label **l, u32 **p, int instance)
{
switch (instance) {
case 0 ... 7:
uasm_build_label(l, *p, label_tlbw_hazard_0 + instance);
break;
default:
BUG();
}
}
/*
* pgtable bits are assigned dynamically depending on processor feature
* and statically based on kernel configuration. This spits out the actual
* values the kernel is using. Required to make sense from disassembled
* TLB exception handlers.
*/
static void output_pgtable_bits_defines(void)
{
#define pr_define(fmt, ...) \
pr_debug("#define " fmt, ##__VA_ARGS__)
pr_debug("#include <asm/asm.h>\n");
pr_debug("#include <asm/regdef.h>\n");
pr_debug("\n");
pr_define("_PAGE_PRESENT_SHIFT %d\n", _PAGE_PRESENT_SHIFT);
pr_define("_PAGE_NO_READ_SHIFT %d\n", _PAGE_NO_READ_SHIFT);
pr_define("_PAGE_WRITE_SHIFT %d\n", _PAGE_WRITE_SHIFT);
pr_define("_PAGE_ACCESSED_SHIFT %d\n", _PAGE_ACCESSED_SHIFT);
pr_define("_PAGE_MODIFIED_SHIFT %d\n", _PAGE_MODIFIED_SHIFT);
#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
pr_define("_PAGE_HUGE_SHIFT %d\n", _PAGE_HUGE_SHIFT);
#endif
#ifdef _PAGE_NO_EXEC_SHIFT
if (cpu_has_rixi)
pr_define("_PAGE_NO_EXEC_SHIFT %d\n", _PAGE_NO_EXEC_SHIFT);
#endif
pr_define("_PAGE_GLOBAL_SHIFT %d\n", _PAGE_GLOBAL_SHIFT);
pr_define("_PAGE_VALID_SHIFT %d\n", _PAGE_VALID_SHIFT);
pr_define("_PAGE_DIRTY_SHIFT %d\n", _PAGE_DIRTY_SHIFT);
pr_define("_PFN_SHIFT %d\n", _PFN_SHIFT);
pr_debug("\n");
}
static inline void dump_handler(const char *symbol, const void *start, const void *end)
{
unsigned int count = (end - start) / sizeof(u32);
const u32 *handler = start;
int i;
pr_debug("LEAF(%s)\n", symbol);
pr_debug("\t.set push\n");
pr_debug("\t.set noreorder\n");
for (i = 0; i < count; i++)
pr_debug("\t.word\t0x%08x\t\t# %p\n", handler[i], &handler[i]);
pr_debug("\t.set\tpop\n");
pr_debug("\tEND(%s)\n", symbol);
}
/* 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_PWBASE 5, 5
#define C0_PWFIELD 5, 6
#define C0_PWSIZE 5, 7
#define C0_PWCTL 6, 6
#define C0_BADVADDR 8, 0
#define C0_PGD 9, 7
#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];
/* simply assume worst case size for labels and relocs */
static struct uasm_label labels[128];
static struct uasm_reloc relocs[128];
static int check_for_high_segbits;
static bool fill_includes_sw_bits;
static unsigned int kscratch_used_mask;
static inline int __maybe_unused c0_kscratch(void)
{
switch (current_cpu_type()) {
case CPU_XLP:
case CPU_XLR:
return 22;
default:
return 31;
}
}
static int 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;
int pgd_reg;
EXPORT_SYMBOL_GPL(pgd_reg);
enum vmalloc64_mode {not_refill, refill_scratch, refill_noscratch};
static struct work_registers build_get_work_registers(u32 **p)
{
struct work_registers r;
if (scratch_reg >= 0) {
/* Save in CPU local C0_KScratch? */
UASM_i_MTC0(p, 1, c0_kscratch(), scratch_reg);
r.r1 = K0;
r.r2 = K1;
r.r3 = 1;
return r;
}
if (num_possible_cpus() > 1) {
/* Get smp_processor_id */
UASM_i_CPUID_MFC0(p, K0, SMP_CPUID_REG);
UASM_i_SRL_SAFE(p, K0, K0, SMP_CPUID_REGSHIFT);
/* 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 build_restore_work_registers(u32 **p)
{
if (scratch_reg >= 0) {
UASM_i_MFC0(p, 1, c0_kscratch(), 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.
*
* The R3000 TLB handler is simple.
*/
static void 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);
local_flush_icache_range(ebase, ebase + 0x80);
dump_handler("r3000_tlb_refill", (u32 *)ebase, (u32 *)(ebase + 0x80));
}
#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];
/*
* 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 __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_NEVADA:
uasm_i_nop(p);
uasm_i_tlbp(p);
break;
default:
uasm_i_tlbp(p);
break;
}
}
void 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_r6) {
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_bgezl_hazard(p, r, hazard_instance);
tlbw(p);
uasm_bgezl_label(l, p, hazard_instance);
hazard_instance++;
uasm_i_nop(p);
break;
case CPU_R4600:
case CPU_R4700:
uasm_i_nop(p);
tlbw(p);
uasm_i_nop(p);
break;
case CPU_R5000:
case CPU_NEVADA:
uasm_i_nop(p); /* QED specifies 2 nops hazard */
uasm_i_nop(p); /* QED specifies 2 nops hazard */
tlbw(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_R16000:
case CPU_4KC:
case CPU_4KEC:
case CPU_M14KC:
case CPU_M14KEC:
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_LOONGSON3:
case CPU_R5500:
if (m4kc_tlbp_war())
uasm_i_nop(p);
/* fall through */
case CPU_ALCHEMY:
tlbw(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_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_type());
break;
}
}
EXPORT_SYMBOL_GPL(build_tlb_write_entry);
static __maybe_unused void build_convert_pte_to_entrylo(u32 **p,
unsigned int reg)
{
if (_PAGE_GLOBAL_SHIFT == 0) {
/* pte_t is already in EntryLo format */
return;
}
if (cpu_has_rixi && _PAGE_NO_EXEC) {
if (fill_includes_sw_bits) {
UASM_i_ROTR(p, reg, reg, ilog2(_PAGE_GLOBAL));
} else {
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_PHYS_ADDR_T_64BIT
uasm_i_dsrl_safe(p, reg, reg, ilog2(_PAGE_GLOBAL));
#else
UASM_i_SRL(p, reg, reg, ilog2(_PAGE_GLOBAL));
#endif
}
}
#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
static 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, c0_kscratch(), 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 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
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 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 void build_huge_handler_tail(u32 **p, struct uasm_reloc **r,
struct uasm_label **l,
unsigned int pte,
unsigned int ptr,
unsigned int flush)
{
#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
if (cpu_has_ftlb && flush) {
BUG_ON(!cpu_has_tlbinv);
UASM_i_MFC0(p, ptr, C0_ENTRYHI);
uasm_i_ori(p, ptr, ptr, MIPS_ENTRYHI_EHINV);
UASM_i_MTC0(p, ptr, C0_ENTRYHI);
build_tlb_write_entry(p, l, r, tlb_indexed);
uasm_i_xori(p, ptr, ptr, MIPS_ENTRYHI_EHINV);
UASM_i_MTC0(p, ptr, C0_ENTRYHI);
build_huge_update_entries(p, pte, ptr);
build_huge_tlb_write_entry(p, l, r, pte, tlb_random, 0);
return;
}
build_huge_update_entries(p, pte, ptr);
build_huge_tlb_write_entry(p, l, r, pte, tlb_indexed, 0);
}
#endif /* CONFIG_MIPS_HUGE_TLB_SUPPORT */
#ifdef CONFIG_64BIT
/*
* TMP and PTR are scratch.
* TMP will be clobbered, PTR will hold the pmd entry.
*/
void 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. */
if (pgd_reg != -1) {
/* pgd is in pgd_reg */
if (cpu_has_ldpte)
UASM_i_MFC0(p, ptr, C0_PWBASE);
else
UASM_i_MFC0(p, ptr, c0_kscratch(), pgd_reg);
} else {
#if defined(CONFIG_MIPS_PGD_C0_CONTEXT)
/*
* &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)
UASM_i_CPUID_MFC0(p, ptr, SMP_CPUID_REG);
uasm_i_dsrl_safe(p, ptr, ptr, SMP_CPUID_PTRSHIFT);
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_PUD_FOLDED
uasm_i_dmfc0(p, tmp, C0_BADVADDR); /* get faulting address */
uasm_i_ld(p, ptr, 0, ptr); /* get pud pointer */
uasm_i_dsrl_safe(p, tmp, tmp, PUD_SHIFT - 3); /* get pud offset in bytes */
uasm_i_andi(p, tmp, tmp, (PTRS_PER_PUD - 1) << 3);
uasm_i_daddu(p, ptr, ptr, tmp); /* add in pud offset */
#endif
#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
}
EXPORT_SYMBOL_GPL(build_get_pmde64);
/*
* BVADDR is the faulting address, PTR is scratch.
* PTR will hold the pgd for vmalloc.
*/
static void
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 (single_insn_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.
*/
if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS))
uasm_i_sync(p, 0);
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, c0_kscratch(), 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.
*/
void build_get_pgde32(u32 **p, unsigned int tmp, unsigned int ptr)
{
if (pgd_reg != -1) {
/* pgd is in pgd_reg */
uasm_i_mfc0(p, ptr, c0_kscratch(), pgd_reg);
uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */
} else {
long pgdc = (long)pgd_current;
/* 32 bit SMP has smp_processor_id() stored in CONTEXT. */
#ifdef CONFIG_SMP
uasm_i_mfc0(p, ptr, SMP_CPUID_REG);
UASM_i_LA_mostly(p, tmp, pgdc);
uasm_i_srl(p, ptr, ptr, SMP_CPUID_PTRSHIFT);
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 */
}
EXPORT_SYMBOL_GPL(build_get_pgde32);
#endif /* !CONFIG_64BIT */
static void 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);
}
void 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 */
}
EXPORT_SYMBOL_GPL(build_get_ptep);
void build_update_entries(u32 **p, unsigned int tmp, unsigned int ptep)
{
int pte_off_even = 0;
int pte_off_odd = sizeof(pte_t);
#if defined(CONFIG_CPU_MIPS32) && defined(CONFIG_PHYS_ADDR_T_64BIT)
/* The low 32 bits of EntryLo is stored in pte_high */
pte_off_even += offsetof(pte_t, pte_high);
pte_off_odd += offsetof(pte_t, pte_high);
#endif
if (IS_ENABLED(CONFIG_XPA)) {
uasm_i_lw(p, tmp, pte_off_even, ptep); /* even pte */
UASM_i_ROTR(p, tmp, tmp, ilog2(_PAGE_GLOBAL));
UASM_i_MTC0(p, tmp, C0_ENTRYLO0);
if (cpu_has_xpa && !mips_xpa_disabled) {
uasm_i_lw(p, tmp, 0, ptep);
uasm_i_ext(p, tmp, tmp, 0, 24);
uasm_i_mthc0(p, tmp, C0_ENTRYLO0);
}
uasm_i_lw(p, tmp, pte_off_odd, ptep); /* odd pte */
UASM_i_ROTR(p, tmp, tmp, ilog2(_PAGE_GLOBAL));
UASM_i_MTC0(p, tmp, C0_ENTRYLO1);
if (cpu_has_xpa && !mips_xpa_disabled) {
uasm_i_lw(p, tmp, sizeof(pte_t), ptep);
uasm_i_ext(p, tmp, tmp, 0, 24);
uasm_i_mthc0(p, tmp, C0_ENTRYLO1);
}
return;
}
UASM_i_LW(p, tmp, pte_off_even, ptep); /* get even pte */
UASM_i_LW(p, ptep, pte_off_odd, ptep); /* get odd pte */
if (r45k_bvahwbug())
build_tlb_probe_entry(p);
build_convert_pte_to_entrylo(p, tmp);
if (r4k_250MHZhwbug())
UASM_i_MTC0(p, 0, C0_ENTRYLO0);
UASM_i_MTC0(p, tmp, C0_ENTRYLO0); /* load it */
build_convert_pte_to_entrylo(p, ptep);
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 */
}
EXPORT_SYMBOL_GPL(build_update_entries);
struct mips_huge_tlb_info {
int huge_pte;
int restore_scratch;
bool need_reload_pte;
};
static struct mips_huge_tlb_info
build_fast_tlb_refill_handler (u32 **p, struct uasm_label **l,
struct uasm_reloc **r, unsigned int tmp,
unsigned int ptr, int c0_scratch_reg)
{
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;
rv.need_reload_pte = false;
if (check_for_high_segbits) {
UASM_i_MFC0(p, tmp, C0_BADVADDR);
if (pgd_reg != -1)
UASM_i_MFC0(p, ptr, c0_kscratch(), pgd_reg);
else
UASM_i_MFC0(p, ptr, C0_CONTEXT);
if (c0_scratch_reg >= 0)
UASM_i_MTC0(p, scratch, c0_kscratch(), c0_scratch_reg);
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, c0_kscratch(), pgd_reg);
else
UASM_i_MFC0(p, ptr, C0_CONTEXT);
UASM_i_MFC0(p, tmp, C0_BADVADDR);
if (c0_scratch_reg >= 0)
UASM_i_MTC0(p, scratch, c0_kscratch(), c0_scratch_reg);
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_PUD_FOLDED
/* get pud offset in bytes */
uasm_i_dsrl_safe(p, scratch, tmp, PUD_SHIFT - 3);
uasm_i_andi(p, scratch, scratch, (PTRS_PER_PUD - 1) << 3);
if (use_lwx_insns()) {
UASM_i_LWX(p, ptr, scratch, ptr);
} else {
uasm_i_daddu(p, ptr, ptr, scratch); /* add in pmd offset */
UASM_i_LW(p, ptr, 0, ptr);
}
/* ptr contains a pointer to PMD entry */
/* tmp contains the address */
#endif
#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_MIPS_HUGE_TLB_SUPPORT
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_MIPS_HUGE_TLB_SUPPORT */
/* 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 (cpu_has_rixi) {
uasm_i_drotr(p, even, even, ilog2(_PAGE_GLOBAL));
UASM_i_MTC0(p, even, C0_ENTRYLO0); /* load it */
uasm_i_drotr(p, odd, odd, ilog2(_PAGE_GLOBAL));
} 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_reg >= 0) {
UASM_i_MFC0(p, scratch, c0_kscratch(), c0_scratch_reg);
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 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 (IS_ENABLED(CONFIG_64BIT) && (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;
htlb_info.need_reload_pte = true;
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_MIPS_HUGE_TLB_SUPPORT
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_MIPS_HUGE_TLB_SUPPORT
uasm_l_tlb_huge_update(&l, p);
if (htlb_info.need_reload_pte)
UASM_i_LW(&p, htlb_info.huge_pte, 0, K1);
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.
*/
switch (boot_cpu_type()) {
default:
if (sizeof(long) == 4) {
case CPU_LOONGSON2:
/* Loongson2 ebase is different than r4k, we have more space */
if ((p - tlb_handler) > 64)
panic("TLB refill handler space exceeded");
/*
* Now fold the handler in the TLB refill handler space.
*/
f = final_handler;
/* Simplest case, just copy the handler. */
uasm_copy_handler(relocs, labels, tlb_handler, p, f);
final_len = p - tlb_handler;
break;
} 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");
/*
* Now fold the handler in the TLB refill handler space.
*/
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 {
#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
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);
}
}
break;
}
uasm_resolve_relocs(relocs, labels);
pr_debug("Wrote TLB refill handler (%u instructions).\n",
final_len);
memcpy((void *)ebase, final_handler, 0x100);
local_flush_icache_range(ebase, ebase + 0x100);
dump_handler("r4000_tlb_refill", (u32 *)ebase, (u32 *)(ebase + 0x100));
}
static void setup_pw(void)
{
unsigned long pgd_i, pgd_w;
#ifndef __PAGETABLE_PMD_FOLDED
unsigned long pmd_i, pmd_w;
#endif
unsigned long pt_i, pt_w;
unsigned long pte_i, pte_w;
#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
unsigned long psn;
psn = ilog2(_PAGE_HUGE); /* bit used to indicate huge page */
#endif
pgd_i = PGDIR_SHIFT; /* 1st level PGD */
#ifndef __PAGETABLE_PMD_FOLDED
pgd_w = PGDIR_SHIFT - PMD_SHIFT + PGD_ORDER;
pmd_i = PMD_SHIFT; /* 2nd level PMD */
pmd_w = PMD_SHIFT - PAGE_SHIFT;
#else
pgd_w = PGDIR_SHIFT - PAGE_SHIFT + PGD_ORDER;
#endif
pt_i = PAGE_SHIFT; /* 3rd level PTE */
pt_w = PAGE_SHIFT - 3;
pte_i = ilog2(_PAGE_GLOBAL);
pte_w = 0;
#ifndef __PAGETABLE_PMD_FOLDED
write_c0_pwfield(pgd_i << 24 | pmd_i << 12 | pt_i << 6 | pte_i);
write_c0_pwsize(1 << 30 | pgd_w << 24 | pmd_w << 12 | pt_w << 6 | pte_w);
#else
write_c0_pwfield(pgd_i << 24 | pt_i << 6 | pte_i);
write_c0_pwsize(1 << 30 | pgd_w << 24 | pt_w << 6 | pte_w);
#endif
#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
write_c0_pwctl(1 << 6 | psn);
#endif
write_c0_kpgd((long)swapper_pg_dir);
kscratch_used_mask |= (1 << 7); /* KScratch6 is used for KPGD */
}
static void build_loongson3_tlb_refill_handler(void)
{
u32 *p = tlb_handler;
struct uasm_label *l = labels;
struct uasm_reloc *r = relocs;
memset(labels, 0, sizeof(labels));
memset(relocs, 0, sizeof(relocs));
memset(tlb_handler, 0, sizeof(tlb_handler));
if (check_for_high_segbits) {
uasm_i_dmfc0(&p, K0, C0_BADVADDR);
uasm_i_dsrl_safe(&p, K1, K0, PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3);
uasm_il_beqz(&p, &r, K1, label_vmalloc);
uasm_i_nop(&p);
uasm_il_bgez(&p, &r, K0, label_large_segbits_fault);
uasm_i_nop(&p);
uasm_l_vmalloc(&l, p);
}
uasm_i_dmfc0(&p, K1, C0_PGD);
uasm_i_lddir(&p, K0, K1, 3); /* global page dir */
#ifndef __PAGETABLE_PMD_FOLDED
uasm_i_lddir(&p, K1, K0, 1); /* middle page dir */
#endif
uasm_i_ldpte(&p, K1, 0); /* even */
uasm_i_ldpte(&p, K1, 1); /* odd */
uasm_i_tlbwr(&p);
/* restore page mask */
if (PM_DEFAULT_MASK >> 16) {
uasm_i_lui(&p, K0, PM_DEFAULT_MASK >> 16);
uasm_i_ori(&p, K0, K0, PM_DEFAULT_MASK & 0xffff);
uasm_i_mtc0(&p, K0, C0_PAGEMASK);
} else if (PM_DEFAULT_MASK) {
uasm_i_ori(&p, K0, 0, PM_DEFAULT_MASK);
uasm_i_mtc0(&p, K0, C0_PAGEMASK);
} else {
uasm_i_mtc0(&p, 0, C0_PAGEMASK);
}
uasm_i_eret(&p);
if (check_for_high_segbits) {
uasm_l_large_segbits_fault(&l, p);
UASM_i_LA(&p, K1, (unsigned long)tlb_do_page_fault_0);
uasm_i_jr(&p, K1);
uasm_i_nop(&p);
}
uasm_resolve_relocs(relocs, labels);
memcpy((void *)(ebase + 0x80), tlb_handler, 0x80);
local_flush_icache_range(ebase + 0x80, ebase + 0x100);
dump_handler("loongson3_tlb_refill",
(u32 *)(ebase + 0x80), (u32 *)(ebase + 0x100));
}
static void build_setup_pgd(void)
{
const int a0 = 4;
const int __maybe_unused a1 = 5;
const int __maybe_unused a2 = 6;
u32 *p = (u32 *)msk_isa16_mode((ulong)tlbmiss_handler_setup_pgd);
#ifndef CONFIG_MIPS_PGD_C0_CONTEXT
long pgdc = (long)pgd_current;
#endif
memset(p, 0, tlbmiss_handler_setup_pgd_end - (char *)p);
memset(labels, 0, sizeof(labels));
memset(relocs, 0, sizeof(relocs));
pgd_reg = allocate_kscratch();
#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
if (pgd_reg == -1) {
struct uasm_label *l = labels;
struct uasm_reloc *r = relocs;
/* 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);
if (cpu_has_ldpte)
UASM_i_MTC0(&p, a0, C0_PWBASE);
else
UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg);
}
#else
#ifdef CONFIG_SMP
/* Save PGD to pgd_current[smp_processor_id()] */
UASM_i_CPUID_MFC0(&p, a1, SMP_CPUID_REG);
UASM_i_SRL_SAFE(&p, a1, a1, SMP_CPUID_PTRSHIFT);
UASM_i_LA_mostly(&p, a2, pgdc);
UASM_i_ADDU(&p, a2, a2, a1);
UASM_i_SW(&p, a0, uasm_rel_lo(pgdc), a2);
#else
UASM_i_LA_mostly(&p, a2, pgdc);
UASM_i_SW(&p, a0, uasm_rel_lo(pgdc), a2);
#endif /* SMP */
uasm_i_jr(&p, 31);
/* if pgd_reg is allocated, save PGD also to scratch register */
if (pgd_reg != -1)
UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg);
else
uasm_i_nop(&p);
#endif
if (p >= (u32 *)tlbmiss_handler_setup_pgd_end)
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 - (u32 *)tlbmiss_handler_setup_pgd));
dump_handler("tlbmiss_handler", tlbmiss_handler_setup_pgd,
tlbmiss_handler_setup_pgd_end);
}
static void
iPTE_LW(u32 **p, unsigned int pte, unsigned int ptr)
{
#ifdef CONFIG_SMP
if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS))
uasm_i_sync(p, 0);
# ifdef CONFIG_PHYS_ADDR_T_64BIT
if (cpu_has_64bits)
uasm_i_lld(p, pte, 0, ptr);
else
# endif
UASM_i_LL(p, pte, 0, ptr);
#else
# ifdef CONFIG_PHYS_ADDR_T_64BIT
if (cpu_has_64bits)
uasm_i_ld(p, pte, 0, ptr);
else
# endif
UASM_i_LW(p, pte, 0, ptr);
#endif
}
static void
iPTE_SW(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr,
unsigned int mode, unsigned int scratch)
{
unsigned int hwmode = mode & (_PAGE_VALID | _PAGE_DIRTY);
unsigned int swmode = mode & ~hwmode;
if (IS_ENABLED(CONFIG_XPA) && !cpu_has_64bits) {
uasm_i_lui(p, scratch, swmode >> 16);
uasm_i_or(p, pte, pte, scratch);
BUG_ON(swmode & 0xffff);
} else {
uasm_i_ori(p, pte, pte, mode);
}
#ifdef CONFIG_SMP
# ifdef CONFIG_PHYS_ADDR_T_64BIT
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_PHYS_ADDR_T_64BIT
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);
BUG_ON(hwmode & ~0xffff);
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_PHYS_ADDR_T_64BIT
if (cpu_has_64bits)
uasm_i_sd(p, pte, 0, ptr);
else
# endif
UASM_i_SW(p, pte, 0, ptr);
# ifdef CONFIG_PHYS_ADDR_T_64BIT
if (!cpu_has_64bits) {
uasm_i_lw(p, pte, sizeof(pte_t) / 2, ptr);
uasm_i_ori(p, pte, pte, hwmode);
BUG_ON(hwmode & ~0xffff);
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
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;
int cur = pte;
if (cpu_has_rixi) {
if (use_bbit_insns()) {
uasm_il_bbit0(p, r, pte, ilog2(_PAGE_PRESENT), lid);
uasm_i_nop(p);
} else {
if (_PAGE_PRESENT_SHIFT) {
uasm_i_srl(p, t, cur, _PAGE_PRESENT_SHIFT);
cur = t;
}
uasm_i_andi(p, t, cur, 1);
uasm_il_beqz(p, r, t, lid);
if (pte == t)
/* You lose the SMP race :-(*/
iPTE_LW(p, pte, ptr);
}
} else {
if (_PAGE_PRESENT_SHIFT) {
uasm_i_srl(p, t, cur, _PAGE_PRESENT_SHIFT);
cur = t;
}
uasm_i_andi(p, t, cur,
(_PAGE_PRESENT | _PAGE_NO_READ) >> _PAGE_PRESENT_SHIFT);
uasm_i_xori(p, t, t, _PAGE_PRESENT >> _PAGE_PRESENT_SHIFT);
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
build_make_valid(u32 **p, struct uasm_reloc **r, unsigned int pte,
unsigned int ptr, unsigned int scratch)
{
unsigned int mode = _PAGE_VALID | _PAGE_ACCESSED;
iPTE_SW(p, r, pte, ptr, mode, scratch);
}
/*
* Check if PTE can be written to, if not branch to LABEL. Regardless
* restore PTE with value from PTR when done.
*/
static void
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;
int cur = pte;
if (_PAGE_PRESENT_SHIFT) {
uasm_i_srl(p, t, cur, _PAGE_PRESENT_SHIFT);
cur = t;
}
uasm_i_andi(p, t, cur,
(_PAGE_PRESENT | _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT);
uasm_i_xori(p, t, t,
(_PAGE_PRESENT | _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT);
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
build_make_write(u32 **p, struct uasm_reloc **r, unsigned int pte,
unsigned int ptr, unsigned int scratch)
{
unsigned int mode = (_PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID
| _PAGE_DIRTY);
iPTE_SW(p, r, pte, ptr, mode, scratch);
}
/*
* Check if PTE can be modified, if not branch to LABEL. Regardless
* restore PTE with value from PTR when done.
*/
static void
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_srl(p, t, pte, _PAGE_WRITE_SHIFT);
uasm_i_andi(p, t, t, 1);
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
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
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
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 build_r3000_tlb_load_handler(void)
{
u32 *p = (u32 *)handle_tlbl;
struct uasm_label *l = labels;
struct uasm_reloc *r = relocs;
memset(p, 0, handle_tlbl_end - (char *)p);
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, -1);
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 >= (u32 *)handle_tlbl_end)
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 - (u32 *)handle_tlbl));
dump_handler("r3000_tlb_load", handle_tlbl, handle_tlbl_end);
}
static void build_r3000_tlb_store_handler(void)
{
u32 *p = (u32 *)handle_tlbs;
struct uasm_label *l = labels;
struct uasm_reloc *r = relocs;
memset(p, 0, handle_tlbs_end - (char *)p);
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, -1);
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 >= (u32 *)handle_tlbs_end)
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 - (u32 *)handle_tlbs));
dump_handler("r3000_tlb_store", handle_tlbs, handle_tlbs_end);
}
static void build_r3000_tlb_modify_handler(void)
{
u32 *p = (u32 *)handle_tlbm;
struct uasm_label *l = labels;
struct uasm_reloc *r = relocs;
memset(p, 0, handle_tlbm_end - (char *)p);
memset(labels, 0, sizeof(labels));
memset(relocs, 0, sizeof(relocs));
build_r3000_tlbchange_handler_head(&p, K0, K1);
build_pte_modifiable(&p, &r, K0, K1, -1, label_nopage_tlbm);
uasm_i_nop(&p); /* load delay */
build_make_write(&p, &r, K0, K1, -1);
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 >= (u32 *)handle_tlbm_end)
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 - (u32 *)handle_tlbm));
dump_handler("r3000_tlb_modify", handle_tlbm, handle_tlbm_end);
}
#endif /* CONFIG_MIPS_PGD_C0_CONTEXT */
static bool cpu_has_tlbex_tlbp_race(void)
{
/*
* When a Hardware Table Walker is running it can replace TLB entries
* at any time, leading to a race between it & the CPU.
*/
if (cpu_has_htw)
return true;
/*
* If the CPU shares FTLB RAM with its siblings then our entry may be
* replaced at any time by a sibling performing a write to the FTLB.
*/
if (cpu_has_shared_ftlb_ram)
return true;
/* In all other cases there ought to be no race condition to handle */
return false;
}
/*
* R4000 style TLB load/store/modify handlers.
*/
static struct work_registers
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_MIPS_HUGE_TLB_SUPPORT
/*
* 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);
if (cpu_has_tlbex_tlbp_race()) {
/* race condition happens, leaving */
uasm_i_ehb(p);
uasm_i_mfc0(p, wr.r3, C0_INDEX);
uasm_il_bltz(p, r, wr.r3, label_leave);
uasm_i_nop(p);
}
}
return wr;
}
static void
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 build_r4000_tlb_load_handler(void)
{
u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbl);
struct uasm_label *l = labels;
struct uasm_reloc *r = relocs;
struct work_registers wr;
memset(p, 0, handle_tlbl_end - (char *)p);
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 (cpu_has_rixi && !cpu_has_rixiex) {
/*
* 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);
/*
* Warn if something may race with us & replace the TLB entry
* before we read it here. Everything with such races should
* also have dedicated RiXi exception handlers, so this
* shouldn't be hit.
*/
WARN(cpu_has_tlbex_tlbp_race(), "Unhandled race in RiXi path");
uasm_i_tlbr(&p);
switch (current_cpu_type()) {
default:
if (cpu_has_mips_r2_exec_hazard) {
uasm_i_ehb(&p);
case CPU_CAVIUM_OCTEON:
case CPU_CAVIUM_OCTEON_PLUS:
case CPU_CAVIUM_OCTEON2:
break;
}
}
/* 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, wr.r3);
build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);
#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
/*
* 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 (cpu_has_rixi && !cpu_has_rixiex) {
/*
* 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);
/*
* Warn if something may race with us & replace the TLB entry
* before we read it here. Everything with such races should
* also have dedicated RiXi exception handlers, so this
* shouldn't be hit.
*/
WARN(cpu_has_tlbex_tlbp_race(), "Unhandled race in RiXi path");
uasm_i_tlbr(&p);
switch (current_cpu_type()) {
default:
if (cpu_has_mips_r2_exec_hazard) {
uasm_i_ehb(&p);
case CPU_CAVIUM_OCTEON:
case CPU_CAVIUM_OCTEON_PLUS:
case CPU_CAVIUM_OCTEON2:
break;
}
}
/* 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);
}
if (PM_DEFAULT_MASK == 0)
uasm_i_nop(&p);
/*
* 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, 1);
#endif
uasm_l_nopage_tlbl(&l, p);
if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS))
uasm_i_sync(&p, 0);
build_restore_work_registers(&p);
#ifdef CONFIG_CPU_MICROMIPS
if ((unsigned long)tlb_do_page_fault_0 & 1) {
uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_0));
uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_0));
uasm_i_jr(&p, K0);
} else
#endif
uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
uasm_i_nop(&p);
if (p >= (u32 *)handle_tlbl_end)
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 - (u32 *)handle_tlbl));
dump_handler("r4000_tlb_load", handle_tlbl, handle_tlbl_end);
}
static void build_r4000_tlb_store_handler(void)
{
u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbs);
struct uasm_label *l = labels;
struct uasm_reloc *r = relocs;
struct work_registers wr;
memset(p, 0, handle_tlbs_end - (char *)p);
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, wr.r3);
build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);
#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
/*
* 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, 1);
#endif
uasm_l_nopage_tlbs(&l, p);
if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS))
uasm_i_sync(&p, 0);
build_restore_work_registers(&p);
#ifdef CONFIG_CPU_MICROMIPS
if ((unsigned long)tlb_do_page_fault_1 & 1) {
uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_1));
uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_1));
uasm_i_jr(&p, K0);
} else
#endif
uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
uasm_i_nop(&p);
if (p >= (u32 *)handle_tlbs_end)
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 - (u32 *)handle_tlbs));
dump_handler("r4000_tlb_store", handle_tlbs, handle_tlbs_end);
}
static void build_r4000_tlb_modify_handler(void)
{
u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbm);
struct uasm_label *l = labels;
struct uasm_reloc *r = relocs;
struct work_registers wr;
memset(p, 0, handle_tlbm_end - (char *)p);
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, wr.r3);
build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);
#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
/*
* 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, 0);
#endif
uasm_l_nopage_tlbm(&l, p);
if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS))
uasm_i_sync(&p, 0);
build_restore_work_registers(&p);
#ifdef CONFIG_CPU_MICROMIPS
if ((unsigned long)tlb_do_page_fault_1 & 1) {
uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_1));
uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_1));
uasm_i_jr(&p, K0);
} else
#endif
uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
uasm_i_nop(&p);
if (p >= (u32 *)handle_tlbm_end)
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 - (u32 *)handle_tlbm));
dump_handler("r4000_tlb_modify", handle_tlbm, handle_tlbm_end);
}
static void flush_tlb_handlers(void)
{
local_flush_icache_range((unsigned long)handle_tlbl,
(unsigned long)handle_tlbl_end);
local_flush_icache_range((unsigned long)handle_tlbs,
(unsigned long)handle_tlbs_end);
local_flush_icache_range((unsigned long)handle_tlbm,
(unsigned long)handle_tlbm_end);
local_flush_icache_range((unsigned long)tlbmiss_handler_setup_pgd,
(unsigned long)tlbmiss_handler_setup_pgd_end);
}
static void print_htw_config(void)
{
unsigned long config;
unsigned int pwctl;
const int field = 2 * sizeof(unsigned long);
config = read_c0_pwfield();
pr_debug("PWField (0x%0*lx): GDI: 0x%02lx UDI: 0x%02lx MDI: 0x%02lx PTI: 0x%02lx PTEI: 0x%02lx\n",
field, config,
(config & MIPS_PWFIELD_GDI_MASK) >> MIPS_PWFIELD_GDI_SHIFT,
(config & MIPS_PWFIELD_UDI_MASK) >> MIPS_PWFIELD_UDI_SHIFT,
(config & MIPS_PWFIELD_MDI_MASK) >> MIPS_PWFIELD_MDI_SHIFT,
(config & MIPS_PWFIELD_PTI_MASK) >> MIPS_PWFIELD_PTI_SHIFT,
(config & MIPS_PWFIELD_PTEI_MASK) >> MIPS_PWFIELD_PTEI_SHIFT);
config = read_c0_pwsize();
pr_debug("PWSize (0x%0*lx): PS: 0x%lx GDW: 0x%02lx UDW: 0x%02lx MDW: 0x%02lx PTW: 0x%02lx PTEW: 0x%02lx\n",
field, config,
(config & MIPS_PWSIZE_PS_MASK) >> MIPS_PWSIZE_PS_SHIFT,
(config & MIPS_PWSIZE_GDW_MASK) >> MIPS_PWSIZE_GDW_SHIFT,
(config & MIPS_PWSIZE_UDW_MASK) >> MIPS_PWSIZE_UDW_SHIFT,
(config & MIPS_PWSIZE_MDW_MASK) >> MIPS_PWSIZE_MDW_SHIFT,
(config & MIPS_PWSIZE_PTW_MASK) >> MIPS_PWSIZE_PTW_SHIFT,
(config & MIPS_PWSIZE_PTEW_MASK) >> MIPS_PWSIZE_PTEW_SHIFT);
pwctl = read_c0_pwctl();
pr_debug("PWCtl (0x%x): PWEn: 0x%x XK: 0x%x XS: 0x%x XU: 0x%x DPH: 0x%x HugePg: 0x%x Psn: 0x%x\n",
pwctl,
(pwctl & MIPS_PWCTL_PWEN_MASK) >> MIPS_PWCTL_PWEN_SHIFT,
(pwctl & MIPS_PWCTL_XK_MASK) >> MIPS_PWCTL_XK_SHIFT,
(pwctl & MIPS_PWCTL_XS_MASK) >> MIPS_PWCTL_XS_SHIFT,
(pwctl & MIPS_PWCTL_XU_MASK) >> MIPS_PWCTL_XU_SHIFT,
(pwctl & MIPS_PWCTL_DPH_MASK) >> MIPS_PWCTL_DPH_SHIFT,
(pwctl & MIPS_PWCTL_HUGEPG_MASK) >> MIPS_PWCTL_HUGEPG_SHIFT,
(pwctl & MIPS_PWCTL_PSN_MASK) >> MIPS_PWCTL_PSN_SHIFT);
}
static void config_htw_params(void)
{
unsigned long pwfield, pwsize, ptei;
unsigned int config;
/*
* We are using 2-level page tables, so we only need to
* setup GDW and PTW appropriately. UDW and MDW will remain 0.
* The default value of GDI/UDI/MDI/PTI is 0xc. It is illegal to
* write values less than 0xc in these fields because the entire
* write will be dropped. As a result of which, we must preserve
* the original reset values and overwrite only what we really want.
*/
pwfield = read_c0_pwfield();
/* re-initialize the GDI field */
pwfield &= ~MIPS_PWFIELD_GDI_MASK;
pwfield |= PGDIR_SHIFT << MIPS_PWFIELD_GDI_SHIFT;
/* re-initialize the PTI field including the even/odd bit */
pwfield &= ~MIPS_PWFIELD_PTI_MASK;
pwfield |= PAGE_SHIFT << MIPS_PWFIELD_PTI_SHIFT;
if (CONFIG_PGTABLE_LEVELS >= 3) {
pwfield &= ~MIPS_PWFIELD_MDI_MASK;
pwfield |= PMD_SHIFT << MIPS_PWFIELD_MDI_SHIFT;
}
/* Set the PTEI right shift */
ptei = _PAGE_GLOBAL_SHIFT << MIPS_PWFIELD_PTEI_SHIFT;
pwfield |= ptei;
write_c0_pwfield(pwfield);
/* Check whether the PTEI value is supported */
back_to_back_c0_hazard();
pwfield = read_c0_pwfield();
if (((pwfield & MIPS_PWFIELD_PTEI_MASK) << MIPS_PWFIELD_PTEI_SHIFT)
!= ptei) {
pr_warn("Unsupported PTEI field value: 0x%lx. HTW will not be enabled",
ptei);
/*
* Drop option to avoid HTW being enabled via another path
* (eg htw_reset())
*/
current_cpu_data.options &= ~MIPS_CPU_HTW;
return;
}
pwsize = ilog2(PTRS_PER_PGD) << MIPS_PWSIZE_GDW_SHIFT;
pwsize |= ilog2(PTRS_PER_PTE) << MIPS_PWSIZE_PTW_SHIFT;
if (CONFIG_PGTABLE_LEVELS >= 3)
pwsize |= ilog2(PTRS_PER_PMD) << MIPS_PWSIZE_MDW_SHIFT;
/* Set pointer size to size of directory pointers */
if (IS_ENABLED(CONFIG_64BIT))
pwsize |= MIPS_PWSIZE_PS_MASK;
/* PTEs may be multiple pointers long (e.g. with XPA) */
pwsize |= ((PTE_T_LOG2 - PGD_T_LOG2) << MIPS_PWSIZE_PTEW_SHIFT)
& MIPS_PWSIZE_PTEW_MASK;
write_c0_pwsize(pwsize);
/* Make sure everything is set before we enable the HTW */
back_to_back_c0_hazard();
/*
* Enable HTW (and only for XUSeg on 64-bit), and disable the rest of
* the pwctl fields.
*/
config = 1 << MIPS_PWCTL_PWEN_SHIFT;
if (IS_ENABLED(CONFIG_64BIT))
config |= MIPS_PWCTL_XU_MASK;
write_c0_pwctl(config);
pr_info("Hardware Page Table Walker enabled\n");
print_htw_config();
}
static void config_xpa_params(void)
{
#ifdef CONFIG_XPA
unsigned int pagegrain;
if (mips_xpa_disabled) {
pr_info("Extended Physical Addressing (XPA) disabled\n");
return;
}
pagegrain = read_c0_pagegrain();
write_c0_pagegrain(pagegrain | PG_ELPA);
back_to_back_c0_hazard();
pagegrain = read_c0_pagegrain();
if (pagegrain & PG_ELPA)
pr_info("Extended Physical Addressing (XPA) enabled\n");
else
panic("Extended Physical Addressing (XPA) disabled");
#endif
}
static void check_pabits(void)
{
unsigned long entry;
unsigned pabits, fillbits;
if (!cpu_has_rixi || !_PAGE_NO_EXEC) {
/*
* We'll only be making use of the fact that we can rotate bits
* into the fill if the CPU supports RIXI, so don't bother
* probing this for CPUs which don't.
*/
return;
}
write_c0_entrylo0(~0ul);
back_to_back_c0_hazard();
entry = read_c0_entrylo0();
/* clear all non-PFN bits */
entry &= ~((1 << MIPS_ENTRYLO_PFN_SHIFT) - 1);
entry &= ~(MIPS_ENTRYLO_RI | MIPS_ENTRYLO_XI);
/* find a lower bound on PABITS, and upper bound on fill bits */
pabits = fls_long(entry) + 6;
fillbits = max_t(int, (int)BITS_PER_LONG - pabits, 0);
/* minus the RI & XI bits */
fillbits -= min_t(unsigned, fillbits, 2);
if (fillbits >= ilog2(_PAGE_NO_EXEC))
fill_includes_sw_bits = true;
pr_debug("Entry* registers contain %u fill bits\n", fillbits);
}
void 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;
if (IS_ENABLED(CONFIG_XPA) && !cpu_has_rixi)
panic("Kernels supporting XPA currently require CPUs with RIXI");
output_pgtable_bits_defines();
check_pabits();
#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
if (cpu_has_local_ebase)
build_r3000_tlb_refill_handler();
if (!run_once) {
if (!cpu_has_local_ebase)
build_r3000_tlb_refill_handler();
build_setup_pgd();
build_r3000_tlb_load_handler();
build_r3000_tlb_store_handler();
build_r3000_tlb_modify_handler();
flush_tlb_handlers();
run_once++;
}
#else
panic("No R3000 TLB refill handler");
#endif
break;
case CPU_R8000:
panic("No R8000 TLB refill handler yet");
break;
default:
if (cpu_has_ldpte)
setup_pw();
if (!run_once) {
scratch_reg = allocate_kscratch();
build_setup_pgd();
build_r4000_tlb_load_handler();
build_r4000_tlb_store_handler();
build_r4000_tlb_modify_handler();
if (cpu_has_ldpte)
build_loongson3_tlb_refill_handler();
else if (!cpu_has_local_ebase)
build_r4000_tlb_refill_handler();
flush_tlb_handlers();
run_once++;
}
if (cpu_has_local_ebase)
build_r4000_tlb_refill_handler();
if (cpu_has_xpa)
config_xpa_params();
if (cpu_has_htw)
config_htw_params();
}
}
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