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linux/arch/mips/mm/tlbex.c
Manuel Lauss 2f794d099d MIPS: Alchemy: MIPS hazard workarounds are not required. 
The Alchemy manuals state:

"All pipeline hazards and dependencies are enforced by hardware interlocks
 so that any sequence of instructions is guaranteed to execute correctly.
 Therefore, it is not necessary to pad legacy MIPS hazards (such as
 load delay slots and coprocessor accesses) with NOPs."

Run-tested on Au12x0, without any ill effects.

Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-03-30 14:49:46 +02:00

1279 lines
33 KiB
C
Raw Blame History

/*
* 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 Maciej W. Rozycki
* Copyright (C) 2006 Ralf Baechle (ralf@linux-mips.org)
*
* ... 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/kernel.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/init.h>
#include <asm/mmu_context.h>
#include <asm/war.h>
#include "uasm.h"
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;
}
/*
* 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,
#ifdef MODULE_START
label_module_alloc,
#endif
label_vmalloc,
label_vmalloc_done,
label_tlbw_hazard,
label_split,
label_nopage_tlbl,
label_nopage_tlbs,
label_nopage_tlbm,
label_smp_pgtable_change,
label_r3000_write_probe_fail,
};
UASM_L_LA(_second_part)
UASM_L_LA(_leave)
#ifdef MODULE_START
UASM_L_LA(_module_alloc)
#endif
UASM_L_LA(_vmalloc)
UASM_L_LA(_vmalloc_done)
UASM_L_LA(_tlbw_hazard)
UASM_L_LA(_split)
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)
/*
* 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_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;
/*
* 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);
}
/*
* 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 preceeding 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) {
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:
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_BCM3302:
case CPU_BCM4710:
case CPU_LOONGSON2:
case CPU_CAVIUM_OCTEON:
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;
default:
panic("No TLB refill handler yet (CPU type: %d)",
current_cpu_data.cputype);
break;
}
}
#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)
{
long pgdc = (long)pgd_current;
/*
* The vmalloc handling is not in the hotpath.
*/
uasm_i_dmfc0(p, tmp, C0_BADVADDR);
#ifdef MODULE_START
uasm_il_bltz(p, r, tmp, label_module_alloc);
#else
uasm_il_bltz(p, r, tmp, label_vmalloc);
#endif
/* No uasm_i_nop needed here, since the next insn doesn't touch TMP. */
#ifdef CONFIG_SMP
# ifdef CONFIG_MIPS_MT_SMTC
/*
* SMTC uses TCBind value as "CPU" index
*/
uasm_i_mfc0(p, ptr, C0_TCBIND);
uasm_i_dsrl(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(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);
if (PGDIR_SHIFT - 3 < 32) /* get pgd offset in bytes */
uasm_i_dsrl(p, tmp, tmp, PGDIR_SHIFT-3);
else
uasm_i_dsrl32(p, tmp, tmp, PGDIR_SHIFT - 3 - 32);
uasm_i_andi(p, tmp, tmp, (PTRS_PER_PGD - 1)<<3);
uasm_i_daddu(p, ptr, ptr, tmp); /* add in pgd offset */
uasm_i_dmfc0(p, tmp, C0_BADVADDR); /* get faulting address */
uasm_i_ld(p, ptr, 0, ptr); /* get pmd pointer */
uasm_i_dsrl(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 */
}
/*
* 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)
{
long swpd = (long)swapper_pg_dir;
#ifdef MODULE_START
long modd = (long)module_pg_dir;
uasm_l_module_alloc(l, *p);
/*
* Assumption:
* VMALLOC_START >= 0xc000000000000000UL
* MODULE_START >= 0xe000000000000000UL
*/
UASM_i_SLL(p, ptr, bvaddr, 2);
uasm_il_bgez(p, r, ptr, label_vmalloc);
if (uasm_in_compat_space_p(MODULE_START) &&
!uasm_rel_lo(MODULE_START)) {
uasm_i_lui(p, ptr, uasm_rel_hi(MODULE_START)); /* delay slot */
} else {
/* unlikely configuration */
uasm_i_nop(p); /* delay slot */
UASM_i_LA(p, ptr, MODULE_START);
}
uasm_i_dsubu(p, bvaddr, bvaddr, ptr);
if (uasm_in_compat_space_p(modd) && !uasm_rel_lo(modd)) {
uasm_il_b(p, r, label_vmalloc_done);
uasm_i_lui(p, ptr, uasm_rel_hi(modd));
} else {
UASM_i_LA_mostly(p, ptr, modd);
uasm_il_b(p, r, label_vmalloc_done);
if (uasm_in_compat_space_p(modd))
uasm_i_addiu(p, ptr, ptr, uasm_rel_lo(modd));
else
uasm_i_daddiu(p, ptr, ptr, uasm_rel_lo(modd));
}
uasm_l_vmalloc(l, *p);
if (uasm_in_compat_space_p(MODULE_START) &&
!uasm_rel_lo(MODULE_START) &&
MODULE_START << 32 == VMALLOC_START)
uasm_i_dsll32(p, ptr, ptr, 0); /* typical case */
else
UASM_i_LA(p, ptr, VMALLOC_START);
#else
uasm_l_vmalloc(l, *p);
UASM_i_LA(p, ptr, VMALLOC_START);
#endif
uasm_i_dsubu(p, bvaddr, bvaddr, ptr);
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));
}
}
#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 */
uasm_i_dsrl(p, tmp, tmp, 6); /* convert to entrylo0 */
uasm_i_mtc0(p, tmp, C0_ENTRYLO0); /* load it */
uasm_i_dsrl(p, ptep, ptep, 6); /* 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);
UASM_i_SRL(p, tmp, tmp, 6); /* 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, 6); /* 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
}
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;
memset(tlb_handler, 0, sizeof(tlb_handler));
memset(labels, 0, sizeof(labels));
memset(relocs, 0, sizeof(relocs));
memset(final_handler, 0, sizeof(final_handler));
/*
* create the plain linear handler
*/
if (bcm1250_m3_war()) {
UASM_i_MFC0(&p, K0, C0_BADVADDR);
UASM_i_MFC0(&p, K1, C0_ENTRYHI);
uasm_i_xor(&p, K0, K0, K1);
UASM_i_SRL(&p, K0, K0, PAGE_SHIFT + 1);
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
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_64BIT
build_get_pgd_vmalloc64(&p, &l, &r, K0, K1);
#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) > 63)
|| (((p - tlb_handler) > 61)
&& uasm_insn_has_bdelay(relocs, tlb_handler + 29)))
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 + 32;
if ((p - tlb_handler) <= 32) {
/* Just copy the handler. */
uasm_copy_handler(relocs, labels, tlb_handler, p, f);
final_len = p - tlb_handler;
} else {
u32 *split = tlb_handler + 30;
/*
* Find the split point.
*/
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;
/* 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 + 32)) + (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);
}
/*
* 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);
/*
* 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;
static void __cpuinit
iPTE_LW(u32 **p, struct uasm_label **l, 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_label **l, struct uasm_reloc **r,
unsigned int pte, unsigned int ptr, enum label_id lid)
{
uasm_i_andi(p, pte, pte, _PAGE_PRESENT | _PAGE_READ);
uasm_i_xori(p, pte, pte, _PAGE_PRESENT | _PAGE_READ);
uasm_il_bnez(p, r, pte, lid);
iPTE_LW(p, l, 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_label **l, struct uasm_reloc **r,
unsigned int pte, unsigned int ptr, enum label_id lid)
{
uasm_i_andi(p, pte, pte, _PAGE_PRESENT | _PAGE_WRITE);
uasm_i_xori(p, pte, pte, _PAGE_PRESENT | _PAGE_WRITE);
uasm_il_bnez(p, r, pte, lid);
iPTE_LW(p, l, pte, ptr);
}
/* 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_label **l, struct uasm_reloc **r,
unsigned int pte, unsigned int ptr, enum label_id lid)
{
uasm_i_andi(p, pte, pte, _PAGE_WRITE);
uasm_il_beqz(p, r, pte, lid);
iPTE_LW(p, l, pte, ptr);
}
/*
* 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, &l, &r, K0, K1, 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, &l, &r, K0, K1, 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;
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, &l, &r, K0, K1, 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));
}
/*
* R4000 style TLB load/store/modify handlers.
*/
static void __cpuinit
build_r4000_tlbchange_handler_head(u32 **p, struct uasm_label **l,
struct uasm_reloc **r, unsigned int pte,
unsigned int ptr)
{
#ifdef CONFIG_64BIT
build_get_pmde64(p, l, r, pte, ptr); /* get pmd in ptr */
#else
build_get_pgde32(p, pte, ptr); /* get pgd in ptr */
#endif
UASM_i_MFC0(p, pte, C0_BADVADDR);
UASM_i_LW(p, ptr, 0, ptr);
UASM_i_SRL(p, pte, pte, PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2);
uasm_i_andi(p, pte, pte, (PTRS_PER_PTE - 1) << PTE_T_LOG2);
UASM_i_ADDU(p, ptr, ptr, pte);
#ifdef CONFIG_SMP
uasm_l_smp_pgtable_change(l, *p);
#endif
iPTE_LW(p, l, pte, ptr); /* get even pte */
if (!m4kc_tlbp_war())
build_tlb_probe_entry(p);
}
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);
uasm_i_eret(p); /* return from trap */
#ifdef CONFIG_64BIT
build_get_pgd_vmalloc64(p, l, r, tmp, ptr);
#endif
}
static void __cpuinit build_r4000_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));
if (bcm1250_m3_war()) {
UASM_i_MFC0(&p, K0, C0_BADVADDR);
UASM_i_MFC0(&p, K1, C0_ENTRYHI);
uasm_i_xor(&p, K0, K0, K1);
UASM_i_SRL(&p, K0, K0, PAGE_SHIFT + 1);
uasm_il_bnez(&p, &r, K0, label_leave);
/* No need for uasm_i_nop */
}
build_r4000_tlbchange_handler_head(&p, &l, &r, K0, K1);
build_pte_present(&p, &l, &r, K0, K1, label_nopage_tlbl);
if (m4kc_tlbp_war())
build_tlb_probe_entry(&p);
build_make_valid(&p, &r, K0, K1);
build_r4000_tlbchange_handler_tail(&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_r4000_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_r4000_tlbchange_handler_head(&p, &l, &r, K0, K1);
build_pte_writable(&p, &l, &r, K0, K1, label_nopage_tlbs);
if (m4kc_tlbp_war())
build_tlb_probe_entry(&p);
build_make_write(&p, &r, K0, K1);
build_r4000_tlbchange_handler_tail(&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_r4000_tlb_modify_handler(void)
{
u32 *p = handle_tlbm;
struct uasm_label *l = labels;
struct uasm_reloc *r = relocs;
memset(handle_tlbm, 0, sizeof(handle_tlbm));
memset(labels, 0, sizeof(labels));
memset(relocs, 0, sizeof(relocs));
build_r4000_tlbchange_handler_head(&p, &l, &r, K0, K1);
build_pte_modifiable(&p, &l, &r, K0, K1, 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, K0, K1);
build_r4000_tlbchange_handler_tail(&p, &l, &r, 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));
}
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;
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:
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++;
}
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:
build_r4000_tlb_refill_handler();
if (!run_once) {
build_r4000_tlb_load_handler();
build_r4000_tlb_store_handler();
build_r4000_tlb_modify_handler();
run_once++;
}
}
}
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));
}
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