head_32.S 35 KB

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991001011021031041051061071081091101111121131141151161171181191201211221231241251261271281291301311321331341351361371381391401411421431441451461471481491501511521531541551561571581591601611621631641651661671681691701711721731741751761771781791801811821831841851861871881891901911921931941951961971981992002012022032042052062072082092102112122132142152162172182192202212222232242252262272282292302312322332342352362372382392402412422432442452462472482492502512522532542552562572582592602612622632642652662672682692702712722732742752762772782792802812822832842852862872882892902912922932942952962972982993003013023033043053063073083093103113123133143153163173183193203213223233243253263273283293303313323333343353363373383393403413423433443453463473483493503513523533543553563573583593603613623633643653663673683693703713723733743753763773783793803813823833843853863873883893903913923933943953963973983994004014024034044054064074084094104114124134144154164174184194204214224234244254264274284294304314324334344354364374384394404414424434444454464474484494504514524534544554564574584594604614624634644654664674684694704714724734744754764774784794804814824834844854864874884894904914924934944954964974984995005015025035045055065075085095105115125135145155165175185195205215225235245255265275285295305315325335345355365375385395405415425435445455465475485495505515525535545555565575585595605615625635645655665675685695705715725735745755765775785795805815825835845855865875885895905915925935945955965975985996006016026036046056066076086096106116126136146156166176186196206216226236246256266276286296306316326336346356366376386396406416426436446456466476486496506516526536546556566576586596606616626636646656666676686696706716726736746756766776786796806816826836846856866876886896906916926936946956966976986997007017027037047057067077087097107117127137147157167177187197207217227237247257267277287297307317327337347357367377387397407417427437447457467477487497507517527537547557567577587597607617627637647657667677687697707717727737747757767777787797807817827837847857867877887897907917927937947957967977987998008018028038048058068078088098108118128138148158168178188198208218228238248258268278288298308318328338348358368378388398408418428438448458468478488498508518528538548558568578588598608618628638648658668678688698708718728738748758768778788798808818828838848858868878888898908918928938948958968978988999009019029039049059069079089099109119129139149159169179189199209219229239249259269279289299309319329339349359369379389399409419429439449459469479489499509519529539549559569579589599609619629639649659669679689699709719729739749759769779789799809819829839849859869879889899909919929939949959969979989991000100110021003100410051006100710081009101010111012101310141015101610171018101910201021102210231024102510261027102810291030103110321033103410351036103710381039104010411042104310441045104610471048104910501051105210531054105510561057105810591060106110621063106410651066106710681069107010711072107310741075107610771078107910801081108210831084108510861087108810891090109110921093109410951096109710981099110011011102110311041105110611071108110911101111111211131114111511161117111811191120112111221123112411251126112711281129113011311132113311341135113611371138113911401141114211431144114511461147114811491150115111521153115411551156115711581159116011611162116311641165116611671168116911701171117211731174117511761177117811791180118111821183118411851186118711881189119011911192119311941195119611971198119912001201120212031204120512061207120812091210121112121213121412151216121712181219122012211222122312241225122612271228122912301231123212331234123512361237123812391240124112421243124412451246124712481249125012511252125312541255125612571258125912601261126212631264126512661267126812691270127112721273127412751276127712781279128012811282
  1. /*
  2. * PowerPC version
  3. * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
  4. *
  5. * Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
  6. * Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
  7. * Adapted for Power Macintosh by Paul Mackerras.
  8. * Low-level exception handlers and MMU support
  9. * rewritten by Paul Mackerras.
  10. * Copyright (C) 1996 Paul Mackerras.
  11. * MPC8xx modifications Copyright (C) 1997 Dan Malek (dmalek@jlc.net).
  12. *
  13. * This file contains the low-level support and setup for the
  14. * PowerPC platform, including trap and interrupt dispatch.
  15. * (The PPC 8xx embedded CPUs use head_8xx.S instead.)
  16. *
  17. * This program is free software; you can redistribute it and/or
  18. * modify it under the terms of the GNU General Public License
  19. * as published by the Free Software Foundation; either version
  20. * 2 of the License, or (at your option) any later version.
  21. *
  22. */
  23. #include <linux/init.h>
  24. #include <asm/reg.h>
  25. #include <asm/page.h>
  26. #include <asm/mmu.h>
  27. #include <asm/pgtable.h>
  28. #include <asm/cputable.h>
  29. #include <asm/cache.h>
  30. #include <asm/thread_info.h>
  31. #include <asm/ppc_asm.h>
  32. #include <asm/asm-offsets.h>
  33. #include <asm/ptrace.h>
  34. #include <asm/bug.h>
  35. #include <asm/kvm_book3s_asm.h>
  36. #include <asm/export.h>
  37. #include <asm/feature-fixups.h>
  38. /* 601 only have IBAT; cr0.eq is set on 601 when using this macro */
  39. #define LOAD_BAT(n, reg, RA, RB) \
  40. /* see the comment for clear_bats() -- Cort */ \
  41. li RA,0; \
  42. mtspr SPRN_IBAT##n##U,RA; \
  43. mtspr SPRN_DBAT##n##U,RA; \
  44. lwz RA,(n*16)+0(reg); \
  45. lwz RB,(n*16)+4(reg); \
  46. mtspr SPRN_IBAT##n##U,RA; \
  47. mtspr SPRN_IBAT##n##L,RB; \
  48. beq 1f; \
  49. lwz RA,(n*16)+8(reg); \
  50. lwz RB,(n*16)+12(reg); \
  51. mtspr SPRN_DBAT##n##U,RA; \
  52. mtspr SPRN_DBAT##n##L,RB; \
  53. 1:
  54. __HEAD
  55. .stabs "arch/powerpc/kernel/",N_SO,0,0,0f
  56. .stabs "head_32.S",N_SO,0,0,0f
  57. 0:
  58. _ENTRY(_stext);
  59. /*
  60. * _start is defined this way because the XCOFF loader in the OpenFirmware
  61. * on the powermac expects the entry point to be a procedure descriptor.
  62. */
  63. _ENTRY(_start);
  64. /*
  65. * These are here for legacy reasons, the kernel used to
  66. * need to look like a coff function entry for the pmac
  67. * but we're always started by some kind of bootloader now.
  68. * -- Cort
  69. */
  70. nop /* used by __secondary_hold on prep (mtx) and chrp smp */
  71. nop /* used by __secondary_hold on prep (mtx) and chrp smp */
  72. nop
  73. /* PMAC
  74. * Enter here with the kernel text, data and bss loaded starting at
  75. * 0, running with virtual == physical mapping.
  76. * r5 points to the prom entry point (the client interface handler
  77. * address). Address translation is turned on, with the prom
  78. * managing the hash table. Interrupts are disabled. The stack
  79. * pointer (r1) points to just below the end of the half-meg region
  80. * from 0x380000 - 0x400000, which is mapped in already.
  81. *
  82. * If we are booted from MacOS via BootX, we enter with the kernel
  83. * image loaded somewhere, and the following values in registers:
  84. * r3: 'BooX' (0x426f6f58)
  85. * r4: virtual address of boot_infos_t
  86. * r5: 0
  87. *
  88. * PREP
  89. * This is jumped to on prep systems right after the kernel is relocated
  90. * to its proper place in memory by the boot loader. The expected layout
  91. * of the regs is:
  92. * r3: ptr to residual data
  93. * r4: initrd_start or if no initrd then 0
  94. * r5: initrd_end - unused if r4 is 0
  95. * r6: Start of command line string
  96. * r7: End of command line string
  97. *
  98. * This just gets a minimal mmu environment setup so we can call
  99. * start_here() to do the real work.
  100. * -- Cort
  101. */
  102. .globl __start
  103. __start:
  104. /*
  105. * We have to do any OF calls before we map ourselves to KERNELBASE,
  106. * because OF may have I/O devices mapped into that area
  107. * (particularly on CHRP).
  108. */
  109. cmpwi 0,r5,0
  110. beq 1f
  111. #ifdef CONFIG_PPC_OF_BOOT_TRAMPOLINE
  112. /* find out where we are now */
  113. bcl 20,31,$+4
  114. 0: mflr r8 /* r8 = runtime addr here */
  115. addis r8,r8,(_stext - 0b)@ha
  116. addi r8,r8,(_stext - 0b)@l /* current runtime base addr */
  117. bl prom_init
  118. #endif /* CONFIG_PPC_OF_BOOT_TRAMPOLINE */
  119. /* We never return. We also hit that trap if trying to boot
  120. * from OF while CONFIG_PPC_OF_BOOT_TRAMPOLINE isn't selected */
  121. trap
  122. /*
  123. * Check for BootX signature when supporting PowerMac and branch to
  124. * appropriate trampoline if it's present
  125. */
  126. #ifdef CONFIG_PPC_PMAC
  127. 1: lis r31,0x426f
  128. ori r31,r31,0x6f58
  129. cmpw 0,r3,r31
  130. bne 1f
  131. bl bootx_init
  132. trap
  133. #endif /* CONFIG_PPC_PMAC */
  134. 1: mr r31,r3 /* save device tree ptr */
  135. li r24,0 /* cpu # */
  136. /*
  137. * early_init() does the early machine identification and does
  138. * the necessary low-level setup and clears the BSS
  139. * -- Cort <cort@fsmlabs.com>
  140. */
  141. bl early_init
  142. /* Switch MMU off, clear BATs and flush TLB. At this point, r3 contains
  143. * the physical address we are running at, returned by early_init()
  144. */
  145. bl mmu_off
  146. __after_mmu_off:
  147. bl clear_bats
  148. bl flush_tlbs
  149. bl initial_bats
  150. #if defined(CONFIG_BOOTX_TEXT)
  151. bl setup_disp_bat
  152. #endif
  153. #ifdef CONFIG_PPC_EARLY_DEBUG_CPM
  154. bl setup_cpm_bat
  155. #endif
  156. #ifdef CONFIG_PPC_EARLY_DEBUG_USBGECKO
  157. bl setup_usbgecko_bat
  158. #endif
  159. /*
  160. * Call setup_cpu for CPU 0 and initialize 6xx Idle
  161. */
  162. bl reloc_offset
  163. li r24,0 /* cpu# */
  164. bl call_setup_cpu /* Call setup_cpu for this CPU */
  165. #ifdef CONFIG_6xx
  166. bl reloc_offset
  167. bl init_idle_6xx
  168. #endif /* CONFIG_6xx */
  169. /*
  170. * We need to run with _start at physical address 0.
  171. * On CHRP, we are loaded at 0x10000 since OF on CHRP uses
  172. * the exception vectors at 0 (and therefore this copy
  173. * overwrites OF's exception vectors with our own).
  174. * The MMU is off at this point.
  175. */
  176. bl reloc_offset
  177. mr r26,r3
  178. addis r4,r3,KERNELBASE@h /* current address of _start */
  179. lis r5,PHYSICAL_START@h
  180. cmplw 0,r4,r5 /* already running at PHYSICAL_START? */
  181. bne relocate_kernel
  182. /*
  183. * we now have the 1st 16M of ram mapped with the bats.
  184. * prep needs the mmu to be turned on here, but pmac already has it on.
  185. * this shouldn't bother the pmac since it just gets turned on again
  186. * as we jump to our code at KERNELBASE. -- Cort
  187. * Actually no, pmac doesn't have it on any more. BootX enters with MMU
  188. * off, and in other cases, we now turn it off before changing BATs above.
  189. */
  190. turn_on_mmu:
  191. mfmsr r0
  192. ori r0,r0,MSR_DR|MSR_IR
  193. mtspr SPRN_SRR1,r0
  194. lis r0,start_here@h
  195. ori r0,r0,start_here@l
  196. mtspr SPRN_SRR0,r0
  197. SYNC
  198. RFI /* enables MMU */
  199. /*
  200. * We need __secondary_hold as a place to hold the other cpus on
  201. * an SMP machine, even when we are running a UP kernel.
  202. */
  203. . = 0xc0 /* for prep bootloader */
  204. li r3,1 /* MTX only has 1 cpu */
  205. .globl __secondary_hold
  206. __secondary_hold:
  207. /* tell the master we're here */
  208. stw r3,__secondary_hold_acknowledge@l(0)
  209. #ifdef CONFIG_SMP
  210. 100: lwz r4,0(0)
  211. /* wait until we're told to start */
  212. cmpw 0,r4,r3
  213. bne 100b
  214. /* our cpu # was at addr 0 - go */
  215. mr r24,r3 /* cpu # */
  216. b __secondary_start
  217. #else
  218. b .
  219. #endif /* CONFIG_SMP */
  220. .globl __secondary_hold_spinloop
  221. __secondary_hold_spinloop:
  222. .long 0
  223. .globl __secondary_hold_acknowledge
  224. __secondary_hold_acknowledge:
  225. .long -1
  226. /*
  227. * Exception entry code. This code runs with address translation
  228. * turned off, i.e. using physical addresses.
  229. * We assume sprg3 has the physical address of the current
  230. * task's thread_struct.
  231. */
  232. #define EXCEPTION_PROLOG \
  233. mtspr SPRN_SPRG_SCRATCH0,r10; \
  234. mtspr SPRN_SPRG_SCRATCH1,r11; \
  235. mfcr r10; \
  236. EXCEPTION_PROLOG_1; \
  237. EXCEPTION_PROLOG_2
  238. #define EXCEPTION_PROLOG_1 \
  239. mfspr r11,SPRN_SRR1; /* check whether user or kernel */ \
  240. andi. r11,r11,MSR_PR; \
  241. tophys(r11,r1); /* use tophys(r1) if kernel */ \
  242. beq 1f; \
  243. mfspr r11,SPRN_SPRG_THREAD; \
  244. lwz r11,THREAD_INFO-THREAD(r11); \
  245. addi r11,r11,THREAD_SIZE; \
  246. tophys(r11,r11); \
  247. 1: subi r11,r11,INT_FRAME_SIZE /* alloc exc. frame */
  248. #define EXCEPTION_PROLOG_2 \
  249. stw r10,_CCR(r11); /* save registers */ \
  250. stw r12,GPR12(r11); \
  251. stw r9,GPR9(r11); \
  252. mfspr r10,SPRN_SPRG_SCRATCH0; \
  253. stw r10,GPR10(r11); \
  254. mfspr r12,SPRN_SPRG_SCRATCH1; \
  255. stw r12,GPR11(r11); \
  256. mflr r10; \
  257. stw r10,_LINK(r11); \
  258. mfspr r12,SPRN_SRR0; \
  259. mfspr r9,SPRN_SRR1; \
  260. stw r1,GPR1(r11); \
  261. stw r1,0(r11); \
  262. tovirt(r1,r11); /* set new kernel sp */ \
  263. li r10,MSR_KERNEL & ~(MSR_IR|MSR_DR); /* can take exceptions */ \
  264. MTMSRD(r10); /* (except for mach check in rtas) */ \
  265. stw r0,GPR0(r11); \
  266. lis r10,STACK_FRAME_REGS_MARKER@ha; /* exception frame marker */ \
  267. addi r10,r10,STACK_FRAME_REGS_MARKER@l; \
  268. stw r10,8(r11); \
  269. SAVE_4GPRS(3, r11); \
  270. SAVE_2GPRS(7, r11)
  271. /*
  272. * Note: code which follows this uses cr0.eq (set if from kernel),
  273. * r11, r12 (SRR0), and r9 (SRR1).
  274. *
  275. * Note2: once we have set r1 we are in a position to take exceptions
  276. * again, and we could thus set MSR:RI at that point.
  277. */
  278. /*
  279. * Exception vectors.
  280. */
  281. #define EXCEPTION(n, label, hdlr, xfer) \
  282. . = n; \
  283. DO_KVM n; \
  284. label: \
  285. EXCEPTION_PROLOG; \
  286. addi r3,r1,STACK_FRAME_OVERHEAD; \
  287. xfer(n, hdlr)
  288. #define EXC_XFER_TEMPLATE(n, hdlr, trap, copyee, tfer, ret) \
  289. li r10,trap; \
  290. stw r10,_TRAP(r11); \
  291. li r10,MSR_KERNEL; \
  292. copyee(r10, r9); \
  293. bl tfer; \
  294. i##n: \
  295. .long hdlr; \
  296. .long ret
  297. #define COPY_EE(d, s) rlwimi d,s,0,16,16
  298. #define NOCOPY(d, s)
  299. #define EXC_XFER_STD(n, hdlr) \
  300. EXC_XFER_TEMPLATE(n, hdlr, n, NOCOPY, transfer_to_handler_full, \
  301. ret_from_except_full)
  302. #define EXC_XFER_LITE(n, hdlr) \
  303. EXC_XFER_TEMPLATE(n, hdlr, n+1, NOCOPY, transfer_to_handler, \
  304. ret_from_except)
  305. #define EXC_XFER_EE(n, hdlr) \
  306. EXC_XFER_TEMPLATE(n, hdlr, n, COPY_EE, transfer_to_handler_full, \
  307. ret_from_except_full)
  308. #define EXC_XFER_EE_LITE(n, hdlr) \
  309. EXC_XFER_TEMPLATE(n, hdlr, n+1, COPY_EE, transfer_to_handler, \
  310. ret_from_except)
  311. /* System reset */
  312. /* core99 pmac starts the seconary here by changing the vector, and
  313. putting it back to what it was (unknown_exception) when done. */
  314. EXCEPTION(0x100, Reset, unknown_exception, EXC_XFER_STD)
  315. /* Machine check */
  316. /*
  317. * On CHRP, this is complicated by the fact that we could get a
  318. * machine check inside RTAS, and we have no guarantee that certain
  319. * critical registers will have the values we expect. The set of
  320. * registers that might have bad values includes all the GPRs
  321. * and all the BATs. We indicate that we are in RTAS by putting
  322. * a non-zero value, the address of the exception frame to use,
  323. * in SPRG2. The machine check handler checks SPRG2 and uses its
  324. * value if it is non-zero. If we ever needed to free up SPRG2,
  325. * we could use a field in the thread_info or thread_struct instead.
  326. * (Other exception handlers assume that r1 is a valid kernel stack
  327. * pointer when we take an exception from supervisor mode.)
  328. * -- paulus.
  329. */
  330. . = 0x200
  331. DO_KVM 0x200
  332. mtspr SPRN_SPRG_SCRATCH0,r10
  333. mtspr SPRN_SPRG_SCRATCH1,r11
  334. mfcr r10
  335. #ifdef CONFIG_PPC_CHRP
  336. mfspr r11,SPRN_SPRG_RTAS
  337. cmpwi 0,r11,0
  338. bne 7f
  339. #endif /* CONFIG_PPC_CHRP */
  340. EXCEPTION_PROLOG_1
  341. 7: EXCEPTION_PROLOG_2
  342. addi r3,r1,STACK_FRAME_OVERHEAD
  343. #ifdef CONFIG_PPC_CHRP
  344. mfspr r4,SPRN_SPRG_RTAS
  345. cmpwi cr1,r4,0
  346. bne cr1,1f
  347. #endif
  348. EXC_XFER_STD(0x200, machine_check_exception)
  349. #ifdef CONFIG_PPC_CHRP
  350. 1: b machine_check_in_rtas
  351. #endif
  352. /* Data access exception. */
  353. . = 0x300
  354. DO_KVM 0x300
  355. DataAccess:
  356. EXCEPTION_PROLOG
  357. mfspr r10,SPRN_DSISR
  358. stw r10,_DSISR(r11)
  359. andis. r0,r10,(DSISR_BAD_FAULT_32S|DSISR_DABRMATCH)@h
  360. bne 1f /* if not, try to put a PTE */
  361. mfspr r4,SPRN_DAR /* into the hash table */
  362. rlwinm r3,r10,32-15,21,21 /* DSISR_STORE -> _PAGE_RW */
  363. bl hash_page
  364. 1: lwz r5,_DSISR(r11) /* get DSISR value */
  365. mfspr r4,SPRN_DAR
  366. EXC_XFER_LITE(0x300, handle_page_fault)
  367. /* Instruction access exception. */
  368. . = 0x400
  369. DO_KVM 0x400
  370. InstructionAccess:
  371. EXCEPTION_PROLOG
  372. andis. r0,r9,SRR1_ISI_NOPT@h /* no pte found? */
  373. beq 1f /* if so, try to put a PTE */
  374. li r3,0 /* into the hash table */
  375. mr r4,r12 /* SRR0 is fault address */
  376. bl hash_page
  377. 1: mr r4,r12
  378. andis. r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */
  379. EXC_XFER_LITE(0x400, handle_page_fault)
  380. /* External interrupt */
  381. EXCEPTION(0x500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE)
  382. /* Alignment exception */
  383. . = 0x600
  384. DO_KVM 0x600
  385. Alignment:
  386. EXCEPTION_PROLOG
  387. mfspr r4,SPRN_DAR
  388. stw r4,_DAR(r11)
  389. mfspr r5,SPRN_DSISR
  390. stw r5,_DSISR(r11)
  391. addi r3,r1,STACK_FRAME_OVERHEAD
  392. EXC_XFER_EE(0x600, alignment_exception)
  393. /* Program check exception */
  394. EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD)
  395. /* Floating-point unavailable */
  396. . = 0x800
  397. DO_KVM 0x800
  398. FPUnavailable:
  399. BEGIN_FTR_SECTION
  400. /*
  401. * Certain Freescale cores don't have a FPU and treat fp instructions
  402. * as a FP Unavailable exception. Redirect to illegal/emulation handling.
  403. */
  404. b ProgramCheck
  405. END_FTR_SECTION_IFSET(CPU_FTR_FPU_UNAVAILABLE)
  406. EXCEPTION_PROLOG
  407. beq 1f
  408. bl load_up_fpu /* if from user, just load it up */
  409. b fast_exception_return
  410. 1: addi r3,r1,STACK_FRAME_OVERHEAD
  411. EXC_XFER_EE_LITE(0x800, kernel_fp_unavailable_exception)
  412. /* Decrementer */
  413. EXCEPTION(0x900, Decrementer, timer_interrupt, EXC_XFER_LITE)
  414. EXCEPTION(0xa00, Trap_0a, unknown_exception, EXC_XFER_EE)
  415. EXCEPTION(0xb00, Trap_0b, unknown_exception, EXC_XFER_EE)
  416. /* System call */
  417. . = 0xc00
  418. DO_KVM 0xc00
  419. SystemCall:
  420. EXCEPTION_PROLOG
  421. EXC_XFER_EE_LITE(0xc00, DoSyscall)
  422. /* Single step - not used on 601 */
  423. EXCEPTION(0xd00, SingleStep, single_step_exception, EXC_XFER_STD)
  424. EXCEPTION(0xe00, Trap_0e, unknown_exception, EXC_XFER_EE)
  425. /*
  426. * The Altivec unavailable trap is at 0x0f20. Foo.
  427. * We effectively remap it to 0x3000.
  428. * We include an altivec unavailable exception vector even if
  429. * not configured for Altivec, so that you can't panic a
  430. * non-altivec kernel running on a machine with altivec just
  431. * by executing an altivec instruction.
  432. */
  433. . = 0xf00
  434. DO_KVM 0xf00
  435. b PerformanceMonitor
  436. . = 0xf20
  437. DO_KVM 0xf20
  438. b AltiVecUnavailable
  439. /*
  440. * Handle TLB miss for instruction on 603/603e.
  441. * Note: we get an alternate set of r0 - r3 to use automatically.
  442. */
  443. . = 0x1000
  444. InstructionTLBMiss:
  445. /*
  446. * r0: scratch
  447. * r1: linux style pte ( later becomes ppc hardware pte )
  448. * r2: ptr to linux-style pte
  449. * r3: scratch
  450. */
  451. /* Get PTE (linux-style) and check access */
  452. mfspr r3,SPRN_IMISS
  453. lis r1,PAGE_OFFSET@h /* check if kernel address */
  454. cmplw 0,r1,r3
  455. mfspr r2,SPRN_SPRG_THREAD
  456. li r1,_PAGE_USER|_PAGE_PRESENT /* low addresses tested as user */
  457. lwz r2,PGDIR(r2)
  458. bge- 112f
  459. mfspr r2,SPRN_SRR1 /* and MSR_PR bit from SRR1 */
  460. rlwimi r1,r2,32-12,29,29 /* shift MSR_PR to _PAGE_USER posn */
  461. lis r2,swapper_pg_dir@ha /* if kernel address, use */
  462. addi r2,r2,swapper_pg_dir@l /* kernel page table */
  463. 112: tophys(r2,r2)
  464. rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
  465. lwz r2,0(r2) /* get pmd entry */
  466. rlwinm. r2,r2,0,0,19 /* extract address of pte page */
  467. beq- InstructionAddressInvalid /* return if no mapping */
  468. rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
  469. lwz r0,0(r2) /* get linux-style pte */
  470. andc. r1,r1,r0 /* check access & ~permission */
  471. bne- InstructionAddressInvalid /* return if access not permitted */
  472. ori r0,r0,_PAGE_ACCESSED /* set _PAGE_ACCESSED in pte */
  473. /*
  474. * NOTE! We are assuming this is not an SMP system, otherwise
  475. * we would need to update the pte atomically with lwarx/stwcx.
  476. */
  477. stw r0,0(r2) /* update PTE (accessed bit) */
  478. /* Convert linux-style PTE to low word of PPC-style PTE */
  479. rlwinm r1,r0,32-10,31,31 /* _PAGE_RW -> PP lsb */
  480. rlwinm r2,r0,32-7,31,31 /* _PAGE_DIRTY -> PP lsb */
  481. and r1,r1,r2 /* writable if _RW and _DIRTY */
  482. rlwimi r0,r0,32-1,30,30 /* _PAGE_USER -> PP msb */
  483. rlwimi r0,r0,32-1,31,31 /* _PAGE_USER -> PP lsb */
  484. ori r1,r1,0xe04 /* clear out reserved bits */
  485. andc r1,r0,r1 /* PP = user? (rw&dirty? 2: 3): 0 */
  486. BEGIN_FTR_SECTION
  487. rlwinm r1,r1,0,~_PAGE_COHERENT /* clear M (coherence not required) */
  488. END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT)
  489. mtspr SPRN_RPA,r1
  490. tlbli r3
  491. mfspr r3,SPRN_SRR1 /* Need to restore CR0 */
  492. mtcrf 0x80,r3
  493. rfi
  494. InstructionAddressInvalid:
  495. mfspr r3,SPRN_SRR1
  496. rlwinm r1,r3,9,6,6 /* Get load/store bit */
  497. addis r1,r1,0x2000
  498. mtspr SPRN_DSISR,r1 /* (shouldn't be needed) */
  499. andi. r2,r3,0xFFFF /* Clear upper bits of SRR1 */
  500. or r2,r2,r1
  501. mtspr SPRN_SRR1,r2
  502. mfspr r1,SPRN_IMISS /* Get failing address */
  503. rlwinm. r2,r2,0,31,31 /* Check for little endian access */
  504. rlwimi r2,r2,1,30,30 /* change 1 -> 3 */
  505. xor r1,r1,r2
  506. mtspr SPRN_DAR,r1 /* Set fault address */
  507. mfmsr r0 /* Restore "normal" registers */
  508. xoris r0,r0,MSR_TGPR>>16
  509. mtcrf 0x80,r3 /* Restore CR0 */
  510. mtmsr r0
  511. b InstructionAccess
  512. /*
  513. * Handle TLB miss for DATA Load operation on 603/603e
  514. */
  515. . = 0x1100
  516. DataLoadTLBMiss:
  517. /*
  518. * r0: scratch
  519. * r1: linux style pte ( later becomes ppc hardware pte )
  520. * r2: ptr to linux-style pte
  521. * r3: scratch
  522. */
  523. /* Get PTE (linux-style) and check access */
  524. mfspr r3,SPRN_DMISS
  525. lis r1,PAGE_OFFSET@h /* check if kernel address */
  526. cmplw 0,r1,r3
  527. mfspr r2,SPRN_SPRG_THREAD
  528. li r1,_PAGE_USER|_PAGE_PRESENT /* low addresses tested as user */
  529. lwz r2,PGDIR(r2)
  530. bge- 112f
  531. mfspr r2,SPRN_SRR1 /* and MSR_PR bit from SRR1 */
  532. rlwimi r1,r2,32-12,29,29 /* shift MSR_PR to _PAGE_USER posn */
  533. lis r2,swapper_pg_dir@ha /* if kernel address, use */
  534. addi r2,r2,swapper_pg_dir@l /* kernel page table */
  535. 112: tophys(r2,r2)
  536. rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
  537. lwz r2,0(r2) /* get pmd entry */
  538. rlwinm. r2,r2,0,0,19 /* extract address of pte page */
  539. beq- DataAddressInvalid /* return if no mapping */
  540. rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
  541. lwz r0,0(r2) /* get linux-style pte */
  542. andc. r1,r1,r0 /* check access & ~permission */
  543. bne- DataAddressInvalid /* return if access not permitted */
  544. ori r0,r0,_PAGE_ACCESSED /* set _PAGE_ACCESSED in pte */
  545. /*
  546. * NOTE! We are assuming this is not an SMP system, otherwise
  547. * we would need to update the pte atomically with lwarx/stwcx.
  548. */
  549. stw r0,0(r2) /* update PTE (accessed bit) */
  550. /* Convert linux-style PTE to low word of PPC-style PTE */
  551. rlwinm r1,r0,32-10,31,31 /* _PAGE_RW -> PP lsb */
  552. rlwinm r2,r0,32-7,31,31 /* _PAGE_DIRTY -> PP lsb */
  553. and r1,r1,r2 /* writable if _RW and _DIRTY */
  554. rlwimi r0,r0,32-1,30,30 /* _PAGE_USER -> PP msb */
  555. rlwimi r0,r0,32-1,31,31 /* _PAGE_USER -> PP lsb */
  556. ori r1,r1,0xe04 /* clear out reserved bits */
  557. andc r1,r0,r1 /* PP = user? (rw&dirty? 2: 3): 0 */
  558. BEGIN_FTR_SECTION
  559. rlwinm r1,r1,0,~_PAGE_COHERENT /* clear M (coherence not required) */
  560. END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT)
  561. mtspr SPRN_RPA,r1
  562. mfspr r2,SPRN_SRR1 /* Need to restore CR0 */
  563. mtcrf 0x80,r2
  564. BEGIN_MMU_FTR_SECTION
  565. li r0,1
  566. mfspr r1,SPRN_SPRG_603_LRU
  567. rlwinm r2,r3,20,27,31 /* Get Address bits 15:19 */
  568. slw r0,r0,r2
  569. xor r1,r0,r1
  570. srw r0,r1,r2
  571. mtspr SPRN_SPRG_603_LRU,r1
  572. mfspr r2,SPRN_SRR1
  573. rlwimi r2,r0,31-14,14,14
  574. mtspr SPRN_SRR1,r2
  575. END_MMU_FTR_SECTION_IFSET(MMU_FTR_NEED_DTLB_SW_LRU)
  576. tlbld r3
  577. rfi
  578. DataAddressInvalid:
  579. mfspr r3,SPRN_SRR1
  580. rlwinm r1,r3,9,6,6 /* Get load/store bit */
  581. addis r1,r1,0x2000
  582. mtspr SPRN_DSISR,r1
  583. andi. r2,r3,0xFFFF /* Clear upper bits of SRR1 */
  584. mtspr SPRN_SRR1,r2
  585. mfspr r1,SPRN_DMISS /* Get failing address */
  586. rlwinm. r2,r2,0,31,31 /* Check for little endian access */
  587. beq 20f /* Jump if big endian */
  588. xori r1,r1,3
  589. 20: mtspr SPRN_DAR,r1 /* Set fault address */
  590. mfmsr r0 /* Restore "normal" registers */
  591. xoris r0,r0,MSR_TGPR>>16
  592. mtcrf 0x80,r3 /* Restore CR0 */
  593. mtmsr r0
  594. b DataAccess
  595. /*
  596. * Handle TLB miss for DATA Store on 603/603e
  597. */
  598. . = 0x1200
  599. DataStoreTLBMiss:
  600. /*
  601. * r0: scratch
  602. * r1: linux style pte ( later becomes ppc hardware pte )
  603. * r2: ptr to linux-style pte
  604. * r3: scratch
  605. */
  606. /* Get PTE (linux-style) and check access */
  607. mfspr r3,SPRN_DMISS
  608. lis r1,PAGE_OFFSET@h /* check if kernel address */
  609. cmplw 0,r1,r3
  610. mfspr r2,SPRN_SPRG_THREAD
  611. li r1,_PAGE_RW|_PAGE_USER|_PAGE_PRESENT /* access flags */
  612. lwz r2,PGDIR(r2)
  613. bge- 112f
  614. mfspr r2,SPRN_SRR1 /* and MSR_PR bit from SRR1 */
  615. rlwimi r1,r2,32-12,29,29 /* shift MSR_PR to _PAGE_USER posn */
  616. lis r2,swapper_pg_dir@ha /* if kernel address, use */
  617. addi r2,r2,swapper_pg_dir@l /* kernel page table */
  618. 112: tophys(r2,r2)
  619. rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
  620. lwz r2,0(r2) /* get pmd entry */
  621. rlwinm. r2,r2,0,0,19 /* extract address of pte page */
  622. beq- DataAddressInvalid /* return if no mapping */
  623. rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
  624. lwz r0,0(r2) /* get linux-style pte */
  625. andc. r1,r1,r0 /* check access & ~permission */
  626. bne- DataAddressInvalid /* return if access not permitted */
  627. ori r0,r0,_PAGE_ACCESSED|_PAGE_DIRTY
  628. /*
  629. * NOTE! We are assuming this is not an SMP system, otherwise
  630. * we would need to update the pte atomically with lwarx/stwcx.
  631. */
  632. stw r0,0(r2) /* update PTE (accessed/dirty bits) */
  633. /* Convert linux-style PTE to low word of PPC-style PTE */
  634. rlwimi r0,r0,32-1,30,30 /* _PAGE_USER -> PP msb */
  635. li r1,0xe05 /* clear out reserved bits & PP lsb */
  636. andc r1,r0,r1 /* PP = user? 2: 0 */
  637. BEGIN_FTR_SECTION
  638. rlwinm r1,r1,0,~_PAGE_COHERENT /* clear M (coherence not required) */
  639. END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT)
  640. mtspr SPRN_RPA,r1
  641. mfspr r2,SPRN_SRR1 /* Need to restore CR0 */
  642. mtcrf 0x80,r2
  643. BEGIN_MMU_FTR_SECTION
  644. li r0,1
  645. mfspr r1,SPRN_SPRG_603_LRU
  646. rlwinm r2,r3,20,27,31 /* Get Address bits 15:19 */
  647. slw r0,r0,r2
  648. xor r1,r0,r1
  649. srw r0,r1,r2
  650. mtspr SPRN_SPRG_603_LRU,r1
  651. mfspr r2,SPRN_SRR1
  652. rlwimi r2,r0,31-14,14,14
  653. mtspr SPRN_SRR1,r2
  654. END_MMU_FTR_SECTION_IFSET(MMU_FTR_NEED_DTLB_SW_LRU)
  655. tlbld r3
  656. rfi
  657. #ifndef CONFIG_ALTIVEC
  658. #define altivec_assist_exception unknown_exception
  659. #endif
  660. EXCEPTION(0x1300, Trap_13, instruction_breakpoint_exception, EXC_XFER_EE)
  661. EXCEPTION(0x1400, SMI, SMIException, EXC_XFER_EE)
  662. EXCEPTION(0x1500, Trap_15, unknown_exception, EXC_XFER_EE)
  663. EXCEPTION(0x1600, Trap_16, altivec_assist_exception, EXC_XFER_EE)
  664. EXCEPTION(0x1700, Trap_17, TAUException, EXC_XFER_STD)
  665. EXCEPTION(0x1800, Trap_18, unknown_exception, EXC_XFER_EE)
  666. EXCEPTION(0x1900, Trap_19, unknown_exception, EXC_XFER_EE)
  667. EXCEPTION(0x1a00, Trap_1a, unknown_exception, EXC_XFER_EE)
  668. EXCEPTION(0x1b00, Trap_1b, unknown_exception, EXC_XFER_EE)
  669. EXCEPTION(0x1c00, Trap_1c, unknown_exception, EXC_XFER_EE)
  670. EXCEPTION(0x1d00, Trap_1d, unknown_exception, EXC_XFER_EE)
  671. EXCEPTION(0x1e00, Trap_1e, unknown_exception, EXC_XFER_EE)
  672. EXCEPTION(0x1f00, Trap_1f, unknown_exception, EXC_XFER_EE)
  673. EXCEPTION(0x2000, RunMode, RunModeException, EXC_XFER_EE)
  674. EXCEPTION(0x2100, Trap_21, unknown_exception, EXC_XFER_EE)
  675. EXCEPTION(0x2200, Trap_22, unknown_exception, EXC_XFER_EE)
  676. EXCEPTION(0x2300, Trap_23, unknown_exception, EXC_XFER_EE)
  677. EXCEPTION(0x2400, Trap_24, unknown_exception, EXC_XFER_EE)
  678. EXCEPTION(0x2500, Trap_25, unknown_exception, EXC_XFER_EE)
  679. EXCEPTION(0x2600, Trap_26, unknown_exception, EXC_XFER_EE)
  680. EXCEPTION(0x2700, Trap_27, unknown_exception, EXC_XFER_EE)
  681. EXCEPTION(0x2800, Trap_28, unknown_exception, EXC_XFER_EE)
  682. EXCEPTION(0x2900, Trap_29, unknown_exception, EXC_XFER_EE)
  683. EXCEPTION(0x2a00, Trap_2a, unknown_exception, EXC_XFER_EE)
  684. EXCEPTION(0x2b00, Trap_2b, unknown_exception, EXC_XFER_EE)
  685. EXCEPTION(0x2c00, Trap_2c, unknown_exception, EXC_XFER_EE)
  686. EXCEPTION(0x2d00, Trap_2d, unknown_exception, EXC_XFER_EE)
  687. EXCEPTION(0x2e00, Trap_2e, unknown_exception, EXC_XFER_EE)
  688. EXCEPTION(0x2f00, Trap_2f, unknown_exception, EXC_XFER_EE)
  689. . = 0x3000
  690. AltiVecUnavailable:
  691. EXCEPTION_PROLOG
  692. #ifdef CONFIG_ALTIVEC
  693. beq 1f
  694. bl load_up_altivec /* if from user, just load it up */
  695. b fast_exception_return
  696. #endif /* CONFIG_ALTIVEC */
  697. 1: addi r3,r1,STACK_FRAME_OVERHEAD
  698. EXC_XFER_EE_LITE(0xf20, altivec_unavailable_exception)
  699. PerformanceMonitor:
  700. EXCEPTION_PROLOG
  701. addi r3,r1,STACK_FRAME_OVERHEAD
  702. EXC_XFER_STD(0xf00, performance_monitor_exception)
  703. /*
  704. * This code is jumped to from the startup code to copy
  705. * the kernel image to physical address PHYSICAL_START.
  706. */
  707. relocate_kernel:
  708. addis r9,r26,klimit@ha /* fetch klimit */
  709. lwz r25,klimit@l(r9)
  710. addis r25,r25,-KERNELBASE@h
  711. lis r3,PHYSICAL_START@h /* Destination base address */
  712. li r6,0 /* Destination offset */
  713. li r5,0x4000 /* # bytes of memory to copy */
  714. bl copy_and_flush /* copy the first 0x4000 bytes */
  715. addi r0,r3,4f@l /* jump to the address of 4f */
  716. mtctr r0 /* in copy and do the rest. */
  717. bctr /* jump to the copy */
  718. 4: mr r5,r25
  719. bl copy_and_flush /* copy the rest */
  720. b turn_on_mmu
  721. /*
  722. * Copy routine used to copy the kernel to start at physical address 0
  723. * and flush and invalidate the caches as needed.
  724. * r3 = dest addr, r4 = source addr, r5 = copy limit, r6 = start offset
  725. * on exit, r3, r4, r5 are unchanged, r6 is updated to be >= r5.
  726. */
  727. _ENTRY(copy_and_flush)
  728. addi r5,r5,-4
  729. addi r6,r6,-4
  730. 4: li r0,L1_CACHE_BYTES/4
  731. mtctr r0
  732. 3: addi r6,r6,4 /* copy a cache line */
  733. lwzx r0,r6,r4
  734. stwx r0,r6,r3
  735. bdnz 3b
  736. dcbst r6,r3 /* write it to memory */
  737. sync
  738. icbi r6,r3 /* flush the icache line */
  739. cmplw 0,r6,r5
  740. blt 4b
  741. sync /* additional sync needed on g4 */
  742. isync
  743. addi r5,r5,4
  744. addi r6,r6,4
  745. blr
  746. #ifdef CONFIG_SMP
  747. .globl __secondary_start_mpc86xx
  748. __secondary_start_mpc86xx:
  749. mfspr r3, SPRN_PIR
  750. stw r3, __secondary_hold_acknowledge@l(0)
  751. mr r24, r3 /* cpu # */
  752. b __secondary_start
  753. .globl __secondary_start_pmac_0
  754. __secondary_start_pmac_0:
  755. /* NB the entries for cpus 0, 1, 2 must each occupy 8 bytes. */
  756. li r24,0
  757. b 1f
  758. li r24,1
  759. b 1f
  760. li r24,2
  761. b 1f
  762. li r24,3
  763. 1:
  764. /* on powersurge, we come in here with IR=0 and DR=1, and DBAT 0
  765. set to map the 0xf0000000 - 0xffffffff region */
  766. mfmsr r0
  767. rlwinm r0,r0,0,28,26 /* clear DR (0x10) */
  768. SYNC
  769. mtmsr r0
  770. isync
  771. .globl __secondary_start
  772. __secondary_start:
  773. /* Copy some CPU settings from CPU 0 */
  774. bl __restore_cpu_setup
  775. lis r3,-KERNELBASE@h
  776. mr r4,r24
  777. bl call_setup_cpu /* Call setup_cpu for this CPU */
  778. #ifdef CONFIG_6xx
  779. lis r3,-KERNELBASE@h
  780. bl init_idle_6xx
  781. #endif /* CONFIG_6xx */
  782. /* get current_thread_info and current */
  783. lis r1,secondary_ti@ha
  784. tophys(r1,r1)
  785. lwz r1,secondary_ti@l(r1)
  786. tophys(r2,r1)
  787. lwz r2,TI_TASK(r2)
  788. /* stack */
  789. addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
  790. li r0,0
  791. tophys(r3,r1)
  792. stw r0,0(r3)
  793. /* load up the MMU */
  794. bl load_up_mmu
  795. /* ptr to phys current thread */
  796. tophys(r4,r2)
  797. addi r4,r4,THREAD /* phys address of our thread_struct */
  798. mtspr SPRN_SPRG_THREAD,r4
  799. li r3,0
  800. mtspr SPRN_SPRG_RTAS,r3 /* 0 => not in RTAS */
  801. /* enable MMU and jump to start_secondary */
  802. li r4,MSR_KERNEL
  803. lis r3,start_secondary@h
  804. ori r3,r3,start_secondary@l
  805. mtspr SPRN_SRR0,r3
  806. mtspr SPRN_SRR1,r4
  807. SYNC
  808. RFI
  809. #endif /* CONFIG_SMP */
  810. #ifdef CONFIG_KVM_BOOK3S_HANDLER
  811. #include "../kvm/book3s_rmhandlers.S"
  812. #endif
  813. /*
  814. * Those generic dummy functions are kept for CPUs not
  815. * included in CONFIG_6xx
  816. */
  817. #if !defined(CONFIG_6xx)
  818. _ENTRY(__save_cpu_setup)
  819. blr
  820. _ENTRY(__restore_cpu_setup)
  821. blr
  822. #endif /* !defined(CONFIG_6xx) */
  823. /*
  824. * Load stuff into the MMU. Intended to be called with
  825. * IR=0 and DR=0.
  826. */
  827. load_up_mmu:
  828. sync /* Force all PTE updates to finish */
  829. isync
  830. tlbia /* Clear all TLB entries */
  831. sync /* wait for tlbia/tlbie to finish */
  832. TLBSYNC /* ... on all CPUs */
  833. /* Load the SDR1 register (hash table base & size) */
  834. lis r6,_SDR1@ha
  835. tophys(r6,r6)
  836. lwz r6,_SDR1@l(r6)
  837. mtspr SPRN_SDR1,r6
  838. li r0,16 /* load up segment register values */
  839. mtctr r0 /* for context 0 */
  840. lis r3,0x2000 /* Ku = 1, VSID = 0 */
  841. li r4,0
  842. 3: mtsrin r3,r4
  843. addi r3,r3,0x111 /* increment VSID */
  844. addis r4,r4,0x1000 /* address of next segment */
  845. bdnz 3b
  846. /* Load the BAT registers with the values set up by MMU_init.
  847. MMU_init takes care of whether we're on a 601 or not. */
  848. mfpvr r3
  849. srwi r3,r3,16
  850. cmpwi r3,1
  851. lis r3,BATS@ha
  852. addi r3,r3,BATS@l
  853. tophys(r3,r3)
  854. LOAD_BAT(0,r3,r4,r5)
  855. LOAD_BAT(1,r3,r4,r5)
  856. LOAD_BAT(2,r3,r4,r5)
  857. LOAD_BAT(3,r3,r4,r5)
  858. BEGIN_MMU_FTR_SECTION
  859. LOAD_BAT(4,r3,r4,r5)
  860. LOAD_BAT(5,r3,r4,r5)
  861. LOAD_BAT(6,r3,r4,r5)
  862. LOAD_BAT(7,r3,r4,r5)
  863. END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
  864. blr
  865. /*
  866. * This is where the main kernel code starts.
  867. */
  868. start_here:
  869. /* ptr to current */
  870. lis r2,init_task@h
  871. ori r2,r2,init_task@l
  872. /* Set up for using our exception vectors */
  873. /* ptr to phys current thread */
  874. tophys(r4,r2)
  875. addi r4,r4,THREAD /* init task's THREAD */
  876. mtspr SPRN_SPRG_THREAD,r4
  877. li r3,0
  878. mtspr SPRN_SPRG_RTAS,r3 /* 0 => not in RTAS */
  879. /* stack */
  880. lis r1,init_thread_union@ha
  881. addi r1,r1,init_thread_union@l
  882. li r0,0
  883. stwu r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
  884. /*
  885. * Do early platform-specific initialization,
  886. * and set up the MMU.
  887. */
  888. li r3,0
  889. mr r4,r31
  890. bl machine_init
  891. bl __save_cpu_setup
  892. bl MMU_init
  893. /*
  894. * Go back to running unmapped so we can load up new values
  895. * for SDR1 (hash table pointer) and the segment registers
  896. * and change to using our exception vectors.
  897. */
  898. lis r4,2f@h
  899. ori r4,r4,2f@l
  900. tophys(r4,r4)
  901. li r3,MSR_KERNEL & ~(MSR_IR|MSR_DR)
  902. mtspr SPRN_SRR0,r4
  903. mtspr SPRN_SRR1,r3
  904. SYNC
  905. RFI
  906. /* Load up the kernel context */
  907. 2: bl load_up_mmu
  908. #ifdef CONFIG_BDI_SWITCH
  909. /* Add helper information for the Abatron bdiGDB debugger.
  910. * We do this here because we know the mmu is disabled, and
  911. * will be enabled for real in just a few instructions.
  912. */
  913. lis r5, abatron_pteptrs@h
  914. ori r5, r5, abatron_pteptrs@l
  915. stw r5, 0xf0(r0) /* This much match your Abatron config */
  916. lis r6, swapper_pg_dir@h
  917. ori r6, r6, swapper_pg_dir@l
  918. tophys(r5, r5)
  919. stw r6, 0(r5)
  920. #endif /* CONFIG_BDI_SWITCH */
  921. /* Now turn on the MMU for real! */
  922. li r4,MSR_KERNEL
  923. lis r3,start_kernel@h
  924. ori r3,r3,start_kernel@l
  925. mtspr SPRN_SRR0,r3
  926. mtspr SPRN_SRR1,r4
  927. SYNC
  928. RFI
  929. /*
  930. * void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next);
  931. *
  932. * Set up the segment registers for a new context.
  933. */
  934. _ENTRY(switch_mmu_context)
  935. lwz r3,MMCONTEXTID(r4)
  936. cmpwi cr0,r3,0
  937. blt- 4f
  938. mulli r3,r3,897 /* multiply context by skew factor */
  939. rlwinm r3,r3,4,8,27 /* VSID = (context & 0xfffff) << 4 */
  940. addis r3,r3,0x6000 /* Set Ks, Ku bits */
  941. li r0,NUM_USER_SEGMENTS
  942. mtctr r0
  943. #ifdef CONFIG_BDI_SWITCH
  944. /* Context switch the PTE pointer for the Abatron BDI2000.
  945. * The PGDIR is passed as second argument.
  946. */
  947. lwz r4,MM_PGD(r4)
  948. lis r5, KERNELBASE@h
  949. lwz r5, 0xf0(r5)
  950. stw r4, 0x4(r5)
  951. #endif
  952. li r4,0
  953. isync
  954. 3:
  955. mtsrin r3,r4
  956. addi r3,r3,0x111 /* next VSID */
  957. rlwinm r3,r3,0,8,3 /* clear out any overflow from VSID field */
  958. addis r4,r4,0x1000 /* address of next segment */
  959. bdnz 3b
  960. sync
  961. isync
  962. blr
  963. 4: trap
  964. EMIT_BUG_ENTRY 4b,__FILE__,__LINE__,0
  965. blr
  966. EXPORT_SYMBOL(switch_mmu_context)
  967. /*
  968. * An undocumented "feature" of 604e requires that the v bit
  969. * be cleared before changing BAT values.
  970. *
  971. * Also, newer IBM firmware does not clear bat3 and 4 so
  972. * this makes sure it's done.
  973. * -- Cort
  974. */
  975. clear_bats:
  976. li r10,0
  977. mfspr r9,SPRN_PVR
  978. rlwinm r9,r9,16,16,31 /* r9 = 1 for 601, 4 for 604 */
  979. cmpwi r9, 1
  980. beq 1f
  981. mtspr SPRN_DBAT0U,r10
  982. mtspr SPRN_DBAT0L,r10
  983. mtspr SPRN_DBAT1U,r10
  984. mtspr SPRN_DBAT1L,r10
  985. mtspr SPRN_DBAT2U,r10
  986. mtspr SPRN_DBAT2L,r10
  987. mtspr SPRN_DBAT3U,r10
  988. mtspr SPRN_DBAT3L,r10
  989. 1:
  990. mtspr SPRN_IBAT0U,r10
  991. mtspr SPRN_IBAT0L,r10
  992. mtspr SPRN_IBAT1U,r10
  993. mtspr SPRN_IBAT1L,r10
  994. mtspr SPRN_IBAT2U,r10
  995. mtspr SPRN_IBAT2L,r10
  996. mtspr SPRN_IBAT3U,r10
  997. mtspr SPRN_IBAT3L,r10
  998. BEGIN_MMU_FTR_SECTION
  999. /* Here's a tweak: at this point, CPU setup have
  1000. * not been called yet, so HIGH_BAT_EN may not be
  1001. * set in HID0 for the 745x processors. However, it
  1002. * seems that doesn't affect our ability to actually
  1003. * write to these SPRs.
  1004. */
  1005. mtspr SPRN_DBAT4U,r10
  1006. mtspr SPRN_DBAT4L,r10
  1007. mtspr SPRN_DBAT5U,r10
  1008. mtspr SPRN_DBAT5L,r10
  1009. mtspr SPRN_DBAT6U,r10
  1010. mtspr SPRN_DBAT6L,r10
  1011. mtspr SPRN_DBAT7U,r10
  1012. mtspr SPRN_DBAT7L,r10
  1013. mtspr SPRN_IBAT4U,r10
  1014. mtspr SPRN_IBAT4L,r10
  1015. mtspr SPRN_IBAT5U,r10
  1016. mtspr SPRN_IBAT5L,r10
  1017. mtspr SPRN_IBAT6U,r10
  1018. mtspr SPRN_IBAT6L,r10
  1019. mtspr SPRN_IBAT7U,r10
  1020. mtspr SPRN_IBAT7L,r10
  1021. END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
  1022. blr
  1023. flush_tlbs:
  1024. lis r10, 0x40
  1025. 1: addic. r10, r10, -0x1000
  1026. tlbie r10
  1027. bgt 1b
  1028. sync
  1029. blr
  1030. mmu_off:
  1031. addi r4, r3, __after_mmu_off - _start
  1032. mfmsr r3
  1033. andi. r0,r3,MSR_DR|MSR_IR /* MMU enabled? */
  1034. beqlr
  1035. andc r3,r3,r0
  1036. mtspr SPRN_SRR0,r4
  1037. mtspr SPRN_SRR1,r3
  1038. sync
  1039. RFI
  1040. /*
  1041. * On 601, we use 3 BATs to map up to 24M of RAM at _PAGE_OFFSET
  1042. * (we keep one for debugging) and on others, we use one 256M BAT.
  1043. */
  1044. initial_bats:
  1045. lis r11,PAGE_OFFSET@h
  1046. mfspr r9,SPRN_PVR
  1047. rlwinm r9,r9,16,16,31 /* r9 = 1 for 601, 4 for 604 */
  1048. cmpwi 0,r9,1
  1049. bne 4f
  1050. ori r11,r11,4 /* set up BAT registers for 601 */
  1051. li r8,0x7f /* valid, block length = 8MB */
  1052. mtspr SPRN_IBAT0U,r11 /* N.B. 601 has valid bit in */
  1053. mtspr SPRN_IBAT0L,r8 /* lower BAT register */
  1054. addis r11,r11,0x800000@h
  1055. addis r8,r8,0x800000@h
  1056. mtspr SPRN_IBAT1U,r11
  1057. mtspr SPRN_IBAT1L,r8
  1058. addis r11,r11,0x800000@h
  1059. addis r8,r8,0x800000@h
  1060. mtspr SPRN_IBAT2U,r11
  1061. mtspr SPRN_IBAT2L,r8
  1062. isync
  1063. blr
  1064. 4: tophys(r8,r11)
  1065. #ifdef CONFIG_SMP
  1066. ori r8,r8,0x12 /* R/W access, M=1 */
  1067. #else
  1068. ori r8,r8,2 /* R/W access */
  1069. #endif /* CONFIG_SMP */
  1070. ori r11,r11,BL_256M<<2|0x2 /* set up BAT registers for 604 */
  1071. mtspr SPRN_DBAT0L,r8 /* N.B. 6xx (not 601) have valid */
  1072. mtspr SPRN_DBAT0U,r11 /* bit in upper BAT register */
  1073. mtspr SPRN_IBAT0L,r8
  1074. mtspr SPRN_IBAT0U,r11
  1075. isync
  1076. blr
  1077. #ifdef CONFIG_BOOTX_TEXT
  1078. setup_disp_bat:
  1079. /*
  1080. * setup the display bat prepared for us in prom.c
  1081. */
  1082. mflr r8
  1083. bl reloc_offset
  1084. mtlr r8
  1085. addis r8,r3,disp_BAT@ha
  1086. addi r8,r8,disp_BAT@l
  1087. cmpwi cr0,r8,0
  1088. beqlr
  1089. lwz r11,0(r8)
  1090. lwz r8,4(r8)
  1091. mfspr r9,SPRN_PVR
  1092. rlwinm r9,r9,16,16,31 /* r9 = 1 for 601, 4 for 604 */
  1093. cmpwi 0,r9,1
  1094. beq 1f
  1095. mtspr SPRN_DBAT3L,r8
  1096. mtspr SPRN_DBAT3U,r11
  1097. blr
  1098. 1: mtspr SPRN_IBAT3L,r8
  1099. mtspr SPRN_IBAT3U,r11
  1100. blr
  1101. #endif /* CONFIG_BOOTX_TEXT */
  1102. #ifdef CONFIG_PPC_EARLY_DEBUG_CPM
  1103. setup_cpm_bat:
  1104. lis r8, 0xf000
  1105. ori r8, r8, 0x002a
  1106. mtspr SPRN_DBAT1L, r8
  1107. lis r11, 0xf000
  1108. ori r11, r11, (BL_1M << 2) | 2
  1109. mtspr SPRN_DBAT1U, r11
  1110. blr
  1111. #endif
  1112. #ifdef CONFIG_PPC_EARLY_DEBUG_USBGECKO
  1113. setup_usbgecko_bat:
  1114. /* prepare a BAT for early io */
  1115. #if defined(CONFIG_GAMECUBE)
  1116. lis r8, 0x0c00
  1117. #elif defined(CONFIG_WII)
  1118. lis r8, 0x0d00
  1119. #else
  1120. #error Invalid platform for USB Gecko based early debugging.
  1121. #endif
  1122. /*
  1123. * The virtual address used must match the virtual address
  1124. * associated to the fixmap entry FIX_EARLY_DEBUG_BASE.
  1125. */
  1126. lis r11, 0xfffe /* top 128K */
  1127. ori r8, r8, 0x002a /* uncached, guarded ,rw */
  1128. ori r11, r11, 0x2 /* 128K, Vs=1, Vp=0 */
  1129. mtspr SPRN_DBAT1L, r8
  1130. mtspr SPRN_DBAT1U, r11
  1131. blr
  1132. #endif
  1133. #ifdef CONFIG_8260
  1134. /* Jump into the system reset for the rom.
  1135. * We first disable the MMU, and then jump to the ROM reset address.
  1136. *
  1137. * r3 is the board info structure, r4 is the location for starting.
  1138. * I use this for building a small kernel that can load other kernels,
  1139. * rather than trying to write or rely on a rom monitor that can tftp load.
  1140. */
  1141. .globl m8260_gorom
  1142. m8260_gorom:
  1143. mfmsr r0
  1144. rlwinm r0,r0,0,17,15 /* clear MSR_EE in r0 */
  1145. sync
  1146. mtmsr r0
  1147. sync
  1148. mfspr r11, SPRN_HID0
  1149. lis r10, 0
  1150. ori r10,r10,HID0_ICE|HID0_DCE
  1151. andc r11, r11, r10
  1152. mtspr SPRN_HID0, r11
  1153. isync
  1154. li r5, MSR_ME|MSR_RI
  1155. lis r6,2f@h
  1156. addis r6,r6,-KERNELBASE@h
  1157. ori r6,r6,2f@l
  1158. mtspr SPRN_SRR0,r6
  1159. mtspr SPRN_SRR1,r5
  1160. isync
  1161. sync
  1162. rfi
  1163. 2:
  1164. mtlr r4
  1165. blr
  1166. #endif
  1167. /*
  1168. * We put a few things here that have to be page-aligned.
  1169. * This stuff goes at the beginning of the data segment,
  1170. * which is page-aligned.
  1171. */
  1172. .data
  1173. .globl sdata
  1174. sdata:
  1175. .globl empty_zero_page
  1176. empty_zero_page:
  1177. .space 4096
  1178. EXPORT_SYMBOL(empty_zero_page)
  1179. .globl swapper_pg_dir
  1180. swapper_pg_dir:
  1181. .space PGD_TABLE_SIZE
  1182. /* Room for two PTE pointers, usually the kernel and current user pointers
  1183. * to their respective root page table.
  1184. */
  1185. abatron_pteptrs:
  1186. .space 8