diff options
Diffstat (limited to 'arch/powerpc/cpu/mpc85xx/start.S')
| -rw-r--r-- | arch/powerpc/cpu/mpc85xx/start.S | 84 |
1 files changed, 82 insertions, 2 deletions
diff --git a/arch/powerpc/cpu/mpc85xx/start.S b/arch/powerpc/cpu/mpc85xx/start.S index 5e0d78d0064..7bd5cc0b0fc 100644 --- a/arch/powerpc/cpu/mpc85xx/start.S +++ b/arch/powerpc/cpu/mpc85xx/start.S @@ -319,6 +319,55 @@ l2_disabled: #endif /* CONFIG_MPC8569 */ /* + * Search for the TLB that covers the code we're executing, and shrink it + * so that it covers only this 4K page. That will ensure that any other + * TLB we create won't interfere with it. We assume that the TLB exists, + * which is why we don't check the Valid bit of MAS1. + * + * This is necessary, for example, when booting from the on-chip ROM, + * which (oddly) creates a single 4GB TLB that covers CCSR and DDR. + * If we don't shrink this TLB now, then we'll accidentally delete it + * in "purge_old_ccsr_tlb" below. + */ + bl nexti /* Find our address */ +nexti: mflr r1 /* R1 = our PC */ + li r2, 0 + mtspr MAS6, r2 /* Assume the current PID and AS are 0 */ + isync + msync + tlbsx 0, r1 /* This must succeed */ + + /* Set the size of the TLB to 4KB */ + mfspr r3, MAS1 + li r2, 0xF00 + andc r3, r3, r2 /* Clear the TSIZE bits */ + ori r3, r3, MAS1_TSIZE(BOOKE_PAGESZ_4K)@l + mtspr MAS1, r3 + + /* + * Set the base address of the TLB to our PC. We assume that + * virtual == physical. We also assume that MAS2_EPN == MAS3_RPN. + */ + lis r3, MAS2_EPN@h + ori r3, r3, MAS2_EPN@l /* R3 = MAS2_EPN */ + + and r1, r1, r3 /* Our PC, rounded down to the nearest page */ + + mfspr r2, MAS2 + andc r2, r2, r3 + or r2, r2, r1 + mtspr MAS2, r2 /* Set the EPN to our PC base address */ + + mfspr r2, MAS3 + andc r2, r2, r3 + or r2, r2, r1 + mtspr MAS3, r2 /* Set the RPN to our PC base address */ + + isync + msync + tlbwe + +/* * Relocate CCSR, if necessary. We relocate CCSR if (obviously) the default * location is not where we want it. This typically happens on a 36-bit * system, where we want to move CCSR to near the top of 36-bit address space. @@ -352,6 +401,8 @@ purge_old_ccsr_tlb: li r1, 0 mtspr MAS6, r1 /* Search the current address space and PID */ + isync + msync tlbsx 0, r8 mfspr r1, MAS1 andis. r2, r1, MAS1_VALID@h /* Check for the Valid bit */ @@ -359,6 +410,8 @@ purge_old_ccsr_tlb: rlwinm r1, r1, 0, 1, 31 /* Clear Valid bit */ mtspr MAS1, r1 + isync + msync tlbwe 1: @@ -387,7 +440,7 @@ create_ccsr_new_tlb: tlbwe /* - * Create a TLB for the old location of CCSR. Register R9 is reserved + * Create a TLB for the current location of CCSR. Register R9 is reserved * for the virtual address of this TLB (CONFIG_SYS_CCSRBAR + 0x1000). */ create_ccsr_old_tlb: @@ -407,6 +460,33 @@ create_ccsr_old_tlb: msync tlbwe + /* + * We have a TLB for what we think is the current (old) CCSR. Let's + * verify that, otherwise we won't be able to move it. + * CONFIG_SYS_CCSRBAR_DEFAULT is always a 32-bit number, so we only + * need to compare the lower 32 bits of CCSRBAR on CoreNet systems. + */ +verify_old_ccsr: + lis r0, CONFIG_SYS_CCSRBAR_DEFAULT@h + ori r0, r0, CONFIG_SYS_CCSRBAR_DEFAULT@l +#ifdef CONFIG_FSL_CORENET + lwz r1, 4(r9) /* CCSRBARL */ +#else + lwz r1, 0(r9) /* CCSRBAR, shifted right by 12 */ + slwi r1, r1, 12 +#endif + + cmpl 0, r0, r1 + + /* + * If the value we read from CCSRBARL is not what we expect, then + * enter an infinite loop. This will at least allow a debugger to + * halt execution and examine TLBs, etc. There's no point in going + * on. + */ +infinite_debug_loop: + bne infinite_debug_loop + #ifdef CONFIG_FSL_CORENET #define CCSR_LAWBARH0 (CONFIG_SYS_CCSRBAR + 0x1000) @@ -446,7 +526,7 @@ create_temp_law: */ read_old_ccsrbar: lwz r0, 0(r9) /* CCSRBARH */ - lwz r0, 4(r9) /* CCSRBARH */ + lwz r0, 4(r9) /* CCSRBARL */ isync /* |