On Fri, Aug 09, 2019 at 06:07:52PM +0800, Jason Yan wrote: > Add a new helper create_tlb_entry() to create a tlb entry by the virtual > and physical address. This is a preparation to support boot kernel at a > randomized address. > > Signed-off-by: Jason Yan <yanaijie@xxxxxxxxxx> > Cc: Diana Craciun <diana.craciun@xxxxxxx> > Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> > Cc: Christophe Leroy <christophe.leroy@xxxxxx> > Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> > Cc: Paul Mackerras <paulus@xxxxxxxxx> > Cc: Nicholas Piggin <npiggin@xxxxxxxxx> > Cc: Kees Cook <keescook@xxxxxxxxxxxx> > Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxx> > Reviewed-by: Diana Craciun <diana.craciun@xxxxxxx> > Tested-by: Diana Craciun <diana.craciun@xxxxxxx> > --- > arch/powerpc/kernel/head_fsl_booke.S | 29 ++++++++++++++++++++++++++++ > arch/powerpc/mm/mmu_decl.h | 1 + > 2 files changed, 30 insertions(+) > > diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S > index adf0505dbe02..04d124fee17d 100644 > --- a/arch/powerpc/kernel/head_fsl_booke.S > +++ b/arch/powerpc/kernel/head_fsl_booke.S > @@ -1114,6 +1114,35 @@ __secondary_hold_acknowledge: > .long -1 > #endif > > +/* > + * Create a 64M tlb by address and entry > + * r3/r4 - physical address > + * r5 - virtual address > + * r6 - entry > + */ > +_GLOBAL(create_tlb_entry) This function is broadly named but contains various assumptions about the entry being created. I'd just call it create_kaslr_tlb_entry. > + lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */ > + rlwimi r7,r6,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r6) */ > + mtspr SPRN_MAS0,r7 /* Write MAS0 */ > + > + lis r6,(MAS1_VALID|MAS1_IPROT)@h > + ori r6,r6,(MAS1_TSIZE(BOOK3E_PAGESZ_64M))@l > + mtspr SPRN_MAS1,r6 /* Write MAS1 */ > + > + lis r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@h > + ori r6,r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@l > + and r6,r6,r5 > + ori r6,r6,MAS2_M@l > + mtspr SPRN_MAS2,r6 /* Write MAS2(EPN) */ > + > + ori r8,r4,(MAS3_SW|MAS3_SR|MAS3_SX) > + mtspr SPRN_MAS3,r8 /* Write MAS3(RPN) */ > + > + tlbwe /* Write TLB */ > + isync > + sync > + blr Should set MAS7 under MMU_FTR_BIG_PHYS (or CONFIG_PHYS_64BIT if it's too early for features) -- even if relocatable kernels over 4GiB aren't supported (I don't remember if they work or not), MAS7 might be non-zero on entry. And the function claims to take a 64-bit phys addr as input... MAS2_M should be MAS2_M_IF_NEEDED to match other kmem tlb entries. -Scott
