On Tue, Apr 02, 2013 at 02:25:09PM +0100, Marc Zyngier wrote: > The way we populate HYP mappings is a bit convoluted, to say the least. > Passing a pointer around to keep track of the current PFN is quite > odd, and we end-up having two different PTE accessors for no good > reason. > > Simplify the whole thing by unifying the two PTE accessors, passing > a pgprot_t around, and moving the various validity checks to the > upper layers. > > Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> > --- > arch/arm/kvm/mmu.c | 100 ++++++++++++++++++++++------------------------------- > 1 file changed, 41 insertions(+), 59 deletions(-) > > diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c > index 2f12e40..24811d1 100644 > --- a/arch/arm/kvm/mmu.c > +++ b/arch/arm/kvm/mmu.c > @@ -125,54 +125,34 @@ void free_hyp_pmds(void) > } > > static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start, > - unsigned long end) > + unsigned long end, unsigned long pfn, > + pgprot_t prot) > { > pte_t *pte; > unsigned long addr; > - struct page *page; > > - for (addr = start & PAGE_MASK; addr < end; addr += PAGE_SIZE) { > - unsigned long hyp_addr = KERN_TO_HYP(addr); > - > - pte = pte_offset_kernel(pmd, hyp_addr); > - BUG_ON(!virt_addr_valid(addr)); > - page = virt_to_page(addr); > - kvm_set_pte(pte, mk_pte(page, PAGE_HYP)); > - } > -} > - > -static void create_hyp_io_pte_mappings(pmd_t *pmd, unsigned long start, > - unsigned long end, > - unsigned long *pfn_base) > -{ > - pte_t *pte; > - unsigned long addr; > - > - for (addr = start & PAGE_MASK; addr < end; addr += PAGE_SIZE) { > - unsigned long hyp_addr = KERN_TO_HYP(addr); > - > - pte = pte_offset_kernel(pmd, hyp_addr); > - BUG_ON(pfn_valid(*pfn_base)); > - kvm_set_pte(pte, pfn_pte(*pfn_base, PAGE_HYP_DEVICE)); > - (*pfn_base)++; > + for (addr = start; addr < end; addr += PAGE_SIZE) { > + pte = pte_offset_kernel(pmd, addr); > + kvm_set_pte(pte, pfn_pte(pfn, prot)); > + pfn++; > } > } > > static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start, > - unsigned long end, unsigned long *pfn_base) > + unsigned long end, unsigned long pfn, > + pgprot_t prot) > { > pmd_t *pmd; > pte_t *pte; > unsigned long addr, next; > > for (addr = start; addr < end; addr = next) { > - unsigned long hyp_addr = KERN_TO_HYP(addr); > - pmd = pmd_offset(pud, hyp_addr); > + pmd = pmd_offset(pud, addr); > > BUG_ON(pmd_sect(*pmd)); > > if (pmd_none(*pmd)) { > - pte = pte_alloc_one_kernel(NULL, hyp_addr); > + pte = pte_alloc_one_kernel(NULL, addr); > if (!pte) { > kvm_err("Cannot allocate Hyp pte\n"); > return -ENOMEM; > @@ -182,25 +162,17 @@ static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start, > > next = pmd_addr_end(addr, end); > > - /* > - * If pfn_base is NULL, we map kernel pages into HYP with the > - * virtual address. Otherwise, this is considered an I/O > - * mapping and we map the physical region starting at > - * *pfn_base to [start, end[. > - */ > - if (!pfn_base) > - create_hyp_pte_mappings(pmd, addr, next); > - else > - create_hyp_io_pte_mappings(pmd, addr, next, pfn_base); > + create_hyp_pte_mappings(pmd, addr, next, pfn, prot); > + pfn += (next - addr) >> PAGE_SHIFT; so this scheme always assumes a physically contiguous memory reason, and I wasn't sure if we ever wanted to support mapping vmalloc'ed regions into Hyp mode, which is why I wrote the code the way it was (which goes to your "for no good reason" comment above). I'm fine with assuming that this only works for contiguous regions, but I think it deserves a line in the comments on the exported functions (the non-IO one anyway). > } > > return 0; > } > > -static int __create_hyp_mappings(void *from, void *to, unsigned long *pfn_base) > +static int __create_hyp_mappings(pgd_t *pgdp, > + unsigned long start, unsigned long end, > + unsigned long pfn, pgprot_t prot) > { > - unsigned long start = (unsigned long)from; > - unsigned long end = (unsigned long)to; > pgd_t *pgd; > pud_t *pud; > pmd_t *pmd; > @@ -209,21 +181,14 @@ static int __create_hyp_mappings(void *from, void *to, unsigned long *pfn_base) > > if (start >= end) > return -EINVAL; > - /* Check for a valid kernel memory mapping */ > - if (!pfn_base && (!virt_addr_valid(from) || !virt_addr_valid(to - 1))) > - return -EINVAL; > - /* Check for a valid kernel IO mapping */ > - if (pfn_base && (!is_vmalloc_addr(from) || !is_vmalloc_addr(to - 1))) > - return -EINVAL; > > mutex_lock(&kvm_hyp_pgd_mutex); > - for (addr = start; addr < end; addr = next) { > - unsigned long hyp_addr = KERN_TO_HYP(addr); > - pgd = hyp_pgd + pgd_index(hyp_addr); > - pud = pud_offset(pgd, hyp_addr); > + for (addr = start & PAGE_MASK; addr < end; addr = next) { > + pgd = pgdp + pgd_index(addr); > + pud = pud_offset(pgd, addr); > > if (pud_none_or_clear_bad(pud)) { > - pmd = pmd_alloc_one(NULL, hyp_addr); > + pmd = pmd_alloc_one(NULL, addr); > if (!pmd) { > kvm_err("Cannot allocate Hyp pmd\n"); > err = -ENOMEM; > @@ -233,9 +198,10 @@ static int __create_hyp_mappings(void *from, void *to, unsigned long *pfn_base) > } > > next = pgd_addr_end(addr, end); > - err = create_hyp_pmd_mappings(pud, addr, next, pfn_base); > + err = create_hyp_pmd_mappings(pud, addr, next, pfn, prot); > if (err) > goto out; > + pfn += (next - addr) >> PAGE_SHIFT; nit: consider passing a pointer to pfn instead? Not sure if it's nicer. > } > out: > mutex_unlock(&kvm_hyp_pgd_mutex); > @@ -255,7 +221,16 @@ out: > */ > int create_hyp_mappings(void *from, void *to) > { > - return __create_hyp_mappings(from, to, NULL); > + unsigned long phys_addr = virt_to_phys(from); > + unsigned long start = KERN_TO_HYP((unsigned long)from); > + unsigned long end = KERN_TO_HYP((unsigned long)to); > + > + /* Check for a valid kernel memory mapping */ > + if (!virt_addr_valid(from) || !virt_addr_valid(to - 1)) > + return -EINVAL; > + > + return __create_hyp_mappings(hyp_pgd, start, end, > + __phys_to_pfn(phys_addr), PAGE_HYP); > } > > /** > @@ -267,10 +242,17 @@ int create_hyp_mappings(void *from, void *to) > * The resulting HYP VA is the same as the kernel VA, modulo > * HYP_PAGE_OFFSET. > */ > -int create_hyp_io_mappings(void *from, void *to, phys_addr_t addr) > +int create_hyp_io_mappings(void *from, void *to, phys_addr_t phys_addr) nit: change the parameter documentation name as well. > { > - unsigned long pfn = __phys_to_pfn(addr); > - return __create_hyp_mappings(from, to, &pfn); > + unsigned long start = KERN_TO_HYP((unsigned long)from); > + unsigned long end = KERN_TO_HYP((unsigned long)to); > + > + /* Check for a valid kernel IO mapping */ > + if (!is_vmalloc_addr(from) || !is_vmalloc_addr(to - 1)) > + return -EINVAL; > + > + return __create_hyp_mappings(hyp_pgd, start, end, > + __phys_to_pfn(phys_addr), PAGE_HYP_DEVICE); > } > > /** > -- > 1.8.1.4 > If the contigous thing is not a concern, then I'm happy about the simplification. -Christoffer -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html