On 04/04/13 00:13, Christoffer Dall wrote: > 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). So let's look at what we're actually mapping: - kernel code/kmalloc-ed data: this is always physically contiguous - MMIO: While this is mapped in the vmalloc region, this is actually physically contiguous. > 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). Sure, I'll add that. >> } >> >> 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. That's what we had before, and it wasn't that nice... >> } >> 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. Sure. > >> { >> - 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. Thanks, M. -- Jazz is not dead. It just smells funny... -- 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