Skip to content

Commit

Permalink
ARM: KVM: simplify HYP mapping population
Browse files Browse the repository at this point in the history 
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@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
  • Loading branch information
Marc Zyngier authored and Christoffer Dall committed Apr 29, 2013
1 parent 372b7c1 commit 6060df8
Showing 1 changed file with 42 additions and 60 deletions.
102 changes: 42 additions & 60 deletions arch/arm/kvm/mmu.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -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;
}

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;
Expand All @@ -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;
Expand All @@ -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;
}
out:
mutex_unlock(&kvm_hyp_pgd_mutex);
Expand All @@ -255,22 +221,38 @@ static int __create_hyp_mappings(void *from, void *to, unsigned long *pfn_base)
*/
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);
}

/**
* create_hyp_io_mappings - duplicate a kernel IO mapping into Hyp mode
* @from: The kernel start VA of the range
* @to: The kernel end VA of the range (exclusive)
* @addr: The physical start address which gets mapped
* @phys_addr: The physical start address which gets mapped
*
* 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)
{
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);
}

/**
Expand Down

0 comments on commit 6060df8

Please sign in to comment.