Commit 6060df84 authored by Marc Zyngier's avatar Marc Zyngier Committed by Christoffer Dall
Browse files

ARM: KVM: simplify HYP mapping population 



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: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <cdall@cs.columbia.edu>
parent 372b7c1b

arch/arm/kvm/mmu.c

+42 −60
Original line number Diff line number Diff line
@@ -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;

	}



	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;

	}

out:

	mutex_unlock(&kvm_hyp_pgd_mutex);
@@ -255,22 +221,38 @@ 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);

}



/**

 * 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);

}



/**

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