Commit f2e39e8c authored by Juergen Gross's avatar Juergen Gross
Browse files

x86/xen: drop tests for highmem in pv code 



With support for 32-bit pv guests gone pure pv-code no longer needs to
test for highmem. Dropping those tests removes the need for flushing
in some places.

Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Reviewed-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
parent 56415c4c

arch/x86/xen/enlighten_pv.c

+4 −10
Original line number Diff line number Diff line
@@ -345,15 +345,13 @@ static void set_aliased_prot(void *v, pgprot_t prot) 
	pte_t *ptep;

	pte_t pte;

	unsigned long pfn;

	struct page *page;

	unsigned char dummy;

	void *va;



	ptep = lookup_address((unsigned long)v, &level);

	BUG_ON(ptep == NULL);



	pfn = pte_pfn(*ptep);

	page = pfn_to_page(pfn);



	pte = pfn_pte(pfn, prot);



	/*
@@ -383,14 +381,10 @@ static void set_aliased_prot(void *v, pgprot_t prot) 
	if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0))

		BUG();



	if (!PageHighMem(page)) {

		void *av = __va(PFN_PHYS(pfn));

	va = __va(PFN_PHYS(pfn));



		if (av != v)

			if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0))

	if (va != v && HYPERVISOR_update_va_mapping((unsigned long)va, pte, 0))

		BUG();

	} else

		kmap_flush_unused();



	preempt_enable();

}

arch/x86/xen/mmu_pv.c

+53 −85
Original line number Diff line number Diff line
@@ -537,25 +537,26 @@ __visible p4d_t xen_make_p4d(p4dval_t p4d) 
PV_CALLEE_SAVE_REGS_THUNK(xen_make_p4d);

#endif  /* CONFIG_PGTABLE_LEVELS >= 5 */



static int xen_pmd_walk(struct mm_struct *mm, pmd_t *pmd,

		int (*func)(struct mm_struct *mm, struct page *, enum pt_level),

static void xen_pmd_walk(struct mm_struct *mm, pmd_t *pmd,

			 void (*func)(struct mm_struct *mm, struct page *,

				      enum pt_level),

			 bool last, unsigned long limit)

{

	int i, nr, flush = 0;

	int i, nr;



	nr = last ? pmd_index(limit) + 1 : PTRS_PER_PMD;

	for (i = 0; i < nr; i++) {

		if (!pmd_none(pmd[i]))

			flush |= (*func)(mm, pmd_page(pmd[i]), PT_PTE);

			(*func)(mm, pmd_page(pmd[i]), PT_PTE);

	}

	return flush;

}



static int xen_pud_walk(struct mm_struct *mm, pud_t *pud,

		int (*func)(struct mm_struct *mm, struct page *, enum pt_level),

static void xen_pud_walk(struct mm_struct *mm, pud_t *pud,

			 void (*func)(struct mm_struct *mm, struct page *,

				      enum pt_level),

			 bool last, unsigned long limit)

{

	int i, nr, flush = 0;

	int i, nr;



	nr = last ? pud_index(limit) + 1 : PTRS_PER_PUD;

	for (i = 0; i < nr; i++) {
@@ -566,29 +567,26 @@ static int xen_pud_walk(struct mm_struct *mm, pud_t *pud, 


		pmd = pmd_offset(&pud[i], 0);

		if (PTRS_PER_PMD > 1)

			flush |= (*func)(mm, virt_to_page(pmd), PT_PMD);

		flush |= xen_pmd_walk(mm, pmd, func,

				last && i == nr - 1, limit);

			(*func)(mm, virt_to_page(pmd), PT_PMD);

		xen_pmd_walk(mm, pmd, func, last && i == nr - 1, limit);

	}

	return flush;

}



static int xen_p4d_walk(struct mm_struct *mm, p4d_t *p4d,

		int (*func)(struct mm_struct *mm, struct page *, enum pt_level),

static void xen_p4d_walk(struct mm_struct *mm, p4d_t *p4d,

			 void (*func)(struct mm_struct *mm, struct page *,

				      enum pt_level),

			 bool last, unsigned long limit)

{

	int flush = 0;

	pud_t *pud;





	if (p4d_none(*p4d))

		return flush;

		return;



	pud = pud_offset(p4d, 0);

	if (PTRS_PER_PUD > 1)

		flush |= (*func)(mm, virt_to_page(pud), PT_PUD);

	flush |= xen_pud_walk(mm, pud, func, last, limit);

	return flush;

		(*func)(mm, virt_to_page(pud), PT_PUD);

	xen_pud_walk(mm, pud, func, last, limit);

}



/*
@@ -603,12 +601,12 @@ static int xen_p4d_walk(struct mm_struct *mm, p4d_t *p4d, 
 * We must skip the Xen hole in the middle of the address space, just after

 * the big x86-64 virtual hole.

 */

static int __xen_pgd_walk(struct mm_struct *mm, pgd_t *pgd,

			  int (*func)(struct mm_struct *mm, struct page *,

static void __xen_pgd_walk(struct mm_struct *mm, pgd_t *pgd,

			   void (*func)(struct mm_struct *mm, struct page *,

					enum pt_level),

			   unsigned long limit)

{

	int i, nr, flush = 0;

	int i, nr;

	unsigned hole_low = 0, hole_high = 0;



	/* The limit is the last byte to be touched */
@@ -633,22 +631,20 @@ static int __xen_pgd_walk(struct mm_struct *mm, pgd_t *pgd, 
			continue;



		p4d = p4d_offset(&pgd[i], 0);

		flush |= xen_p4d_walk(mm, p4d, func, i == nr - 1, limit);

		xen_p4d_walk(mm, p4d, func, i == nr - 1, limit);

	}



	/* Do the top level last, so that the callbacks can use it as

	   a cue to do final things like tlb flushes. */

	flush |= (*func)(mm, virt_to_page(pgd), PT_PGD);



	return flush;

	(*func)(mm, virt_to_page(pgd), PT_PGD);

}



static int xen_pgd_walk(struct mm_struct *mm,

			int (*func)(struct mm_struct *mm, struct page *,

static void xen_pgd_walk(struct mm_struct *mm,

			 void (*func)(struct mm_struct *mm, struct page *,

				      enum pt_level),

			 unsigned long limit)

{

	return __xen_pgd_walk(mm, mm->pgd, func, limit);

	__xen_pgd_walk(mm, mm->pgd, func, limit);

}



/* If we're using split pte locks, then take the page's lock and
@@ -681,26 +677,17 @@ static void xen_do_pin(unsigned level, unsigned long pfn) 
	xen_extend_mmuext_op(&op);

}



static int xen_pin_page(struct mm_struct *mm, struct page *page,

static void xen_pin_page(struct mm_struct *mm, struct page *page,

			 enum pt_level level)

{

	unsigned pgfl = TestSetPagePinned(page);

	int flush;



	if (pgfl)

		flush = 0;		/* already pinned */

	else if (PageHighMem(page))

		/* kmaps need flushing if we found an unpinned

		   highpage */

		flush = 1;

	else {



	if (!pgfl) {

		void *pt = lowmem_page_address(page);

		unsigned long pfn = page_to_pfn(page);

		struct multicall_space mcs = __xen_mc_entry(0);

		spinlock_t *ptl;



		flush = 0;



		/*

		 * We need to hold the pagetable lock between the time

		 * we make the pagetable RO and when we actually pin
@@ -737,8 +724,6 @@ static int xen_pin_page(struct mm_struct *mm, struct page *page, 
			xen_mc_callback(xen_pte_unlock, ptl);

		}

	}



	return flush;

}



/* This is called just after a mm has been created, but it has not
@@ -752,14 +737,7 @@ static void __xen_pgd_pin(struct mm_struct *mm, pgd_t *pgd) 


	xen_mc_batch();



	if (__xen_pgd_walk(mm, pgd, xen_pin_page, USER_LIMIT)) {

		/* re-enable interrupts for flushing */

		xen_mc_issue(0);



		kmap_flush_unused();



		xen_mc_batch();

	}

	__xen_pgd_walk(mm, pgd, xen_pin_page, USER_LIMIT);



	xen_do_pin(MMUEXT_PIN_L4_TABLE, PFN_DOWN(__pa(pgd)));
@@ -803,11 +781,10 @@ void xen_mm_pin_all(void) 
	spin_unlock(&pgd_lock);

}



static int __init xen_mark_pinned(struct mm_struct *mm, struct page *page,

static void __init xen_mark_pinned(struct mm_struct *mm, struct page *page,

				   enum pt_level level)

{

	SetPagePinned(page);

	return 0;

}



/*
@@ -823,12 +800,12 @@ static void __init xen_after_bootmem(void) 
	xen_pgd_walk(&init_mm, xen_mark_pinned, FIXADDR_TOP);

}



static int xen_unpin_page(struct mm_struct *mm, struct page *page,

static void xen_unpin_page(struct mm_struct *mm, struct page *page,

			   enum pt_level level)

{

	unsigned pgfl = TestClearPagePinned(page);



	if (pgfl && !PageHighMem(page)) {

	if (pgfl) {

		void *pt = lowmem_page_address(page);

		unsigned long pfn = page_to_pfn(page);

		spinlock_t *ptl = NULL;
@@ -859,8 +836,6 @@ static int xen_unpin_page(struct mm_struct *mm, struct page *page, 
			xen_mc_callback(xen_pte_unlock, ptl);

		}

	}



	return 0;		/* never need to flush on unpin */

}



/* Release a pagetables pages back as normal RW */
@@ -1554,7 +1529,6 @@ static inline void xen_alloc_ptpage(struct mm_struct *mm, unsigned long pfn, 
		if (static_branch_likely(&xen_struct_pages_ready))

			SetPagePinned(page);



		if (!PageHighMem(page)) {

		xen_mc_batch();



		__set_pfn_prot(pfn, PAGE_KERNEL_RO);
@@ -1563,11 +1537,6 @@ static inline void xen_alloc_ptpage(struct mm_struct *mm, unsigned long pfn, 
			__pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn);



		xen_mc_issue(PARAVIRT_LAZY_MMU);

		} else {

			/* make sure there are no stray mappings of

			   this page */

			kmap_flush_unused();

		}

	}

}
@@ -1590,7 +1559,6 @@ static inline void xen_release_ptpage(unsigned long pfn, unsigned level) 
	trace_xen_mmu_release_ptpage(pfn, level, pinned);



	if (pinned) {

		if (!PageHighMem(page)) {

		xen_mc_batch();



		if (level == PT_PTE && USE_SPLIT_PTE_PTLOCKS)
@@ -1599,7 +1567,7 @@ static inline void xen_release_ptpage(unsigned long pfn, unsigned level) 
		__set_pfn_prot(pfn, PAGE_KERNEL);



		xen_mc_issue(PARAVIRT_LAZY_MMU);

		}



		ClearPagePinned(page);

	}

}

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