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Commit 39dbc5bd authored by Jeremy Fitzhardinge's avatar Jeremy Fitzhardinge Committed by Ingo Molnar
Browse files

xen32: create initial mappings like 64-bit 



Rearrange the pagetable initialization to share code with the 64-bit
kernel.  Rather than deferring anything to pagetable_setup_start, just
set up an initial pagetable in swapper_pg_dir early at startup, and
create an additional 8MB of physical memory mappings.  This matches
the native head_32.S mappings to a large degree, and allows the rest
of the pagetable setup to continue without much Xen vs. native
difference.

Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent d114e198

arch/x86/xen/enlighten.c

+52 −78
Original line number Diff line number Diff line
@@ -854,50 +854,6 @@ static __init void xen_set_pte_init(pte_t *ptep, pte_t pte) 


static __init void xen_pagetable_setup_start(pgd_t *base)

{

#ifdef CONFIG_X86_32

	pgd_t *xen_pgd = (pgd_t *)xen_start_info->pt_base;

	int i;



	init_mm.pgd = base;

	/*

	 * copy top-level of Xen-supplied pagetable into place.  This

	 * is a stand-in while we copy the pmd pages.

	 */

	memcpy(base, xen_pgd, PTRS_PER_PGD * sizeof(pgd_t));



	/*

	 * For PAE, need to allocate new pmds, rather than

	 * share Xen's, since Xen doesn't like pmd's being

	 * shared between address spaces.

	 */

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

		if (pgd_val_ma(xen_pgd[i]) & _PAGE_PRESENT) {

			pmd_t *pmd = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE);



			memcpy(pmd, (void *)pgd_page_vaddr(xen_pgd[i]),

			       PAGE_SIZE);



			make_lowmem_page_readonly(pmd);



			set_pgd(&base[i], __pgd(1 + __pa(pmd)));

		} else

			pgd_clear(&base[i]);

	}



	/* make sure zero_page is mapped RO so we can use it in pagetables */

	make_lowmem_page_readonly(empty_zero_page);

	make_lowmem_page_readonly(base);

	/*

	 * Switch to new pagetable.  This is done before

	 * pagetable_init has done anything so that the new pages

	 * added to the table can be prepared properly for Xen.

	 */

	xen_write_cr3(__pa(base));



	/* Unpin initial Xen pagetable */

	pin_pagetable_pfn(MMUEXT_UNPIN_TABLE,

			  PFN_DOWN(__pa(xen_start_info->pt_base)));

#endif	/* CONFIG_X86_32 */

}



void xen_setup_shared_info(void)
@@ -936,12 +892,6 @@ static __init void xen_pagetable_setup_done(pgd_t *base) 
	pv_mmu_ops.set_pte = xen_set_pte;



	xen_setup_shared_info();



#ifdef CONFIG_X86_32

	/* Actually pin the pagetable down, but we can't set PG_pinned

	   yet because the page structures don't exist yet. */

	pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(base)));

#endif

}



static __init void xen_post_allocator_init(void)
@@ -1299,14 +1249,17 @@ static void __init xen_reserve_top(void) 
#endif	/* CONFIG_X86_32 */

}



#ifdef CONFIG_X86_64

/*

 * Like __va(), but returns address in the kernel mapping (which is

 * all we have until the physical memory mapping has been set up.

 */

static void *__ka(phys_addr_t paddr)

{

#ifdef CONFIG_X86_64

	return (void *)(paddr + __START_KERNEL_map);

#else

	return __va(paddr);

#endif

}



/* Convert a machine address to physical address */
@@ -1326,6 +1279,7 @@ static void *m2v(phys_addr_t maddr) 
	return __ka(m2p(maddr));

}



#ifdef CONFIG_X86_64

static void walk(pgd_t *pgd, unsigned long addr)

{

	unsigned l4idx = pgd_index(addr);
@@ -1356,13 +1310,14 @@ static void walk(pgd_t *pgd, unsigned long addr) 
	xen_raw_printk("  l1: %016lx\n", l1.pte);

	xen_raw_printk("      %016lx\n", pte_val(l1));

}

#endif



static void set_page_prot(void *addr, pgprot_t prot)

{

	unsigned long pfn = __pa(addr) >> PAGE_SHIFT;

	pte_t pte = pfn_pte(pfn, prot);



	xen_raw_printk("addr=%p pfn=%lx mfn=%lx prot=%016x pte=%016x\n",

	xen_raw_printk("addr=%p pfn=%lx mfn=%lx prot=%016llx pte=%016llx\n",

		       addr, pfn, get_phys_to_machine(pfn),

		       pgprot_val(prot), pte.pte);
@@ -1370,17 +1325,6 @@ static void set_page_prot(void *addr, pgprot_t prot) 
		BUG();

}



static void convert_pfn_mfn(void *v)

{

	pte_t *pte = v;

	int i;



	/* All levels are converted the same way, so just treat them

	   as ptes. */

	for(i = 0; i < PTRS_PER_PTE; i++)

		pte[i] = xen_make_pte(pte[i].pte);

}



/*

 * Identity map, in addition to plain kernel map.  This needs to be

 * large enough to allocate page table pages to allocate the rest.
@@ -1388,7 +1332,7 @@ static void convert_pfn_mfn(void *v) 
 */

static pte_t level1_ident_pgt[PTRS_PER_PTE * 4] __page_aligned_bss;



static __init void xen_map_identity_early(unsigned long max_pfn)

static __init void xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn)

{

	unsigned pmdidx, pteidx;

	unsigned ident_pte;
@@ -1399,11 +1343,9 @@ static __init void xen_map_identity_early(unsigned long max_pfn) 
	for(pmdidx = 0; pmdidx < PTRS_PER_PMD && pfn < max_pfn; pmdidx++) {

		pte_t *pte_page;



		BUG_ON(level2_ident_pgt[pmdidx].pmd != level2_kernel_pgt[pmdidx].pmd);



		/* Reuse or allocate a page of ptes */

		if (pmd_present(level2_ident_pgt[pmdidx]))

			pte_page = m2v(level2_ident_pgt[pmdidx].pmd);

		if (pmd_present(pmd[pmdidx]))

			pte_page = m2v(pmd[pmdidx].pmd);

		else {

			/* Check for free pte pages */

			if (ident_pte == ARRAY_SIZE(level1_ident_pgt))
@@ -1412,9 +1354,7 @@ static __init void xen_map_identity_early(unsigned long max_pfn) 
			pte_page = &level1_ident_pgt[ident_pte];

			ident_pte += PTRS_PER_PTE;



			/* Install new l1 in l2(s) */

			level2_ident_pgt[pmdidx] = __pmd(__pa(pte_page) | _PAGE_TABLE);

			level2_kernel_pgt[pmdidx] = level2_ident_pgt[pmdidx];

			pmd[pmdidx] = __pmd(__pa(pte_page) | _PAGE_TABLE);

		}



		/* Install mappings */
@@ -1434,6 +1374,20 @@ static __init void xen_map_identity_early(unsigned long max_pfn) 


	for(pteidx = 0; pteidx < ident_pte; pteidx += PTRS_PER_PTE)

		set_page_prot(&level1_ident_pgt[pteidx], PAGE_KERNEL_RO);



	set_page_prot(pmd, PAGE_KERNEL_RO);

}



#ifdef CONFIG_X86_64

static void convert_pfn_mfn(void *v)

{

	pte_t *pte = v;

	int i;



	/* All levels are converted the same way, so just treat them

	   as ptes. */

	for(i = 0; i < PTRS_PER_PTE; i++)

		pte[i] = xen_make_pte(pte[i].pte);

}



/*
@@ -1471,18 +1425,18 @@ static __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pf 
	memcpy(level2_fixmap_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD);



	/* Set up identity map */

	xen_map_identity_early(max_pfn);

	xen_map_identity_early(level2_ident_pgt, max_pfn);



	/* Make pagetable pieces RO */

	set_page_prot(init_level4_pgt, PAGE_KERNEL_RO);

	set_page_prot(level3_ident_pgt, PAGE_KERNEL_RO);

	set_page_prot(level3_kernel_pgt, PAGE_KERNEL_RO);

	set_page_prot(level2_ident_pgt, PAGE_KERNEL_RO);

	set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO);

	set_page_prot(level2_fixmap_pgt, PAGE_KERNEL_RO);



	/* Pin down new L4 */

	pin_pagetable_pfn(MMUEXT_PIN_L4_TABLE, PFN_DOWN(__pa_symbol(init_level4_pgt)));

	pin_pagetable_pfn(MMUEXT_PIN_L4_TABLE,

			  PFN_DOWN(__pa_symbol(init_level4_pgt)));



	/* Unpin Xen-provided one */

	pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
@@ -1498,17 +1452,37 @@ static __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pf 


	return pgd;

}

#else

#else	/* !CONFIG_X86_64 */

static pmd_t level2_kernel_pgt[PTRS_PER_PMD] __page_aligned_bss;



static __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn)

{

	pmd_t *kernel_pmd;



	init_pg_tables_start = __pa(pgd);

	init_pg_tables_end = __pa(pgd) + xen_start_info->nr_pt_frames*PAGE_SIZE;

	max_pfn_mapped = PFN_DOWN(init_pg_tables_end + 512*1024);



	x86_write_percpu(xen_cr3, __pa(pgd));

	x86_write_percpu(xen_current_cr3, __pa(pgd));

	kernel_pmd = m2v(pgd[KERNEL_PGD_BOUNDARY].pgd);

	memcpy(level2_kernel_pgt, kernel_pmd, sizeof(pmd_t) * PTRS_PER_PMD);



	return pgd;

	xen_map_identity_early(level2_kernel_pgt, max_pfn);



	memcpy(swapper_pg_dir, pgd, sizeof(pgd_t) * PTRS_PER_PGD);

	set_pgd(&swapper_pg_dir[KERNEL_PGD_BOUNDARY],

			__pgd(__pa(level2_kernel_pgt) | _PAGE_PRESENT));



	set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO);

	set_page_prot(swapper_pg_dir, PAGE_KERNEL_RO);

	set_page_prot(empty_zero_page, PAGE_KERNEL_RO);



	pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));



	xen_write_cr3(__pa(swapper_pg_dir));



	pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(swapper_pg_dir)));



	return swapper_pg_dir;

}

#endif	/* CONFIG_X86_64 */