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Message-ID: <20070706201625.GT4306@sequoia.sous-sol.org>
Date: Fri, 6 Jul 2007 13:16:25 -0700
From: Chris Wright <chrisw@...s-sol.org>
To: Stefan Richter <stefanr@...6.in-berlin.de>
Cc: "Robert P. J. Day" <rpjday@...dspring.com>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
Andrew Morton <akpm@...l.org>,
Jeremy Fitzhardinge <jeremy@...source.com>,
Chris Wright <chrisw@...s-sol.org>,
Zachary Amsden <zach@...are.com>,
Rusty Russell <rusty@...tcorp.com.au>,
virtualization@...ts.osdl.org
Subject: [PATCH] VMI: remove CONFIG_DEBUG_PAGE_TYPE and associated
bitrotted code
* Stefan Richter (stefanr@...6.in-berlin.de) wrote:
> > -#ifdef CONFIG_DEBUG_PAGE_TYPE
> > +#if 0 /* debug page type */
<snip>
> This misnamed CONFIG_DEBUG_PAGE_TYPE (it's not a Kconfig variable) has
> about 120 lines debug code dangling on it. So, replacing it by #if 0
> will hopefully motivate a kind janitor to send a removal patch for that
> debug code eventually. I don't do so just now because that code went in
> between 2.6.20 and 2.6.21-rc1, i.e. not so long ago.
This is Zach's code, his final call. I know it was pretty useful early
on, and used to be an actual Kconfig option for VMI. However, it's
completely disconnected; the setup call to vmi_apply_boot_page_allocations
isn't merged and the page->type field isn't either (no surprise on that),
and some of the VMI_PAGE_ constants have changed names. Clearly, it is
ripe for bitrot (already has !CONFIG_NEED_MULTIPLE_NODES dependency,
dunno if VMI has the same limitation). It definitely should not have
a misleading Kconfig name. I'd nuke it all rather than #if 0.
thanks,
-chris
--
Subject: [PATCH] VMI: remove CONFIG_DEBUG_PAGE_TYPE and associated bitrotted code
From: Chris Wright <chrisw@...s-sol.org>
Remove the poorly named (non Kconfig) CONFIG_DEBUG_PAGE_TYPE compile
time conditional as well as the associated bitrotted debug code.
Cc: "Robert P. J. Day" <rpjday@...dspring.com>
Cc: Stefan Richter <stefanr@...6.in-berlin.de>
Cc: Zachary Amsden <zach@...are.com>
Signed-off-by: Chris Wright <chrisw@...s-sol.org>
---
diff --git a/arch/i386/kernel/vmi.c b/arch/i386/kernel/vmi.c
index c12720d..45c55e4 100644
--- a/arch/i386/kernel/vmi.c
+++ b/arch/i386/kernel/vmi.c
@@ -235,109 +235,6 @@ static void vmi_nop(void)
{
}
-#ifdef CONFIG_DEBUG_PAGE_TYPE
-
-#ifdef CONFIG_X86_PAE
-#define MAX_BOOT_PTS (2048+4+1)
-#else
-#define MAX_BOOT_PTS (1024+1)
-#endif
-
-/*
- * During boot, mem_map is not yet available in paging_init, so stash
- * all the boot page allocations here.
- */
-static struct {
- u32 pfn;
- int type;
-} boot_page_allocations[MAX_BOOT_PTS];
-static int num_boot_page_allocations;
-static int boot_allocations_applied;
-
-void vmi_apply_boot_page_allocations(void)
-{
- int i;
- BUG_ON(!mem_map);
- for (i = 0; i < num_boot_page_allocations; i++) {
- struct page *page = pfn_to_page(boot_page_allocations[i].pfn);
- page->type = boot_page_allocations[i].type;
- page->type = boot_page_allocations[i].type &
- ~(VMI_PAGE_ZEROED | VMI_PAGE_CLONE);
- }
- boot_allocations_applied = 1;
-}
-
-static void record_page_type(u32 pfn, int type)
-{
- BUG_ON(num_boot_page_allocations >= MAX_BOOT_PTS);
- boot_page_allocations[num_boot_page_allocations].pfn = pfn;
- boot_page_allocations[num_boot_page_allocations].type = type;
- num_boot_page_allocations++;
-}
-
-static void check_zeroed_page(u32 pfn, int type, struct page *page)
-{
- u32 *ptr;
- int i;
- int limit = PAGE_SIZE / sizeof(int);
-
- if (page_address(page))
- ptr = (u32 *)page_address(page);
- else
- ptr = (u32 *)__va(pfn << PAGE_SHIFT);
- /*
- * When cloning the root in non-PAE mode, only the userspace
- * pdes need to be zeroed.
- */
- if (type & VMI_PAGE_CLONE)
- limit = USER_PTRS_PER_PGD;
- for (i = 0; i < limit; i++)
- BUG_ON(ptr[i]);
-}
-
-/*
- * We stash the page type into struct page so we can verify the page
- * types are used properly.
- */
-static void vmi_set_page_type(u32 pfn, int type)
-{
- /* PAE can have multiple roots per page - don't track */
- if (PTRS_PER_PMD > 1 && (type & VMI_PAGE_PDP))
- return;
-
- if (boot_allocations_applied) {
- struct page *page = pfn_to_page(pfn);
- if (type != VMI_PAGE_NORMAL)
- BUG_ON(page->type);
- else
- BUG_ON(page->type == VMI_PAGE_NORMAL);
- page->type = type & ~(VMI_PAGE_ZEROED | VMI_PAGE_CLONE);
- if (type & VMI_PAGE_ZEROED)
- check_zeroed_page(pfn, type, page);
- } else {
- record_page_type(pfn, type);
- }
-}
-
-static void vmi_check_page_type(u32 pfn, int type)
-{
- /* PAE can have multiple roots per page - skip checks */
- if (PTRS_PER_PMD > 1 && (type & VMI_PAGE_PDP))
- return;
-
- type &= ~(VMI_PAGE_ZEROED | VMI_PAGE_CLONE);
- if (boot_allocations_applied) {
- struct page *page = pfn_to_page(pfn);
- BUG_ON((page->type ^ type) & VMI_PAGE_PAE);
- BUG_ON(type == VMI_PAGE_NORMAL && page->type);
- BUG_ON((type & page->type) == 0);
- }
-}
-#else
-#define vmi_set_page_type(p,t) do { } while (0)
-#define vmi_check_page_type(p,t) do { } while (0)
-#endif
-
#ifdef CONFIG_HIGHPTE
static void *vmi_kmap_atomic_pte(struct page *page, enum km_type type)
{
@@ -364,7 +261,6 @@ static void *vmi_kmap_atomic_pte(struct page *page, enum km_type type)
static void vmi_allocate_pt(u32 pfn)
{
- vmi_set_page_type(pfn, VMI_PAGE_L1);
vmi_ops.allocate_page(pfn, VMI_PAGE_L1, 0, 0, 0);
}
@@ -375,27 +271,22 @@ static void vmi_allocate_pd(u32 pfn)
* It is called only for swapper_pg_dir, which already has
* data on it.
*/
- vmi_set_page_type(pfn, VMI_PAGE_L2);
vmi_ops.allocate_page(pfn, VMI_PAGE_L2, 0, 0, 0);
}
static void vmi_allocate_pd_clone(u32 pfn, u32 clonepfn, u32 start, u32 count)
{
- vmi_set_page_type(pfn, VMI_PAGE_L2 | VMI_PAGE_CLONE);
- vmi_check_page_type(clonepfn, VMI_PAGE_L2);
vmi_ops.allocate_page(pfn, VMI_PAGE_L2 | VMI_PAGE_CLONE, clonepfn, start, count);
}
static void vmi_release_pt(u32 pfn)
{
vmi_ops.release_page(pfn, VMI_PAGE_L1);
- vmi_set_page_type(pfn, VMI_PAGE_NORMAL);
}
static void vmi_release_pd(u32 pfn)
{
vmi_ops.release_page(pfn, VMI_PAGE_L2);
- vmi_set_page_type(pfn, VMI_PAGE_NORMAL);
}
/*
@@ -419,26 +310,22 @@ static void vmi_release_pd(u32 pfn)
static void vmi_update_pte(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
- vmi_check_page_type(__pa(ptep) >> PAGE_SHIFT, VMI_PAGE_PTE);
vmi_ops.update_pte(ptep, vmi_flags_addr(mm, addr, VMI_PAGE_PT, 0));
}
static void vmi_update_pte_defer(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
- vmi_check_page_type(__pa(ptep) >> PAGE_SHIFT, VMI_PAGE_PTE);
vmi_ops.update_pte(ptep, vmi_flags_addr_defer(mm, addr, VMI_PAGE_PT, 0));
}
static void vmi_set_pte(pte_t *ptep, pte_t pte)
{
/* XXX because of set_pmd_pte, this can be called on PT or PD layers */
- vmi_check_page_type(__pa(ptep) >> PAGE_SHIFT, VMI_PAGE_PTE | VMI_PAGE_PD);
vmi_ops.set_pte(pte, ptep, VMI_PAGE_PT);
}
static void vmi_set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
{
- vmi_check_page_type(__pa(ptep) >> PAGE_SHIFT, VMI_PAGE_PTE);
vmi_ops.set_pte(pte, ptep, vmi_flags_addr(mm, addr, VMI_PAGE_PT, 0));
}
@@ -446,10 +333,8 @@ static void vmi_set_pmd(pmd_t *pmdp, pmd_t pmdval)
{
#ifdef CONFIG_X86_PAE
const pte_t pte = { pmdval.pmd, pmdval.pmd >> 32 };
- vmi_check_page_type(__pa(pmdp) >> PAGE_SHIFT, VMI_PAGE_PMD);
#else
const pte_t pte = { pmdval.pud.pgd.pgd };
- vmi_check_page_type(__pa(pmdp) >> PAGE_SHIFT, VMI_PAGE_PGD);
#endif
vmi_ops.set_pte(pte, (pte_t *)pmdp, VMI_PAGE_PD);
}
@@ -471,7 +356,6 @@ static void vmi_set_pte_atomic(pte_t *ptep, pte_t pteval)
static void vmi_set_pte_present(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
{
- vmi_check_page_type(__pa(ptep) >> PAGE_SHIFT, VMI_PAGE_PTE);
vmi_ops.set_pte(pte, ptep, vmi_flags_addr_defer(mm, addr, VMI_PAGE_PT, 1));
}
@@ -479,21 +363,18 @@ static void vmi_set_pud(pud_t *pudp, pud_t pudval)
{
/* Um, eww */
const pte_t pte = { pudval.pgd.pgd, pudval.pgd.pgd >> 32 };
- vmi_check_page_type(__pa(pudp) >> PAGE_SHIFT, VMI_PAGE_PGD);
vmi_ops.set_pte(pte, (pte_t *)pudp, VMI_PAGE_PDP);
}
static void vmi_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
const pte_t pte = { 0 };
- vmi_check_page_type(__pa(ptep) >> PAGE_SHIFT, VMI_PAGE_PTE);
vmi_ops.set_pte(pte, ptep, vmi_flags_addr(mm, addr, VMI_PAGE_PT, 0));
}
static void vmi_pmd_clear(pmd_t *pmd)
{
const pte_t pte = { 0 };
- vmi_check_page_type(__pa(pmd) >> PAGE_SHIFT, VMI_PAGE_PMD);
vmi_ops.set_pte(pte, (pte_t *)pmd, VMI_PAGE_PD);
}
#endif
diff --git a/include/asm-i386/vmi.h b/include/asm-i386/vmi.h
index eb8bd89..70d7d6f 100644
--- a/include/asm-i386/vmi.h
+++ b/include/asm-i386/vmi.h
@@ -225,7 +225,6 @@ struct pci_header {
/* Function prototypes for bootstrapping */
extern void vmi_init(void);
extern void vmi_bringup(void);
-extern void vmi_apply_boot_page_allocations(void);
/* State needed to start an application processor in an SMP system. */
struct vmi_ap_state {
-
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