Commit 20cee16c authored by David Gibson's avatar David Gibson Committed by Linus Torvalds
Browse files

[PATCH] ppc64: Abolish ioremap_mm 



Currently ppc64 has two mm_structs for the kernel, init_mm and also
ioremap_mm.  The latter really isn't necessary: this patch abolishes it,
instead restricting vmallocs to the lower 1TB of the init_mm's range and
placing io mappings in the upper 1TB.  This simplifies the code in a number
of places and eliminates an unecessary set of pagetables.  It also tweaks
the unmap/free path a little, allowing us to remove the unmap_im_area() set
of page table walkers, replacing them with unmap_vm_area().

Signed-off-by: default avatarDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 6879dc13

arch/ppc64/kernel/eeh.c

+1 −1
Original line number Diff line number Diff line
@@ -505,7 +505,7 @@ static inline unsigned long eeh_token_to_phys(unsigned long token) 
	pte_t *ptep;

	unsigned long pa;



	ptep = find_linux_pte(ioremap_mm.pgd, token);

	ptep = find_linux_pte(init_mm.pgd, token);

	if (!ptep)

		return token;

	pa = pte_pfn(*ptep) << PAGE_SHIFT;

arch/ppc64/kernel/head.S

+0 −4
Original line number Diff line number Diff line
@@ -2121,10 +2121,6 @@ empty_zero_page: 
swapper_pg_dir:

	.space	4096



	.globl	ioremap_dir

ioremap_dir:

	.space	4096



#ifdef CONFIG_SMP

/* 1 page segment table per cpu (max 48, cpu0 allocated at STAB0_PHYS_ADDR) */

	.globl	stab_array

arch/ppc64/kernel/process.c

+0 −8
Original line number Diff line number Diff line
@@ -58,14 +58,6 @@ struct task_struct *last_task_used_math = NULL; 
struct task_struct *last_task_used_altivec = NULL;

#endif



struct mm_struct ioremap_mm = {

	.pgd		= ioremap_dir,

	.mm_users	= ATOMIC_INIT(2),

	.mm_count	= ATOMIC_INIT(1),

	.cpu_vm_mask	= CPU_MASK_ALL,

	.page_table_lock = SPIN_LOCK_UNLOCKED,

};



/*

 * Make sure the floating-point register state in the

 * the thread_struct is up to date for task tsk.

arch/ppc64/mm/hash_utils.c

+0 −4
Original line number Diff line number Diff line
@@ -310,10 +310,6 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap) 


		vsid = get_vsid(mm->context.id, ea);

		break;

	case IO_REGION_ID:

		mm = &ioremap_mm;

		vsid = get_kernel_vsid(ea);

		break;

	case VMALLOC_REGION_ID:

		mm = &init_mm;

		vsid = get_kernel_vsid(ea);

arch/ppc64/mm/imalloc.c

+12 −8
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <asm/pgtable.h>

#include <asm/semaphore.h>

#include <asm/imalloc.h>

#include <asm/cacheflush.h>



static DECLARE_MUTEX(imlist_sem);

struct vm_struct * imlist = NULL;
@@ -285,29 +286,32 @@ struct vm_struct * im_get_area(unsigned long v_addr, unsigned long size, 
	return area;

}



unsigned long im_free(void * addr)

void im_free(void * addr)

{

	struct vm_struct **p, *tmp;

	unsigned long ret_size = 0;

  

	if (!addr)

		return ret_size;

	if ((PAGE_SIZE-1) & (unsigned long) addr) {

		return;

	if ((unsigned long) addr & ~PAGE_MASK) {

		printk(KERN_ERR "Trying to %s bad address (%p)\n", __FUNCTION__,			addr);

		return ret_size;

		return;

	}

	down(&imlist_sem);

	for (p = &imlist ; (tmp = *p) ; p = &tmp->next) {

		if (tmp->addr == addr) {

			ret_size = tmp->size;

			*p = tmp->next;



			/* XXX: do we need the lock? */

			spin_lock(&init_mm.page_table_lock);

			unmap_vm_area(tmp);

			spin_unlock(&init_mm.page_table_lock);



			kfree(tmp);

			up(&imlist_sem);

			return ret_size;

			return;

		}

	}

	up(&imlist_sem);

	printk(KERN_ERR "Trying to %s nonexistent area (%p)\n", __FUNCTION__,

			addr);

	return ret_size;

}

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