[POWERPC] Rewrite IO allocation & mapping on powerpc64

This rewrites pretty much from scratch the handling of MMIO and PIO
space allocations on powerpc64.  The main goals are:

 - Get rid of imalloc and use more common code where possible
 - Simplify the current mess so that PIO space is allocated and
   mapped in a single place for PCI bridges
 - Handle allocation constraints of PIO for all bridges including
   hot plugged ones within the 2GB space reserved for IO ports,
   so that devices on hotplugged busses will now work with drivers
   that assume IO ports fit in an int.
 - Cleanup and separate tracking of the ISA space in the reserved
   low 64K of IO space. No ISA -> Nothing mapped there.

I booted a cell blade with IDE on PIO and MMIO and a dual G5 so
far, that's it :-)

With this patch, all allocations are done using the code in
mm/vmalloc.c, though we use the low level __get_vm_area with
explicit start/stop constraints in order to manage separate
areas for vmalloc/vmap, ioremap, and PCI IOs.

This greatly simplifies a lot of things, as you can see in the
diffstat of that patch :-)

A new pair of functions pcibios_map/unmap_io_space() now replace
all of the previous code that used to manipulate PCI IOs space.
The allocation is done at mapping time, which is now called from
scan_phb's, just before the devices are probed (instead of after,
which is by itself a bug fix). The only other caller is the PCI
hotplug code for hot adding PCI-PCI bridges (slots).

imalloc is gone, as is the "sub-allocation" thing, but I do beleive
that hotplug should still work in the sense that the space allocation
is always done by the PHB, but if you unmap a child bus of this PHB
(which seems to be possible), then the code should properly tear
down all the HPTE mappings for that area of the PHB allocated IO space.

I now always reserve the first 64K of IO space for the bridge with
the ISA bus on it. I have moved the code for tracking ISA in a separate
file which should also make it smarter if we ever are capable of
hot unplugging or re-plugging an ISA bridge.

This should have a side effect on platforms like powermac where VGA IOs
will no longer work. This is done on purpose though as they would have
worked semi-randomly before. The idea at this point is to isolate drivers
that might need to access those and fix them by providing a proper
function to obtain an offset to the legacy IOs of a given bus.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 0 insertions, 314 deletions

diff --git a/arch/powerpc/mm/imalloc.c b/arch/powerpc/mm/imalloc.c
deleted file mode 100644
index 9eddf37303d7..000000000000
--- a/arch/powerpc/mm/imalloc.c
+++ /dev/null
@@ -1,314 +0,0 @@
-/*
- * c 2001 PPC 64 Team, IBM Corp
- * 
- *      This program is free software; you can redistribute it and/or
- *      modify it under the terms of the GNU General Public License
- *      as published by the Free Software Foundation; either version
- *      2 of the License, or (at your option) any later version.
- */
-
-#include <linux/slab.h>
-#include <linux/vmalloc.h>
-
-#include <asm/uaccess.h>
-#include <asm/pgalloc.h>
-#include <asm/pgtable.h>
-#include <linux/mutex.h>
-#include <asm/cacheflush.h>
-
-#include "mmu_decl.h"
-
-static DEFINE_MUTEX(imlist_mutex);
-struct vm_struct * imlist = NULL;
-
-static int get_free_im_addr(unsigned long size, unsigned long *im_addr)
-{
-        unsigned long addr;
-        struct vm_struct **p, *tmp;
-
-        addr = ioremap_bot;
-        for (p = &imlist; (tmp = *p) ; p = &tmp->next) {
-                if (size + addr < (unsigned long) tmp->addr)
-                        break;
-                if ((unsigned long)tmp->addr >= ioremap_bot)
-                        addr = tmp->size + (unsigned long) tmp->addr;
-                if (addr >= IMALLOC_END-size)
-                        return 1;
-        }
-        *im_addr = addr;
-
-        return 0;
-}
-
-/* Return whether the region described by v_addr and size is a subset
- * of the region described by parent
- */
-static inline int im_region_is_subset(unsigned long v_addr, unsigned long size,
-                        struct vm_struct *parent)
-{
-        return (int) (v_addr >= (unsigned long) parent->addr &&
-                      v_addr < (unsigned long) parent->addr + parent->size &&
-                      size < parent->size);
-}
-
-/* Return whether the region described by v_addr and size is a superset
- * of the region described by child
- */
-static int im_region_is_superset(unsigned long v_addr, unsigned long size,
-                struct vm_struct *child)
-{
-        struct vm_struct parent;
-
-        parent.addr = (void *) v_addr;
-        parent.size = size;
-
-        return im_region_is_subset((unsigned long) child->addr, child->size,
-                        &parent);
-}
-
-/* Return whether the region described by v_addr and size overlaps
- * the region described by vm.  Overlapping regions meet the
- * following conditions:
- * 1) The regions share some part of the address space
- * 2) The regions aren't identical
- * 3) Neither region is a subset of the other
- */
-static int im_region_overlaps(unsigned long v_addr, unsigned long size,
-                     struct vm_struct *vm)
-{
-        if (im_region_is_superset(v_addr, size, vm))
-                return 0;
-
-        return (v_addr + size > (unsigned long) vm->addr + vm->size &&
-                v_addr < (unsigned long) vm->addr + vm->size) ||
-               (v_addr < (unsigned long) vm->addr &&
-                v_addr + size > (unsigned long) vm->addr);
-}
-
-/* Determine imalloc status of region described by v_addr and size.
- * Can return one of the following:
- * IM_REGION_UNUSED   -  Entire region is unallocated in imalloc space.
- * IM_REGION_SUBSET -    Region is a subset of a region that is already
- *                       allocated in imalloc space.
- *                       vm will be assigned to a ptr to the parent region.
- * IM_REGION_EXISTS -    Exact region already allocated in imalloc space.
- *                       vm will be assigned to a ptr to the existing imlist
- *                       member.
- * IM_REGION_OVERLAPS -  Region overlaps an allocated region in imalloc space.
- * IM_REGION_SUPERSET -  Region is a superset of a region that is already
- *                       allocated in imalloc space.
- */
-static int im_region_status(unsigned long v_addr, unsigned long size,
-                    struct vm_struct **vm)
-{
-        struct vm_struct *tmp;
-
-        for (tmp = imlist; tmp; tmp = tmp->next)
-                if (v_addr < (unsigned long) tmp->addr + tmp->size)
-                        break;
-
-        *vm = NULL;
-        if (tmp) {
-                if (im_region_overlaps(v_addr, size, tmp))
-                        return IM_REGION_OVERLAP;
-
-                *vm = tmp;
-                if (im_region_is_subset(v_addr, size, tmp)) {
-                        /* Return with tmp pointing to superset */
-                        return IM_REGION_SUBSET;
-                }
-                if (im_region_is_superset(v_addr, size, tmp)) {
-                        /* Return with tmp pointing to first subset */
-                        return IM_REGION_SUPERSET;
-                }
-                else if (v_addr == (unsigned long) tmp->addr &&
-                         size == tmp->size) {
-                        /* Return with tmp pointing to exact region */
-                        return IM_REGION_EXISTS;
-                }
-        }
-
-        return IM_REGION_UNUSED;
-}
-
-static struct vm_struct * split_im_region(unsigned long v_addr, 
-                unsigned long size, struct vm_struct *parent)
-{
-        struct vm_struct *vm1 = NULL;
-        struct vm_struct *vm2 = NULL;
-        struct vm_struct *new_vm = NULL;
-        
-        vm1 = kmalloc(sizeof(*vm1), GFP_KERNEL);
-        if (vm1 == NULL) {
-                printk(KERN_ERR "%s() out of memory\n", __FUNCTION__);
-                return NULL;
-        }
-
-        if (v_addr == (unsigned long) parent->addr) {
-                /* Use existing parent vm_struct to represent child, allocate
-                 * new one for the remainder of parent range
-                 */
-                vm1->size = parent->size - size;
-                vm1->addr = (void *) (v_addr + size);
-                vm1->next = parent->next;
-
-                parent->size = size;
-                parent->next = vm1;
-                new_vm = parent;
-        } else if (v_addr + size == (unsigned long) parent->addr + 
-                        parent->size) {
-                /* Allocate new vm_struct to represent child, use existing
-                 * parent one for remainder of parent range
-                 */
-                vm1->size = size;
-                vm1->addr = (void *) v_addr;
-                vm1->next = parent->next;
-                new_vm = vm1;
-
-                parent->size -= size;
-                parent->next = vm1;
-        } else {
-                /* Allocate two new vm_structs for the new child and 
-                 * uppermost remainder, and use existing parent one for the
-                 * lower remainder of parent range
-                 */
-                vm2 = kmalloc(sizeof(*vm2), GFP_KERNEL);
-                if (vm2 == NULL) {
-                        printk(KERN_ERR "%s() out of memory\n", __FUNCTION__);
-                        kfree(vm1);
-                        return NULL;
-                }
-
-                vm1->size = size;
-                vm1->addr = (void *) v_addr;
-                vm1->next = vm2;
-                new_vm = vm1;
-
-                vm2->size = ((unsigned long) parent->addr + parent->size) - 
-                                (v_addr + size);
-                vm2->addr = (void *) v_addr + size;
-                vm2->next = parent->next;
-
-                parent->size = v_addr - (unsigned long) parent->addr;
-                parent->next = vm1;
-        }
-
-        return new_vm;
-}
-
-static struct vm_struct * __add_new_im_area(unsigned long req_addr, 
-                                            unsigned long size)
-{
-        struct vm_struct **p, *tmp, *area;
-                
-        for (p = &imlist; (tmp = *p) ; p = &tmp->next) {
-                if (req_addr + size <= (unsigned long)tmp->addr)
-                        break;
-        }
-        
-        area = kmalloc(sizeof(*area), GFP_KERNEL);
-        if (!area)
-                return NULL;
-        area->flags = 0;
-        area->addr = (void *)req_addr;
-        area->size = size;
-        area->next = *p;
-        *p = area;
-
-        return area;
-}
-
-static struct vm_struct * __im_get_area(unsigned long req_addr, 
-                                        unsigned long size,
-                                        int criteria)
-{
-        struct vm_struct *tmp;
-        int status;
-
-        status = im_region_status(req_addr, size, &tmp);
-        if ((criteria & status) == 0) {
-                return NULL;
-        }
-        
-        switch (status) {
-        case IM_REGION_UNUSED:
-                tmp = __add_new_im_area(req_addr, size);
-                break;
-        case IM_REGION_SUBSET:
-                tmp = split_im_region(req_addr, size, tmp);
-                break;
-        case IM_REGION_EXISTS:
-                /* Return requested region */
-                break;
-        case IM_REGION_SUPERSET:
-                /* Return first existing subset of requested region */
-                break;
-        default:
-                printk(KERN_ERR "%s() unexpected imalloc region status\n",
-                                __FUNCTION__);
-                tmp = NULL;
-        }
-
-        return tmp;
-}
-
-struct vm_struct * im_get_free_area(unsigned long size)
-{
-        struct vm_struct *area;
-        unsigned long addr;
-        
-        mutex_lock(&imlist_mutex);
-        if (get_free_im_addr(size, &addr)) {
-                printk(KERN_ERR "%s() cannot obtain addr for size 0x%lx\n",
-                                __FUNCTION__, size);
-                area = NULL;
-                goto next_im_done;
-        }
-
-        area = __im_get_area(addr, size, IM_REGION_UNUSED);
-        if (area == NULL) {
-                printk(KERN_ERR 
-                       "%s() cannot obtain area for addr 0x%lx size 0x%lx\n",
-                        __FUNCTION__, addr, size);
-        }
-next_im_done:
-        mutex_unlock(&imlist_mutex);
-        return area;
-}
-
-struct vm_struct * im_get_area(unsigned long v_addr, unsigned long size,
-                int criteria)
-{
-        struct vm_struct *area;
-
-        mutex_lock(&imlist_mutex);
-        area = __im_get_area(v_addr, size, criteria);
-        mutex_unlock(&imlist_mutex);
-        return area;
-}
-
-void im_free(void * addr)
-{
-        struct vm_struct **p, *tmp;
-  
-        if (!addr)
-                return;
-        if ((unsigned long) addr & ~PAGE_MASK) {
-                printk(KERN_ERR "Trying to %s bad address (%p)\n", __FUNCTION__,                        addr);
-                return;
-        }
-        mutex_lock(&imlist_mutex);
-        for (p = &imlist ; (tmp = *p) ; p = &tmp->next) {
-                if (tmp->addr == addr) {
-                        *p = tmp->next;
-                        unmap_kernel_range((unsigned long)tmp->addr,
-                                           tmp->size);
-                        kfree(tmp);
-                        mutex_unlock(&imlist_mutex);
-                        return;
-                }
-        }
-        mutex_unlock(&imlist_mutex);
-        printk(KERN_ERR "Trying to %s nonexistent area (%p)\n", __FUNCTION__,
-                        addr);
-}