PNP: convert resource options to single linked list

ISAPNP, PNPBIOS, and ACPI describe the "possible resource settings" of
a device, i.e., the possibilities an OS bus driver has when it assigns
I/O port, MMIO, and other resources to the device.

PNP used to maintain this "possible resource setting" information in
one independent option structure and a list of dependent option
structures for each device.  Each of these option structures had lists
of I/O, memory, IRQ, and DMA resources, for example:

  dev
    independent options
      ind-io0  -> ind-io1  ...
      ind-mem0 -> ind-mem1 ...
      ...
    dependent option set 0
      dep0-io0  -> dep0-io1  ...
      dep0-mem0 -> dep0-mem1 ...
      ...
    dependent option set 1
      dep1-io0  -> dep1-io1  ...
      dep1-mem0 -> dep1-mem1 ...
      ...
    ...

This data structure was designed for ISAPNP, where the OS configures
device resource settings by writing directly to configuration
registers.  The OS can write the registers in arbitrary order much
like it writes PCI BARs.

However, for PNPBIOS and ACPI devices, the OS uses firmware interfaces
that perform device configuration, and it is important to pass the
desired settings to those interfaces in the correct order.  The OS
learns the correct order by using firmware interfaces that return the
"current resource settings" and "possible resource settings," but the
option structures above doesn't store the ordering information.

This patch replaces the independent and dependent lists with a single
list of options.  For example, a device might have possible resource
settings like this:

  dev
    options
      ind-io0 -> dep0-io0 -> dep1->io0 -> ind-io1 ...

All the possible settings are in the same list, in the order they
come from the firmware "possible resource settings" list.  Each entry
is tagged with an independent/dependent flag.  Dependent entries also
have a "set number" and an optional priority value.  All dependent
entries must be assigned from the same set.  For example, the OS can
use all the entries from dependent set 0, or all the entries from
dependent set 1, but it cannot mix entries from set 0 with entries
from set 1.

Prior to this patch PNP didn't keep track of the order of this list,
and it assigned all independent options first, then all dependent
ones.  Using the example above, that resulted in a "desired
configuration" list like this:

  ind->io0 -> ind->io1 -> depN-io0 ...

instead of the list the firmware expects, which looks like this:

  ind->io0 -> depN-io0 -> ind-io1 ...

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 65 insertions, 203 deletions

diff --git a/drivers/pnp/resource.c b/drivers/pnp/resource.c
index a795864dc695..d6388970a1a4 100644
--- a/drivers/pnp/resource.c
+++ b/drivers/pnp/resource.c
@@ -3,6 +3,8 @@
  *
  * based on isapnp.c resource management (c) Jaroslav Kysela <perex@perex.cz>
  * Copyright 2003 Adam Belay <ambx1@neo.rr.com>
+ * Copyright (C) 2008 Hewlett-Packard Development Company, L.P.
+ *      Bjorn Helgaas <bjorn.helgaas@hp.com>
  */
 
 #include <linux/module.h>
@@ -28,78 +30,36 @@ static int pnp_reserve_mem[16] = {[0 ... 15] = -1 };	/* reserve (don't use) some
  * option registration
  */
 
-struct pnp_option *pnp_build_option(int priority)
+struct pnp_option *pnp_build_option(struct pnp_dev *dev, unsigned long type,
+                                    unsigned int option_flags)
 {
-        struct pnp_option *option = pnp_alloc(sizeof(struct pnp_option));
+        struct pnp_option *option;
 
+        option = kzalloc(sizeof(struct pnp_option), GFP_KERNEL);
         if (!option)
                 return NULL;
 
-        option->priority = priority & 0xff;
-        /* make sure the priority is valid */
-        if (option->priority > PNP_RES_PRIORITY_FUNCTIONAL)
-                option->priority = PNP_RES_PRIORITY_INVALID;
-
-        return option;
-}
-
-struct pnp_option *pnp_register_independent_option(struct pnp_dev *dev)
-{
-        struct pnp_option *option;
-
-        option = pnp_build_option(PNP_RES_PRIORITY_PREFERRED);
-
-        /* this should never happen but if it does we'll try to continue */
-        if (dev->independent)
-                dev_err(&dev->dev, "independent resource already registered\n");
-        dev->independent = option;
-
-        dev_dbg(&dev->dev, "new independent option\n");
-        return option;
-}
-
-struct pnp_option *pnp_register_dependent_option(struct pnp_dev *dev,
-                                                 int priority)
-{
-        struct pnp_option *option;
+        option->flags = option_flags;
+        option->type = type;
 
-        option = pnp_build_option(priority);
-
-        if (dev->dependent) {
-                struct pnp_option *parent = dev->dependent;
-                while (parent->next)
-                        parent = parent->next;
-                parent->next = option;
-        } else
-                dev->dependent = option;
-
-        dev_dbg(&dev->dev, "new dependent option (priority %#x)\n", priority);
+        list_add_tail(&option->list, &dev->options);
         return option;
 }
 
-int pnp_register_irq_resource(struct pnp_dev *dev, struct pnp_option *option,
+int pnp_register_irq_resource(struct pnp_dev *dev, unsigned int option_flags,
                               pnp_irq_mask_t *map, unsigned char flags)
 {
-        struct pnp_irq *irq, *ptr;
-#ifdef DEBUG
-        char buf[PNP_IRQ_NR];   /* hex-encoded, so this is overkill but safe */
-#endif
+        struct pnp_option *option;
+        struct pnp_irq *irq;
 
-        irq = kzalloc(sizeof(struct pnp_irq), GFP_KERNEL);
-        if (!irq)
+        option = pnp_build_option(dev, IORESOURCE_IRQ, option_flags);
+        if (!option)
                 return -ENOMEM;
 
+        irq = &option->u.irq;
         irq->map = *map;
         irq->flags = flags;
 
-        ptr = option->irq;
-        while (ptr && ptr->next)
-                ptr = ptr->next;
-        if (ptr)
-                ptr->next = irq;
-        else
-                option->irq = irq;
-
 #ifdef CONFIG_PCI
         {
                 int i;
@@ -110,163 +70,81 @@ int pnp_register_irq_resource(struct pnp_dev *dev, struct pnp_option *option,
         }
 #endif
 
-#ifdef DEBUG
-        bitmap_scnprintf(buf, sizeof(buf), irq->map.bits, PNP_IRQ_NR);
-        dev_dbg(&dev->dev, "  irq bitmask %s flags %#x\n", buf,
-                irq->flags);
-#endif
+        dbg_pnp_show_option(dev, option);
         return 0;
 }
 
-int pnp_register_dma_resource(struct pnp_dev *dev, struct pnp_option *option,
+int pnp_register_dma_resource(struct pnp_dev *dev, unsigned int option_flags,
                               unsigned char map, unsigned char flags)
 {
-        struct pnp_dma *dma, *ptr;
+        struct pnp_option *option;
+        struct pnp_dma *dma;
 
-        dma = kzalloc(sizeof(struct pnp_dma), GFP_KERNEL);
-        if (!dma)
+        option = pnp_build_option(dev, IORESOURCE_DMA, option_flags);
+        if (!option)
                 return -ENOMEM;
 
+        dma = &option->u.dma;
         dma->map = map;
         dma->flags = flags;
 
-        ptr = option->dma;
-        while (ptr && ptr->next)
-                ptr = ptr->next;
-        if (ptr)
-                ptr->next = dma;
-        else
-                option->dma = dma;
-
-        dev_dbg(&dev->dev, "  dma bitmask %#x flags %#x\n", dma->map,
-                dma->flags);
+        dbg_pnp_show_option(dev, option);
         return 0;
 }
 
-int pnp_register_port_resource(struct pnp_dev *dev, struct pnp_option *option,
+int pnp_register_port_resource(struct pnp_dev *dev, unsigned int option_flags,
                                resource_size_t min, resource_size_t max,
                                resource_size_t align, resource_size_t size,
                                unsigned char flags)
 {
-        struct pnp_port *port, *ptr;
+        struct pnp_option *option;
+        struct pnp_port *port;
 
-        port = kzalloc(sizeof(struct pnp_port), GFP_KERNEL);
-        if (!port)
+        option = pnp_build_option(dev, IORESOURCE_IO, option_flags);
+        if (!option)
                 return -ENOMEM;
 
+        port = &option->u.port;
         port->min = min;
         port->max = max;
         port->align = align;
         port->size = size;
         port->flags = flags;
 
-        ptr = option->port;
-        while (ptr && ptr->next)
-                ptr = ptr->next;
-        if (ptr)
-                ptr->next = port;
-        else
-                option->port = port;
-
-        dev_dbg(&dev->dev, "  io  "
-                "min %#llx max %#llx align %lld size %lld flags %#x\n",
-                (unsigned long long) port->min,
-                (unsigned long long) port->max,
-                (unsigned long long) port->align,
-                (unsigned long long) port->size, port->flags);
+        dbg_pnp_show_option(dev, option);
         return 0;
 }
 
-int pnp_register_mem_resource(struct pnp_dev *dev, struct pnp_option *option,
+int pnp_register_mem_resource(struct pnp_dev *dev, unsigned int option_flags,
                               resource_size_t min, resource_size_t max,
                               resource_size_t align, resource_size_t size,
                               unsigned char flags)
 {
-        struct pnp_mem *mem, *ptr;
+        struct pnp_option *option;
+        struct pnp_mem *mem;
 
-        mem = kzalloc(sizeof(struct pnp_mem), GFP_KERNEL);
-        if (!mem)
+        option = pnp_build_option(dev, IORESOURCE_MEM, option_flags);
+        if (!option)
                 return -ENOMEM;
 
+        mem = &option->u.mem;
         mem->min = min;
         mem->max = max;
         mem->align = align;
         mem->size = size;
         mem->flags = flags;
 
-        ptr = option->mem;
-        while (ptr && ptr->next)
-                ptr = ptr->next;
-        if (ptr)
-                ptr->next = mem;
-        else
-                option->mem = mem;
-
-        dev_dbg(&dev->dev, "  mem "
-                "min %#llx max %#llx align %lld size %lld flags %#x\n",
-                (unsigned long long) mem->min,
-                (unsigned long long) mem->max,
-                (unsigned long long) mem->align,
-                (unsigned long long) mem->size, mem->flags);
+        dbg_pnp_show_option(dev, option);
         return 0;
 }
 
-static void pnp_free_port(struct pnp_port *port)
-{
-        struct pnp_port *next;
-
-        while (port) {
-                next = port->next;
-                kfree(port);
-                port = next;
-        }
-}
-
-static void pnp_free_irq(struct pnp_irq *irq)
-{
-        struct pnp_irq *next;
-
-        while (irq) {
-                next = irq->next;
-                kfree(irq);
-                irq = next;
-        }
-}
-
-static void pnp_free_dma(struct pnp_dma *dma)
-{
-        struct pnp_dma *next;
-
-        while (dma) {
-                next = dma->next;
-                kfree(dma);
-                dma = next;
-        }
-}
-
-static void pnp_free_mem(struct pnp_mem *mem)
+void pnp_free_options(struct pnp_dev *dev)
 {
-        struct pnp_mem *next;
-
-        while (mem) {
-                next = mem->next;
-                kfree(mem);
-                mem = next;
-        }
-}
+        struct pnp_option *option, *tmp;
 
-void pnp_free_option(struct pnp_option *option)
-{
-        struct pnp_option *next;
-
-        while (option) {
-                next = option->next;
-                pnp_free_port(option->port);
-                pnp_free_irq(option->irq);
-                pnp_free_dma(option->dma);
-                pnp_free_mem(option->mem);
+        list_for_each_entry_safe(option, tmp, &dev->options, list) {
+                list_del(&option->list);
                 kfree(option);
-                option = next;
         }
 }
 
@@ -668,66 +546,50 @@ struct pnp_resource *pnp_add_mem_resource(struct pnp_dev *dev,
         return pnp_res;
 }
 
-static int pnp_possible_option(struct pnp_option *option, int type,
-                               resource_size_t start, resource_size_t size)
+/*
+ * Determine whether the specified resource is a possible configuration
+ * for this device.
+ */
+int pnp_possible_config(struct pnp_dev *dev, int type, resource_size_t start,
+                        resource_size_t size)
 {
-        struct pnp_option *tmp;
+        struct pnp_option *option;
         struct pnp_port *port;
         struct pnp_mem *mem;
         struct pnp_irq *irq;
         struct pnp_dma *dma;
 
-        if (!option)
-                return 0;
+        list_for_each_entry(option, &dev->options, list) {
+                if (option->type != type)
+                        continue;
 
-        for (tmp = option; tmp; tmp = tmp->next) {
-                switch (type) {
+                switch (option->type) {
                 case IORESOURCE_IO:
-                        for (port = tmp->port; port; port = port->next) {
-                                if (port->min == start && port->size == size)
-                                        return 1;
-                        }
+                        port = &option->u.port;
+                        if (port->min == start && port->size == size)
+                                return 1;
                         break;
                 case IORESOURCE_MEM:
-                        for (mem = tmp->mem; mem; mem = mem->next) {
-                                if (mem->min == start && mem->size == size)
-                                        return 1;
-                        }
+                        mem = &option->u.mem;
+                        if (mem->min == start && mem->size == size)
+                                return 1;
                         break;
                 case IORESOURCE_IRQ:
-                        for (irq = tmp->irq; irq; irq = irq->next) {
-                                if (start < PNP_IRQ_NR &&
-                                    test_bit(start, irq->map.bits))
-                                        return 1;
-                        }
+                        irq = &option->u.irq;
+                        if (start < PNP_IRQ_NR &&
+                            test_bit(start, irq->map.bits))
+                                return 1;
                         break;
                 case IORESOURCE_DMA:
-                        for (dma = tmp->dma; dma; dma = dma->next) {
-                                if (dma->map & (1 << start))
-                                        return 1;
-                        }
+                        dma = &option->u.dma;
+                        if (dma->map & (1 << start))
+                                return 1;
                         break;
                 }
         }
 
         return 0;
 }
-
-/*
- * Determine whether the specified resource is a possible configuration
- * for this device.
- */
-int pnp_possible_config(struct pnp_dev *dev, int type, resource_size_t start,
-                        resource_size_t size)
-{
-        if (pnp_possible_option(dev->independent, type, start, size))
-                return 1;
-
-        if (pnp_possible_option(dev->dependent, type, start, size))
-                return 1;
-
-        return 0;
-}
 EXPORT_SYMBOL(pnp_possible_config);
 
 /* format is: pnp_reserve_irq=irq1[,irq2] .... */