resource: Add I/O resource descriptor

walk_iomem_res() and region_intersects() still need to use
strcmp() for searching a resource entry by @name in the iomem
table.

This patch introduces I/O resource descriptor 'desc' in struct
resource for the iomem search interfaces. Drivers can assign
their unique descriptor to a range when they support the search
interfaces.

Otherwise, 'desc' is set to IORES_DESC_NONE (0). This avoids
changing most of the drivers as they typically allocate resource
entries statically, or by calling alloc_resource(), kzalloc(),
or alloc_bootmem_low(), which set the field to zero by default.
A later patch will address some drivers that use kmalloc()
without zero'ing the field.

Also change release_mem_region_adjustable() to set 'desc' when
its resource entry gets separated. Other resource interfaces are
also changed to initialize 'desc' explicitly although
alloc_resource() sets it to 0.

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jakub Sitnicki <jsitnicki@gmail.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm <linux-mm@kvack.org>
Link: http://lkml.kernel.org/r/1453841853-11383-4-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 4b65d94..983bea0 100644 (file)
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -20,6 +20,7 @@ struct resource {
        resource_size_t end;
        const char *name;
        unsigned long flags;
+       unsigned long desc;
        struct resource *parent, *sibling, *child;
 };
 
@@ -112,6 +113,22 @@ struct resource {
 /* PCI control bits.  Shares IORESOURCE_BITS with above PCI ROM.  */
 #define IORESOURCE_PCI_FIXED           (1<<4)  /* Do not move resource */
 
+/*
+ * I/O Resource Descriptors
+ *
+ * Descriptors are used by walk_iomem_res_desc() and region_intersects()
+ * for searching a specific resource range in the iomem table.  Assign
+ * a new descriptor when a resource range supports the search interfaces.
+ * Otherwise, resource.desc must be set to IORES_DESC_NONE (0).
+ */
+enum {
+       IORES_DESC_NONE                         = 0,
+       IORES_DESC_CRASH_KERNEL                 = 1,
+       IORES_DESC_ACPI_TABLES                  = 2,
+       IORES_DESC_ACPI_NV_STORAGE              = 3,
+       IORES_DESC_PERSISTENT_MEMORY            = 4,
+       IORES_DESC_PERSISTENT_MEMORY_LEGACY     = 5,
+};
 
 /* helpers to define resources */
 #define DEFINE_RES_NAMED(_start, _size, _name, _flags)                 \
@@ -120,6 +137,7 @@ struct resource {
                .end = (_start) + (_size) - 1,                          \
                .name = (_name),                                        \
                .flags = (_flags),                                      \
+               .desc = IORES_DESC_NONE,                                \
        }
 
 #define DEFINE_RES_IO_NAMED(_start, _size, _name)                      \

diff --git a/kernel/resource.c b/kernel/resource.c
index 96afc80..61512e9 100644 (file)
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -949,6 +949,7 @@ static void __init __reserve_region_with_split(struct resource *root,
        res->start = start;
        res->end = end;
        res->flags = IORESOURCE_BUSY;
+       res->desc = IORES_DESC_NONE;
 
        while (1) {
 
@@ -983,6 +984,7 @@ static void __init __reserve_region_with_split(struct resource *root,
                                next_res->start = conflict->end + 1;
                                next_res->end = end;
                                next_res->flags = IORESOURCE_BUSY;
+                               next_res->desc = IORES_DESC_NONE;
                        }
                } else {
                        res->start = conflict->end + 1;
@@ -1074,6 +1076,7 @@ struct resource * __request_region(struct resource *parent,
        res->end = start + n - 1;
        res->flags = resource_type(parent) | resource_ext_type(parent);
        res->flags |= IORESOURCE_BUSY | flags;
+       res->desc = IORES_DESC_NONE;
 
        write_lock(&resource_lock);
 
@@ -1238,6 +1241,7 @@ int release_mem_region_adjustable(struct resource *parent,
                        new_res->start = end + 1;
                        new_res->end = res->end;
                        new_res->flags = res->flags;
+                       new_res->desc = res->desc;
                        new_res->parent = res->parent;
                        new_res->sibling = res->sibling;
                        new_res->child = NULL;
@@ -1413,6 +1417,7 @@ static int __init reserve_setup(char *str)
                        res->start = io_start;
                        res->end = io_start + io_num - 1;
                        res->flags = IORESOURCE_BUSY;
+                       res->desc = IORES_DESC_NONE;
                        res->child = NULL;
                        if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
                                reserved = x+1;