[PATCH] i386/x86_64: Insert HPET firmware resource after PCI enumeration has completed

[Aaron Durbin <adurbin@google.com>]

Insert HPET resources after pci probing has been completed in order to avoid
resource conflicts with PCI resource reservation. With this change the
HPET firmware resources will be identified, but it should also not cause
issues when the HPET address falls on a BAR in a PCI device, and the PCI
enumeration cannot reserve the resources.

Signed-off-by: Aaron Durbin <adurbin@google.com>

---
 arch/i386/kernel/acpi/boot.c |   36 ++++++++++++++++++++++++++++++++++++
 1 files changed, 36 insertions(+), 0 deletions(-)

diff --git a/arch/i386/kernel/acpi/boot.c b/arch/i386/kernel/acpi/boot.c
index a574cd2..ca12b84 100644
--- a/arch/i386/kernel/acpi/boot.c
+++ b/arch/i386/kernel/acpi/boot.c
@@ -618,6 +618,8 @@ static int __init acpi_parse_sbf(struct 
 #ifdef CONFIG_HPET_TIMER
 #include <asm/hpet.h>
 
+static struct __initdata resource *hpet_res;
+
 static int __init acpi_parse_hpet(struct acpi_table_header *table)
 {
 	struct acpi_table_hpet *hpet_tbl;
@@ -638,8 +640,42 @@ static int __init acpi_parse_hpet(struct
 	printk(KERN_INFO PREFIX "HPET id: %#x base: %#lx\n",
 	       hpet_tbl->id, hpet_address);
 
+	/*
+	 * Allocate and initialize the HPET firmware resource for adding into
+	 * the resource tree during the lateinit timeframe.
+	 */
+#define HPET_RESOURCE_NAME_SIZE 9
+	hpet_res = alloc_bootmem(sizeof(*hpet_res) + HPET_RESOURCE_NAME_SIZE);
+
+	if (!hpet_res)
+		return 0;
+
+	memset(hpet_res, 0, sizeof(*hpet_res));
+	hpet_res->name = (void *)&hpet_res[1];
+	hpet_res->flags = IORESOURCE_MEM;
+	snprintf((char *)hpet_res->name, HPET_RESOURCE_NAME_SIZE, "HPET %u",
+		 hpet_tbl->sequence);
+
+	hpet_res->start = hpet_address;
+	hpet_res->end = hpet_address + (1 * 1024) - 1;
+
 	return 0;
 }
+
+/*
+ * hpet_insert_resource inserts the HPET resources used into the resource
+ * tree.
+ */
+static __init int hpet_insert_resource(void)
+{
+	if (!hpet_res)
+		return 1;
+
+	return insert_resource(&iomem_resource, hpet_res);
+}
+
+late_initcall(hpet_insert_resource);
+
 #else
 #define	acpi_parse_hpet	NULL
 #endif
-- 
1.4.1