PCI hotplug: clean up acpi_run_hpp()

This patch cleans up acpi_run_hpp() and follows the style of acpi_run_hpx():
    - remove unnecessary METHOD_NAME__HPP #define
    - use ACPI_ALLOCATE_BUFFER rather than evaluating _HPP twice
    - validate _HPP package length (defined as 4 by the spec)
    - avoid ref to undefined data if FW provides < 4 elements
    - remove temporary nui[] array

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Reviewed-by: Alex Chiang <achiang@hp.com>
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 22 insertions, 62 deletions

diff --git a/drivers/pci/hotplug/acpi_pcihp.c b/drivers/pci/hotplug/acpi_pcihp.c
index ee24de1c5fae..a73028ec52e5 100644
--- a/drivers/pci/hotplug/acpi_pcihp.c
+++ b/drivers/pci/hotplug/acpi_pcihp.c
@@ -41,7 +41,6 @@
 #define warn(format, arg...) printk(KERN_WARNING "%s: " format , MY_NAME , ## arg)
 
 #define METHOD_NAME__SUN        "_SUN"
-#define METHOD_NAME__HPP        "_HPP"
 #define METHOD_NAME_OSHP        "OSHP"
 
 static int debug_acpi;
@@ -215,80 +214,41 @@ acpi_run_hpx(acpi_handle handle, struct hotplug_params *hpx)
 static acpi_status
 acpi_run_hpp(acpi_handle handle, struct hotplug_params *hpp)
 {
-        acpi_status             status;
-        u8                      nui[4];
-        struct acpi_buffer      ret_buf = { 0, NULL};
-        struct acpi_buffer      string = { ACPI_ALLOCATE_BUFFER, NULL };
-        union acpi_object       *ext_obj, *package;
-        int                     i, len = 0;
-
-        acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
+        acpi_status status;
+        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+        union acpi_object *package, *fields;
+        int i;
 
-        /* Clear the return buffer with zeros */
         memset(hpp, 0, sizeof(struct hotplug_params));
 
-        /* get _hpp */
-        status = acpi_evaluate_object(handle, METHOD_NAME__HPP, NULL, &ret_buf);
-        switch (status) {
-        case AE_BUFFER_OVERFLOW:
-                ret_buf.pointer = kmalloc (ret_buf.length, GFP_KERNEL);
-                if (!ret_buf.pointer) {
-                        printk(KERN_ERR "%s:%s alloc for _HPP fail\n",
-                                __func__, (char *)string.pointer);
-                        kfree(string.pointer);
-                        return AE_NO_MEMORY;
-                }
-                status = acpi_evaluate_object(handle, METHOD_NAME__HPP,
-                                NULL, &ret_buf);
-                if (ACPI_SUCCESS(status))
-                        break;
-        default:
-                if (ACPI_FAILURE(status)) {
-                        pr_debug("%s:%s _HPP fail=0x%x\n", __func__,
-                                (char *)string.pointer, status);
-                        kfree(string.pointer);
-                        return status;
-                }
-        }
+        status = acpi_evaluate_object(handle, "_HPP", NULL, &buffer);
+        if (ACPI_FAILURE(status))
+                return status;
 
-        ext_obj = (union acpi_object *) ret_buf.pointer;
-        if (ext_obj->type != ACPI_TYPE_PACKAGE) {
-                printk(KERN_ERR "%s:%s _HPP obj not a package\n", __func__,
-                                (char *)string.pointer);
+        package = (union acpi_object *) buffer.pointer;
+        if (package->type != ACPI_TYPE_PACKAGE ||
+            package->package.count != 4) {
                 status = AE_ERROR;
-                goto free_and_return;
+                goto exit;
         }
 
-        len = ext_obj->package.count;
-        package = (union acpi_object *) ret_buf.pointer;
-        for ( i = 0; (i < len) || (i < 4); i++) {
-                ext_obj = (union acpi_object *) &package->package.elements[i];
-                switch (ext_obj->type) {
-                case ACPI_TYPE_INTEGER:
-                        nui[i] = (u8)ext_obj->integer.value;
-                        break;
-                default:
-                        printk(KERN_ERR "%s:%s _HPP obj type incorrect\n",
-                                __func__, (char *)string.pointer);
+        fields = package->package.elements;
+        for (i = 0; i < 4; i++) {
+                if (fields[i].type != ACPI_TYPE_INTEGER) {
                         status = AE_ERROR;
-                        goto free_and_return;
+                        goto exit;
                 }
         }
 
         hpp->t0 = &hpp->type0_data;
-        hpp->t0->cache_line_size = nui[0];
-        hpp->t0->latency_timer = nui[1];
-        hpp->t0->enable_serr = nui[2];
-        hpp->t0->enable_perr = nui[3];
-
-        pr_debug("  _HPP: cache_line_size=0x%x\n", hpp->t0->cache_line_size);
-        pr_debug("  _HPP: latency timer  =0x%x\n", hpp->t0->latency_timer);
-        pr_debug("  _HPP: enable SERR    =0x%x\n", hpp->t0->enable_serr);
-        pr_debug("  _HPP: enable PERR    =0x%x\n", hpp->t0->enable_perr);
+        hpp->t0->revision        = 1;
+        hpp->t0->cache_line_size = fields[0].integer.value;
+        hpp->t0->latency_timer   = fields[1].integer.value;
+        hpp->t0->enable_serr     = fields[2].integer.value;
+        hpp->t0->enable_perr     = fields[3].integer.value;
 
-free_and_return:
-        kfree(string.pointer);
-        kfree(ret_buf.pointer);
+exit:
+        kfree(buffer.pointer);
         return status;
 }