3 files changed, 247 insertions, 0 deletions

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 8c39913d1729..2e6310b8eab7 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -461,6 +461,16 @@ config IA64_ESI
           firmware extensions, such as the ability to inject memory-errors
           for test-purposes.  If you're unsure, say N.
 
+config IA64_HP_AML_NFW
+        bool "Support ACPI AML calls to native firmware"
+        help
+          This driver installs a global ACPI Operation Region handler for
+          region 0xA1.  AML methods can use this OpRegion to call arbitrary
+          native firmware functions.  The driver installs the OpRegion
+          handler if there is an HPQ5001 device or if the user supplies
+          the "force" module parameter, e.g., with the "aml_nfw.force"
+          kernel command line option.
+
 source "drivers/sn/Kconfig"
 
 config KEXEC
diff --git a/arch/ia64/hp/common/Makefile b/arch/ia64/hp/common/Makefile
index f61a60057ff7..9e179dd06b85 100644
--- a/arch/ia64/hp/common/Makefile
+++ b/arch/ia64/hp/common/Makefile
@@ -8,3 +8,4 @@
 obj-y := sba_iommu.o
 obj-$(CONFIG_IA64_HP_ZX1_SWIOTLB) += hwsw_iommu.o
 obj-$(CONFIG_IA64_GENERIC) += hwsw_iommu.o
+obj-$(CONFIG_IA64_HP_AML_NFW) += aml_nfw.o
diff --git a/arch/ia64/hp/common/aml_nfw.c b/arch/ia64/hp/common/aml_nfw.c
new file mode 100644
index 000000000000..4abd2c79bb1d
--- /dev/null
+++ b/arch/ia64/hp/common/aml_nfw.c
@@ -0,0 +1,236 @@
+/*
+ * OpRegion handler to allow AML to call native firmware
+ *
+ * (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
+ *      Bjorn Helgaas <bjorn.helgaas@hp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This driver implements HP Open Source Review Board proposal 1842,
+ * which was approved on 9/20/2006.
+ *
+ * For technical documentation, see the HP SPPA Firmware EAS, Appendix F.
+ *
+ * ACPI does not define a mechanism for AML methods to call native firmware
+ * interfaces such as PAL or SAL.  This OpRegion handler adds such a mechanism.
+ * After the handler is installed, an AML method can call native firmware by
+ * storing the arguments and firmware entry point to specific offsets in the
+ * OpRegion.  When AML reads the "return value" offset from the OpRegion, this
+ * handler loads up the arguments, makes the firmware call, and returns the
+ * result.
+ */
+
+#include <linux/module.h>
+#include <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+#include <asm/sal.h>
+
+MODULE_AUTHOR("Bjorn Helgaas <bjorn.helgaas@hp.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ACPI opregion handler for native firmware calls");
+
+static int force_register;
+module_param_named(force, force_register, bool, 0);
+MODULE_PARM_DESC(force, "Install opregion handler even without HPQ5001 device");
+
+#define AML_NFW_SPACE           0xA1
+
+struct ia64_pdesc {
+        void *ip;
+        void *gp;
+};
+
+/*
+ * N.B.  The layout of this structure is defined in the HP SPPA FW EAS, and
+ *       the member offsets are embedded in AML methods.
+ */
+struct ia64_nfw_context {
+        u64 arg[8];
+        struct ia64_sal_retval ret;
+        u64 ip;
+        u64 gp;
+        u64 pad[2];
+};
+
+static void *virt_map(u64 address)
+{
+        if (address & (1UL << 63))
+                return (void *) (__IA64_UNCACHED_OFFSET | address);
+
+        return __va(address);
+}
+
+static void aml_nfw_execute(struct ia64_nfw_context *c)
+{
+        struct ia64_pdesc virt_entry;
+        ia64_sal_handler entry;
+
+        virt_entry.ip = virt_map(c->ip);
+        virt_entry.gp = virt_map(c->gp);
+
+        entry = (ia64_sal_handler) &virt_entry;
+
+        IA64_FW_CALL(entry, c->ret,
+                     c->arg[0], c->arg[1], c->arg[2], c->arg[3],
+                     c->arg[4], c->arg[5], c->arg[6], c->arg[7]);
+}
+
+static void aml_nfw_read_arg(u8 *offset, u32 bit_width, acpi_integer *value)
+{
+        switch (bit_width) {
+        case 8:
+                *value = *(u8 *)offset;
+                break;
+        case 16:
+                *value = *(u16 *)offset;
+                break;
+        case 32:
+                *value = *(u32 *)offset;
+                break;
+        case 64:
+                *value = *(u64 *)offset;
+                break;
+        }
+}
+
+static void aml_nfw_write_arg(u8 *offset, u32 bit_width, acpi_integer *value)
+{
+        switch (bit_width) {
+        case 8:
+                *(u8 *) offset = *value;
+                break;
+        case 16:
+                *(u16 *) offset = *value;
+                break;
+        case 32:
+                *(u32 *) offset = *value;
+                break;
+        case 64:
+                *(u64 *) offset = *value;
+                break;
+        }
+}
+
+static acpi_status aml_nfw_handler(u32 function, acpi_physical_address address,
+        u32 bit_width, acpi_integer *value, void *handler_context,
+        void *region_context)
+{
+        struct ia64_nfw_context *context = handler_context;
+        u8 *offset = (u8 *) context + address;
+
+        if (bit_width !=  8 && bit_width != 16 &&
+            bit_width != 32 && bit_width != 64)
+                return AE_BAD_PARAMETER;
+
+        if (address + (bit_width >> 3) > sizeof(struct ia64_nfw_context))
+                return AE_BAD_PARAMETER;
+
+        switch (function) {
+        case ACPI_READ:
+                if (address == offsetof(struct ia64_nfw_context, ret))
+                        aml_nfw_execute(context);
+                aml_nfw_read_arg(offset, bit_width, value);
+                break;
+        case ACPI_WRITE:
+                aml_nfw_write_arg(offset, bit_width, value);
+                break;
+        }
+
+        return AE_OK;
+}
+
+static struct ia64_nfw_context global_context;
+static int global_handler_registered;
+
+static int aml_nfw_add_global_handler(void)
+{
+        acpi_status status;
+
+        if (global_handler_registered)
+                return 0;
+
+        status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT,
+                AML_NFW_SPACE, aml_nfw_handler, NULL, &global_context);
+        if (ACPI_FAILURE(status))
+                return -ENODEV;
+
+        global_handler_registered = 1;
+        printk(KERN_INFO "Global 0x%02X opregion handler registered\n",
+                AML_NFW_SPACE);
+        return 0;
+}
+
+static int aml_nfw_remove_global_handler(void)
+{
+        acpi_status status;
+
+        if (!global_handler_registered)
+                return 0;
+
+        status = acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,
+                AML_NFW_SPACE, aml_nfw_handler);
+        if (ACPI_FAILURE(status))
+                return -ENODEV;
+
+        global_handler_registered = 0;
+        printk(KERN_INFO "Global 0x%02X opregion handler removed\n",
+                AML_NFW_SPACE);
+        return 0;
+}
+
+static int aml_nfw_add(struct acpi_device *device)
+{
+        /*
+         * We would normally allocate a new context structure and install
+         * the address space handler for the specific device we found.
+         * But the HP-UX implementation shares a single global context
+         * and always puts the handler at the root, so we'll do the same.
+         */
+        return aml_nfw_add_global_handler();
+}
+
+static int aml_nfw_remove(struct acpi_device *device, int type)
+{
+        return aml_nfw_remove_global_handler();
+}
+
+static const struct acpi_device_id aml_nfw_ids[] = {
+        {"HPQ5001", 0},
+        {"", 0}
+};
+
+static struct acpi_driver acpi_aml_nfw_driver = {
+        .name = "native firmware",
+        .ids = aml_nfw_ids,
+        .ops = {
+                .add = aml_nfw_add,
+                .remove = aml_nfw_remove,
+                },
+};
+
+static int __init aml_nfw_init(void)
+{
+        int result;
+
+        if (force_register)
+                aml_nfw_add_global_handler();
+
+        result = acpi_bus_register_driver(&acpi_aml_nfw_driver);
+        if (result < 0) {
+                aml_nfw_remove_global_handler();
+                return result;
+        }
+
+        return 0;
+}
+
+static void __exit aml_nfw_exit(void)
+{
+        acpi_bus_unregister_driver(&acpi_aml_nfw_driver);
+        aml_nfw_remove_global_handler();
+}
+
+module_init(aml_nfw_init);
+module_exit(aml_nfw_exit);