diff options
Diffstat (limited to 'arch/ia64/hp')
| -rw-r--r-- | arch/ia64/hp/common/Makefile | 1 | ||||
| -rw-r--r-- | arch/ia64/hp/common/aml_nfw.c | 236 |
2 files changed, 237 insertions, 0 deletions
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); |