--- /dev/null
+/*
+ * drivers/acpi/resource.c - ACPI device resources interpretation.
+ *
+ * Copyright (C) 2012, Intel Corp.
+ * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.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 program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/ioport.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+
+#ifdef CONFIG_X86
+#define valid_IRQ(i) (((i) != 0) && ((i) != 2))
+#else
+#define valid_IRQ(i) (true)
+#endif
+
+static bool acpi_dev_resource_len_valid(u64 start, u64 end, u64 len, bool io)
+{
+ u64 reslen = end - start + 1;
+
+ /*
+ * CHECKME: len might be required to check versus a minimum
+ * length as well. 1 for io is fine, but for memory it does
+ * not make any sense at all.
+ * Note: some BIOSes report incorrect length for ACPI address space
+ * descriptor, so remove check of 'reslen == len' to avoid regression.
+ */
+ if (len && reslen && start <= end)
+ return true;
+
+ pr_debug("ACPI: invalid or unassigned resource %s [%016llx - %016llx] length [%016llx]\n",
+ io ? "io" : "mem", start, end, len);
+
+ return false;
+}
+
+static void acpi_dev_memresource_flags(struct resource *res, u64 len,
+ u8 write_protect)
+{
+ res->flags = IORESOURCE_MEM;
+
+ if (!acpi_dev_resource_len_valid(res->start, res->end, len, false))
+ res->flags |= IORESOURCE_DISABLED | IORESOURCE_UNSET;
+
+ if (write_protect == ACPI_READ_WRITE_MEMORY)
+ res->flags |= IORESOURCE_MEM_WRITEABLE;
+}
+
+static void acpi_dev_get_memresource(struct resource *res, u64 start, u64 len,
+ u8 write_protect)
+{
+ res->start = start;
+ res->end = start + len - 1;
+ acpi_dev_memresource_flags(res, len, write_protect);
+}
+
+/**
+ * acpi_dev_resource_memory - Extract ACPI memory resource information.
+ * @ares: Input ACPI resource object.
+ * @res: Output generic resource object.
+ *
+ * Check if the given ACPI resource object represents a memory resource and
+ * if that's the case, use the information in it to populate the generic
+ * resource object pointed to by @res.
+ *
+ * Return:
+ * 1) false with res->flags setting to zero: not the expected resource type
+ * 2) false with IORESOURCE_DISABLED in res->flags: valid unassigned resource
+ * 3) true: valid assigned resource
+ */
+bool acpi_dev_resource_memory(struct acpi_resource *ares, struct resource *res)
+{
+ struct acpi_resource_memory24 *memory24;
+ struct acpi_resource_memory32 *memory32;
+ struct acpi_resource_fixed_memory32 *fixed_memory32;
+
+ switch (ares->type) {
+ case ACPI_RESOURCE_TYPE_MEMORY24:
+ memory24 = &ares->data.memory24;
+ acpi_dev_get_memresource(res, memory24->minimum << 8,
+ memory24->address_length << 8,
+ memory24->write_protect);
+ break;
+ case ACPI_RESOURCE_TYPE_MEMORY32:
+ memory32 = &ares->data.memory32;
+ acpi_dev_get_memresource(res, memory32->minimum,
+ memory32->address_length,
+ memory32->write_protect);
+ break;
+ case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
+ fixed_memory32 = &ares->data.fixed_memory32;
+ acpi_dev_get_memresource(res, fixed_memory32->address,
+ fixed_memory32->address_length,
+ fixed_memory32->write_protect);
+ break;
+ default:
+ res->flags = 0;
+ return false;
+ }
+
+ return !(res->flags & IORESOURCE_DISABLED);
+}
+EXPORT_SYMBOL_GPL(acpi_dev_resource_memory);
+
+static void acpi_dev_ioresource_flags(struct resource *res, u64 len,
+ u8 io_decode)
+{
+ res->flags = IORESOURCE_IO;
+
+ if (!acpi_dev_resource_len_valid(res->start, res->end, len, true))
+ res->flags |= IORESOURCE_DISABLED | IORESOURCE_UNSET;
+
+ if (res->end >= 0x10003)
+ res->flags |= IORESOURCE_DISABLED | IORESOURCE_UNSET;
+
+ if (io_decode == ACPI_DECODE_16)
+ res->flags |= IORESOURCE_IO_16BIT_ADDR;
+}
+
+static void acpi_dev_get_ioresource(struct resource *res, u64 start, u64 len,
+ u8 io_decode)
+{
+ res->start = start;
+ res->end = start + len - 1;
+ acpi_dev_ioresource_flags(res, len, io_decode);
+}
+
+/**
+ * acpi_dev_resource_io - Extract ACPI I/O resource information.
+ * @ares: Input ACPI resource object.
+ * @res: Output generic resource object.
+ *
+ * Check if the given ACPI resource object represents an I/O resource and
+ * if that's the case, use the information in it to populate the generic
+ * resource object pointed to by @res.
+ *
+ * Return:
+ * 1) false with res->flags setting to zero: not the expected resource type
+ * 2) false with IORESOURCE_DISABLED in res->flags: valid unassigned resource
+ * 3) true: valid assigned resource
+ */
+bool acpi_dev_resource_io(struct acpi_resource *ares, struct resource *res)
+{
+ struct acpi_resource_io *io;
+ struct acpi_resource_fixed_io *fixed_io;
+
+ switch (ares->type) {
+ case ACPI_RESOURCE_TYPE_IO:
+ io = &ares->data.io;
+ acpi_dev_get_ioresource(res, io->minimum,
+ io->address_length,
+ io->io_decode);
+ break;
+ case ACPI_RESOURCE_TYPE_FIXED_IO:
+ fixed_io = &ares->data.fixed_io;
+ acpi_dev_get_ioresource(res, fixed_io->address,
+ fixed_io->address_length,
+ ACPI_DECODE_10);
+ break;
+ default:
+ res->flags = 0;
+ return false;
+ }
+
+ return !(res->flags & IORESOURCE_DISABLED);
+}
+EXPORT_SYMBOL_GPL(acpi_dev_resource_io);
+
+static bool acpi_decode_space(struct resource_win *win,
+ struct acpi_resource_address *addr,
+ struct acpi_address64_attribute *attr)
+{
+ u8 iodec = attr->granularity == 0xfff ? ACPI_DECODE_10 : ACPI_DECODE_16;
+ bool wp = addr->info.mem.write_protect;
+ u64 len = attr->address_length;
+ struct resource *res = &win->res;
+
+ /*
+ * Filter out invalid descriptor according to ACPI Spec 5.0, section
+ * 6.4.3.5 Address Space Resource Descriptors.
+ */
+ if ((addr->min_address_fixed != addr->max_address_fixed && len) ||
+ (addr->min_address_fixed && addr->max_address_fixed && !len))
+ pr_debug("ACPI: Invalid address space min_addr_fix %d, max_addr_fix %d, len %llx\n",
+ addr->min_address_fixed, addr->max_address_fixed, len);
+
+ res->start = attr->minimum;
+ res->end = attr->maximum;
+
+ /*
+ * For bridges that translate addresses across the bridge,
+ * translation_offset is the offset that must be added to the
+ * address on the secondary side to obtain the address on the
+ * primary side. Non-bridge devices must list 0 for all Address
+ * Translation offset bits.
+ */
+ if (addr->producer_consumer == ACPI_PRODUCER) {
+ res->start += attr->translation_offset;
+ res->end += attr->translation_offset;
+ } else if (attr->translation_offset) {
+ pr_debug("ACPI: translation_offset(%lld) is invalid for non-bridge device.\n",
+ attr->translation_offset);
+ }
+
+ switch (addr->resource_type) {
+ case ACPI_MEMORY_RANGE:
+ acpi_dev_memresource_flags(res, len, wp);
+ break;
+ case ACPI_IO_RANGE:
+ acpi_dev_ioresource_flags(res, len, iodec);
+ break;
+ case ACPI_BUS_NUMBER_RANGE:
+ res->flags = IORESOURCE_BUS;
+ break;
+ default:
+ return false;
+ }
+
+ win->offset = attr->translation_offset;
+
+ if (addr->producer_consumer == ACPI_PRODUCER)
+ res->flags |= IORESOURCE_WINDOW;
+
+ if (addr->info.mem.caching == ACPI_PREFETCHABLE_MEMORY)
+ res->flags |= IORESOURCE_PREFETCH;
+
+ return !(res->flags & IORESOURCE_DISABLED);
+}
+
+/**
+ * acpi_dev_resource_address_space - Extract ACPI address space information.
+ * @ares: Input ACPI resource object.
+ * @win: Output generic resource object.
+ *
+ * Check if the given ACPI resource object represents an address space resource
+ * and if that's the case, use the information in it to populate the generic
+ * resource object pointed to by @win.
+ *
+ * Return:
+ * 1) false with win->res.flags setting to zero: not the expected resource type
+ * 2) false with IORESOURCE_DISABLED in win->res.flags: valid unassigned
+ * resource
+ * 3) true: valid assigned resource
+ */
+bool acpi_dev_resource_address_space(struct acpi_resource *ares,
+ struct resource_win *win)
+{
+ struct acpi_resource_address64 addr;
+
+ win->res.flags = 0;
+ if (ACPI_FAILURE(acpi_resource_to_address64(ares, &addr)))
+ return false;
+
+ return acpi_decode_space(win, (struct acpi_resource_address *)&addr,
+ &addr.address);
+}
+EXPORT_SYMBOL_GPL(acpi_dev_resource_address_space);
+
+/**
+ * acpi_dev_resource_ext_address_space - Extract ACPI address space information.
+ * @ares: Input ACPI resource object.
+ * @win: Output generic resource object.
+ *
+ * Check if the given ACPI resource object represents an extended address space
+ * resource and if that's the case, use the information in it to populate the
+ * generic resource object pointed to by @win.
+ *
+ * Return:
+ * 1) false with win->res.flags setting to zero: not the expected resource type
+ * 2) false with IORESOURCE_DISABLED in win->res.flags: valid unassigned
+ * resource
+ * 3) true: valid assigned resource
+ */
+bool acpi_dev_resource_ext_address_space(struct acpi_resource *ares,
+ struct resource_win *win)
+{
+ struct acpi_resource_extended_address64 *ext_addr;
+
+ win->res.flags = 0;
+ if (ares->type != ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64)
+ return false;
+
+ ext_addr = &ares->data.ext_address64;
+
+ return acpi_decode_space(win, (struct acpi_resource_address *)ext_addr,
+ &ext_addr->address);
+}
+EXPORT_SYMBOL_GPL(acpi_dev_resource_ext_address_space);
+
+/**
+ * acpi_dev_irq_flags - Determine IRQ resource flags.
+ * @triggering: Triggering type as provided by ACPI.
+ * @polarity: Interrupt polarity as provided by ACPI.
+ * @shareable: Whether or not the interrupt is shareable.
+ */
+unsigned long acpi_dev_irq_flags(u8 triggering, u8 polarity, u8 shareable)
+{
+ unsigned long flags;
+
+ if (triggering == ACPI_LEVEL_SENSITIVE)
+ flags = polarity == ACPI_ACTIVE_LOW ?
+ IORESOURCE_IRQ_LOWLEVEL : IORESOURCE_IRQ_HIGHLEVEL;
+ else
+ flags = polarity == ACPI_ACTIVE_LOW ?
+ IORESOURCE_IRQ_LOWEDGE : IORESOURCE_IRQ_HIGHEDGE;
+
+ if (shareable == ACPI_SHARED)
+ flags |= IORESOURCE_IRQ_SHAREABLE;
+
+ return flags | IORESOURCE_IRQ;
+}
+EXPORT_SYMBOL_GPL(acpi_dev_irq_flags);
+
+static void acpi_dev_irqresource_disabled(struct resource *res, u32 gsi)
+{
+ res->start = gsi;
+ res->end = gsi;
+ res->flags = IORESOURCE_IRQ | IORESOURCE_DISABLED | IORESOURCE_UNSET;
+}
+
+static void acpi_dev_get_irqresource(struct resource *res, u32 gsi,
+ u8 triggering, u8 polarity, u8 shareable,
+ bool legacy)
+{
+ int irq, p, t;
+
+ if (!valid_IRQ(gsi)) {
+ acpi_dev_irqresource_disabled(res, gsi);
+ return;
+ }
+
+ /*
+ * In IO-APIC mode, use overrided attribute. Two reasons:
+ * 1. BIOS bug in DSDT
+ * 2. BIOS uses IO-APIC mode Interrupt Source Override
+ *
+ * We do this only if we are dealing with IRQ() or IRQNoFlags()
+ * resource (the legacy ISA resources). With modern ACPI 5 devices
+ * using extended IRQ descriptors we take the IRQ configuration
+ * from _CRS directly.
+ */
+ if (legacy && !acpi_get_override_irq(gsi, &t, &p)) {
+ u8 trig = t ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
+ u8 pol = p ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;
+
+ if (triggering != trig || polarity != pol) {
+ pr_warning("ACPI: IRQ %d override to %s, %s\n", gsi,
+ t ? "level" : "edge", p ? "low" : "high");
+ triggering = trig;
+ polarity = pol;
+ }
+ }
+
+ res->flags = acpi_dev_irq_flags(triggering, polarity, shareable);
+ irq = acpi_register_gsi(NULL, gsi, triggering, polarity);
+ if (irq >= 0) {
+ res->start = irq;
+ res->end = irq;
+ } else {
+ acpi_dev_irqresource_disabled(res, gsi);
+ }
+}
+
+/**
+ * acpi_dev_resource_interrupt - Extract ACPI interrupt resource information.
+ * @ares: Input ACPI resource object.
+ * @index: Index into the array of GSIs represented by the resource.
+ * @res: Output generic resource object.
+ *
+ * Check if the given ACPI resource object represents an interrupt resource
+ * and @index does not exceed the resource's interrupt count (true is returned
+ * in that case regardless of the results of the other checks)). If that's the
+ * case, register the GSI corresponding to @index from the array of interrupts
+ * represented by the resource and populate the generic resource object pointed
+ * to by @res accordingly. If the registration of the GSI is not successful,
+ * IORESOURCE_DISABLED will be set it that object's flags.
+ *
+ * Return:
+ * 1) false with res->flags setting to zero: not the expected resource type
+ * 2) false with IORESOURCE_DISABLED in res->flags: valid unassigned resource
+ * 3) true: valid assigned resource
+ */
+bool acpi_dev_resource_interrupt(struct acpi_resource *ares, int index,
+ struct resource *res)
+{
+ struct acpi_resource_irq *irq;
+ struct acpi_resource_extended_irq *ext_irq;
+
+ switch (ares->type) {
+ case ACPI_RESOURCE_TYPE_IRQ:
+ /*
+ * Per spec, only one interrupt per descriptor is allowed in
+ * _CRS, but some firmware violates this, so parse them all.
+ */
+ irq = &ares->data.irq;
+ if (index >= irq->interrupt_count) {
+ acpi_dev_irqresource_disabled(res, 0);
+ return false;
+ }
+ acpi_dev_get_irqresource(res, irq->interrupts[index],
+ irq->triggering, irq->polarity,
+ irq->sharable, true);
+ break;
+ case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
+ ext_irq = &ares->data.extended_irq;
+ if (index >= ext_irq->interrupt_count) {
+ acpi_dev_irqresource_disabled(res, 0);
+ return false;
+ }
+ acpi_dev_get_irqresource(res, ext_irq->interrupts[index],
+ ext_irq->triggering, ext_irq->polarity,
+ ext_irq->sharable, false);
+ break;
+ default:
+ res->flags = 0;
+ return false;
+ }
+
+ return true;
+}
+EXPORT_SYMBOL_GPL(acpi_dev_resource_interrupt);
+
+/**
+ * acpi_dev_free_resource_list - Free resource from %acpi_dev_get_resources().
+ * @list: The head of the resource list to free.
+ */
+void acpi_dev_free_resource_list(struct list_head *list)
+{
+ resource_list_free(list);
+}
+EXPORT_SYMBOL_GPL(acpi_dev_free_resource_list);
+
+struct res_proc_context {
+ struct list_head *list;
+ int (*preproc)(struct acpi_resource *, void *);
+ void *preproc_data;
+ int count;
+ int error;
+};
+
+static acpi_status acpi_dev_new_resource_entry(struct resource_win *win,
+ struct res_proc_context *c)
+{
+ struct resource_entry *rentry;
+
+ rentry = resource_list_create_entry(NULL, 0);
+ if (!rentry) {
+ c->error = -ENOMEM;
+ return AE_NO_MEMORY;
+ }
+ *rentry->res = win->res;
+ rentry->offset = win->offset;
+ resource_list_add_tail(rentry, c->list);
+ c->count++;
+ return AE_OK;
+}
+
+static acpi_status acpi_dev_process_resource(struct acpi_resource *ares,
+ void *context)
+{
+ struct res_proc_context *c = context;
+ struct resource_win win;
+ struct resource *res = &win.res;
+ int i;
+
+ if (c->preproc) {
+ int ret;
+
+ ret = c->preproc(ares, c->preproc_data);
+ if (ret < 0) {
+ c->error = ret;
+ return AE_CTRL_TERMINATE;
+ } else if (ret > 0) {
+ return AE_OK;
+ }
+ }
+
+ memset(&win, 0, sizeof(win));
+
+ if (acpi_dev_resource_memory(ares, res)
+ || acpi_dev_resource_io(ares, res)
+ || acpi_dev_resource_address_space(ares, &win)
+ || acpi_dev_resource_ext_address_space(ares, &win))
+ return acpi_dev_new_resource_entry(&win, c);
+
+ for (i = 0; acpi_dev_resource_interrupt(ares, i, res); i++) {
+ acpi_status status;
+
+ status = acpi_dev_new_resource_entry(&win, c);
+ if (ACPI_FAILURE(status))
+ return status;
+ }
+
+ return AE_OK;
+}
+
+/**
+ * acpi_dev_get_resources - Get current resources of a device.
+ * @adev: ACPI device node to get the resources for.
+ * @list: Head of the resultant list of resources (must be empty).
+ * @preproc: The caller's preprocessing routine.
+ * @preproc_data: Pointer passed to the caller's preprocessing routine.
+ *
+ * Evaluate the _CRS method for the given device node and process its output by
+ * (1) executing the @preproc() rountine provided by the caller, passing the
+ * resource pointer and @preproc_data to it as arguments, for each ACPI resource
+ * returned and (2) converting all of the returned ACPI resources into struct
+ * resource objects if possible. If the return value of @preproc() in step (1)
+ * is different from 0, step (2) is not applied to the given ACPI resource and
+ * if that value is negative, the whole processing is aborted and that value is
+ * returned as the final error code.
+ *
+ * The resultant struct resource objects are put on the list pointed to by
+ * @list, that must be empty initially, as members of struct resource_entry
+ * objects. Callers of this routine should use %acpi_dev_free_resource_list() to
+ * free that list.
+ *
+ * The number of resources in the output list is returned on success, an error
+ * code reflecting the error condition is returned otherwise.
+ */
+int acpi_dev_get_resources(struct acpi_device *adev, struct list_head *list,
+ int (*preproc)(struct acpi_resource *, void *),
+ void *preproc_data)
+{
+ struct res_proc_context c;
+ acpi_status status;
+
+ if (!adev || !adev->handle || !list_empty(list))
+ return -EINVAL;
+
+ if (!acpi_has_method(adev->handle, METHOD_NAME__CRS))
+ return 0;
+
+ c.list = list;
+ c.preproc = preproc;
+ c.preproc_data = preproc_data;
+ c.count = 0;
+ c.error = 0;
+ status = acpi_walk_resources(adev->handle, METHOD_NAME__CRS,
+ acpi_dev_process_resource, &c);
+ if (ACPI_FAILURE(status)) {
+ acpi_dev_free_resource_list(list);
+ return c.error ? c.error : -EIO;
+ }
+
+ return c.count;
+}
+EXPORT_SYMBOL_GPL(acpi_dev_get_resources);
+
+/**
+ * acpi_dev_filter_resource_type - Filter ACPI resource according to resource
+ * types
+ * @ares: Input ACPI resource object.
+ * @types: Valid resource types of IORESOURCE_XXX
+ *
+ * This is a helper function to support acpi_dev_get_resources(), which filters
+ * ACPI resource objects according to resource types.
+ */
+int acpi_dev_filter_resource_type(struct acpi_resource *ares,
+ unsigned long types)
+{
+ unsigned long type = 0;
+
+ switch (ares->type) {
+ case ACPI_RESOURCE_TYPE_MEMORY24:
+ case ACPI_RESOURCE_TYPE_MEMORY32:
+ case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
+ type = IORESOURCE_MEM;
+ break;
+ case ACPI_RESOURCE_TYPE_IO:
+ case ACPI_RESOURCE_TYPE_FIXED_IO:
+ type = IORESOURCE_IO;
+ break;
+ case ACPI_RESOURCE_TYPE_IRQ:
+ case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
+ type = IORESOURCE_IRQ;
+ break;
+ case ACPI_RESOURCE_TYPE_DMA:
+ case ACPI_RESOURCE_TYPE_FIXED_DMA:
+ type = IORESOURCE_DMA;
+ break;
+ case ACPI_RESOURCE_TYPE_GENERIC_REGISTER:
+ type = IORESOURCE_REG;
+ break;
+ case ACPI_RESOURCE_TYPE_ADDRESS16:
+ case ACPI_RESOURCE_TYPE_ADDRESS32:
+ case ACPI_RESOURCE_TYPE_ADDRESS64:
+ case ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64:
+ if (ares->data.address.resource_type == ACPI_MEMORY_RANGE)
+ type = IORESOURCE_MEM;
+ else if (ares->data.address.resource_type == ACPI_IO_RANGE)
+ type = IORESOURCE_IO;
+ else if (ares->data.address.resource_type ==
+ ACPI_BUS_NUMBER_RANGE)
+ type = IORESOURCE_BUS;
+ break;
+ default:
+ break;
+ }
+
+ return (type & types) ? 0 : 1;
+}
+EXPORT_SYMBOL_GPL(acpi_dev_filter_resource_type);
+
+struct reserved_region {
+ struct list_head node;
+ u64 start;
+ u64 end;
+};
+
+static LIST_HEAD(reserved_io_regions);
+static LIST_HEAD(reserved_mem_regions);
+
+static int request_range(u64 start, u64 end, u8 space_id, unsigned long flags,
+ char *desc)
+{
+ unsigned int length = end - start + 1;
+ struct resource *res;
+
+ res = space_id == ACPI_ADR_SPACE_SYSTEM_IO ?
+ request_region(start, length, desc) :
+ request_mem_region(start, length, desc);
+ if (!res)
+ return -EIO;
+
+ res->flags &= ~flags;
+ return 0;
+}
+
+static int add_region_before(u64 start, u64 end, u8 space_id,
+ unsigned long flags, char *desc,
+ struct list_head *head)
+{
+ struct reserved_region *reg;
+ int error;
+
+ reg = kmalloc(sizeof(*reg), GFP_KERNEL);
+ if (!reg)
+ return -ENOMEM;
+
+ error = request_range(start, end, space_id, flags, desc);
+ if (error)
+ return error;
+
+ reg->start = start;
+ reg->end = end;
+ list_add_tail(®->node, head);
+ return 0;
+}
+
+/**
+ * acpi_reserve_region - Reserve an I/O or memory region as a system resource.
+ * @start: Starting address of the region.
+ * @length: Length of the region.
+ * @space_id: Identifier of address space to reserve the region from.
+ * @flags: Resource flags to clear for the region after requesting it.
+ * @desc: Region description (for messages).
+ *
+ * Reserve an I/O or memory region as a system resource to prevent others from
+ * using it. If the new region overlaps with one of the regions (in the given
+ * address space) already reserved by this routine, only the non-overlapping
+ * parts of it will be reserved.
+ *
+ * Returned is either 0 (success) or a negative error code indicating a resource
+ * reservation problem. It is the code of the first encountered error, but the
+ * routine doesn't abort until it has attempted to request all of the parts of
+ * the new region that don't overlap with other regions reserved previously.
+ *
+ * The resources requested by this routine are never released.
+ */
+int acpi_reserve_region(u64 start, unsigned int length, u8 space_id,
+ unsigned long flags, char *desc)
+{
+ struct list_head *regions;
+ struct reserved_region *reg;
+ u64 end = start + length - 1;
+ int ret = 0, error = 0;
+
+ if (space_id == ACPI_ADR_SPACE_SYSTEM_IO)
+ regions = &reserved_io_regions;
+ else if (space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
+ regions = &reserved_mem_regions;
+ else
+ return -EINVAL;
+
+ if (list_empty(regions))
+ return add_region_before(start, end, space_id, flags, desc, regions);
+
+ list_for_each_entry(reg, regions, node)
+ if (reg->start == end + 1) {
+ /* The new region can be prepended to this one. */
+ ret = request_range(start, end, space_id, flags, desc);
+ if (!ret)
+ reg->start = start;
+
+ return ret;
+ } else if (reg->start > end) {
+ /* No overlap. Add the new region here and get out. */
+ return add_region_before(start, end, space_id, flags,
+ desc, ®->node);
+ } else if (reg->end == start - 1) {
+ goto combine;
+ } else if (reg->end >= start) {
+ goto overlap;
+ }
+
+ /* The new region goes after the last existing one. */
+ return add_region_before(start, end, space_id, flags, desc, regions);
+
+ overlap:
+ /*
+ * The new region overlaps an existing one.
+ *
+ * The head part of the new region immediately preceding the existing
+ * overlapping one can be combined with it right away.
+ */
+ if (reg->start > start) {
+ error = request_range(start, reg->start - 1, space_id, flags, desc);
+ if (error)
+ ret = error;
+ else
+ reg->start = start;
+ }
+
+ combine:
+ /*
+ * The new region is adjacent to an existing one. If it extends beyond
+ * that region all the way to the next one, it is possible to combine
+ * all three of them.
+ */
+ while (reg->end < end) {
+ struct reserved_region *next = NULL;
+ u64 a = reg->end + 1, b = end;
+
+ if (!list_is_last(®->node, regions)) {
+ next = list_next_entry(reg, node);
+ if (next->start <= end)
+ b = next->start - 1;
+ }
+ error = request_range(a, b, space_id, flags, desc);
+ if (!error) {
+ if (next && next->start == b + 1) {
+ reg->end = next->end;
+ list_del(&next->node);
+ kfree(next);
+ } else {
+ reg->end = end;
+ break;
+ }
+ } else if (next) {
+ if (!ret)
+ ret = error;
+
+ reg = next;
+ } else {
+ break;
+ }
+ }
+
+ return ret ? ret : error;
+}
+EXPORT_SYMBOL_GPL(acpi_reserve_region);
Code Review / kvmfornfv.git / blobdiff