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| void dev_configure(void)
{
struct resource *res;
struct device *root;
struct device *child;
set_vga_bridge_bits();
printk(BIOS_INFO, "Allocating resources...\n");
root = &dev_root; // 根设备
/*
* Each domain should create resources which contain the entire address
* space for IO, MEM, and PREFMEM resources in the domain. The
* allocation of device resources will be done from this address space.
*/
/* Read the resources for the entire tree. */
// 先读一次
printk(BIOS_INFO, "Reading resources...\n");
read_resources(root->link_list);
printk(BIOS_INFO, "Done reading resources.\n");
// 打印设备树的资源
print_resource_tree(root, BIOS_SPEW, "After reading.");
/* Compute resources for all domains. */
// 计算资源
for (child = root->link_list->children; child; child = child->sibling) {
if (!(child->path.type == DEVICE_PATH_DOMAIN))
continue;
post_log_path(child);
for (res = child->resource_list; res; res = res->next) {
if (res->flags & IORESOURCE_FIXED)
continue;
if (res->flags & IORESOURCE_MEM) {
compute_resources(child->link_list,
res, IORESOURCE_TYPE_MASK, IORESOURCE_MEM);
continue;
}
if (res->flags & IORESOURCE_IO) {
compute_resources(child->link_list,
res, IORESOURCE_TYPE_MASK, IORESOURCE_IO);
continue;
}
}
}
/* For all domains. */
for (child = root->link_list->children; child; child=child->sibling)
if (child->path.type == DEVICE_PATH_DOMAIN)
avoid_fixed_resources(child); // 此函数作用? 感觉是对范围的限制
/* Store the computed resource allocations into device registers ... */
printk(BIOS_INFO, "Setting resources...\n");
for (child = root->link_list->children; child; child = child->sibling) {
if (!(child->path.type == DEVICE_PATH_DOMAIN))
continue;
post_log_path(child);
// 分mem和io两种资源
for (res = child->resource_list; res; res = res->next) {
if (res->flags & IORESOURCE_FIXED)
continue;
if (res->flags & IORESOURCE_MEM) {
allocate_resources(child->link_list,
res, IORESOURCE_TYPE_MASK, IORESOURCE_MEM);
continue;
}
if (res->flags & IORESOURCE_IO) {
allocate_resources(child->link_list,
res, IORESOURCE_TYPE_MASK, IORESOURCE_IO);
continue;
}
}
}
assign_resources(root->link_list);
printk(BIOS_INFO, "Done setting resources.\n");
print_resource_tree(root, BIOS_SPEW, "After assigning values.");
printk(BIOS_INFO, "Done allocating resources.\n");
}
|
