| /* |
| * Machine specific setup for xen |
| * |
| * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007 |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/sched.h> |
| #include <linux/mm.h> |
| #include <linux/pm.h> |
| #include <linux/memblock.h> |
| #include <linux/cpuidle.h> |
| |
| #include <asm/elf.h> |
| #include <asm/vdso.h> |
| #include <asm/e820.h> |
| #include <asm/setup.h> |
| #include <asm/acpi.h> |
| #include <asm/xen/hypervisor.h> |
| #include <asm/xen/hypercall.h> |
| |
| #include <xen/xen.h> |
| #include <xen/page.h> |
| #include <xen/interface/callback.h> |
| #include <xen/interface/memory.h> |
| #include <xen/interface/physdev.h> |
| #include <xen/features.h> |
| |
| #include "xen-ops.h" |
| #include "vdso.h" |
| |
| /* These are code, but not functions. Defined in entry.S */ |
| extern const char xen_hypervisor_callback[]; |
| extern const char xen_failsafe_callback[]; |
| extern void xen_sysenter_target(void); |
| extern void xen_syscall_target(void); |
| extern void xen_syscall32_target(void); |
| |
| /* Amount of extra memory space we add to the e820 ranges */ |
| phys_addr_t xen_extra_mem_start, xen_extra_mem_size; |
| |
| /* |
| * The maximum amount of extra memory compared to the base size. The |
| * main scaling factor is the size of struct page. At extreme ratios |
| * of base:extra, all the base memory can be filled with page |
| * structures for the extra memory, leaving no space for anything |
| * else. |
| * |
| * 10x seems like a reasonable balance between scaling flexibility and |
| * leaving a practically usable system. |
| */ |
| #define EXTRA_MEM_RATIO (10) |
| |
| static void __init xen_add_extra_mem(unsigned long pages) |
| { |
| unsigned long pfn; |
| |
| u64 size = (u64)pages * PAGE_SIZE; |
| u64 extra_start = xen_extra_mem_start + xen_extra_mem_size; |
| |
| if (!pages) |
| return; |
| |
| e820_add_region(extra_start, size, E820_RAM); |
| sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map); |
| |
| memblock_x86_reserve_range(extra_start, extra_start + size, "XEN EXTRA"); |
| |
| xen_extra_mem_size += size; |
| |
| xen_max_p2m_pfn = PFN_DOWN(extra_start + size); |
| |
| for (pfn = PFN_DOWN(extra_start); pfn <= xen_max_p2m_pfn; pfn++) |
| __set_phys_to_machine(pfn, INVALID_P2M_ENTRY); |
| } |
| |
| static unsigned long __init xen_release_chunk(phys_addr_t start_addr, |
| phys_addr_t end_addr) |
| { |
| struct xen_memory_reservation reservation = { |
| .address_bits = 0, |
| .extent_order = 0, |
| .domid = DOMID_SELF |
| }; |
| unsigned long start, end; |
| unsigned long len = 0; |
| unsigned long pfn; |
| int ret; |
| |
| start = PFN_UP(start_addr); |
| end = PFN_DOWN(end_addr); |
| |
| if (end <= start) |
| return 0; |
| |
| for(pfn = start; pfn < end; pfn++) { |
| unsigned long mfn = pfn_to_mfn(pfn); |
| |
| /* Make sure pfn exists to start with */ |
| if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn) |
| continue; |
| |
| set_xen_guest_handle(reservation.extent_start, &mfn); |
| reservation.nr_extents = 1; |
| |
| ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation, |
| &reservation); |
| WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret); |
| if (ret == 1) { |
| __set_phys_to_machine(pfn, INVALID_P2M_ENTRY); |
| len++; |
| } |
| } |
| printk(KERN_INFO "Freeing %lx-%lx pfn range: %lu pages freed\n", |
| start, end, len); |
| |
| return len; |
| } |
| |
| static unsigned long __init xen_return_unused_memory(unsigned long max_pfn, |
| const struct e820map *e820) |
| { |
| phys_addr_t max_addr = PFN_PHYS(max_pfn); |
| phys_addr_t last_end = ISA_END_ADDRESS; |
| unsigned long released = 0; |
| int i; |
| |
| /* Free any unused memory above the low 1Mbyte. */ |
| for (i = 0; i < e820->nr_map && last_end < max_addr; i++) { |
| phys_addr_t end = e820->map[i].addr; |
| end = min(max_addr, end); |
| |
| if (last_end < end) |
| released += xen_release_chunk(last_end, end); |
| last_end = max(last_end, e820->map[i].addr + e820->map[i].size); |
| } |
| |
| if (last_end < max_addr) |
| released += xen_release_chunk(last_end, max_addr); |
| |
| printk(KERN_INFO "released %lu pages of unused memory\n", released); |
| return released; |
| } |
| |
| static unsigned long __init xen_set_identity(const struct e820entry *list, |
| ssize_t map_size) |
| { |
| phys_addr_t last = xen_initial_domain() ? 0 : ISA_END_ADDRESS; |
| phys_addr_t start_pci = last; |
| const struct e820entry *entry; |
| unsigned long identity = 0; |
| int i; |
| |
| for (i = 0, entry = list; i < map_size; i++, entry++) { |
| phys_addr_t start = entry->addr; |
| phys_addr_t end = start + entry->size; |
| |
| if (start < last) |
| start = last; |
| |
| if (end <= start) |
| continue; |
| |
| /* Skip over the 1MB region. */ |
| if (last > end) |
| continue; |
| |
| if ((entry->type == E820_RAM) || (entry->type == E820_UNUSABLE)) { |
| if (start > start_pci) |
| identity += set_phys_range_identity( |
| PFN_UP(start_pci), PFN_DOWN(start)); |
| |
| /* Without saving 'last' we would gooble RAM too |
| * at the end of the loop. */ |
| last = end; |
| start_pci = end; |
| continue; |
| } |
| start_pci = min(start, start_pci); |
| last = end; |
| } |
| if (last > start_pci) |
| identity += set_phys_range_identity( |
| PFN_UP(start_pci), PFN_DOWN(last)); |
| return identity; |
| } |
| |
| static unsigned long __init xen_get_max_pages(void) |
| { |
| unsigned long max_pages = MAX_DOMAIN_PAGES; |
| domid_t domid = DOMID_SELF; |
| int ret; |
| |
| ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid); |
| if (ret > 0) |
| max_pages = ret; |
| return min(max_pages, MAX_DOMAIN_PAGES); |
| } |
| |
| /** |
| * machine_specific_memory_setup - Hook for machine specific memory setup. |
| **/ |
| char * __init xen_memory_setup(void) |
| { |
| static struct e820entry map[E820MAX] __initdata; |
| static struct e820entry map_raw[E820MAX] __initdata; |
| |
| unsigned long max_pfn = xen_start_info->nr_pages; |
| unsigned long long mem_end; |
| int rc; |
| struct xen_memory_map memmap; |
| unsigned long extra_pages = 0; |
| unsigned long extra_limit; |
| unsigned long identity_pages = 0; |
| int i; |
| int op; |
| |
| max_pfn = min(MAX_DOMAIN_PAGES, max_pfn); |
| mem_end = PFN_PHYS(max_pfn); |
| |
| memmap.nr_entries = E820MAX; |
| set_xen_guest_handle(memmap.buffer, map); |
| |
| op = xen_initial_domain() ? |
| XENMEM_machine_memory_map : |
| XENMEM_memory_map; |
| rc = HYPERVISOR_memory_op(op, &memmap); |
| if (rc == -ENOSYS) { |
| BUG_ON(xen_initial_domain()); |
| memmap.nr_entries = 1; |
| map[0].addr = 0ULL; |
| map[0].size = mem_end; |
| /* 8MB slack (to balance backend allocations). */ |
| map[0].size += 8ULL << 20; |
| map[0].type = E820_RAM; |
| rc = 0; |
| } |
| BUG_ON(rc); |
| |
| memcpy(map_raw, map, sizeof(map)); |
| e820.nr_map = 0; |
| xen_extra_mem_start = mem_end; |
| for (i = 0; i < memmap.nr_entries; i++) { |
| unsigned long long end; |
| |
| /* Guard against non-page aligned E820 entries. */ |
| if (map[i].type == E820_RAM) |
| map[i].size -= (map[i].size + map[i].addr) % PAGE_SIZE; |
| |
| end = map[i].addr + map[i].size; |
| if (map[i].type == E820_RAM && end > mem_end) { |
| /* RAM off the end - may be partially included */ |
| u64 delta = min(map[i].size, end - mem_end); |
| |
| map[i].size -= delta; |
| end -= delta; |
| |
| extra_pages += PFN_DOWN(delta); |
| /* |
| * Set RAM below 4GB that is not for us to be unusable. |
| * This prevents "System RAM" address space from being |
| * used as potential resource for I/O address (happens |
| * when 'allocate_resource' is called). |
| */ |
| if (delta && |
| (xen_initial_domain() && end < 0x100000000ULL)) |
| e820_add_region(end, delta, E820_UNUSABLE); |
| } |
| |
| if (map[i].size > 0 && end > xen_extra_mem_start) |
| xen_extra_mem_start = end; |
| |
| /* Add region if any remains */ |
| if (map[i].size > 0) |
| e820_add_region(map[i].addr, map[i].size, map[i].type); |
| } |
| /* Align the balloon area so that max_low_pfn does not get set |
| * to be at the _end_ of the PCI gap at the far end (fee01000). |
| * Note that xen_extra_mem_start gets set in the loop above to be |
| * past the last E820 region. */ |
| if (xen_initial_domain() && (xen_extra_mem_start < (1ULL<<32))) |
| xen_extra_mem_start = (1ULL<<32); |
| |
| /* |
| * In domU, the ISA region is normal, usable memory, but we |
| * reserve ISA memory anyway because too many things poke |
| * about in there. |
| * |
| * In Dom0, the host E820 information can leave gaps in the |
| * ISA range, which would cause us to release those pages. To |
| * avoid this, we unconditionally reserve them here. |
| */ |
| e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, |
| E820_RESERVED); |
| |
| /* |
| * Reserve Xen bits: |
| * - mfn_list |
| * - xen_start_info |
| * See comment above "struct start_info" in <xen/interface/xen.h> |
| */ |
| memblock_x86_reserve_range(__pa(xen_start_info->mfn_list), |
| __pa(xen_start_info->pt_base), |
| "XEN START INFO"); |
| |
| sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map); |
| |
| extra_limit = xen_get_max_pages(); |
| if (max_pfn + extra_pages > extra_limit) { |
| if (extra_limit > max_pfn) |
| extra_pages = extra_limit - max_pfn; |
| else |
| extra_pages = 0; |
| } |
| |
| extra_pages += xen_return_unused_memory(xen_start_info->nr_pages, &e820); |
| |
| /* |
| * Clamp the amount of extra memory to a EXTRA_MEM_RATIO |
| * factor the base size. On non-highmem systems, the base |
| * size is the full initial memory allocation; on highmem it |
| * is limited to the max size of lowmem, so that it doesn't |
| * get completely filled. |
| * |
| * In principle there could be a problem in lowmem systems if |
| * the initial memory is also very large with respect to |
| * lowmem, but we won't try to deal with that here. |
| */ |
| extra_limit = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)), |
| max_pfn + extra_pages); |
| |
| if (extra_limit >= max_pfn) |
| extra_pages = extra_limit - max_pfn; |
| else |
| extra_pages = 0; |
| |
| xen_add_extra_mem(extra_pages); |
| |
| /* |
| * Set P2M for all non-RAM pages and E820 gaps to be identity |
| * type PFNs. We supply it with the non-sanitized version |
| * of the E820. |
| */ |
| identity_pages = xen_set_identity(map_raw, memmap.nr_entries); |
| printk(KERN_INFO "Set %ld page(s) to 1-1 mapping.\n", identity_pages); |
| return "Xen"; |
| } |
| |
| /* |
| * Set the bit indicating "nosegneg" library variants should be used. |
| * We only need to bother in pure 32-bit mode; compat 32-bit processes |
| * can have un-truncated segments, so wrapping around is allowed. |
| */ |
| static void __init fiddle_vdso(void) |
| { |
| #ifdef CONFIG_X86_32 |
| u32 *mask; |
| mask = VDSO32_SYMBOL(&vdso32_int80_start, NOTE_MASK); |
| *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT; |
| mask = VDSO32_SYMBOL(&vdso32_sysenter_start, NOTE_MASK); |
| *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT; |
| #endif |
| } |
| |
| static int __cpuinit register_callback(unsigned type, const void *func) |
| { |
| struct callback_register callback = { |
| .type = type, |
| .address = XEN_CALLBACK(__KERNEL_CS, func), |
| .flags = CALLBACKF_mask_events, |
| }; |
| |
| return HYPERVISOR_callback_op(CALLBACKOP_register, &callback); |
| } |
| |
| void __cpuinit xen_enable_sysenter(void) |
| { |
| int ret; |
| unsigned sysenter_feature; |
| |
| #ifdef CONFIG_X86_32 |
| sysenter_feature = X86_FEATURE_SEP; |
| #else |
| sysenter_feature = X86_FEATURE_SYSENTER32; |
| #endif |
| |
| if (!boot_cpu_has(sysenter_feature)) |
| return; |
| |
| ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target); |
| if(ret != 0) |
| setup_clear_cpu_cap(sysenter_feature); |
| } |
| |
| void __cpuinit xen_enable_syscall(void) |
| { |
| #ifdef CONFIG_X86_64 |
| int ret; |
| |
| ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target); |
| if (ret != 0) { |
| printk(KERN_ERR "Failed to set syscall callback: %d\n", ret); |
| /* Pretty fatal; 64-bit userspace has no other |
| mechanism for syscalls. */ |
| } |
| |
| if (boot_cpu_has(X86_FEATURE_SYSCALL32)) { |
| ret = register_callback(CALLBACKTYPE_syscall32, |
| xen_syscall32_target); |
| if (ret != 0) |
| setup_clear_cpu_cap(X86_FEATURE_SYSCALL32); |
| } |
| #endif /* CONFIG_X86_64 */ |
| } |
| |
| void __init xen_arch_setup(void) |
| { |
| xen_panic_handler_init(); |
| |
| HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments); |
| HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables); |
| |
| if (!xen_feature(XENFEAT_auto_translated_physmap)) |
| HYPERVISOR_vm_assist(VMASST_CMD_enable, |
| VMASST_TYPE_pae_extended_cr3); |
| |
| if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) || |
| register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback)) |
| BUG(); |
| |
| xen_enable_sysenter(); |
| xen_enable_syscall(); |
| |
| #ifdef CONFIG_ACPI |
| if (!(xen_start_info->flags & SIF_INITDOMAIN)) { |
| printk(KERN_INFO "ACPI in unprivileged domain disabled\n"); |
| disable_acpi(); |
| } |
| #endif |
| |
| memcpy(boot_command_line, xen_start_info->cmd_line, |
| MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ? |
| COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE); |
| |
| /* Set up idle, making sure it calls safe_halt() pvop */ |
| #ifdef CONFIG_X86_32 |
| boot_cpu_data.hlt_works_ok = 1; |
| #endif |
| disable_cpuidle(); |
| boot_option_idle_override = IDLE_HALT; |
| |
| fiddle_vdso(); |
| } |