1 files changed, 489 insertions, 0 deletions

diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 39a0e7f1f0a3..290d397e1dd9 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -38,10 +38,30 @@
 #include <asm/efi.h>
 #include <asm/cacheflush.h>
 #include <asm/fixmap.h>
+#include <asm/realmode.h>
+#include <asm/time.h>
 
 static pgd_t *save_pgd __initdata;
 static unsigned long efi_flags __initdata;
 
+/*
+ * We allocate runtime services regions bottom-up, starting from -4G, i.e.
+ * 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G.
+ */
+static u64 efi_va	= -4 * (1UL << 30);
+#define EFI_VA_END	(-68 * (1UL << 30))
+
+/*
+ * Scratch space used for switching the pagetable in the EFI stub
+ */
+struct efi_scratch {
+	u64 r15;
+	u64 prev_cr3;
+	pgd_t *efi_pgt;
+	bool use_pgd;
+	u64 phys_stack;
+} __packed;
+
 static void __init early_code_mapping_set_exec(int executable)
 {
 	efi_memory_desc_t *md;
@@ -65,6 +85,9 @@ void __init efi_call_phys_prelog(void)
 	int pgd;
 	int n_pgds;
 
+	if (!efi_enabled(EFI_OLD_MEMMAP))
+		return;
+
 	early_code_mapping_set_exec(1);
 	local_irq_save(efi_flags);
 
@@ -86,6 +109,10 @@ void __init efi_call_phys_epilog(void)
 	 */
 	int pgd;
 	int n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);
+
+	if (!efi_enabled(EFI_OLD_MEMMAP))
+		return;
+
 	for (pgd = 0; pgd < n_pgds; pgd++)
 		set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), save_pgd[pgd]);
 	kfree(save_pgd);
@@ -94,6 +121,158 @@ void __init efi_call_phys_epilog(void)
 	early_code_mapping_set_exec(0);
 }
 
+/*
+ * Add low kernel mappings for passing arguments to EFI functions.
+ */
+void efi_sync_low_kernel_mappings(void)
+{
+	unsigned num_pgds;
+	pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
+
+	if (efi_enabled(EFI_OLD_MEMMAP))
+		return;
+
+	num_pgds = pgd_index(MODULES_END - 1) - pgd_index(PAGE_OFFSET);
+
+	memcpy(pgd + pgd_index(PAGE_OFFSET),
+		init_mm.pgd + pgd_index(PAGE_OFFSET),
+		sizeof(pgd_t) * num_pgds);
+}
+
+int efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
+{
+	unsigned long text;
+	struct page *page;
+	unsigned npages;
+	pgd_t *pgd;
+
+	if (efi_enabled(EFI_OLD_MEMMAP))
+		return 0;
+
+	efi_scratch.efi_pgt = (pgd_t *)(unsigned long)real_mode_header->trampoline_pgd;
+	pgd = __va(efi_scratch.efi_pgt);
+
+	/*
+	 * It can happen that the physical address of new_memmap lands in memory
+	 * which is not mapped in the EFI page table. Therefore we need to go
+	 * and ident-map those pages containing the map before calling
+	 * phys_efi_set_virtual_address_map().
+	 */
+	if (kernel_map_pages_in_pgd(pgd, pa_memmap, pa_memmap, num_pages, _PAGE_NX)) {
+		pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
+		return 1;
+	}
+
+	efi_scratch.use_pgd = true;
+
+	/*
+	 * When making calls to the firmware everything needs to be 1:1
+	 * mapped and addressable with 32-bit pointers. Map the kernel
+	 * text and allocate a new stack because we can't rely on the
+	 * stack pointer being < 4GB.
+	 */
+	if (!IS_ENABLED(CONFIG_EFI_MIXED))
+		return 0;
+
+	page = alloc_page(GFP_KERNEL|__GFP_DMA32);
+	if (!page)
+		panic("Unable to allocate EFI runtime stack < 4GB\n");
+
+	efi_scratch.phys_stack = virt_to_phys(page_address(page));
+	efi_scratch.phys_stack += PAGE_SIZE; /* stack grows down */
+
+	npages = (_end - _text) >> PAGE_SHIFT;
+	text = __pa(_text);
+
+	if (kernel_map_pages_in_pgd(pgd, text >> PAGE_SHIFT, text, npages, 0)) {
+		pr_err("Failed to map kernel text 1:1\n");
+		return 1;
+	}
+
+	return 0;
+}
+
+void efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages)
+{
+	pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
+
+	kernel_unmap_pages_in_pgd(pgd, pa_memmap, num_pages);
+}
+
+static void __init __map_region(efi_memory_desc_t *md, u64 va)
+{
+	pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
+	unsigned long pf = 0;
+
+	if (!(md->attribute & EFI_MEMORY_WB))
+		pf |= _PAGE_PCD;
+
+	if (kernel_map_pages_in_pgd(pgd, md->phys_addr, va, md->num_pages, pf))
+		pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
+			   md->phys_addr, va);
+}
+
+void __init efi_map_region(efi_memory_desc_t *md)
+{
+	unsigned long size = md->num_pages << PAGE_SHIFT;
+	u64 pa = md->phys_addr;
+
+	if (efi_enabled(EFI_OLD_MEMMAP))
+		return old_map_region(md);
+
+	/*
+	 * Make sure the 1:1 mappings are present as a catch-all for b0rked
+	 * firmware which doesn't update all internal pointers after switching
+	 * to virtual mode and would otherwise crap on us.
+	 */
+	__map_region(md, md->phys_addr);
+
+	/*
+	 * Enforce the 1:1 mapping as the default virtual address when
+	 * booting in EFI mixed mode, because even though we may be
+	 * running a 64-bit kernel, the firmware may only be 32-bit.
+	 */
+	if (!efi_is_native () && IS_ENABLED(CONFIG_EFI_MIXED)) {
+		md->virt_addr = md->phys_addr;
+		return;
+	}
+
+	efi_va -= size;
+
+	/* Is PA 2M-aligned? */
+	if (!(pa & (PMD_SIZE - 1))) {
+		efi_va &= PMD_MASK;
+	} else {
+		u64 pa_offset = pa & (PMD_SIZE - 1);
+		u64 prev_va = efi_va;
+
+		/* get us the same offset within this 2M page */
+		efi_va = (efi_va & PMD_MASK) + pa_offset;
+
+		if (efi_va > prev_va)
+			efi_va -= PMD_SIZE;
+	}
+
+	if (efi_va < EFI_VA_END) {
+		pr_warn(FW_WARN "VA address range overflow!\n");
+		return;
+	}
+
+	/* Do the VA map */
+	__map_region(md, efi_va);
+	md->virt_addr = efi_va;
+}
+
+/*
+ * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges.
+ * md->virt_addr is the original virtual address which had been mapped in kexec
+ * 1st kernel.
+ */
+void __init efi_map_region_fixed(efi_memory_desc_t *md)
+{
+	__map_region(md, md->virt_addr);
+}
+
 void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size,
 				 u32 type, u64 attribute)
 {
@@ -113,3 +292,313 @@ void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size,
 
 	return (void __iomem *)__va(phys_addr);
 }
+
+void __init parse_efi_setup(u64 phys_addr, u32 data_len)
+{
+	efi_setup = phys_addr + sizeof(struct setup_data);
+}
+
+void __init efi_runtime_mkexec(void)
+{
+	if (!efi_enabled(EFI_OLD_MEMMAP))
+		return;
+
+	if (__supported_pte_mask & _PAGE_NX)
+		runtime_code_page_mkexec();
+}
+
+void __init efi_dump_pagetable(void)
+{
+#ifdef CONFIG_EFI_PGT_DUMP
+	pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
+
+	ptdump_walk_pgd_level(NULL, pgd);
+#endif
+}
+
+#ifdef CONFIG_EFI_MIXED
+extern efi_status_t efi64_thunk(u32, ...);
+
+#define runtime_service32(func)						 \
+({									 \
+	u32 table = (u32)(unsigned long)efi.systab;			 \
+	u32 *rt, *___f;							 \
+									 \
+	rt = (u32 *)(table + offsetof(efi_system_table_32_t, runtime));	 \
+	___f = (u32 *)(*rt + offsetof(efi_runtime_services_32_t, func)); \
+	*___f;								 \
+})
+
+/*
+ * Switch to the EFI page tables early so that we can access the 1:1
+ * runtime services mappings which are not mapped in any other page
+ * tables. This function must be called before runtime_service32().
+ *
+ * Also, disable interrupts because the IDT points to 64-bit handlers,
+ * which aren't going to function correctly when we switch to 32-bit.
+ */
+#define efi_thunk(f, ...)						\
+({									\
+	efi_status_t __s;						\
+	unsigned long flags;						\
+	u32 func;							\
+									\
+	efi_sync_low_kernel_mappings();					\
+	local_irq_save(flags);						\
+									\
+	efi_scratch.prev_cr3 = read_cr3();				\
+	write_cr3((unsigned long)efi_scratch.efi_pgt);			\
+	__flush_tlb_all();						\
+									\
+	func = runtime_service32(f);					\
+	__s = efi64_thunk(func, __VA_ARGS__);			\
+									\
+	write_cr3(efi_scratch.prev_cr3);				\
+	__flush_tlb_all();						\
+	local_irq_restore(flags);					\
+									\
+	__s;								\
+})
+
+efi_status_t efi_thunk_set_virtual_address_map(
+	void *phys_set_virtual_address_map,
+	unsigned long memory_map_size,
+	unsigned long descriptor_size,
+	u32 descriptor_version,
+	efi_memory_desc_t *virtual_map)
+{
+	efi_status_t status;
+	unsigned long flags;
+	u32 func;
+
+	efi_sync_low_kernel_mappings();
+	local_irq_save(flags);
+
+	efi_scratch.prev_cr3 = read_cr3();
+	write_cr3((unsigned long)efi_scratch.efi_pgt);
+	__flush_tlb_all();
+
+	func = (u32)(unsigned long)phys_set_virtual_address_map;
+	status = efi64_thunk(func, memory_map_size, descriptor_size,
+			     descriptor_version, virtual_map);
+
+	write_cr3(efi_scratch.prev_cr3);
+	__flush_tlb_all();
+	local_irq_restore(flags);
+
+	return status;
+}
+
+static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
+{
+	efi_status_t status;
+	u32 phys_tm, phys_tc;
+
+	spin_lock(&rtc_lock);
+
+	phys_tm = virt_to_phys(tm);
+	phys_tc = virt_to_phys(tc);
+
+	status = efi_thunk(get_time, phys_tm, phys_tc);
+
+	spin_unlock(&rtc_lock);
+
+	return status;
+}
+
+static efi_status_t efi_thunk_set_time(efi_time_t *tm)
+{
+	efi_status_t status;
+	u32 phys_tm;
+
+	spin_lock(&rtc_lock);
+
+	phys_tm = virt_to_phys(tm);
+
+	status = efi_thunk(set_time, phys_tm);
+
+	spin_unlock(&rtc_lock);
+
+	return status;
+}
+
+static efi_status_t
+efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
+			  efi_time_t *tm)
+{
+	efi_status_t status;
+	u32 phys_enabled, phys_pending, phys_tm;
+
+	spin_lock(&rtc_lock);
+
+	phys_enabled = virt_to_phys(enabled);
+	phys_pending = virt_to_phys(pending);
+	phys_tm = virt_to_phys(tm);
+
+	status = efi_thunk(get_wakeup_time, phys_enabled,
+			     phys_pending, phys_tm);
+
+	spin_unlock(&rtc_lock);
+
+	return status;
+}
+
+static efi_status_t
+efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
+{
+	efi_status_t status;
+	u32 phys_tm;
+
+	spin_lock(&rtc_lock);
+
+	phys_tm = virt_to_phys(tm);
+
+	status = efi_thunk(set_wakeup_time, enabled, phys_tm);
+
+	spin_unlock(&rtc_lock);
+
+	return status;
+}
+
+
+static efi_status_t
+efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
+		       u32 *attr, unsigned long *data_size, void *data)
+{
+	efi_status_t status;
+	u32 phys_name, phys_vendor, phys_attr;
+	u32 phys_data_size, phys_data;
+
+	phys_data_size = virt_to_phys(data_size);
+	phys_vendor = virt_to_phys(vendor);
+	phys_name = virt_to_phys(name);
+	phys_attr = virt_to_phys(attr);
+	phys_data = virt_to_phys(data);
+
+	status = efi_thunk(get_variable, phys_name, phys_vendor,
+			   phys_attr, phys_data_size, phys_data);
+
+	return status;
+}
+
+static efi_status_t
+efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
+		       u32 attr, unsigned long data_size, void *data)
+{
+	u32 phys_name, phys_vendor, phys_data;
+	efi_status_t status;
+
+	phys_name = virt_to_phys(name);
+	phys_vendor = virt_to_phys(vendor);
+	phys_data = virt_to_phys(data);
+
+	/* If data_size is > sizeof(u32) we've got problems */
+	status = efi_thunk(set_variable, phys_name, phys_vendor,
+			   attr, data_size, phys_data);
+
+	return status;
+}
+
+static efi_status_t
+efi_thunk_get_next_variable(unsigned long *name_size,
+			    efi_char16_t *name,
+			    efi_guid_t *vendor)
+{
+	efi_status_t status;
+	u32 phys_name_size, phys_name, phys_vendor;
+
+	phys_name_size = virt_to_phys(name_size);
+	phys_vendor = virt_to_phys(vendor);
+	phys_name = virt_to_phys(name);
+
+	status = efi_thunk(get_next_variable, phys_name_size,
+			   phys_name, phys_vendor);
+
+	return status;
+}
+
+static efi_status_t
+efi_thunk_get_next_high_mono_count(u32 *count)
+{
+	efi_status_t status;
+	u32 phys_count;
+
+	phys_count = virt_to_phys(count);
+	status = efi_thunk(get_next_high_mono_count, phys_count);
+
+	return status;
+}
+
+static void
+efi_thunk_reset_system(int reset_type, efi_status_t status,
+		       unsigned long data_size, efi_char16_t *data)
+{
+	u32 phys_data;
+
+	phys_data = virt_to_phys(data);
+
+	efi_thunk(reset_system, reset_type, status, data_size, phys_data);
+}
+
+static efi_status_t
+efi_thunk_update_capsule(efi_capsule_header_t **capsules,
+			 unsigned long count, unsigned long sg_list)
+{
+	/*
+	 * To properly support this function we would need to repackage
+	 * 'capsules' because the firmware doesn't understand 64-bit
+	 * pointers.
+	 */
+	return EFI_UNSUPPORTED;
+}
+
+static efi_status_t
+efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
+			      u64 *remaining_space,
+			      u64 *max_variable_size)
+{
+	efi_status_t status;
+	u32 phys_storage, phys_remaining, phys_max;
+
+	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
+		return EFI_UNSUPPORTED;
+
+	phys_storage = virt_to_phys(storage_space);
+	phys_remaining = virt_to_phys(remaining_space);
+	phys_max = virt_to_phys(max_variable_size);
+
+	status = efi_thunk(query_variable_info, attr, phys_storage,
+			   phys_remaining, phys_max);
+
+	return status;
+}
+
+static efi_status_t
+efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules,
+			     unsigned long count, u64 *max_size,
+			     int *reset_type)
+{
+	/*
+	 * To properly support this function we would need to repackage
+	 * 'capsules' because the firmware doesn't understand 64-bit
+	 * pointers.
+	 */
+	return EFI_UNSUPPORTED;
+}
+
+void efi_thunk_runtime_setup(void)
+{
+	efi.get_time = efi_thunk_get_time;
+	efi.set_time = efi_thunk_set_time;
+	efi.get_wakeup_time = efi_thunk_get_wakeup_time;
+	efi.set_wakeup_time = efi_thunk_set_wakeup_time;
+	efi.get_variable = efi_thunk_get_variable;
+	efi.get_next_variable = efi_thunk_get_next_variable;
+	efi.set_variable = efi_thunk_set_variable;
+	efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count;
+	efi.reset_system = efi_thunk_reset_system;
+	efi.query_variable_info = efi_thunk_query_variable_info;
+	efi.update_capsule = efi_thunk_update_capsule;
+	efi.query_capsule_caps = efi_thunk_query_capsule_caps;
+}
+#endif /* CONFIG_EFI_MIXED */