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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/x86/mm/ioremap.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/mm/ioremap.c')
-rw-r--r-- | arch/x86/mm/ioremap.c | 931 |
1 files changed, 931 insertions, 0 deletions
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c new file mode 100644 index 000000000..6453fbaed --- /dev/null +++ b/arch/x86/mm/ioremap.c @@ -0,0 +1,931 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Re-map IO memory to kernel address space so that we can access it. + * This is needed for high PCI addresses that aren't mapped in the + * 640k-1MB IO memory area on PC's + * + * (C) Copyright 1995 1996 Linus Torvalds + */ + +#include <linux/memblock.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/ioport.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/mmiotrace.h> +#include <linux/cc_platform.h> +#include <linux/efi.h> +#include <linux/pgtable.h> +#include <linux/kmsan.h> + +#include <asm/set_memory.h> +#include <asm/e820/api.h> +#include <asm/efi.h> +#include <asm/fixmap.h> +#include <asm/tlbflush.h> +#include <asm/pgalloc.h> +#include <asm/memtype.h> +#include <asm/setup.h> + +#include "physaddr.h" + +/* + * Descriptor controlling ioremap() behavior. + */ +struct ioremap_desc { + unsigned int flags; +}; + +/* + * Fix up the linear direct mapping of the kernel to avoid cache attribute + * conflicts. + */ +int ioremap_change_attr(unsigned long vaddr, unsigned long size, + enum page_cache_mode pcm) +{ + unsigned long nrpages = size >> PAGE_SHIFT; + int err; + + switch (pcm) { + case _PAGE_CACHE_MODE_UC: + default: + err = _set_memory_uc(vaddr, nrpages); + break; + case _PAGE_CACHE_MODE_WC: + err = _set_memory_wc(vaddr, nrpages); + break; + case _PAGE_CACHE_MODE_WT: + err = _set_memory_wt(vaddr, nrpages); + break; + case _PAGE_CACHE_MODE_WB: + err = _set_memory_wb(vaddr, nrpages); + break; + } + + return err; +} + +/* Does the range (or a subset of) contain normal RAM? */ +static unsigned int __ioremap_check_ram(struct resource *res) +{ + unsigned long start_pfn, stop_pfn; + unsigned long i; + + if ((res->flags & IORESOURCE_SYSTEM_RAM) != IORESOURCE_SYSTEM_RAM) + return 0; + + start_pfn = (res->start + PAGE_SIZE - 1) >> PAGE_SHIFT; + stop_pfn = (res->end + 1) >> PAGE_SHIFT; + if (stop_pfn > start_pfn) { + for (i = 0; i < (stop_pfn - start_pfn); ++i) + if (pfn_valid(start_pfn + i) && + !PageReserved(pfn_to_page(start_pfn + i))) + return IORES_MAP_SYSTEM_RAM; + } + + return 0; +} + +/* + * In a SEV guest, NONE and RESERVED should not be mapped encrypted because + * there the whole memory is already encrypted. + */ +static unsigned int __ioremap_check_encrypted(struct resource *res) +{ + if (!cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) + return 0; + + switch (res->desc) { + case IORES_DESC_NONE: + case IORES_DESC_RESERVED: + break; + default: + return IORES_MAP_ENCRYPTED; + } + + return 0; +} + +/* + * The EFI runtime services data area is not covered by walk_mem_res(), but must + * be mapped encrypted when SEV is active. + */ +static void __ioremap_check_other(resource_size_t addr, struct ioremap_desc *desc) +{ + if (!cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) + return; + + if (!IS_ENABLED(CONFIG_EFI)) + return; + + if (efi_mem_type(addr) == EFI_RUNTIME_SERVICES_DATA || + (efi_mem_type(addr) == EFI_BOOT_SERVICES_DATA && + efi_mem_attributes(addr) & EFI_MEMORY_RUNTIME)) + desc->flags |= IORES_MAP_ENCRYPTED; +} + +static int __ioremap_collect_map_flags(struct resource *res, void *arg) +{ + struct ioremap_desc *desc = arg; + + if (!(desc->flags & IORES_MAP_SYSTEM_RAM)) + desc->flags |= __ioremap_check_ram(res); + + if (!(desc->flags & IORES_MAP_ENCRYPTED)) + desc->flags |= __ioremap_check_encrypted(res); + + return ((desc->flags & (IORES_MAP_SYSTEM_RAM | IORES_MAP_ENCRYPTED)) == + (IORES_MAP_SYSTEM_RAM | IORES_MAP_ENCRYPTED)); +} + +/* + * To avoid multiple resource walks, this function walks resources marked as + * IORESOURCE_MEM and IORESOURCE_BUSY and looking for system RAM and/or a + * resource described not as IORES_DESC_NONE (e.g. IORES_DESC_ACPI_TABLES). + * + * After that, deal with misc other ranges in __ioremap_check_other() which do + * not fall into the above category. + */ +static void __ioremap_check_mem(resource_size_t addr, unsigned long size, + struct ioremap_desc *desc) +{ + u64 start, end; + + start = (u64)addr; + end = start + size - 1; + memset(desc, 0, sizeof(struct ioremap_desc)); + + walk_mem_res(start, end, desc, __ioremap_collect_map_flags); + + __ioremap_check_other(addr, desc); +} + +/* + * Remap an arbitrary physical address space into the kernel virtual + * address space. It transparently creates kernel huge I/O mapping when + * the physical address is aligned by a huge page size (1GB or 2MB) and + * the requested size is at least the huge page size. + * + * NOTE: MTRRs can override PAT memory types with a 4KB granularity. + * Therefore, the mapping code falls back to use a smaller page toward 4KB + * when a mapping range is covered by non-WB type of MTRRs. + * + * NOTE! We need to allow non-page-aligned mappings too: we will obviously + * have to convert them into an offset in a page-aligned mapping, but the + * caller shouldn't need to know that small detail. + */ +static void __iomem * +__ioremap_caller(resource_size_t phys_addr, unsigned long size, + enum page_cache_mode pcm, void *caller, bool encrypted) +{ + unsigned long offset, vaddr; + resource_size_t last_addr; + const resource_size_t unaligned_phys_addr = phys_addr; + const unsigned long unaligned_size = size; + struct ioremap_desc io_desc; + struct vm_struct *area; + enum page_cache_mode new_pcm; + pgprot_t prot; + int retval; + void __iomem *ret_addr; + + /* Don't allow wraparound or zero size */ + last_addr = phys_addr + size - 1; + if (!size || last_addr < phys_addr) + return NULL; + + if (!phys_addr_valid(phys_addr)) { + printk(KERN_WARNING "ioremap: invalid physical address %llx\n", + (unsigned long long)phys_addr); + WARN_ON_ONCE(1); + return NULL; + } + + __ioremap_check_mem(phys_addr, size, &io_desc); + + /* + * Don't allow anybody to remap normal RAM that we're using.. + */ + if (io_desc.flags & IORES_MAP_SYSTEM_RAM) { + WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n", + &phys_addr, &last_addr); + return NULL; + } + + /* + * Mappings have to be page-aligned + */ + offset = phys_addr & ~PAGE_MASK; + phys_addr &= PAGE_MASK; + size = PAGE_ALIGN(last_addr+1) - phys_addr; + + /* + * Mask out any bits not part of the actual physical + * address, like memory encryption bits. + */ + phys_addr &= PHYSICAL_PAGE_MASK; + + retval = memtype_reserve(phys_addr, (u64)phys_addr + size, + pcm, &new_pcm); + if (retval) { + printk(KERN_ERR "ioremap memtype_reserve failed %d\n", retval); + return NULL; + } + + if (pcm != new_pcm) { + if (!is_new_memtype_allowed(phys_addr, size, pcm, new_pcm)) { + printk(KERN_ERR + "ioremap error for 0x%llx-0x%llx, requested 0x%x, got 0x%x\n", + (unsigned long long)phys_addr, + (unsigned long long)(phys_addr + size), + pcm, new_pcm); + goto err_free_memtype; + } + pcm = new_pcm; + } + + /* + * If the page being mapped is in memory and SEV is active then + * make sure the memory encryption attribute is enabled in the + * resulting mapping. + * In TDX guests, memory is marked private by default. If encryption + * is not requested (using encrypted), explicitly set decrypt + * attribute in all IOREMAPPED memory. + */ + prot = PAGE_KERNEL_IO; + if ((io_desc.flags & IORES_MAP_ENCRYPTED) || encrypted) + prot = pgprot_encrypted(prot); + else + prot = pgprot_decrypted(prot); + + switch (pcm) { + case _PAGE_CACHE_MODE_UC: + default: + prot = __pgprot(pgprot_val(prot) | + cachemode2protval(_PAGE_CACHE_MODE_UC)); + break; + case _PAGE_CACHE_MODE_UC_MINUS: + prot = __pgprot(pgprot_val(prot) | + cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS)); + break; + case _PAGE_CACHE_MODE_WC: + prot = __pgprot(pgprot_val(prot) | + cachemode2protval(_PAGE_CACHE_MODE_WC)); + break; + case _PAGE_CACHE_MODE_WT: + prot = __pgprot(pgprot_val(prot) | + cachemode2protval(_PAGE_CACHE_MODE_WT)); + break; + case _PAGE_CACHE_MODE_WB: + break; + } + + /* + * Ok, go for it.. + */ + area = get_vm_area_caller(size, VM_IOREMAP, caller); + if (!area) + goto err_free_memtype; + area->phys_addr = phys_addr; + vaddr = (unsigned long) area->addr; + + if (memtype_kernel_map_sync(phys_addr, size, pcm)) + goto err_free_area; + + if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) + goto err_free_area; + + ret_addr = (void __iomem *) (vaddr + offset); + mmiotrace_ioremap(unaligned_phys_addr, unaligned_size, ret_addr); + + /* + * Check if the request spans more than any BAR in the iomem resource + * tree. + */ + if (iomem_map_sanity_check(unaligned_phys_addr, unaligned_size)) + pr_warn("caller %pS mapping multiple BARs\n", caller); + + return ret_addr; +err_free_area: + free_vm_area(area); +err_free_memtype: + memtype_free(phys_addr, phys_addr + size); + return NULL; +} + +/** + * ioremap - map bus memory into CPU space + * @phys_addr: bus address of the memory + * @size: size of the resource to map + * + * ioremap performs a platform specific sequence of operations to + * make bus memory CPU accessible via the readb/readw/readl/writeb/ + * writew/writel functions and the other mmio helpers. The returned + * address is not guaranteed to be usable directly as a virtual + * address. + * + * This version of ioremap ensures that the memory is marked uncachable + * on the CPU as well as honouring existing caching rules from things like + * the PCI bus. Note that there are other caches and buffers on many + * busses. In particular driver authors should read up on PCI writes + * + * It's useful if some control registers are in such an area and + * write combining or read caching is not desirable: + * + * Must be freed with iounmap. + */ +void __iomem *ioremap(resource_size_t phys_addr, unsigned long size) +{ + /* + * Ideally, this should be: + * pat_enabled() ? _PAGE_CACHE_MODE_UC : _PAGE_CACHE_MODE_UC_MINUS; + * + * Till we fix all X drivers to use ioremap_wc(), we will use + * UC MINUS. Drivers that are certain they need or can already + * be converted over to strong UC can use ioremap_uc(). + */ + enum page_cache_mode pcm = _PAGE_CACHE_MODE_UC_MINUS; + + return __ioremap_caller(phys_addr, size, pcm, + __builtin_return_address(0), false); +} +EXPORT_SYMBOL(ioremap); + +/** + * ioremap_uc - map bus memory into CPU space as strongly uncachable + * @phys_addr: bus address of the memory + * @size: size of the resource to map + * + * ioremap_uc performs a platform specific sequence of operations to + * make bus memory CPU accessible via the readb/readw/readl/writeb/ + * writew/writel functions and the other mmio helpers. The returned + * address is not guaranteed to be usable directly as a virtual + * address. + * + * This version of ioremap ensures that the memory is marked with a strong + * preference as completely uncachable on the CPU when possible. For non-PAT + * systems this ends up setting page-attribute flags PCD=1, PWT=1. For PAT + * systems this will set the PAT entry for the pages as strong UC. This call + * will honor existing caching rules from things like the PCI bus. Note that + * there are other caches and buffers on many busses. In particular driver + * authors should read up on PCI writes. + * + * It's useful if some control registers are in such an area and + * write combining or read caching is not desirable: + * + * Must be freed with iounmap. + */ +void __iomem *ioremap_uc(resource_size_t phys_addr, unsigned long size) +{ + enum page_cache_mode pcm = _PAGE_CACHE_MODE_UC; + + return __ioremap_caller(phys_addr, size, pcm, + __builtin_return_address(0), false); +} +EXPORT_SYMBOL_GPL(ioremap_uc); + +/** + * ioremap_wc - map memory into CPU space write combined + * @phys_addr: bus address of the memory + * @size: size of the resource to map + * + * This version of ioremap ensures that the memory is marked write combining. + * Write combining allows faster writes to some hardware devices. + * + * Must be freed with iounmap. + */ +void __iomem *ioremap_wc(resource_size_t phys_addr, unsigned long size) +{ + return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WC, + __builtin_return_address(0), false); +} +EXPORT_SYMBOL(ioremap_wc); + +/** + * ioremap_wt - map memory into CPU space write through + * @phys_addr: bus address of the memory + * @size: size of the resource to map + * + * This version of ioremap ensures that the memory is marked write through. + * Write through stores data into memory while keeping the cache up-to-date. + * + * Must be freed with iounmap. + */ +void __iomem *ioremap_wt(resource_size_t phys_addr, unsigned long size) +{ + return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WT, + __builtin_return_address(0), false); +} +EXPORT_SYMBOL(ioremap_wt); + +void __iomem *ioremap_encrypted(resource_size_t phys_addr, unsigned long size) +{ + return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WB, + __builtin_return_address(0), true); +} +EXPORT_SYMBOL(ioremap_encrypted); + +void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size) +{ + return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WB, + __builtin_return_address(0), false); +} +EXPORT_SYMBOL(ioremap_cache); + +void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size, + unsigned long prot_val) +{ + return __ioremap_caller(phys_addr, size, + pgprot2cachemode(__pgprot(prot_val)), + __builtin_return_address(0), false); +} +EXPORT_SYMBOL(ioremap_prot); + +/** + * iounmap - Free a IO remapping + * @addr: virtual address from ioremap_* + * + * Caller must ensure there is only one unmapping for the same pointer. + */ +void iounmap(volatile void __iomem *addr) +{ + struct vm_struct *p, *o; + + if ((void __force *)addr <= high_memory) + return; + + /* + * The PCI/ISA range special-casing was removed from __ioremap() + * so this check, in theory, can be removed. However, there are + * cases where iounmap() is called for addresses not obtained via + * ioremap() (vga16fb for example). Add a warning so that these + * cases can be caught and fixed. + */ + if ((void __force *)addr >= phys_to_virt(ISA_START_ADDRESS) && + (void __force *)addr < phys_to_virt(ISA_END_ADDRESS)) { + WARN(1, "iounmap() called for ISA range not obtained using ioremap()\n"); + return; + } + + mmiotrace_iounmap(addr); + + addr = (volatile void __iomem *) + (PAGE_MASK & (unsigned long __force)addr); + + /* Use the vm area unlocked, assuming the caller + ensures there isn't another iounmap for the same address + in parallel. Reuse of the virtual address is prevented by + leaving it in the global lists until we're done with it. + cpa takes care of the direct mappings. */ + p = find_vm_area((void __force *)addr); + + if (!p) { + printk(KERN_ERR "iounmap: bad address %p\n", addr); + dump_stack(); + return; + } + + kmsan_iounmap_page_range((unsigned long)addr, + (unsigned long)addr + get_vm_area_size(p)); + memtype_free(p->phys_addr, p->phys_addr + get_vm_area_size(p)); + + /* Finally remove it */ + o = remove_vm_area((void __force *)addr); + BUG_ON(p != o || o == NULL); + kfree(p); +} +EXPORT_SYMBOL(iounmap); + +/* + * Convert a physical pointer to a virtual kernel pointer for /dev/mem + * access + */ +void *xlate_dev_mem_ptr(phys_addr_t phys) +{ + unsigned long start = phys & PAGE_MASK; + unsigned long offset = phys & ~PAGE_MASK; + void *vaddr; + + /* memremap() maps if RAM, otherwise falls back to ioremap() */ + vaddr = memremap(start, PAGE_SIZE, MEMREMAP_WB); + + /* Only add the offset on success and return NULL if memremap() failed */ + if (vaddr) + vaddr += offset; + + return vaddr; +} + +void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr) +{ + memunmap((void *)((unsigned long)addr & PAGE_MASK)); +} + +#ifdef CONFIG_AMD_MEM_ENCRYPT +/* + * Examine the physical address to determine if it is an area of memory + * that should be mapped decrypted. If the memory is not part of the + * kernel usable area it was accessed and created decrypted, so these + * areas should be mapped decrypted. And since the encryption key can + * change across reboots, persistent memory should also be mapped + * decrypted. + * + * If SEV is active, that implies that BIOS/UEFI also ran encrypted so + * only persistent memory should be mapped decrypted. + */ +static bool memremap_should_map_decrypted(resource_size_t phys_addr, + unsigned long size) +{ + int is_pmem; + + /* + * Check if the address is part of a persistent memory region. + * This check covers areas added by E820, EFI and ACPI. + */ + is_pmem = region_intersects(phys_addr, size, IORESOURCE_MEM, + IORES_DESC_PERSISTENT_MEMORY); + if (is_pmem != REGION_DISJOINT) + return true; + + /* + * Check if the non-volatile attribute is set for an EFI + * reserved area. + */ + if (efi_enabled(EFI_BOOT)) { + switch (efi_mem_type(phys_addr)) { + case EFI_RESERVED_TYPE: + if (efi_mem_attributes(phys_addr) & EFI_MEMORY_NV) + return true; + break; + default: + break; + } + } + + /* Check if the address is outside kernel usable area */ + switch (e820__get_entry_type(phys_addr, phys_addr + size - 1)) { + case E820_TYPE_RESERVED: + case E820_TYPE_ACPI: + case E820_TYPE_NVS: + case E820_TYPE_UNUSABLE: + /* For SEV, these areas are encrypted */ + if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) + break; + fallthrough; + + case E820_TYPE_PRAM: + return true; + default: + break; + } + + return false; +} + +/* + * Examine the physical address to determine if it is EFI data. Check + * it against the boot params structure and EFI tables and memory types. + */ +static bool memremap_is_efi_data(resource_size_t phys_addr, + unsigned long size) +{ + u64 paddr; + + /* Check if the address is part of EFI boot/runtime data */ + if (!efi_enabled(EFI_BOOT)) + return false; + + paddr = boot_params.efi_info.efi_memmap_hi; + paddr <<= 32; + paddr |= boot_params.efi_info.efi_memmap; + if (phys_addr == paddr) + return true; + + paddr = boot_params.efi_info.efi_systab_hi; + paddr <<= 32; + paddr |= boot_params.efi_info.efi_systab; + if (phys_addr == paddr) + return true; + + if (efi_is_table_address(phys_addr)) + return true; + + switch (efi_mem_type(phys_addr)) { + case EFI_BOOT_SERVICES_DATA: + case EFI_RUNTIME_SERVICES_DATA: + return true; + default: + break; + } + + return false; +} + +/* + * Examine the physical address to determine if it is boot data by checking + * it against the boot params setup_data chain. + */ +static bool memremap_is_setup_data(resource_size_t phys_addr, + unsigned long size) +{ + struct setup_indirect *indirect; + struct setup_data *data; + u64 paddr, paddr_next; + + paddr = boot_params.hdr.setup_data; + while (paddr) { + unsigned int len; + + if (phys_addr == paddr) + return true; + + data = memremap(paddr, sizeof(*data), + MEMREMAP_WB | MEMREMAP_DEC); + if (!data) { + pr_warn("failed to memremap setup_data entry\n"); + return false; + } + + paddr_next = data->next; + len = data->len; + + if ((phys_addr > paddr) && (phys_addr < (paddr + len))) { + memunmap(data); + return true; + } + + if (data->type == SETUP_INDIRECT) { + memunmap(data); + data = memremap(paddr, sizeof(*data) + len, + MEMREMAP_WB | MEMREMAP_DEC); + if (!data) { + pr_warn("failed to memremap indirect setup_data\n"); + return false; + } + + indirect = (struct setup_indirect *)data->data; + + if (indirect->type != SETUP_INDIRECT) { + paddr = indirect->addr; + len = indirect->len; + } + } + + memunmap(data); + + if ((phys_addr > paddr) && (phys_addr < (paddr + len))) + return true; + + paddr = paddr_next; + } + + return false; +} + +/* + * Examine the physical address to determine if it is boot data by checking + * it against the boot params setup_data chain (early boot version). + */ +static bool __init early_memremap_is_setup_data(resource_size_t phys_addr, + unsigned long size) +{ + struct setup_indirect *indirect; + struct setup_data *data; + u64 paddr, paddr_next; + + paddr = boot_params.hdr.setup_data; + while (paddr) { + unsigned int len, size; + + if (phys_addr == paddr) + return true; + + data = early_memremap_decrypted(paddr, sizeof(*data)); + if (!data) { + pr_warn("failed to early memremap setup_data entry\n"); + return false; + } + + size = sizeof(*data); + + paddr_next = data->next; + len = data->len; + + if ((phys_addr > paddr) && (phys_addr < (paddr + len))) { + early_memunmap(data, sizeof(*data)); + return true; + } + + if (data->type == SETUP_INDIRECT) { + size += len; + early_memunmap(data, sizeof(*data)); + data = early_memremap_decrypted(paddr, size); + if (!data) { + pr_warn("failed to early memremap indirect setup_data\n"); + return false; + } + + indirect = (struct setup_indirect *)data->data; + + if (indirect->type != SETUP_INDIRECT) { + paddr = indirect->addr; + len = indirect->len; + } + } + + early_memunmap(data, size); + + if ((phys_addr > paddr) && (phys_addr < (paddr + len))) + return true; + + paddr = paddr_next; + } + + return false; +} + +/* + * Architecture function to determine if RAM remap is allowed. By default, a + * RAM remap will map the data as encrypted. Determine if a RAM remap should + * not be done so that the data will be mapped decrypted. + */ +bool arch_memremap_can_ram_remap(resource_size_t phys_addr, unsigned long size, + unsigned long flags) +{ + if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT)) + return true; + + if (flags & MEMREMAP_ENC) + return true; + + if (flags & MEMREMAP_DEC) + return false; + + if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) { + if (memremap_is_setup_data(phys_addr, size) || + memremap_is_efi_data(phys_addr, size)) + return false; + } + + return !memremap_should_map_decrypted(phys_addr, size); +} + +/* + * Architecture override of __weak function to adjust the protection attributes + * used when remapping memory. By default, early_memremap() will map the data + * as encrypted. Determine if an encrypted mapping should not be done and set + * the appropriate protection attributes. + */ +pgprot_t __init early_memremap_pgprot_adjust(resource_size_t phys_addr, + unsigned long size, + pgprot_t prot) +{ + bool encrypted_prot; + + if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT)) + return prot; + + encrypted_prot = true; + + if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) { + if (early_memremap_is_setup_data(phys_addr, size) || + memremap_is_efi_data(phys_addr, size)) + encrypted_prot = false; + } + + if (encrypted_prot && memremap_should_map_decrypted(phys_addr, size)) + encrypted_prot = false; + + return encrypted_prot ? pgprot_encrypted(prot) + : pgprot_decrypted(prot); +} + +bool phys_mem_access_encrypted(unsigned long phys_addr, unsigned long size) +{ + return arch_memremap_can_ram_remap(phys_addr, size, 0); +} + +/* Remap memory with encryption */ +void __init *early_memremap_encrypted(resource_size_t phys_addr, + unsigned long size) +{ + return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_ENC); +} + +/* + * Remap memory with encryption and write-protected - cannot be called + * before pat_init() is called + */ +void __init *early_memremap_encrypted_wp(resource_size_t phys_addr, + unsigned long size) +{ + if (!x86_has_pat_wp()) + return NULL; + return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_ENC_WP); +} + +/* Remap memory without encryption */ +void __init *early_memremap_decrypted(resource_size_t phys_addr, + unsigned long size) +{ + return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_NOENC); +} + +/* + * Remap memory without encryption and write-protected - cannot be called + * before pat_init() is called + */ +void __init *early_memremap_decrypted_wp(resource_size_t phys_addr, + unsigned long size) +{ + if (!x86_has_pat_wp()) + return NULL; + return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_NOENC_WP); +} +#endif /* CONFIG_AMD_MEM_ENCRYPT */ + +static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)] __page_aligned_bss; + +static inline pmd_t * __init early_ioremap_pmd(unsigned long addr) +{ + /* Don't assume we're using swapper_pg_dir at this point */ + pgd_t *base = __va(read_cr3_pa()); + pgd_t *pgd = &base[pgd_index(addr)]; + p4d_t *p4d = p4d_offset(pgd, addr); + pud_t *pud = pud_offset(p4d, addr); + pmd_t *pmd = pmd_offset(pud, addr); + + return pmd; +} + +static inline pte_t * __init early_ioremap_pte(unsigned long addr) +{ + return &bm_pte[pte_index(addr)]; +} + +bool __init is_early_ioremap_ptep(pte_t *ptep) +{ + return ptep >= &bm_pte[0] && ptep < &bm_pte[PAGE_SIZE/sizeof(pte_t)]; +} + +void __init early_ioremap_init(void) +{ + pmd_t *pmd; + +#ifdef CONFIG_X86_64 + BUILD_BUG_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1)); +#else + WARN_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1)); +#endif + + early_ioremap_setup(); + + pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)); + memset(bm_pte, 0, sizeof(bm_pte)); + pmd_populate_kernel(&init_mm, pmd, bm_pte); + + /* + * The boot-ioremap range spans multiple pmds, for which + * we are not prepared: + */ +#define __FIXADDR_TOP (-PAGE_SIZE) + BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT) + != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT)); +#undef __FIXADDR_TOP + if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) { + WARN_ON(1); + printk(KERN_WARNING "pmd %p != %p\n", + pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))); + printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n", + fix_to_virt(FIX_BTMAP_BEGIN)); + printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_END): %08lx\n", + fix_to_virt(FIX_BTMAP_END)); + + printk(KERN_WARNING "FIX_BTMAP_END: %d\n", FIX_BTMAP_END); + printk(KERN_WARNING "FIX_BTMAP_BEGIN: %d\n", + FIX_BTMAP_BEGIN); + } +} + +void __init __early_set_fixmap(enum fixed_addresses idx, + phys_addr_t phys, pgprot_t flags) +{ + unsigned long addr = __fix_to_virt(idx); + pte_t *pte; + + if (idx >= __end_of_fixed_addresses) { + BUG(); + return; + } + pte = early_ioremap_pte(addr); + + /* Sanitize 'prot' against any unsupported bits: */ + pgprot_val(flags) &= __supported_pte_mask; + + if (pgprot_val(flags)) + set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags)); + else + pte_clear(&init_mm, addr, pte); + flush_tlb_one_kernel(addr); +} |