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authorLinus Torvalds <torvalds@linux-foundation.org>2015-02-11 18:03:54 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-02-11 18:03:54 -0800
commit6b00f7efb5303418c231994c91fb8239f5ada260 (patch)
tree1daba87ccda34e632ea39dedc5055391c7e94bdc /drivers/firmware/efi/libstub/arm-stub.c
parentb3d6524ff7956c5a898d51a18eaecb62a60a2b84 (diff)
parentd476d94f180af3f0fca77394651d4a98f4df1c54 (diff)
Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Catalin Marinas: "arm64 updates for 3.20: - reimplementation of the virtual remapping of UEFI Runtime Services in a way that is stable across kexec - emulation of the "setend" instruction for 32-bit tasks (user endianness switching trapped in the kernel, SCTLR_EL1.E0E bit set accordingly) - compat_sys_call_table implemented in C (from asm) and made it a constant array together with sys_call_table - export CPU cache information via /sys (like other architectures) - DMA API implementation clean-up in preparation for IOMMU support - macros clean-up for KVM - dropped some unnecessary cache+tlb maintenance - CONFIG_ARM64_CPU_SUSPEND clean-up - defconfig update (CPU_IDLE) The EFI changes going via the arm64 tree have been acked by Matt Fleming. There is also a patch adding sys_*stat64 prototypes to include/linux/syscalls.h, acked by Andrew Morton" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (47 commits) arm64: compat: Remove incorrect comment in compat_siginfo arm64: Fix section mismatch on alloc_init_p[mu]d() arm64: Avoid breakage caused by .altmacro in fpsimd save/restore macros arm64: mm: use *_sect to check for section maps arm64: drop unnecessary cache+tlb maintenance arm64:mm: free the useless initial page table arm64: Enable CPU_IDLE in defconfig arm64: kernel: remove ARM64_CPU_SUSPEND config option arm64: make sys_call_table const arm64: Remove asm/syscalls.h arm64: Implement the compat_sys_call_table in C syscalls: Declare sys_*stat64 prototypes if __ARCH_WANT_(COMPAT_)STAT64 compat: Declare compat_sys_sigpending and compat_sys_sigprocmask prototypes arm64: uapi: expose our struct ucontext to the uapi headers smp, ARM64: Kill SMP single function call interrupt arm64: Emulate SETEND for AArch32 tasks arm64: Consolidate hotplug notifier for instruction emulation arm64: Track system support for mixed endian EL0 arm64: implement generic IOMMU configuration arm64: Combine coherent and non-coherent swiotlb dma_ops ...
Diffstat (limited to 'drivers/firmware/efi/libstub/arm-stub.c')
-rw-r--r--drivers/firmware/efi/libstub/arm-stub.c59
1 files changed, 59 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c
index 2b3814702dcf..dcae482a9a17 100644
--- a/drivers/firmware/efi/libstub/arm-stub.c
+++ b/drivers/firmware/efi/libstub/arm-stub.c
@@ -295,3 +295,62 @@ fail_free_image:
fail:
return EFI_ERROR;
}
+
+/*
+ * This is the base address at which to start allocating virtual memory ranges
+ * for UEFI Runtime Services. This is in the low TTBR0 range so that we can use
+ * any allocation we choose, and eliminate the risk of a conflict after kexec.
+ * The value chosen is the largest non-zero power of 2 suitable for this purpose
+ * both on 32-bit and 64-bit ARM CPUs, to maximize the likelihood that it can
+ * be mapped efficiently.
+ */
+#define EFI_RT_VIRTUAL_BASE 0x40000000
+
+/*
+ * efi_get_virtmap() - create a virtual mapping for the EFI memory map
+ *
+ * This function populates the virt_addr fields of all memory region descriptors
+ * in @memory_map whose EFI_MEMORY_RUNTIME attribute is set. Those descriptors
+ * are also copied to @runtime_map, and their total count is returned in @count.
+ */
+void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
+ unsigned long desc_size, efi_memory_desc_t *runtime_map,
+ int *count)
+{
+ u64 efi_virt_base = EFI_RT_VIRTUAL_BASE;
+ efi_memory_desc_t *out = runtime_map;
+ int l;
+
+ for (l = 0; l < map_size; l += desc_size) {
+ efi_memory_desc_t *in = (void *)memory_map + l;
+ u64 paddr, size;
+
+ if (!(in->attribute & EFI_MEMORY_RUNTIME))
+ continue;
+
+ /*
+ * Make the mapping compatible with 64k pages: this allows
+ * a 4k page size kernel to kexec a 64k page size kernel and
+ * vice versa.
+ */
+ paddr = round_down(in->phys_addr, SZ_64K);
+ size = round_up(in->num_pages * EFI_PAGE_SIZE +
+ in->phys_addr - paddr, SZ_64K);
+
+ /*
+ * Avoid wasting memory on PTEs by choosing a virtual base that
+ * is compatible with section mappings if this region has the
+ * appropriate size and physical alignment. (Sections are 2 MB
+ * on 4k granule kernels)
+ */
+ if (IS_ALIGNED(in->phys_addr, SZ_2M) && size >= SZ_2M)
+ efi_virt_base = round_up(efi_virt_base, SZ_2M);
+
+ in->virt_addr = efi_virt_base + in->phys_addr - paddr;
+ efi_virt_base += size;
+
+ memcpy(out, in, desc_size);
+ out = (void *)out + desc_size;
+ ++*count;
+ }
+}