Commit ea8c2e11 authored by Catalin Marinas's avatar Catalin Marinas
Browse files

arm64: Extend the idmap to the whole kernel image 



This patch changes the idmap page table creation during boot to cover
the whole kernel image, allowing functions like cpu_reset() to be safely
called with the physical address.

This patch also simplifies the create_block_map asm macro to no longer
take an idmap argument and always use the phys/virt/end parameters. For
the idmap case, phys == virt.

Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 020c1427

arch/arm64/kernel/head.S

+8 −12
Original line number Diff line number Diff line
@@ -384,26 +384,18 @@ ENDPROC(__calc_phys_offset) 
 * Preserves:	tbl, flags

 * Corrupts:	phys, start, end, pstate

 */

	.macro	create_block_map, tbl, flags, phys, start, end, idmap=0

	.macro	create_block_map, tbl, flags, phys, start, end

	lsr	\phys, \phys, #BLOCK_SHIFT

	.if	\idmap

	and	\start, \phys, #PTRS_PER_PTE - 1	// table index

	.else

	lsr	\start, \start, #BLOCK_SHIFT

	and	\start, \start, #PTRS_PER_PTE - 1	// table index

	.endif

	orr	\phys, \flags, \phys, lsl #BLOCK_SHIFT	// table entry

	.ifnc	\start,\end

	lsr	\end, \end, #BLOCK_SHIFT

	and	\end, \end, #PTRS_PER_PTE - 1		// table end index

	.endif

9999:	str	\phys, [\tbl, \start, lsl #3]		// store the entry

	.ifnc	\start,\end

	add	\start, \start, #1			// next entry

	add	\phys, \phys, #BLOCK_SIZE		// next block

	cmp	\start, \end

	b.ls	9999b

	.endif

	.endm



/*
@@ -435,9 +427,13 @@ __create_page_tables: 
	 * Create the identity mapping.

	 */

	add	x0, x25, #PAGE_SIZE		// section table address

	adr	x3, __turn_mmu_on		// virtual/physical address

	ldr	x3, =KERNEL_START

	add	x3, x3, x28			// __pa(KERNEL_START)

	create_pgd_entry x25, x0, x3, x5, x6

	create_block_map x0, x7, x3, x5, x5, idmap=1

	ldr	x6, =KERNEL_END

	mov	x5, x3				// __pa(KERNEL_START)

	add	x6, x6, x28			// __pa(KERNEL_END)

	create_block_map x0, x7, x3, x5, x6



	/*

	 * Map the kernel image (starting with PHYS_OFFSET).
@@ -445,7 +441,7 @@ __create_page_tables: 
	add	x0, x26, #PAGE_SIZE		// section table address

	mov	x5, #PAGE_OFFSET

	create_pgd_entry x26, x0, x5, x3, x6

	ldr	x6, =KERNEL_END - 1

	ldr	x6, =KERNEL_END

	mov	x3, x24				// phys offset

	create_block_map x0, x7, x3, x5, x6

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