Commit a3ae565a authored Apr 27, 2015 by James Hogan Committed by Ralf Baechle Jun 21, 2015

MIPS: tlbex: Fix broken offsets on r2 without XPA



Commit c5b36783 ("MIPS: Add support for XPA.") changed
build_pte_present() and build_pte_writable() to assume a constant offset
of _PAGE_READ and _PAGE_WRITE relative to _PAGE_PRESENT, however this is
no longer true for some MIPS32R2 builds since commit be0c37c9
("MIPS: Rearrange PTE bits into fixed positions.") which moved the
_PAGE_READ PTE bit away from the _PAGE_PRESENT bit, with the _PAGE_WRITE
bit falling into its place.

Make use of the _PAGE_READ and _PAGE_WRITE definitions to calculate the
correct mask to apply instead of hard coding 3 (for _PAGE_PRESENT |
_PAGE_READ) or 5 (for _PAGE_PRESENT | _PAGE_WRITE).

Fixes: c5b36783 ("MIPS: Add support for XPA.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9888/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

parent 8e748c8d

arch/mips/mm/tlbex.c

+8 −4

Original line number	Diff line number	Diff line
		@@ -1623,8 +1623,10 @@ build_pte_present(u32 p, struct uasm_reloc r,
		}
		} else {
		uasm_i_srl(p, t, pte, _PAGE_PRESENT_SHIFT);
		uasm_i_andi(p, t, t, 3);
		uasm_i_xori(p, t, t, 3);
		uasm_i_andi(p, t, t,
		(_PAGE_PRESENT \| _PAGE_READ) >> _PAGE_PRESENT_SHIFT);
		uasm_i_xori(p, t, t,
		(_PAGE_PRESENT \| _PAGE_READ) >> _PAGE_PRESENT_SHIFT);
		uasm_il_bnez(p, r, t, lid);
		if (pte == t)
		/* You lose the SMP race :-(*/
		@@ -1654,8 +1656,10 @@ build_pte_writable(u32 p, struct uasm_reloc r,
		int t = scratch >= 0 ? scratch : pte;

		uasm_i_srl(p, t, pte, _PAGE_PRESENT_SHIFT);
		uasm_i_andi(p, t, t, 5);
		uasm_i_xori(p, t, t, 5);
		uasm_i_andi(p, t, t,
		(_PAGE_PRESENT \| _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT);
		uasm_i_xori(p, t, t,
		(_PAGE_PRESENT \| _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT);
		uasm_il_bnez(p, r, t, lid);
		if (pte == t)
		/* You lose the SMP race :-(*/