Commit 0b2859a7 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/fsl_booke: Allocate separate TLBCAMs for readonly memory 



Reorganise TLBCAM allocation so that when STRICT_KERNEL_RWX is
enabled, TLBCAMs are allocated such that readonly memory uses
different TLBCAMs.

This results in an allocation looking like:

Memory CAM mapping: 4/4/4/1/1/1/1/16/16/16/64/64/64/256/256 Mb, residual: 256Mb

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/8ca169bc288261a0e0558712f979023c3a960ebb.1634292136.git.christophe.leroy@csgroup.eu
parent 52bda69a

arch/powerpc/mm/nohash/fsl_book3e.c

+22 −3
Original line number Diff line number Diff line
@@ -171,15 +171,34 @@ static unsigned long map_mem_in_cams_addr(phys_addr_t phys, unsigned long virt, 
{

	int i;

	unsigned long amount_mapped = 0;

	unsigned long boundary;



	if (strict_kernel_rwx_enabled())

		boundary = (unsigned long)(_sinittext - _stext);

	else

		boundary = ram;



	/* Calculate CAM values */

	for (i = 0; ram && i < max_cam_idx; i++) {

	for (i = 0; boundary && i < max_cam_idx; i++) {

		unsigned long cam_sz;

		pgprot_t prot = PAGE_KERNEL_X;



		cam_sz = calc_cam_sz(boundary, virt, phys);

		if (!dryrun)

			settlbcam(i, virt, phys, cam_sz, pgprot_val(prot), 0);



		boundary -= cam_sz;

		amount_mapped += cam_sz;

		virt += cam_sz;

		phys += cam_sz;

	}

	for (ram -= amount_mapped; ram && i < max_cam_idx; i++) {

		unsigned long cam_sz;

		pgprot_t prot = PAGE_KERNEL_X;



		cam_sz = calc_cam_sz(ram, virt, phys);

		if (!dryrun)

			settlbcam(i, virt, phys, cam_sz,

				  pgprot_val(PAGE_KERNEL_X), 0);

			settlbcam(i, virt, phys, cam_sz, pgprot_val(prot), 0);



		ram -= cam_sz;

		amount_mapped += cam_sz;