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powerpc/fsl_booke: Allocate separate TLBCAMs for readonly memory

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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: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/8ca169bc288261a0e0558712f979023c3a960ebb.1634292136.git.christophe.leroy@csgroup.eu
This commit is contained in:
Christophe Leroy 2021-10-15 12:02:47 +02:00 committed by Michael Ellerman
parent 52bda69ae8
commit 0b2859a743
1 changed files with 22 additions and 3 deletions
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25
arch/powerpc/mm/nohash/fsl_book3e.c
View file

@ -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;