This patch essentially changes the sense of CONFIG_LOWMEM_CAM_NUM
so that all available TLB1 CAM entries can be used for mapping lowmem
unless the user specifies a specific number through CONFIG_LOWMEM_CAM_NUM.
This greatly simplifies using CONFIG_LOWMEM_SIZE with high granularity.
Signed-off-by: Aaron Sierra <[email protected]>
---
arch/powerpc/mm/fsl_booke_mmu.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/arch/powerpc/mm/fsl_booke_mmu.c b/arch/powerpc/mm/fsl_booke_mmu.c
index 92685d8..44378ac 100644
--- a/arch/powerpc/mm/fsl_booke_mmu.c
+++ b/arch/powerpc/mm/fsl_booke_mmu.c
@@ -178,6 +178,14 @@ unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx)
phys_addr_t phys = memstart_addr;
unsigned long amount_mapped = 0;
+ /*
+ * Allow finer resolution for user defined CONFIG_LOWMEM_SIZE by
+ * allowing all TLB1 entries to be utilized if the user doesn't define
+ * a specific max_cam_idx value via CONFIG_LOWMEM_CAM_NUM.
+ */
+ if (!max_cam_idx)
+ max_cam_idx = mfspr(SPRN_TLB1CFG) & 0xfff;
+
/* Calculate CAM values */
for (i = 0; ram && i < max_cam_idx; i++) {
unsigned long cam_sz;
@@ -222,7 +230,11 @@ void __init adjust_total_lowmem(void)
/* adjust lowmem size to __max_low_memory */
ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
+#ifdef CONFIG_LOWMEM_CAM_NUM_BOOL
__max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM);
+#else
+ __max_low_memory = map_mem_in_cams(ram, 0);
+#endif
pr_info("Memory CAM mapping: ");
for (i = 0; i < tlbcam_index - 1; i++)
--
1.7.9.5