linux/arch/microblaze
Michal Simek e02db0aa3e microblaze: Handle TLB skip size dynamically
This patch fix the problem with rootfs on JFFS2 with early printk
console turned on.

The origin version used TLB63 for temporary early printk mapping.
The code expect that kernel is not able to use all 64 TLB entries
till early printk console is remapped by ioremap. After that
temporary mapping on TLB63 is silently lost.
This expectation give the opportunity to have early console pretty
early.

Microblaze systems with JFFS2 rootfs with early printk console turned on
used more than 64 TLB entries before kernel can remap early console.
Based on that kernel does access to bad area because early printk mapping
is rewritten.

This patch introduces tlb_skip variable which dynamically stores number
of skipped TLB entries from the TLB0. skip_tlb=2 means that TLB0 and TLB1
should be skipped.

MICROBLAZE_TLB_SKIP defines how many TLB is skipped at the kernel start.
They can be used for user purpose.

TLB 63 is used for temporary LMB mapping (MICROBLAZE_LMB_TLB_ID).

Also clean TLBLO when kernel starts.

For specific kernel sizes kernel can use just one TLB. Detect this case
and use the second TLB for general purpose.

Change _tlbia function to flush TLB entries from tlb_skip to TLB_SIZE.

Export tlb_skip size through debugfs.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2012-03-23 09:28:19 +01:00
..
boot microblaze: Fix makefile to work with latest toolchain 2012-03-19 07:30:26 +01:00
configs kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT 2011-01-20 17:02:05 -08:00
include/asm microblaze: Handle TLB skip size dynamically 2012-03-23 09:28:19 +01:00
kernel microblaze: Handle TLB skip size dynamically 2012-03-23 09:28:19 +01:00
lib microblaze: Add __cmpdi2 2012-01-05 08:22:01 +01:00
mm microblaze: Improve TLB calculation for small systems 2012-03-23 09:28:18 +01:00
oprofile microblaze: Core oprofile configs and hooks 2009-12-14 08:45:07 +01:00
pci Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci 2012-01-11 18:50:26 -08:00
platform Fix common misspellings 2011-03-31 11:26:23 -03:00
Kconfig microblaze: Improve TLB calculation for small systems 2012-03-23 09:28:18 +01:00
Kconfig.debug microblaze: remove obsolete DEBUG_BOOTMEM 2011-01-10 09:29:51 +01:00
Makefile Fix common misspellings 2011-03-31 11:26:23 -03:00