diff options
| author | Stefan Roese <sr@denx.de> | 2007-07-16 08:53:51 +0200 |
|---|---|---|
| committer | Stefan Roese <sr@denx.de> | 2007-07-16 08:53:51 +0200 |
| commit | 5743a9207a370b90f09b20ebd61167c806b937f3 (patch) | |
| tree | f8a56a22a08648873f5b255084f00d7083dcef83 /cpu/ppc4xx/tlb.c | |
| parent | a2e1c7098cf9574386b0c96841dfc8ea5cc93578 (diff) | |
ppc4xx: Add remove_tlb() function to remove a mem area from TLB setup
The new function remove_tlb() can be used to remove the TLB's used to
map a specific memory region. This is especially useful for the DDR(2)
setup routines which configure the SDRAM area temporarily as a cached
area (for speedup on auto-calibration and ECC generation) and later
need this area uncached for normal usage.
Signed-off-by: Stefan Roese <sr@denx.de>
Diffstat (limited to 'cpu/ppc4xx/tlb.c')
| -rw-r--r-- | cpu/ppc4xx/tlb.c | 62 |
1 files changed, 61 insertions, 1 deletions
diff --git a/cpu/ppc4xx/tlb.c b/cpu/ppc4xx/tlb.c index 049a785495..098694caf4 100644 --- a/cpu/ppc4xx/tlb.c +++ b/cpu/ppc4xx/tlb.c @@ -25,7 +25,6 @@ #if defined(CONFIG_440) -#include <ppc4xx.h> #include <ppc440.h> #include <asm/io.h> #include <asm/mmu.h> @@ -36,6 +35,67 @@ typedef struct region { unsigned long tlb_word2_i_value; } region_t; +void remove_tlb(u32 vaddr, u32 size) +{ + int i; + u32 tlb_word0_value; + u32 tlb_vaddr; + u32 tlb_size = 0; + + /* First, find the index of a TLB entry not being used */ + for (i=0; i<PPC4XX_TLB_SIZE; i++) { + tlb_word0_value = mftlb1(i); + tlb_vaddr = TLB_WORD0_EPN_DECODE(tlb_word0_value); + if (((tlb_word0_value & TLB_WORD0_V_MASK) == TLB_WORD0_V_ENABLE) && + (tlb_vaddr >= vaddr)) { + /* + * TLB is enabled and start address is lower or equal + * than the area we are looking for. Now we only have + * to check the size/end address for a match. + */ + switch (tlb_word0_value & TLB_WORD0_SIZE_MASK) { + case TLB_WORD0_SIZE_1KB: + tlb_size = 1 << 10; + break; + case TLB_WORD0_SIZE_4KB: + tlb_size = 4 << 10; + break; + case TLB_WORD0_SIZE_16KB: + tlb_size = 16 << 10; + break; + case TLB_WORD0_SIZE_64KB: + tlb_size = 64 << 10; + break; + case TLB_WORD0_SIZE_256KB: + tlb_size = 256 << 10; + break; + case TLB_WORD0_SIZE_1MB: + tlb_size = 1 << 20; + break; + case TLB_WORD0_SIZE_16MB: + tlb_size = 16 << 20; + break; + case TLB_WORD0_SIZE_256MB: + tlb_size = 256 << 20; + break; + } + + /* + * Now check the end-address if it's in the range + */ + if ((tlb_vaddr + tlb_size - 1) <= (vaddr + size - 1)) + /* + * Found a TLB in the range. + * Disable it by writing 0 to tlb0 word. + */ + mttlb1(i, 0); + } + } + + /* Execute an ISYNC instruction so that the new TLB entry takes effect */ + asm("isync"); +} + static int add_tlb_entry(unsigned long phys_addr, unsigned long virt_addr, unsigned long tlb_word0_size_value, |