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>
diff --git a/cpu/ppc4xx/tlb.c b/cpu/ppc4xx/tlb.c
index 049a785..098694c 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 @@
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,