From 483e09a223c666269ef81d3573a6591b1046b0ef Mon Sep 17 00:00:00 2001
From: Stefan Roese <sr@denx.de>
Date: Wed, 31 Oct 2007 17:59:22 +0100
Subject: [PATCH] ppc4xx: Add change_tlb function to modify I attribute of
TLB(s)
This function is used to either turn cache on or off in a specific
memory area.
Signed-off-by: Stefan Roese <sr@denx.de>
---
cpu/ppc4xx/tlb.c | 88 ++++++++++++++++++++++++++++++++++++++++++-
include/asm-ppc/mmu.h | 1 +
2 files changed, 88 insertions(+), 1 deletion(-)
diff --git a/cpu/ppc4xx/tlb.c b/cpu/ppc4xx/tlb.c
index 098694caf49..ed493f1a710 100644
--- a/cpu/ppc4xx/tlb.c
+++ b/cpu/ppc4xx/tlb.c
@@ -26,6 +26,7 @@
#if defined(CONFIG_440)
#include <ppc440.h>
+#include <asm/cache.h>
#include <asm/io.h>
#include <asm/mmu.h>
@@ -42,7 +43,6 @@ void remove_tlb(u32 vaddr, u32 size)
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);
@@ -96,6 +96,92 @@ void remove_tlb(u32 vaddr, u32 size)
asm("isync");
}
+/*
+ * Change the I attribute (cache inhibited) of a TLB or multiple TLB's.
+ * This function is used to either turn cache on or off in a specific
+ * memory area.
+ */
+void change_tlb(u32 vaddr, u32 size, u32 tlb_word2_i_value)
+{
+ int i;
+ u32 tlb_word0_value;
+ u32 tlb_word2_value;
+ u32 tlb_vaddr;
+ u32 tlb_size = 0;
+
+ 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.
+ * Change cache attribute in tlb2 word.
+ */
+ tlb_word2_value =
+ TLB_WORD2_U0_DISABLE | TLB_WORD2_U1_DISABLE |
+ TLB_WORD2_U2_DISABLE | TLB_WORD2_U3_DISABLE |
+ TLB_WORD2_W_DISABLE | tlb_word2_i_value |
+ TLB_WORD2_M_DISABLE | TLB_WORD2_G_DISABLE |
+ TLB_WORD2_E_DISABLE | TLB_WORD2_UX_ENABLE |
+ TLB_WORD2_UW_ENABLE | TLB_WORD2_UR_ENABLE |
+ TLB_WORD2_SX_ENABLE | TLB_WORD2_SW_ENABLE |
+ TLB_WORD2_SR_ENABLE;
+
+ /*
+ * Now either flush or invalidate the dcache
+ */
+ if (tlb_word2_i_value)
+ flush_dcache();
+ else
+ invalidate_dcache();
+
+ mttlb3(i, tlb_word2_value);
+ asm("iccci 0,0");
+ }
+ }
+ }
+
+ /* 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,
diff --git a/include/asm-ppc/mmu.h b/include/asm-ppc/mmu.h
index b3cfa9b3726..edcb3b9ca37 100644
--- a/include/asm-ppc/mmu.h
+++ b/include/asm-ppc/mmu.h
@@ -648,6 +648,7 @@ unsigned long mftlb3(unsigned long index);
void program_tlb(u32 phys_addr, u32 virt_addr, u32 size, u32 tlb_word2_i_value);
void remove_tlb(u32 vaddr, u32 size);
+void change_tlb(u32 vaddr, u32 size, u32 tlb_word2_i_value);
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_440 */
--
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