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authorStefan Roese <sr@denx.de>2007-11-20 21:19:16 +1100
committerJosh Boyer <jwboyer@linux.vnet.ibm.com>2007-12-23 13:31:16 -0600
commitf4151b9ba87901eb3a7bc49f418cc352d4e1927e (patch)
tree7481891935cea47d7794e583a6fdfe530575c17d
parent4922566f0394ac41c72fb960f22b4f84333026bc (diff)
[POWERPC] 4xx: Fix TLB 0 problem with CONFIG_SERIAL_TEXT_DEBUG
Right now TLB entry 0 ist used as UART0 mapping for the early debug output (via CONFIG_SERIAL_TEXT_DEBUG). This causes problems when many TLB's get used upon Linux bootup (e.g. while PCIe scanning behind bridges and/or switches on 440SPe platforms). This will overwrite the TLB 0 entry and further debug output's may crash/hang the system. This patch moves the early debug UART0 TLB entry from 0 to 62 as done in arch/powerpc. This way it is in the "pinned" area and will not get overwritten. Also the arch/ppc/mm/44x_mmu.c code is now synced with the newer code from arch/powerpc. Signed-off-by: Stefan Roese <sr@denx.de> Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
-rw-r--r--arch/ppc/kernel/head_44x.S2
-rw-r--r--arch/ppc/mm/44x_mmu.c51
-rw-r--r--include/asm-ppc/mmu.h6
3 files changed, 23 insertions, 36 deletions
diff --git a/arch/ppc/kernel/head_44x.S b/arch/ppc/kernel/head_44x.S
index 75bbc937ed7..ebb5a403829 100644
--- a/arch/ppc/kernel/head_44x.S
+++ b/arch/ppc/kernel/head_44x.S
@@ -195,7 +195,7 @@ skpinv: addi r4,r4,1 /* Increment */
li r5,0
ori r5,r5,(PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_I | PPC44x_TLB_G)
- li r0,0 /* TLB slot 0 */
+ li r0,62 /* TLB slot 62 */
tlbwe r3,r0,PPC44x_TLB_PAGEID /* Load the pageid fields */
tlbwe r4,r0,PPC44x_TLB_XLAT /* Load the translation fields */
diff --git a/arch/ppc/mm/44x_mmu.c b/arch/ppc/mm/44x_mmu.c
index 6536a25cfcb..fbb577a0d16 100644
--- a/arch/ppc/mm/44x_mmu.c
+++ b/arch/ppc/mm/44x_mmu.c
@@ -60,38 +60,28 @@ extern char etext[], _stext[];
* Just needed it declared someplace.
*/
unsigned int tlb_44x_index = 0;
-unsigned int tlb_44x_hwater = 62;
+unsigned int tlb_44x_hwater = PPC4XX_TLB_SIZE - 1 - PPC44x_EARLY_TLBS;
int icache_44x_need_flush;
/*
* "Pins" a 256MB TLB entry in AS0 for kernel lowmem
*/
-static void __init
-ppc44x_pin_tlb(int slot, unsigned int virt, unsigned int phys)
+static void __init ppc44x_pin_tlb(unsigned int virt, unsigned int phys)
{
- unsigned long attrib = 0;
-
- __asm__ __volatile__("\
- clrrwi %2,%2,10\n\
- ori %2,%2,%4\n\
- clrrwi %1,%1,10\n\
- li %0,0\n\
- ori %0,%0,%5\n\
- tlbwe %2,%3,%6\n\
- tlbwe %1,%3,%7\n\
- tlbwe %0,%3,%8"
+ __asm__ __volatile__(
+ "tlbwe %2,%3,%4\n"
+ "tlbwe %1,%3,%5\n"
+ "tlbwe %0,%3,%6\n"
:
- : "r" (attrib), "r" (phys), "r" (virt), "r" (slot),
- "i" (PPC44x_TLB_VALID | PPC44x_TLB_256M),
- "i" (PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G),
+ : "r" (PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G),
+ "r" (phys),
+ "r" (virt | PPC44x_TLB_VALID | PPC44x_TLB_256M),
+ "r" (tlb_44x_hwater--), /* slot for this TLB entry */
"i" (PPC44x_TLB_PAGEID),
"i" (PPC44x_TLB_XLAT),
"i" (PPC44x_TLB_ATTRIB));
}
-/*
- * MMU_init_hw does the chip-specific initialization of the MMU hardware.
- */
void __init MMU_init_hw(void)
{
flush_instruction_cache();
@@ -99,22 +89,13 @@ void __init MMU_init_hw(void)
unsigned long __init mmu_mapin_ram(void)
{
- unsigned int pinned_tlbs = 1;
- int i;
-
- /* Determine number of entries necessary to cover lowmem */
- pinned_tlbs = (unsigned int)
- (_ALIGN(total_lowmem, PPC_PIN_SIZE) >> PPC44x_PIN_SHIFT);
-
- /* Write upper watermark to save location */
- tlb_44x_hwater = PPC44x_LOW_SLOT - pinned_tlbs;
+ unsigned long addr;
- /* If necessary, set additional pinned TLBs */
- if (pinned_tlbs > 1)
- for (i = (PPC44x_LOW_SLOT-(pinned_tlbs-1)); i < PPC44x_LOW_SLOT; i++) {
- unsigned int phys_addr = (PPC44x_LOW_SLOT-i) * PPC_PIN_SIZE;
- ppc44x_pin_tlb(i, phys_addr+PAGE_OFFSET, phys_addr);
- }
+ /* Pin in enough TLBs to cover any lowmem not covered by the
+ * initial 256M mapping established in head_44x.S */
+ for (addr = PPC_PIN_SIZE; addr < total_lowmem;
+ addr += PPC_PIN_SIZE)
+ ppc44x_pin_tlb(addr + PAGE_OFFSET, addr);
return total_lowmem;
}
diff --git a/include/asm-ppc/mmu.h b/include/asm-ppc/mmu.h
index 14584e505ed..d46b57b589a 100644
--- a/include/asm-ppc/mmu.h
+++ b/include/asm-ppc/mmu.h
@@ -383,6 +383,12 @@ typedef struct _P601_BAT {
#define BOOKE_PAGESZ_256GB 14
#define BOOKE_PAGESZ_1TB 15
+#ifndef CONFIG_SERIAL_TEXT_DEBUG
+#define PPC44x_EARLY_TLBS 1
+#else
+#define PPC44x_EARLY_TLBS 2
+#endif
+
/*
* Freescale Book-E MMU support
*/