openrisc: fix up vmalloc page table loading
vmalloc'ed pages are faulted into a process' page tables on demand. In
order to facilitate this, do_page_fault needs to know whether it was
called via a page fault exception or a TLB-miss exception.
This patch adds a wrapper around the _x_page_fault_handler entry points
that the TLB-miss exceptions can call into in order to have the relevant
parameter set to satisfy do_page_fault.
This fixes a bug and is "good enough" for now. That said, this whole
handling of vmalloc needs to be audited for correctness at some point.
Signed-off-by: Jonas Bonn <jonas@southpole.se>
diff --git a/arch/openrisc/kernel/entry.S b/arch/openrisc/kernel/entry.S
index 5e5b306..3de9712 100644
--- a/arch/openrisc/kernel/entry.S
+++ b/arch/openrisc/kernel/entry.S
@@ -201,12 +201,17 @@
l.nop
/* ---[ 0x300: Data Page Fault exception ]------------------------------- */
+EXCEPTION_ENTRY(_dtlb_miss_page_fault_handler)
+ l.and r5,r5,r0
+ l.j 1f
+ l.nop
EXCEPTION_ENTRY(_data_page_fault_handler)
/* set up parameters for do_page_fault */
+ l.ori r5,r0,0x300 // exception vector
+1:
l.addi r3,r1,0 // pt_regs
/* r4 set be EXCEPTION_HANDLE */ // effective address of fault
- l.ori r5,r0,0x300 // exception vector
/*
* __PHX__: TODO
@@ -276,12 +281,17 @@
l.nop
/* ---[ 0x400: Insn Page Fault exception ]------------------------------- */
+EXCEPTION_ENTRY(_itlb_miss_page_fault_handler)
+ l.and r5,r5,r0
+ l.j 1f
+ l.nop
EXCEPTION_ENTRY(_insn_page_fault_handler)
/* set up parameters for do_page_fault */
+ l.ori r5,r0,0x400 // exception vector
+1:
l.addi r3,r1,0 // pt_regs
/* r4 set be EXCEPTION_HANDLE */ // effective address of fault
- l.ori r5,r0,0x400 // exception vector
l.ori r6,r0,0x0 // !write access
/* call fault.c handler in or32/mm/fault.c */