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Commit a81252d7 authored by Jonas Bonn's avatar Jonas Bonn
Browse files

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: default avatarJonas Bonn <jonas@southpole.se>
parent 7f81ea7e

arch/openrisc/kernel/entry.S

+12 −2
Original line number Diff line number Diff line
@@ -201,12 +201,17 @@ EXCEPTION_ENTRY(_bus_fault_handler) 
	 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 @@ EXCEPTION_ENTRY(_data_page_fault_handler) 
	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 */

arch/openrisc/kernel/head.S

+2 −4
Original line number Diff line number Diff line
@@ -1069,8 +1069,7 @@ d_pte_not_present: 
	EXCEPTION_LOAD_GPR4

	EXCEPTION_LOAD_GPR5

	EXCEPTION_LOAD_GPR6

	l.j	_dispatch_do_dpage_fault

	l.nop

	EXCEPTION_HANDLE(_dtlb_miss_page_fault_handler)



/* ==============================================[ ITLB miss handler ]=== */

ENTRY(itlb_miss_handler)
@@ -1192,8 +1191,7 @@ i_pte_not_present: 
	EXCEPTION_LOAD_GPR4

	EXCEPTION_LOAD_GPR5

	EXCEPTION_LOAD_GPR6

	l.j	_dispatch_do_ipage_fault

	l.nop

	EXCEPTION_HANDLE(_itlb_miss_page_fault_handler)



/* ==============================================[ boot tlb handlers ]=== */