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[PARISC] Make sure use of RFI conforms to PA 2.0 and 1.1 arch docs

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2.6.12-rc4-pa3 : first pass at making sure use of RFI conforms to
PA 2.0 arch pages F-4 and F-5, PA 1.1 Arch page 3-19 and 3-20.

The discussion revolves around all the rules for clearing PSW Q-bit.
The hard part is meeting all the rules for "relied upon translation".

.align directive is used to guarantee the critical sequence ends more than
8 instructions (32 bytes) from the end of page.

Signed-off-by: Grant Grundler <grundler@parisc-linux.org>

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
This commit is contained in:
Grant Grundler
2005-10-21 22:40:07 -04:00
committed by Kyle McMartin
parent b2c1fe81df
commit 896a375623
7 changed files with 154 additions and 168 deletions
Download Patch File Download Diff File Expand all files Collapse all files
arch/parisc/kernel/entry.S
+24 -27
View File
@@ -30,9 +30,9 @@
* - save registers to kernel stack and handle in assembly or C */
#include <asm/psw.h>
#include <asm/assembly.h> /* for LDREG/STREG defines */
#include <asm/pgtable.h>
#include <asm/psw.h>
#include <asm/signal.h>
#include <asm/unistd.h>
#include <asm/thread_info.h>
@@ -67,19 +67,22 @@
/* Switch to virtual mapping, trashing only %r1 */
.macro virt_map
rsm PSW_SM_Q,%r0
tovirt_r1 %r29
mfsp %sr7, %r1
or,= %r0,%r1,%r0 /* Only save sr7 in sr3 if sr7 != 0 */
mtsp %r1, %sr3
/* pcxt_ssm_bug */
rsm PSW_SM_I, %r0 /* barrier for "Relied upon Translation */
mtsp %r0, %sr4
mtsp %r0, %sr5
mfsp %sr7, %r1
or,= %r0,%r1,%r0 /* Only save sr7 in sr3 if sr7 != 0 */
mtsp %r1, %sr3
tovirt_r1 %r29
load32 KERNEL_PSW, %r1
rsm PSW_SM_QUIET,%r0 /* second "heavy weight" ctl op */
mtsp %r0, %sr6
mtsp %r0, %sr7
load32 KERNEL_PSW, %r1
mtctl %r1, %cr22
mtctl %r0, %cr17 /* Clear IIASQ tail */
mtctl %r0, %cr17 /* Clear IIASQ head */
mtctl %r1, %ipsw
load32 4f, %r1
mtctl %r1, %cr18 /* Set IIAOQ tail */
ldo 4(%r1), %r1
@@ -888,9 +891,6 @@ _switch_to_ret:
* this way, then we will need to copy %sr3 in to PT_SR[3..7], and
* adjust IASQ[0..1].
*
* Note that the following code uses a "relied upon translation".
* See the parisc ACD for details. The ssm is necessary due to a
* PCXT bug.
*/
.align 4096
@@ -985,24 +985,19 @@ intr_restore:
rest_fp %r1
rest_general %r29
/* Create a "relied upon translation" PA 2.0 Arch. F-5 */
ssm 0,%r0
nop
nop
nop
nop
nop
nop
nop
/* inverse of virt_map */
pcxt_ssm_bug
rsm PSW_SM_QUIET,%r0 /* prepare for rfi */
tophys_r1 %r29
rsm (PSW_SM_Q|PSW_SM_P|PSW_SM_D|PSW_SM_I),%r0
/* Restore space id's and special cr's from PT_REGS
* structure pointed to by r29 */
* structure pointed to by r29
*/
rest_specials %r29
/* Important: Note that rest_stack restores r29
* last (we are using it)! It also restores r1 and r30. */
/* IMPORTANT: rest_stack restores r29 last (we are using it)!
* It also restores r1 and r30.
*/
rest_stack
rfi
@@ -1153,15 +1148,17 @@ intr_save:
CMPIB=,n 6,%r26,skip_save_ior
/* save_specials left ipsw value in r8 for us to test */
mfctl %cr20, %r16 /* isr */
nop /* serialize mfctl on PA 2.0 to avoid 4 cycle penalty */
mfctl %cr21, %r17 /* ior */
#ifdef __LP64__
/*
* If the interrupted code was running with W bit off (32 bit),
* clear the b bits (bits 0 & 1) in the ior.
* save_specials left ipsw value in r8 for us to test.
*/
extrd,u,*<> %r8,PSW_W_BIT,1,%r0
depdi 0,1,2,%r17
@@ -1487,10 +1484,10 @@ nadtlb_emulate:
add,l %r1,%r24,%r1 /* doesn't affect c/b bits */
nadtlb_nullify:
mfctl %cr22,%r8 /* Get ipsw */
mfctl %ipsw,%r8
ldil L%PSW_N,%r9
or %r8,%r9,%r8 /* Set PSW_N */
mtctl %r8,%cr22
mtctl %r8,%ipsw
rfir
nop