LMbench results for large page patch
David Gibson
david at gibson.dropbear.id.au
Wed Jun 5 17:08:32 EST 2002
I've done some more LMbench testing, with the large page patch I
posted earlier. The three cases are:
- "nopintlb", linuxppc_2_4_devel with CONFIG_PIN_TLB=n
- "2pintlb", linuxppc_2_4_devel with CONFIG_PIN_TLB=y
- "largepte", linuxppc_2_4_devel with a slightly updated
version of the large page PTE entries patch I posted last week (patch
attached).
There are 5 runs in each case.
These results shouldn't be compared directly to the numbers in the
last LMbench summary I posted, since some tweaks to the TLB handler
and set_context() in both the normal and largepte cases (which have
been committed to 2_4_devel) have gone in since then.
All tests were done on a Walnut with 200MHz 405GP (PVR 401100c4),
128MB RAM and IDE disk on a Promise PCI IDE controller.
Overall summary:
Performance of the large PTE patch is very similar to that
with pinned large page TLB entries. It is slightly better in a few
cases (more on this below) and slightly worse in one or two (notably
prot fault). It seems to do as well or better than having no large
page entries at all (pinned or otherwise).
I think the improvement over having pinned TLB entries, where it
occurs, is in most cases probably due to the fact that we use large
page entries for all of the kernel mapping of physical RAM, whereas
with pinned entries we only use them for the first 32M. I'll try to
rerun the tests tomorrow with only 32M of RAM - I expect the results
to put largepte and pinned TLBs even closer together. The exception
to this is the main memory latency - that's likely to be due to the
fact that userspace can use all 64 TLB entries, thus slightly reducing
the frequency of TLB misses.
If the largepte code does as well in some more testing, particularly
on low-memory machines, I think we should ditch CONFIG_PIN_TLB and use
this instead. Well, after the implementation has been cleaned up a
little (iopa() especially).
L M B E N C H 2 . 0 S U M M A R Y
------------------------------------
Basic system parameters
----------------------------------------------------
Host OS Description Mhz
--------- ------------- ----------------------- ----
2pintlb Linux 2.4.19- powerpc-linux-gnu 199
2pintlb Linux 2.4.19- powerpc-linux-gnu 199
2pintlb Linux 2.4.19- powerpc-linux-gnu 199
2pintlb Linux 2.4.19- powerpc-linux-gnu 199
2pintlb Linux 2.4.19- powerpc-linux-gnu 199
largepte Linux 2.4.19- powerpc-linux-gnu 199
largepte Linux 2.4.19- powerpc-linux-gnu 199
largepte Linux 2.4.19- powerpc-linux-gnu 199
largepte Linux 2.4.19- powerpc-linux-gnu 199
largepte Linux 2.4.19- powerpc-linux-gnu 199
nopintlb Linux 2.4.19- powerpc-linux-gnu 199
nopintlb Linux 2.4.19- powerpc-linux-gnu 199
nopintlb Linux 2.4.19- powerpc-linux-gnu 199
nopintlb Linux 2.4.19- powerpc-linux-gnu 199
nopintlb Linux 2.4.19- powerpc-linux-gnu 199
Processor, Processes - times in microseconds - smaller is better
----------------------------------------------------------------
Host OS Mhz null null open selct sig sig fork exec sh
call I/O stat clos TCP inst hndl proc proc proc
--------- ------------- ---- ---- ---- ---- ---- ----- ---- ---- ---- ---- ----
2pintlb Linux 2.4.19- 199 1.44 2.73 16.4 24.0 153.4 5.60 19.8 1810 8281 31.K
2pintlb Linux 2.4.19- 199 1.44 2.58 16.3 24.0 156.8 5.60 19.7 1781 8231 30.K
2pintlb Linux 2.4.19- 199 1.44 2.58 16.4 24.4 156.6 5.60 19.6 1796 8244 30.K
2pintlb Linux 2.4.19- 199 1.44 2.57 16.1 24.2 153.6 5.57 19.8 1804 8273 31.K
2pintlb Linux 2.4.19- 199 1.44 2.58 16.1 24.3 154.4 5.57 19.7 1791 8299 31.K
largepte Linux 2.4.19- 199 1.41 2.47 15.9 23.1 138.0 5.55 19.5 1697 7981 29.K
largepte Linux 2.4.19- 199 1.43 2.48 15.8 24.0 161.6 5.59 19.4 1678 7949 29.K
largepte Linux 2.4.19- 199 1.43 2.49 15.9 23.1 138.4 5.59 19.5 1682 8002 29.K
largepte Linux 2.4.19- 199 1.43 2.63 15.9 23.4 137.3 5.59 19.4 1686 7958 30.K
largepte Linux 2.4.19- 199 1.43 2.50 16.4 24.0 141.0 5.59 20.2 1687 7978 29.K
nopintlb Linux 2.4.19- 199 1.46 2.73 17.0 25.4 156.8 6.00 19.5 2042 9039 34.K
nopintlb Linux 2.4.19- 199 1.46 2.73 17.0 26.0 157.4 6.03 19.5 2082 9101 34.K
nopintlb Linux 2.4.19- 199 1.46 2.73 16.8 26.1 157.4 6.01 19.5 2075 9093 34.K
nopintlb Linux 2.4.19- 199 1.46 2.73 16.8 25.6 157.1 6.12 19.2 2053 9061 34.K
nopintlb Linux 2.4.19- 199 1.46 2.73 17.0 25.4 156.9 6.04 19.2 2082 9140 34.K
Context switching - times in microseconds - smaller is better
-------------------------------------------------------------
Host OS 2p/0K 2p/16K 2p/64K 8p/16K 8p/64K 16p/16K 16p/64K
ctxsw ctxsw ctxsw ctxsw ctxsw ctxsw ctxsw
--------- ------------- ----- ------ ------ ------ ------ ------- -------
2pintlb Linux 2.4.19- 5.040 77.4 269.8 90.3 269.5 89.4 270.7
2pintlb Linux 2.4.19- 6.290 78.7 262.1 89.0 268.5 88.7 267.9
2pintlb Linux 2.4.19- 3.420 76.3 255.8 89.3 268.7 89.7 268.4
2pintlb Linux 2.4.19- 2.440 80.5 267.9 90.9 269.7 92.0 270.6
2pintlb Linux 2.4.19- 5.850 76.6 271.3 91.5 270.3 90.0 270.2
largepte Linux 2.4.19- 4.220 77.5 253.6 87.8 264.4 86.3 263.4
largepte Linux 2.4.19- 4.660 78.5 250.3 87.3 262.2 86.8 262.6
largepte Linux 2.4.19- 3.060 75.0 253.0 87.1 265.3 86.7 264.9
largepte Linux 2.4.19- 5.460 79.3 249.7 86.5 263.1 87.1 264.1
largepte Linux 2.4.19- 5.400 75.4 253.5 85.8 264.6 86.0 265.6
nopintlb Linux 2.4.19- 4.740 77.8 276.0 96.7 275.2 97.1 275.2
nopintlb Linux 2.4.19- 5.600 78.8 270.5 93.8 274.0 95.3 276.7
nopintlb Linux 2.4.19- 5.680 78.5 274.6 94.8 275.7 96.6 277.8
nopintlb Linux 2.4.19- 4.250 80.6 275.6 96.2 278.7 96.7 277.4
nopintlb Linux 2.4.19- 4.860 77.4 276.3 94.3 277.5 94.3 278.5
*Local* Communication latencies in microseconds - smaller is better
-------------------------------------------------------------------
Host OS 2p/0K Pipe AF UDP RPC/ TCP RPC/ TCP
ctxsw UNIX UDP TCP conn
--------- ------------- ----- ----- ---- ----- ----- ----- ----- ----
2pintlb Linux 2.4.19- 5.040 35.1 62.5 247.0 891.
2pintlb Linux 2.4.19- 6.290 31.8 65.8 243.3 901.
2pintlb Linux 2.4.19- 3.420 33.6 68.7 238.6 899.
2pintlb Linux 2.4.19- 2.440 36.2 63.6 237.9 903.
2pintlb Linux 2.4.19- 5.850 35.6 70.6 242.6 904.
largepte Linux 2.4.19- 4.220 29.6 55.8 277.9 901.
largepte Linux 2.4.19- 4.660 31.0 66.6 280.2 898.
largepte Linux 2.4.19- 3.060 31.6 67.4 279.3 908.
largepte Linux 2.4.19- 5.460 34.2 66.9 280.2 909.
largepte Linux 2.4.19- 5.400 32.2 57.9 279.0 916.
nopintlb Linux 2.4.19- 4.740 35.3 67.0 364.5 1146
nopintlb Linux 2.4.19- 5.600 38.6 68.4 365.7 1151
nopintlb Linux 2.4.19- 5.680 37.7 64.6 326.0 1171
nopintlb Linux 2.4.19- 4.250 32.2 65.9 326.0 1147
nopintlb Linux 2.4.19- 4.860 37.5 67.0 374.5 1162
File & VM system latencies in microseconds - smaller is better
--------------------------------------------------------------
Host OS 0K File 10K File Mmap Prot Page
Create Delete Create Delete Latency Fault Fault
--------- ------------- ------ ------ ------ ------ ------- ----- -----
2pintlb Linux 2.4.19- 581.7 161.0 1236.1 311.9 1440.0 1.442 21.0
2pintlb Linux 2.4.19- 581.7 160.6 1248.4 303.6 1458.0 0.965 21.0
2pintlb Linux 2.4.19- 583.4 161.8 1265.8 319.7 1450.0 1.001 20.0
2pintlb Linux 2.4.19- 582.1 163.6 1254.7 311.3 1449.0 0.993 20.0
2pintlb Linux 2.4.19- 581.4 160.7 1248.4 302.3 1458.0 0.971 20.0
largepte Linux 2.4.19- 579.7 157.6 1219.5 308.3 1381.0 2.267 20.0
largepte Linux 2.4.19- 580.0 163.5 1218.0 312.9 1393.0 2.131 19.0
largepte Linux 2.4.19- 581.4 165.8 1219.5 297.7 1441.0 2.557 20.0
largepte Linux 2.4.19- 579.4 157.1 1204.8 304.2 1380.0 2.884 20.0
largepte Linux 2.4.19- 581.4 158.8 1222.5 296.2 1385.0 1.666 20.0
nopintlb Linux 2.4.19- 649.4 216.6 1445.1 401.1 1724.0 2.024 24.0
nopintlb Linux 2.4.19- 649.4 216.0 1440.9 410.2 1740.0 2.151 24.0
nopintlb Linux 2.4.19- 650.6 215.6 1445.1 400.2 1742.0 1.985 24.0
nopintlb Linux 2.4.19- 648.1 216.3 1424.5 405.5 1780.0 2.319 24.0
nopintlb Linux 2.4.19- 648.1 218.7 1436.8 414.4 1744.0 2.638 24.0
*Local* Communication bandwidths in MB/s - bigger is better
-----------------------------------------------------------
Host OS Pipe AF TCP File Mmap Bcopy Bcopy Mem Mem
UNIX reread reread (libc) (hand) read write
--------- ------------- ---- ---- ---- ------ ------ ------ ------ ---- -----
2pintlb Linux 2.4.19- 42.7 41.8 32.1 48.0 115.6 86.2 84.3 115. 128.7
2pintlb Linux 2.4.19- 45.6 42.1 62.7 48.3 115.6 86.1 84.4 115. 130.0
2pintlb Linux 2.4.19- 43.8 42.9 32.2 48.3 115.6 85.9 84.3 115. 130.0
2pintlb Linux 2.4.19- 42.0 42.5 30.9 47.5 115.6 85.0 84.2 115. 128.0
2pintlb Linux 2.4.19- 43.1 41.6 31.6 47.8 115.6 85.5 84.0 115. 129.1
largepte Linux 2.4.19- 43.4 42.4 65.3 48.4 115.7 86.2 84.5 115. 128.5
largepte Linux 2.4.19- 43.4 44.0 33.0 49.0 115.7 86.2 84.5 115. 130.9
largepte Linux 2.4.19- 43.8 43.3 65.7 49.0 115.7 86.3 84.3 115. 130.8
largepte Linux 2.4.19- 43.6 43.7 65.5 48.9 115.7 86.2 84.4 115. 130.0
largepte Linux 2.4.19- 44.5 44.1 33.2 48.5 115.7 86.4 84.4 115. 131.3
nopintlb Linux 2.4.19- 41.0 39.3 29.1 47.6 115.5 85.5 84.0 115. 128.5
nopintlb Linux 2.4.19- 40.9 39.7 59.8 47.6 115.5 85.8 84.1 115. 130.6
nopintlb Linux 2.4.19- 41.1 39.3 29.5 47.6 115.5 85.8 84.2 115. 131.2
nopintlb Linux 2.4.19- 39.2 39.3 59.4 47.2 115.5 85.4 83.8 115. 127.7
nopintlb Linux 2.4.19- 41.2 38.6 29.6 47.3 115.5 85.3 83.9 115. 130.3
Memory latencies in nanoseconds - smaller is better
(WARNING - may not be correct, check graphs)
---------------------------------------------------
Host OS Mhz L1 $ L2 $ Main mem Guesses
--------- ------------- ---- ----- ------ -------- -------
2pintlb Linux 2.4.19- 199 15.0 133.9 148.0 No L2 cache?
2pintlb Linux 2.4.19- 199 15.0 133.8 147.9 No L2 cache?
2pintlb Linux 2.4.19- 199 15.0 133.8 148.0 No L2 cache?
2pintlb Linux 2.4.19- 199 15.0 134.0 148.1 No L2 cache?
2pintlb Linux 2.4.19- 199 15.0 133.9 148.0 No L2 cache?
largepte Linux 2.4.19- 199 15.0 133.9 147.4 No L2 cache?
largepte Linux 2.4.19- 199 15.0 133.8 147.4 No L2 cache?
largepte Linux 2.4.19- 199 15.0 133.8 147.4 No L2 cache?
largepte Linux 2.4.19- 199 15.0 133.8 147.4 No L2 cache?
largepte Linux 2.4.19- 199 15.0 133.9 147.4 No L2 cache?
nopintlb Linux 2.4.19- 199 15.0 134.0 147.9 No L2 cache?
nopintlb Linux 2.4.19- 199 15.0 134.0 147.9 No L2 cache?
nopintlb Linux 2.4.19- 199 15.0 134.0 147.9 No L2 cache?
nopintlb Linux 2.4.19- 199 15.0 134.1 147.9 No L2 cache?
nopintlb Linux 2.4.19- 199 15.0 134.0 147.9 No L2 cache?
--
David Gibson | For every complex problem there is a
david at gibson.dropbear.id.au | solution which is simple, neat and
| wrong. -- H.L. Mencken
http://www.ozlabs.org/people/dgibson
-------------- next part --------------
diff -urN /home/dgibson/kernel/linuxppc_2_4_devel/arch/ppc/kernel/head_4xx.S linux-grinch-largepage/arch/ppc/kernel/head_4xx.S
--- /home/dgibson/kernel/linuxppc_2_4_devel/arch/ppc/kernel/head_4xx.S Wed Jun 5 13:11:27 2002
+++ linux-grinch-largepage/arch/ppc/kernel/head_4xx.S Wed Jun 5 16:09:29 2002
@@ -261,10 +261,10 @@
tophys(r21, r21)
rlwimi r21, r20, 12, 20, 29 /* Create L1 (pgdir/pmd) address */
lwz r21, 0(r21) /* Get L1 entry */
- rlwinm. r22, r21, 0, 0, 19 /* Extract L2 (pte) base address */
+ andi. r22, r21, _PMD_PRESENT /* Check if it points to a PTE page */
beq 2f /* Bail if no table */
- tophys(r22, r22)
+ tophys(r22, r21)
rlwimi r22, r20, 22, 20, 29 /* Compute PTE address */
lwz r21, 0(r22) /* Get Linux PTE */
@@ -495,33 +495,40 @@
tophys(r21, r21)
rlwimi r21, r20, 12, 20, 29 /* Create L1 (pgdir/pmd) address */
lwz r21, 0(r21) /* Get L1 entry */
- rlwinm. r22, r21, 0, 0, 19 /* Extract L2 (pte) base address */
+ andi. r22, r21, _PMD_PRESENT /* check if it points to pte page */
beq 2f /* Bail if no table */
- tophys(r22, r22)
+ tophys(r22, r21)
rlwimi r22, r20, 22, 20, 29 /* Compute PTE address */
lwz r21, 0(r22) /* Get Linux PTE */
andi. r23, r21, _PAGE_PRESENT
- beq 2f
+ beq 5f
ori r21, r21, _PAGE_ACCESSED
stw r21, 0(r22)
- /* Most of the Linux PTE is ready to load into the TLB LO.
- * We set ZSEL, where only the LS-bit determines user access.
- * We set execute, because we don't have the granularity to
- * properly set this at the page level (Linux problem).
- * If shared is set, we cause a zero PID->TID load.
- * Many of these bits are software only. Bits we don't set
- * here we (properly should) assume have the appropriate value.
+ /* Create TLB tag. This is the faulting address plus a static
+ * set of bits. These are size, valid, E, U0.
*/
- li r22, 0x0ce2
- andc r21, r21, r22 /* Make sure 20, 21 are zero */
+ li r22, 0x00c0
+ rlwimi r20, r22, 0, 20, 31
b finish_tlb_load
-
+ /* Check for possible large-page pmd entry */
2:
+ rlwinm. r22,r21,2,22,24 /* size != 0 means large-page */
+ beq 5f
+
+ /* Create EPN. This is the faulting address plus a static
+ * set of bits (valid, E, U0) plus the size from the PMD.
+ */
+ ori r22,r22,0x40
+ rlwimi r20, r22, 0, 20, 31
+
+ b finish_tlb_load
+
+5:
/* The bailout. Restore registers to pre-exception conditions
* and call the heavyweights to help us out.
*/
@@ -588,32 +595,40 @@
tophys(r21, r21)
rlwimi r21, r20, 12, 20, 29 /* Create L1 (pgdir/pmd) address */
lwz r21, 0(r21) /* Get L1 entry */
- rlwinm. r22, r21, 0, 0, 19 /* Extract L2 (pte) base address */
+ andi. r22, r21, _PMD_PRESENT /* check if it points to pte page */
beq 2f /* Bail if no table */
- tophys(r22, r22)
+ tophys(r22, r21)
rlwimi r22, r20, 22, 20, 29 /* Compute PTE address */
lwz r21, 0(r22) /* Get Linux PTE */
andi. r23, r21, _PAGE_PRESENT
- beq 2f
+ beq 5f
ori r21, r21, _PAGE_ACCESSED
stw r21, 0(r22)
- /* Most of the Linux PTE is ready to load into the TLB LO.
- * We set ZSEL, where only the LS-bit determines user access.
- * We set execute, because we don't have the granularity to
- * properly set this at the page level (Linux problem).
- * If shared is set, we cause a zero PID->TID load.
- * Many of these bits are software only. Bits we don't set
- * here we (properly should) assume have the appropriate value.
+ /* Create EPN. This is the faulting address plus a static
+ * set of bits. These are size, valid, E, U0.
*/
- li r22, 0x0ce2
- andc r21, r21, r22 /* Make sure 20, 21 are zero */
+ li r22, 0x00c0
+ rlwimi r20, r22, 0, 20, 31
b finish_tlb_load
+ /* Check for possible large-page pmd entry */
2:
+ rlwinm. r22,r21,2,22,24 /* size != 0 means large-page */
+ beq 5f
+
+ /* Create EPN. This is the faulting address plus a static
+ * set of bits (valid=1, E=0, U0=0) plus the size from the PMD.
+ */
+ ori r22,r22,0x40
+ rlwimi r20, r22, 0, 20, 31
+
+ b finish_tlb_load
+
+5:
/* The bailout. Restore registers to pre-exception conditions
* and call the heavyweights to help us out.
*/
@@ -758,14 +773,16 @@
stw r23, tlb_4xx_index at l(0)
6:
+ /*
+ * Clear out the software-only bits in the PTE to generate the
+ * TLB_DATA value. These are the bottom 2 bits of RPN, the
+ * top 3 bits of the zone field, and M.
+ */
+ li r22, 0x0ce2
+ andc r21, r21, r22 /* Make sure 20, 21 are zero */
+
tlbwe r21, r23, TLB_DATA /* Load TLB LO */
- /* Create EPN. This is the faulting address plus a static
- * set of bits. These are size, valid, E, U0, and ensure
- * bits 20 and 21 are zero.
- */
- li r22, 0x00c0
- rlwimi r20, r22, 0, 20, 31
tlbwe r20, r23, TLB_TAG /* Load TLB HI */
/* Done...restore registers and get out of here.
diff -urN /home/dgibson/kernel/linuxppc_2_4_devel/arch/ppc/mm/pgtable.c linux-grinch-largepage/arch/ppc/mm/pgtable.c
--- /home/dgibson/kernel/linuxppc_2_4_devel/arch/ppc/mm/pgtable.c Mon Apr 8 10:29:07 2002
+++ linux-grinch-largepage/arch/ppc/mm/pgtable.c Fri May 31 13:51:48 2002
@@ -348,7 +348,38 @@
v = KERNELBASE;
p = PPC_MEMSTART;
- for (s = 0; s < total_lowmem; s += PAGE_SIZE) {
+ s = 0;
+#if defined(CONFIG_40x)
+ for (; s <= (total_lowmem - 16*1024*1024); s += 16*1024*1024) {
+ pmd_t *pmdp;
+ unsigned long val = p | _PMD_SIZE_16M | _PAGE_HWEXEC | _PAGE_HWWRITE;
+
+ spin_lock(&init_mm.page_table_lock);
+ pmdp = pmd_offset(pgd_offset_k(v), v);
+ pmd_val(*pmdp++) = val;
+ pmd_val(*pmdp++) = val;
+ pmd_val(*pmdp++) = val;
+ pmd_val(*pmdp++) = val;
+ spin_unlock(&init_mm.page_table_lock);
+
+ v += 16*1024*1024;
+ p += 16*1024*1024;
+ }
+
+ for(; s <= (total_lowmem - 4*1024*1024); s += 4*1024*1024) {
+ pmd_t *pmdp;
+ unsigned long val = p | _PMD_SIZE_4M | _PAGE_HWEXEC | _PAGE_HWWRITE;
+
+ spin_lock(&init_mm.page_table_lock);
+ pmdp = pmd_offset(pgd_offset_k(v), v);
+ pmd_val(*pmdp) = val;
+ spin_unlock(&init_mm.page_table_lock);
+
+ v += 4*1024*1024;
+ p += 4*1024*1024;
+ }
+#endif
+ for (; s < total_lowmem; s += PAGE_SIZE) {
/* On the MPC8xx, we want the page shared so we
* don't get ASID compares on kernel space.
*/
@@ -468,8 +499,33 @@
mm = &init_mm;
pa = 0;
+#ifdef CONFIG_40x
+ {
+ pgd_t *pgd;
+ pmd_t *pmd;
+ const unsigned long large_page_mask[] = {
+ 0xfffff800, 0xffffe000, 0xffff8000, 0xfffe0000,
+ 0xfff80000, 0xffe00000, 0xff800000, 0xfe000000
+ };
+
+ pgd = pgd_offset(mm, addr & PAGE_MASK);
+ if (pgd) {
+ pmd = pmd_offset(pgd, addr & PAGE_MASK);
+ if (pmd_present(*pmd)) {
+ pte = pte_offset(pmd, addr & PAGE_MASK);
+ pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK);
+ } else if (pmd_val(*pmd) & _PMD_SIZE) {
+ unsigned long mask =
+ large_page_mask[(pmd_val(*pmd) & _PMD_SIZE) >> 5];
+ pa = (pmd_val(*pmd) & mask) | (addr & ~mask);
+ }
+ }
+ }
+
+#else
if (get_pteptr(mm, addr, &pte))
pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK);
+#endif
return(pa);
}
diff -urN /home/dgibson/kernel/linuxppc_2_4_devel/include/asm-ppc/pgtable.h linux-grinch-largepage/include/asm-ppc/pgtable.h
--- /home/dgibson/kernel/linuxppc_2_4_devel/include/asm-ppc/pgtable.h Mon Jun 3 12:36:27 2002
+++ linux-grinch-largepage/include/asm-ppc/pgtable.h Wed Jun 5 13:40:58 2002
@@ -301,8 +301,12 @@
#define _PAGE_HWWRITE 0x100 /* hardware: Dirty & RW, set in exception */
#define _PAGE_HWEXEC 0x200 /* hardware: EX permission */
#define _PAGE_ACCESSED 0x400 /* software: R: page referenced */
-#define _PMD_PRESENT PAGE_MASK
+#define _PMD_PRESENT 0x400 /* PMD points to page of PTEs */
+#define _PMD_SIZE 0x0e0 /* size field, != 0 for large-page PMD entry */
+#define _PMD_SIZE_4M 0x0c0
+#define _PMD_SIZE_16M 0x0e0
+#define _PMD_BAD 0x802
#elif defined(CONFIG_440)
/*
@@ -357,9 +361,10 @@
#define _PAGE_HWWRITE 0x0100 /* h/w write enable: never set in Linux PTE */
#define _PAGE_USER 0x0800 /* One of the PP bits, the other is USER&~RW */
-#define _PMD_PRESENT PAGE_MASK
+#define _PMD_PRESENT 0x0001
#define _PMD_PAGE_MASK 0x000c
#define _PMD_PAGE_8M 0x000c
+#define _PMD_BAD 0x0ff0
#else /* CONFIG_6xx */
/* Definitions for 60x, 740/750, etc. */
@@ -374,7 +379,9 @@
#define _PAGE_ACCESSED 0x100 /* R: page referenced */
#define _PAGE_EXEC 0x200 /* software: i-cache coherency required */
#define _PAGE_RW 0x400 /* software: user write access allowed */
-#define _PMD_PRESENT PAGE_MASK
+
+#define _PMD_PRESENT 0x800
+#define _PMD_BAD 0x7ff
#endif
/* The non-standard PowerPC MMUs, which includes the 4xx and 8xx (and
@@ -474,7 +481,7 @@
#define pte_clear(ptep) do { set_pte((ptep), __pte(0)); } while (0)
#define pmd_none(pmd) (!pmd_val(pmd))
-#define pmd_bad(pmd) ((pmd_val(pmd) & _PMD_PRESENT) == 0)
+#define pmd_bad(pmd) ((pmd_val(pmd) & _PMD_BAD) != 0)
#define pmd_present(pmd) ((pmd_val(pmd) & _PMD_PRESENT) != 0)
#define pmd_clear(pmdp) do { pmd_val(*(pmdp)) = 0; } while (0)
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