Date: Fri, 28 Jan 2000 13:43:10 +0900 From: YAMAMOTO Shigeru <shigeru@iij.ad.jp> To: imp@village.org Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: how to allocate an alined address for a device? Message-ID: <20000128134310D.shigeru@iij.ad.jp> In-Reply-To: Your message of "Tue, 18 Jan 2000 16:15:36 -0700" <200001182315.QAA20891@harmony.village.org> References: <200001182315.QAA20891@harmony.village.org>
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>>>>> "Warner" == Warner Losh <Warner> writes:
Warner> In a cardbus system, one would force the alignment in the card bus
Warner> bridge. It would reject those things that aren't aligned in a sane
Warner> manner for cardbus. It would try again to get a different range, if
Warner> possible, or would reject the attempt.
I think it is no good to try again to get a different range.
Because, a different system has a different free address range and a device
dirver can not know where is a free address range.
So I change rman_reserve_resource() in @src/sys/kern/subr_rman.c for we can
allocate an aligned address.
My idea is using high bits of flags.
RF_ALIGN_XXX in aflags specifies an alignment request and an alignment
size.
Bad point of my idea is that we need to use a different bit for each an
alignment size.
This is a patch for @src/sys/kern/subr_rman.c (rev. 1.10) and
@src/sys/sys/rman.h (rev. 1.5)
Is my idea good or not?
Thanks,
-------
YAMAMOTO Shigeru Internet Initiative Japan Inc.
<shigeru@iij.ad.jp> Network Engineering Div.
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--- kern/subr_rman.c.org Tue Nov 16 08:28:57 1999
+++ kern/subr_rman.c Thu Jan 27 02:33:03 2000
@@ -227,7 +227,17 @@
continue;
}
rstart = max(s->r_start, start);
- rend = min(s->r_end, max(start + count, end));
+ if (flags & RF_ALIGN_MASK) {
+ /* need to align an address */
+ u_long aligned_rstart;
+
+ aligned_rstart = (rstart & (~((u_long)(flags & RF_ALIGN_MASK)) + 1u));
+ if ((rstart & (~(~((u_long)(flags & RF_ALIGN_MASK)) + 1u))) != 0) {
+ aligned_rstart += ((u_long)(flags & RF_ALIGN_MASK));
+ }
+ rstart = aligned_rstart;
+ }
+ rend = min(s->r_end, max(max(start + count, end), rstart + count));
#ifdef RMAN_DEBUG
printf("truncated region: [%#lx, %#lx]; size %#lx (requested %#lx)\n",
rstart, rend, (rend - rstart + 1), count);
--- sys/rman.h.org Mon Jan 10 08:48:52 2000
+++ sys/rman.h Thu Jan 27 02:36:51 2000
@@ -57,14 +57,33 @@
struct rman *r_rm; /* resource manager from whence this came */
};
-#define RF_ALLOCATED 0x0001 /* resource has been reserved */
-#define RF_ACTIVE 0x0002 /* resource allocation has been activated */
-#define RF_SHAREABLE 0x0004 /* resource permits contemporaneous sharing */
-#define RF_TIMESHARE 0x0008 /* resource permits time-division sharing */
-#define RF_WANTED 0x0010 /* somebody is waiting for this resource */
-#define RF_FIRSTSHARE 0x0020 /* first in sharing list */
+#define RF_ALLOCATED 0x00000001 /* resource has been reserved */
+#define RF_ACTIVE 0x00000002 /* resource allocation has been activated */
+#define RF_SHAREABLE 0x00000004 /* resource permits contemporaneous sharing */
+#define RF_TIMESHARE 0x00000008 /* resource permits time-division sharing */
+#define RF_WANTED 0x00000010 /* somebody is waiting for this resource */
+#define RF_FIRSTSHARE 0x00000020 /* first in sharing list */
-#define RF_PCCARD_ATTR 0x10000 /* PCCARD attribute memory */
+#define RF_ALIGN_4K 0x00001000 /* require 4K byte address alignment */
+#define RF_ALIGN_8K 0x00002000 /* require 8K byte address alignment */
+#define RF_ALIGN_16K 0x00004000 /* require 16K byte address alignment */
+#define RF_ALIGN_32K 0x00008000 /* require 32K byte address alignment */
+#define RF_ALIGN_64K 0x00010000 /* require 64K byte address alignment */
+#define RF_ALIGN_128K 0x00020000 /* require 128K byte address alignment */
+#define RF_ALIGN_256K 0x00040000 /* require 256K byte address alignment */
+#define RF_ALIGN_512K 0x00080000 /* require 512K byte address alignment */
+#define RF_ALIGN_1M 0x00100000 /* require 1M byte address alignment */
+#define RF_ALIGN_2M 0x00200000 /* require 2M byte address alignment */
+#define RF_ALIGN_4M 0x00400000 /* require 4M byte address alignment */
+#define RF_ALIGN_8M 0x00800000 /* require 8M byte address alignment */
+#if 0 /* XXX Is there a device which requires more large address alignment? */
+#define RF_ALIGN_16M 0x01000000 /* require 16M byte address alignment */
+#define RF_ALIGN_32M 0x02000000 /* require 32M byte address alignment */
+#define RF_ALIGN_64M 0x04000000 /* require 64M byte address alignment */
+#define RF_ALIGN_128M 0x08000000 /* require 128M byte address alignment */
+#endif
+#define RF_ALIGN_MASK 0x00FFF000 /* mask for RF_ALIGN_XX */
+#define RF_PCCARD_ATTR RF_ALIGN_4K /* PCCARD attribute memory */
enum rman_type { RMAN_UNINIT = 0, RMAN_GAUGE, RMAN_ARRAY };
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