svn commit: r214457 - in head/sys: amd64/amd64 conf i386/i386
x86/x86
John Baldwin
jhb at freebsd.org
Fri Oct 29 17:06:01 UTC 2010
On Friday, October 29, 2010 10:33:05 am Attilio Rao wrote:
> 2010/10/29 John Baldwin <jhb at freebsd.org>:
> > On Friday, October 29, 2010 10:17:23 am Attilio Rao wrote:
> >> 2010/10/29 John Baldwin <jhb at freebsd.org>:
> >> > On Thursday, October 28, 2010 8:25:38 pm Attilio Rao wrote:
> >> >> 2010/10/28 John Baldwin <jhb at freebsd.org>:
> >> >> > On Thursday, October 28, 2010 4:28:12 pm Attilio Rao wrote:
> >> >> >> 2010/10/28 John Baldwin <jhb at freebsd.org>:
> >> >> >> > On Thursday, October 28, 2010 1:21:34 pm Attilio Rao wrote:
> >> >> >> >> 2010/10/28 John Baldwin <jhb at freebsd.org>:
> >> >> >> >> > On Thursday, October 28, 2010 12:31:39 pm Attilio Rao wrote:
> >> >> >> >> >> Author: attilio
> >> >> >> >> >> Date: Thu Oct 28 16:31:39 2010
> >> >> >> >> >> New Revision: 214457
> >> >> >> >> >> URL: http://svn.freebsd.org/changeset/base/214457
> >> >> >> >> >>
> >> >> >> >> >> Log:
> >> >> >> >> >> Merge nexus.c from amd64 and i386 to x86 subtree.
> >> >> >> >> >>
> >> >> >> >> >> Sponsored by: Sandvine Incorporated
> >> >> >> >> >> Tested by: gianni
> >> >> >> >> >>
> >> >> >> >> >
> >> >> >> >> > It would be better to merge these two routines. The loader now passes
> >> >> > the
> >> >> >> >> > smap to i386 kernels as well, so ram_attach() should probably be
> >> >> > changed to
> >> >> >> >> > try the amd64 approach first and if that fails fall back to using the
> >> >> >> >> > phys_avail[] array instead.
> >> >> >> >>
> >> >> >> >> What do you think about this patch?:
> >> >> >> >> Index: nexus.c
> >> >> >> >> ===================================================================
> >> >> >> >> --- nexus.c (revision 214457)
> >> >> >> >> +++ nexus.c (working copy)
> >> >> >> >> @@ -52,9 +52,7 @@
> >> >> >> >> #include <sys/systm.h>
> >> >> >> >> #include <sys/bus.h>
> >> >> >> >> #include <sys/kernel.h>
> >> >> >> >> -#ifdef __amd64__
> >> >> >> >> #include <sys/linker.h>
> >> >> >> >> -#endif
> >> >> >> >> #include <sys/malloc.h>
> >> >> >> >> #include <sys/module.h>
> >> >> >> >> #include <machine/bus.h>
> >> >> >> >> @@ -67,12 +65,10 @@
> >> >> >> >> #include <vm/pmap.h>
> >> >> >> >> #include <machine/pmap.h>
> >> >> >> >>
> >> >> >> >> -#ifdef __amd64__
> >> >> >> >> #include <machine/metadata.h>
> >> >> >> >> -#include <machine/pc/bios.h>
> >> >> >> >> -#endif
> >> >> >> >> #include <machine/nexusvar.h>
> >> >> >> >> #include <machine/resource.h>
> >> >> >> >> +#include <machine/pc/bios.h>
> >> >> >> >>
> >> >> >> >> #ifdef DEV_APIC
> >> >> >> >> #include "pcib_if.h"
> >> >> >> >> @@ -89,11 +85,13 @@
> >> >> >> >> #include <sys/rtprio.h>
> >> >> >> >>
> >> >> >> >> #ifdef __amd64__
> >> >> >> >> -#define RMAN_BUS_SPACE_IO AMD64_BUS_SPACE_IO
> >> >> >> >> -#define RMAN_BUS_SPACE_MEM AMD64_BUS_SPACE_MEM
> >> >> >> >> +#define X86_BUS_SPACE_IO AMD64_BUS_SPACE_IO
> >> >> >> >> +#define X86_BUS_SPACE_MEM AMD64_BUS_SPACE_MEM
> >> >> >> >> +#define ELF_KERN_STR "elf64 kernel"
> >> >> >> >> #else
> >> >> >> >> -#define RMAN_BUS_SPACE_IO I386_BUS_SPACE_IO
> >> >> >> >> -#define RMAN_BUS_SPACE_MEM I386_BUS_SPACE_MEM
> >> >> >> >> +#define X86_BUS_SPACE_IO I386_BUS_SPACE_IO
> >> >> >> >> +#define X86_BUS_SPACE_MEM I386_BUS_SPACE_MEM
> >> >> >> >> +#define ELF_KERN_STR "elf32 kernel"
> >> >> >> >> #endif
> >> >> >> >> @@ -701,16 +699,11 @@
> >> >> >> >> panic("ram_attach: resource %d failed to attach",
> >> >> > rid);
> >> >> >> >> rid++;
> >> >> >> >> }
> >> >> >> >> - return (0);
> >> >> >> >> -}
> >> >> >> >> -#else
> >> >> >> >> -static int
> >> >> >> >> -ram_attach(device_t dev)
> >> >> >> >> -{
> >> >> >> >> - struct resource *res;
> >> >> >> >> - vm_paddr_t *p;
> >> >> >> >> - int error, i, rid;
> >> >> >> >>
> >> >> >> >> + /* If at least one smap attached, return. */
> >> >> >> >> + if (rid != 0)
> >> >> >> >> + return (0);
> >> >> >> >> +
> >> >> >> >
> >> >> >> > Perhaps this instead:
> >> >> >> >
> >> >> >> > /* If we found an SMAP, return. */
> >> >> >> > if (smapbase != NULL)
> >> >> >> > return (0);
> >> >> >>
> >> >> >> No, I don't think this check is right, smapbase will always be != NULL
> >> >> >> (otherwise the code panics).
> >> >> >
> >> >> > Oh, that needs to be fixed then. It can be NULL on i386 with an old loader
> >> >> > (or on a really old machine without an SMAP). The amd64 nexus code could
> >> >> > assume it would never be NULL, but i386 cannot.
> >> >> >
> >> >> > It should probably more closely match what i386 does during the memory probe
> >> >> > which is:
> >> >> >
> >> >> > kmdp = search("elf kernel");
> >> >> > if (kmdp == NULL)
> >> >> > kmdp = search("elfXX kernel");
> >> >> > if (kmdp != NULL)
> >> >> > smapbase = preload_search(...);
> >> >> > else
> >> >> > smapbase = NULL;
> >> >> > if (smapbase != NULL) {
> >> >> > for (smap = ...) {
> >> >> > }
> >> >> >
> >> >> > return (0);
> >> >> > }
> >> >> >
> >> >> > /* fall through to old i386 code using phys_avail[] */
> >> >>
> >> >> This further patch should address your concerns about nexus.c:
> >> >> Index: nexus.c
> >> >> ===================================================================
> >> >> --- nexus.c (revision 214457)
> >> >> +++ nexus.c (working copy)
> >> >> @@ -52,9 +52,7 @@
> >> >> #include <sys/systm.h>
> >> >> #include <sys/bus.h>
> >> >> #include <sys/kernel.h>
> >> >> -#ifdef __amd64__
> >> >> #include <sys/linker.h>
> >> >> -#endif
> >> >> #include <sys/malloc.h>
> >> >> #include <sys/module.h>
> >> >> #include <machine/bus.h>
> >> >> @@ -67,12 +65,10 @@
> >> >> #include <vm/pmap.h>
> >> >> #include <machine/pmap.h>
> >> >>
> >> >> -#ifdef __amd64__
> >> >> #include <machine/metadata.h>
> >> >> -#include <machine/pc/bios.h>
> >> >> -#endif
> >> >> #include <machine/nexusvar.h>
> >> >> #include <machine/resource.h>
> >> >> +#include <machine/pc/bios.h>
> >> >>
> >> >> #ifdef DEV_APIC
> >> >> #include "pcib_if.h"
> >> >> @@ -89,13 +85,15 @@
> >> >> #include <sys/rtprio.h>
> >> >>
> >> >> #ifdef __amd64__
> >> >> -#define RMAN_BUS_SPACE_IO AMD64_BUS_SPACE_IO
> >> >> -#define RMAN_BUS_SPACE_MEM AMD64_BUS_SPACE_MEM
> >> >> +#define BUS_SPACE_IO AMD64_BUS_SPACE_IO
> >> >> +#define BUS_SPACE_MEM AMD64_BUS_SPACE_MEM
> >> >> #else
> >> >> -#define RMAN_BUS_SPACE_IO I386_BUS_SPACE_IO
> >> >> -#define RMAN_BUS_SPACE_MEM I386_BUS_SPACE_MEM
> >> >> +#define BUS_SPACE_IO I386_BUS_SPACE_IO
> >> >> +#define BUS_SPACE_MEM I386_BUS_SPACE_MEM
> >> >> #endif
> >> >>
> >> >> +#define ELF_KERN_STR ("elf"__XSTRING(__ELF_WORD_SIZE)" kernel")
> >> >> +
> >> >> static MALLOC_DEFINE(M_NEXUSDEV, "nexusdev", "Nexus device");
> >> >>
> >> >> #define DEVTONX(dev) ((struct nexus_device *)device_get_ivars(dev))
> >> >> @@ -435,7 +433,7 @@
> >> >> #else
> >> >> rman_set_bushandle(r, rman_get_start(r));
> >> >> #endif
> >> >> - rman_set_bustag(r, RMAN_BUS_SPACE_IO);
> >> >> + rman_set_bustag(r, BUS_SPACE_IO);
> >> >> break;
> >> >> case SYS_RES_MEMORY:
> >> >> #ifdef PC98
> >> >> @@ -446,7 +444,7 @@
> >> >> #endif
> >> >> vaddr = pmap_mapdev(rman_get_start(r), rman_get_size(r));
> >> >> rman_set_virtual(r, vaddr);
> >> >> - rman_set_bustag(r, RMAN_BUS_SPACE_MEM);
> >> >> + rman_set_bustag(r, BUS_SPACE_MEM);
> >> >> #ifdef PC98
> >> >> /* PC-98: the type of bus_space_handle_t is the structure. */
> >> >> bh->bsh_base = (bus_addr_t) vaddr;
> >> >> @@ -668,48 +666,45 @@
> >> >> return (0);
> >> >> }
> >> >>
> >> >> -#ifdef __amd64__
> >> >> static int
> >> >> ram_attach(device_t dev)
> >> >> {
> >> >> struct bios_smap *smapbase, *smap, *smapend;
> >> >> struct resource *res;
> >> >> + vm_paddr_t *p;
> >> >> caddr_t kmdp;
> >> >> uint32_t smapsize;
> >> >> - int error, rid;
> >> >> + int error, i, rid;
> >> >>
> >> >> /* Retrieve the system memory map from the loader. */
> >> >> kmdp = preload_search_by_type("elf kernel");
> >> >> if (kmdp == NULL)
> >> >> - kmdp = preload_search_by_type("elf64 kernel");
> >> >> - smapbase = (struct bios_smap *)preload_search_info(kmdp,
> >> >> - MODINFO_METADATA | MODINFOMD_SMAP);
> >> >> - smapsize = *((u_int32_t *)smapbase - 1);
> >> >> - smapend = (struct bios_smap *)((uintptr_t)smapbase + smapsize);
> >> >> + kmdp = preload_search_by_type(ELF_KERN_STR);
> >> >> + if (kmdp != NULL) {
> >> >> + smapbase = (struct bios_smap *)preload_search_info(kmdp,
> >> >> + MODINFO_METADATA | MODINFOMD_SMAP);
> >> >> + smapsize = *((u_int32_t *)smapbase - 1);
> >> >> + smapend = (struct bios_smap *)((uintptr_t)smapbase + smapsize);
> >> >
> >> > I think this doesn't check for the case that smapbase is NULL. I would
> >> > expect kmdp to always be non-NULL in practice (it just means we have a
> >> > kernel). However, the preload_search_info() can fail when booting on an old
> >> > machine without an SMAP or an old loader that doesn't pass the SMAP to i386.
> >>
> >> I don't understand where is the problem.
> >> smap is only used when it is consistent in that patch, otherwise it is
> >> not used and fallsthrough the physavail[] approach.
> >> It doesn't need to be set to NULL or checked.
> >>
> >> I guess that you want to patch the file and see how it looks like,
> >> will be easier to review than inline .diff, in this case.
> >
> > The preload_search_info() can fail and return NULL (old machine with no SMAP
> > or an older /boot/loader on i386). Then when you do this:
> >
> > smapsize = *((u_int32_t *)smapbase - 1);
> >
> > the kernel will panic.
>
> Ah, I thought that it could be failing only with a NULL kmdp.
> That patch should fix it then:
I think this looks fine, but I haven't tested it. :)
--
John Baldwin
More information about the svn-src-head
mailing list