svn commit: r214457 - in head/sys: amd64/amd64 conf i386/i386
x86/x86
John Baldwin
jhb at freebsd.org
Fri Oct 29 13:45:16 UTC 2010
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.
Hence the i386 approach of:
if (kmdp! = NULL)
smapbase = preload_search_info();
else
smapbase = NULL;
if (smapbase != NULL) {
...
}
You could do this as:
if (kmdp != NULL) {
smapbase = preload_search_info();
if (smapbase != NULL) {
smapsize = ...;
...
}
}
It just causes the code to indent further.
--
John Baldwin
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