svn commit: r214457 - in head/sys: amd64/amd64 conf i386/i386
x86/x86
Attilio Rao
attilio at freebsd.org
Fri Oct 29 14:17:24 UTC 2010
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.
Attilio
--
Peace can only be achieved by understanding - A. Einstein
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