Date: Wed, 24 Dec 2014 15:40:12 -0700 From: Ian Lepore <ian@freebsd.org> To: Andrew Turner <andrew@fubar.geek.nz> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r276187 - head/sys/arm/arm Message-ID: <1419460812.1018.157.camel@freebsd.org> In-Reply-To: <20141224222637.03a19e57@bender> References: <201412241712.sBOHCqvW039381@svn.freebsd.org> <20141224222637.03a19e57@bender>
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On Wed, 2014-12-24 at 22:26 +0000, Andrew Turner wrote: > On Wed, 24 Dec 2014 17:12:52 +0000 (UTC) > Ian Lepore <ian@FreeBSD.org> wrote: > > > Author: ian > > Date: Wed Dec 24 17:12:51 2014 > > New Revision: 276187 > > URL: https://svnweb.freebsd.org/changeset/base/276187 > > > > Log: > > Eliminate unnecessary references to pte.h internals by using the > > standard pmap_kenter_temporary() to map pages while dumping. > > > > Submitted by: Svatopluk Kraus <onwahe@gmail.com>, > > Michal Meloun <meloun@miracle.cz> > > > > Modified: > > head/sys/arm/arm/dump_machdep.c > > > > Modified: head/sys/arm/arm/dump_machdep.c > > ============================================================================== > > --- head/sys/arm/arm/dump_machdep.c Wed Dec 24 16:11:15 > > 2014 (r276186) +++ head/sys/arm/arm/dump_machdep.c Wed > > Dec 24 17:12:51 2014 (r276187) @@ -160,11 +160,13 @@ static int > > cb_dumpdata(struct md_pa *mdp, int seqnr, void *arg) > > { > > struct dumperinfo *di = (struct dumperinfo*)arg; > > - vm_paddr_t pa; > > + vm_paddr_t a, pa; > > + void *va; > > uint32_t pgs; > > size_t counter, sz, chunk; > > - int c, error; > > + int i, c, error; > > > > + va = 0; > > error = 0; /* catch case in which chunk size is 0 */ > > counter = 0; > > pgs = mdp->md_size / PAGE_SIZE; > > @@ -194,16 +196,14 @@ cb_dumpdata(struct md_pa *mdp, int seqnr > > printf(" %d", pgs * PAGE_SIZE); > > counter &= (1<<24) - 1; > > } > > - if (pa == (pa & L1_ADDR_BITS)) { > > - pmap_kenter_section(0, pa & L1_ADDR_BITS, 0); > > - cpu_tlb_flushID_SE(0); > > - cpu_cpwait(); > > + for (i = 0; i < chunk; i++) { > > + a = pa + i * PAGE_SIZE; > > + va = pmap_kenter_temporary(trunc_page(a), i); > > Is this correct? It may map multiple chunks here. > > } > > #ifdef SW_WATCHDOG > > wdog_kern_pat(WD_LASTVAL); > > #endif > > - error = dump_write(di, > > - (void *)(pa - (pa & L1_ADDR_BITS)),0, dumplo, > > sz); > > + error = dump_write(di, va, 0, dumplo, sz); > > Then uses the last virtual address to dump the data here. Wouldn't this > miss the chunks mapped other than the last one? Yeah, but a quirk of pmap_kenter_temporary() is that its return value is constant, so this wrong-looking code is actually right. -- Ian
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