From mboxrd@z Thu Jan 1 00:00:00 1970 From: Helge Deller Subject: Re: [PATCH] parisc: check hardcoded value of SHMLBA against value reported by firmware Date: Tue, 29 Oct 2013 22:11:29 +0100 Message-ID: <52702481.9050308@gmx.de> References: <20131029210544.GA18167@p100.box> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 To: John David Anglin , linux-parisc@vger.kernel.org, James Bottomley Return-path: In-Reply-To: List-ID: List-Id: linux-parisc.vger.kernel.org On 10/29/2013 10:10 PM, John David Anglin wrote: > I seem to recall the aliasing boundary value returned by my rp3440 is "unknown". Even better, then it would be interesting to see what this patch reports on your machine.... > > On 10/29/2013 5:05 PM, Helge Deller wrote: >> Our value of SHMLBA is hardcoded to 4MB on parisc due to aliasing restrictions >> of the platform. The firmware function PDC_CACHE does return the machine >> dependend value of this aliasing requirement. >> So, if there is a difference between those two - which we don't expect - let's >> report it at least. >> >> Signed-off-by: Helge Deller >> >> diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c >> index c035673..3523e20 100644 >> --- a/arch/parisc/kernel/cache.c >> +++ b/arch/parisc/kernel/cache.c >> @@ -142,6 +142,15 @@ parisc_cache_init(void) >> if (pdc_cache_info(&cache_info) < 0) >> panic("parisc_cache_init: pdc_cache_info failed"); >> + /* >> + * The alias field returned by PDC_CACHE specifies the aliasing >> + * boundaries for virtual addresses. So, let's verify if our hardcoded >> + * value of SHMLBA (4 MB) is correct for this machine. >> + */ >> + if ((4096UL << (cache_info.dc_conf.cc_alias-1)) != SHMLBA) >> + pr_warn("WARNING: PDC_CACHE returns aliasing of %lu kB.\n", >> + (4UL << (cache_info.dc_conf.cc_alias-1))); >> + >> #if 0 >> printk("ic_size %lx dc_size %lx it_size %lx\n", >> cache_info.ic_size, >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-parisc" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> >> > >