Messages in this thread | | | Subject | Re: [PATCH v12 3/6] CPM/QE: use genalloc to manage CPM/QE muram | From | Scott Wood <> | Date | Mon, 26 Oct 2015 23:50:08 -0500 |
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On Sun, 2015-10-25 at 22:15 -0500, Zhao Qiang-B45475 wrote: > On Sat, 2015-10-24 at 04:59 AM, Wood Scott-B07421 <scottwood@freescale.com> > wrote: > > -----Original Message----- > > From: Wood Scott-B07421 > > Sent: Saturday, October 24, 2015 4:59 AM > > To: Zhao Qiang-B45475 <qiang.zhao@freescale.com> > > Cc: linux-kernel@vger.kernel.org; linuxppc-dev@lists.ozlabs.org; > > lauraa@codeaurora.org; Xie Xiaobo-R63061 <X.Xie@freescale.com>; > > benh@kernel.crashing.org; Li Yang-Leo-R58472 <LeoLi@freescale.com>; > > paulus@samba.org > > Subject: Re: [PATCH v12 3/6] CPM/QE: use genalloc to manage CPM/QE muram > > > > Don't send HTML e-mail. > > > > On Fri, 2015-10-23 at 02:06 -0500, Zhao Qiang-B45475 wrote: > > > On Fri, 2015-10-23 at 11:00 AM, Wood Scott-B07421 > > > <scottwood@freescale.com> > > > wrote: > > > > -----Original Message----- > > > > From: Wood Scott-B07421 > > > > Sent: Friday, October 23, 2015 11:00 AM > > > > To: Zhao Qiang-B45475 <qiang.zhao@freescale.com> > > > > Cc: linux-kernel@vger.kernel.org; linuxppc-dev@lists.ozlabs.org; > > > > lauraa@codeaurora.org; Xie Xiaobo-R63061 <X.Xie@freescale.com>; > > > > benh@kernel.crashing.org; Li Yang-Leo-R58472 <LeoLi@freescale.com>; > > > > paulus@samba.org > > > > Subject: Re: [PATCH v12 3/6] CPM/QE: use genalloc to manage CPM/QE > > > > muram > > > > > > > > On Wed, 2015-10-14 at 15:16 +0800, Zhao Qiang wrote: > > > > > -/** > > > > > +/* > > > > > * cpm_muram_alloc - allocate the requested size worth of > > > > > multi-user > > > ram > > > > > * @size: number of bytes to allocate > > > > > * @align: requested alignment, in bytes @@ -141,59 +151,102 @@ > > > > > out: > > > > > */ > > > > > unsigned long cpm_muram_alloc(unsigned long size, unsigned long > > > > > align) { > > > > > - unsigned long start; > > > > > unsigned long flags; > > > > > - > > > > > + unsigned long start; > > > > > + static struct genpool_data_align muram_pool_data; > > > > > spin_lock_irqsave(&cpm_muram_lock, flags); > > > > > - cpm_muram_info.alignment = align; > > > > > - start = rh_alloc(&cpm_muram_info, size, "commproc"); > > > > > - memset(cpm_muram_addr(start), 0, size); > > > > > + muram_pool_data.align = align; > > > > > + gen_pool_set_algo(muram_pool, gen_pool_first_fit_align, > > > > > + &muram_pool_data); > > > > > + start = cpm_muram_alloc_common(size, &muram_pool_data); > > > > > spin_unlock_irqrestore(&cpm_muram_lock, flags); > > > > > - > > > > > return start; > > > > > } > > > > > EXPORT_SYMBOL(cpm_muram_alloc); > > > > > > > > Why is muram_pool_data static? Why is it being passed to > > > > gen_pool_set_algo()? > > > Cpm_muram use both align algo and fixed algo, so we need to set > > > corresponding algo and Algo data. > > > > The data gets passed in via gen_pool_alloc_data(). The point was to > > allow it to > > be on the caller's stack, not a long-lived data structure shared by all > > callers and > > needing synchronization. > > You mean it is not necessary to point pool->data to data, just passing the > data to gen_pool_alloc_data()? > However, the algo it needed to be set. > > > > > > > The whole reason we're adding gen_pool_alloc_data() is to avoid > > > > that. Do we need gen_pool_alloc_algo() too? > > > > > > We add gen_pool_alloc_data() to pass data to algo, because align algo > > > and fixed algo, Because align and fixed algos need specific data. > > > > And my point is that because of that, it seems like we need a version that > > accepts an algorithm as well. > > It the user just use only one algo, it doesn’t need to set algo, > However, qe_muram use two algos with alloc_align function > And alloc_fixed function.
Yes. That is why gen_pool_alloc_data() does not accomplish what we want. When we were discussing gen_pool_alloc_data(), you had not yet mentioned the need for fixed allocations.
-Scott
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