From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from asavdk4.altibox.net ([109.247.116.15]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1fJmCF-0007MS-Mf for barebox@lists.infradead.org; Fri, 18 May 2018 20:41:53 +0000 Date: Fri, 18 May 2018 22:41:37 +0200 From: Sam Ravnborg Message-ID: <20180518204137.GC26895@ravnborg.org> References: <20180517205837.32421-1-andrew.smirnov@gmail.com> <20180517205837.32421-25-andrew.smirnov@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20180517205837.32421-25-andrew.smirnov@gmail.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH v3 24/28] ARM: mmu: Use find_pte() to find PTE in create_vector_table() To: Andrey Smirnov Cc: barebox@lists.infradead.org Hi Andrey. On Thu, May 17, 2018 at 01:58:33PM -0700, Andrey Smirnov wrote: > There's already a function that implement necessary arithemtic to find > offset within page table for a given address, so make use of it > instead of re-implementing it again. > > Signed-off-by: Andrey Smirnov > --- > arch/arm/cpu/mmu.c | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) > > diff --git a/arch/arm/cpu/mmu.c b/arch/arm/cpu/mmu.c > index 21394deb1..f9e4d1a50 100644 > --- a/arch/arm/cpu/mmu.c > +++ b/arch/arm/cpu/mmu.c > @@ -272,8 +272,7 @@ static void create_vector_table(unsigned long adr) > { > struct resource *vectors_sdram; > void *vectors; > - u32 *exc; > - int idx; > + u32 *pte; > > vectors_sdram = request_sdram_region("vector table", adr, PAGE_SIZE); > if (vectors_sdram) { > @@ -293,9 +292,9 @@ static void create_vector_table(unsigned long adr) > vectors = xmemalign(PAGE_SIZE, PAGE_SIZE); > pr_debug("Creating vector table, virt = 0x%p, phys = 0x%08lx\n", > vectors, adr); > - exc = arm_create_pte(adr, pte_flags_uncached); > - idx = (adr & (PGDIR_SIZE - 1)) >> PAGE_SHIFT; > - exc[idx] = (u32)vectors | PTE_TYPE_SMALL | pte_flags_cached; > + arm_create_pte(adr, pte_flags_uncached); > + pte = find_pte(adr); > + *pte = (u32)vectors | PTE_TYPE_SMALL | pte_flags_cached; This looks more elegant, but the cost here is that find_pte() is more expensive than the simple array operations done before. I am not sure if this is needed in followig patches, it just looks a bit expensive. Sam _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox