From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Wed, 17 May 2023 15:09:07 +0200 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1pzGtw-004Jxh-Em for lore@lore.pengutronix.de; Wed, 17 May 2023 15:09:07 +0200 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1pzGtt-0003DA-VN for lore@pengutronix.de; Wed, 17 May 2023 15:09:06 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Cc:Content-ID:Content-Description:Resent-Date:Resent-From :Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=w0uRClvopS+0ly1JCdXX1edAqd3uncSGYfbZst+iv8E=; b=nt1EAXj6ED2YxoQacicexy/W4A FAhq+VP/Y/zuhVb8TCmd7ksdz39QVWfqC3Ssmgx58UGottk/DUCBmI2D4oUs3t8C2R4CgFifSVOog UrNMGi8kOKONr6kjWmbcQsI/9ztHWkrOrKEpK9y7iFRsEsgKgA52Cns80jOHmutzWYmILsn94PkBN 2Uy7sKGW1Xl/8WH9DkAJWoxRnz+lDzcFjWgZsM7/d+TkNEqsLpeTEpZQGKWaX40P2Hd7DN8CQxv9D cU3PBh8EQeAzPjm5TxbFkBAVD62cj2LRKRfSriV4666fJI2jLtxFnBRsW26PB1LTcOM9knwbLp0bv FvHqnVrw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pzGss-009tcs-15; Wed, 17 May 2023 13:08:02 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pzGso-009tcP-11 for barebox@lists.infradead.org; Wed, 17 May 2023 13:07:59 +0000 Received: from ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=[127.0.0.1]) by metis.ext.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1pzGsl-00033v-FB; Wed, 17 May 2023 15:07:56 +0200 Message-ID: <0ecc83c7-dba6-e6d0-9332-d0d21d1d450d@pengutronix.de> Date: Wed, 17 May 2023 15:07:51 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.9.1 Content-Language: en-US To: Sascha Hauer , Barebox List References: <20230517090340.3954615-1-s.hauer@pengutronix.de> <20230517090340.3954615-23-s.hauer@pengutronix.de> From: Ahmad Fatoum In-Reply-To: <20230517090340.3954615-23-s.hauer@pengutronix.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230517_060758_353248_E6AB520D X-CRM114-Status: GOOD ( 25.72 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.ext.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-5.5 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_NONE,T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: [PATCH v2 22/34] ARM: mmu32: create alloc_pte() X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.ext.pengutronix.de) On 17.05.23 11:03, Sascha Hauer wrote: > This is a preparation for using two level page tables in the PBL. > To do that we need a way to allocate page tables in PBL. As malloc > is not available in PBL, implement a function to allocate a page table > from the area we also place the TTB. > > Signed-off-by: Sascha Hauer > --- > arch/arm/cpu/mmu_32.c | 24 ++++++++++++++++++++++-- > 1 file changed, 22 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/cpu/mmu_32.c b/arch/arm/cpu/mmu_32.c > index 4050d96846..a82382ad1e 100644 > --- a/arch/arm/cpu/mmu_32.c > +++ b/arch/arm/cpu/mmu_32.c > @@ -76,6 +76,27 @@ static bool pgd_type_table(u32 pgd) > return (pgd & PMD_TYPE_MASK) == PMD_TYPE_TABLE; > } > > +#define PTE_SIZE (PTRS_PER_PTE * sizeof(u32)) > + > +#ifdef __PBL__ > +static uint32_t *alloc_pte(void) > +{ > + static unsigned int idx = 3; Can you add a comment explaining the choice of initial index? > + > + idx++; I know it's a quite construed example, but if one calls alloc_pte often enough, it will start returning non-NULL pointers after having returned NULL before. > + > + if (idx * PTE_SIZE >= ARM_EARLY_PAGETABLE_SIZE) > + return NULL; > + > + return (void *)ttb + idx * PTE_SIZE; To address above point, just replace idx with idx++ (and 3 with 4?). > +} > +#else > +static uint32_t *alloc_pte(void) > +{ > + return xmemalign(PTE_SIZE, PTE_SIZE); > +} > +#endif > + > static u32 *find_pte(unsigned long adr) > { > u32 *table; > @@ -125,8 +146,7 @@ static u32 *arm_create_pte(unsigned long virt, uint32_t flags) > > virt = ALIGN_DOWN(virt, PGDIR_SIZE); > > - table = xmemalign(PTRS_PER_PTE * sizeof(u32), > - PTRS_PER_PTE * sizeof(u32)); > + table = alloc_pte(); > > if (!ttb) > arm_mmu_not_initialized_error(); -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |