From nobody Tue Feb 10 09:10:46 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1518202965279976.1588408534809; Fri, 9 Feb 2018 11:02:45 -0800 (PST) Received: from localhost ([::1]:57174 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ekDwa-0001mg-7O for importer@patchew.org; Fri, 09 Feb 2018 14:02:44 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43450) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ekDmI-0001Lc-20 for qemu-devel@nongnu.org; Fri, 09 Feb 2018 13:52:07 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ekDmG-0004fA-Jl for qemu-devel@nongnu.org; Fri, 09 Feb 2018 13:52:06 -0500 Received: from chuckie.co.uk ([82.165.15.123]:49636 helo=s16892447.onlinehome-server.info) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ekDmG-0004eO-Da; Fri, 09 Feb 2018 13:52:04 -0500 Received: from host109-156-184-151.range109-156.btcentralplus.com ([109.156.184.151] helo=kentang.home) by s16892447.onlinehome-server.info with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1ekDmR-0004RR-Ep; Fri, 09 Feb 2018 18:52:16 +0000 From: Mark Cave-Ayland To: qemu-devel@nongnu.org, qemu-ppc@nongnu.org, david@gibson.dropbear.id.au, lvivier@redhat.com Date: Fri, 9 Feb 2018 18:51:38 +0000 Message-Id: <20180209185142.17151-9-mark.cave-ayland@ilande.co.uk> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20180209185142.17151-1-mark.cave-ayland@ilande.co.uk> References: <20180209185142.17151-1-mark.cave-ayland@ilande.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-SA-Exim-Connect-IP: 109.156.184.151 X-SA-Exim-Mail-From: mark.cave-ayland@ilande.co.uk X-SA-Exim-Version: 4.2.1 (built Sun, 08 Jan 2012 02:45:44 +0000) X-SA-Exim-Scanned: Yes (on s16892447.onlinehome-server.info) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 82.165.15.123 Subject: [Qemu-devel] [PATCHv2 08/12] cuda: factor out timebase-derived counter value and load time X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Commit b981289c49 "PPC: Cuda: Use cuda timer to expose tbfreq to guest" alt= ered the timer calculations from those based upon the hardware CUDA clock freque= ncy to those based upon the CPU timebase frequency. In fact we can isolate the differences to 2 simple changes: one to the coun= ter read value and another to the counter load time. Move these changes into separate functions so the implementation can be swapped later. Signed-off-by: Mark Cave-Ayland Reviewed-by: Philippe Mathieu-Daud=C3=A9 --- hw/misc/macio/cuda.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/hw/misc/macio/cuda.c b/hw/misc/macio/cuda.c index e00df4a21a..a185252144 100644 --- a/hw/misc/macio/cuda.c +++ b/hw/misc/macio/cuda.c @@ -145,21 +145,29 @@ static void cuda_update_irq(CUDAState *s) } } =20 -static uint64_t get_tb(uint64_t time, uint64_t freq) +static uint64_t get_counter_value(CUDAState *s, CUDATimer *ti) { - return muldiv64(time, freq, NANOSECONDS_PER_SECOND); + /* Reverse of the tb calculation algorithm that Mac OS X uses on bootu= p */ + uint64_t tb_diff =3D muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), + s->tb_frequency, NANOSECONDS_PER_SECOND) - + ti->load_time; + + return (tb_diff * 0xBF401675E5DULL) / (s->tb_frequency << 24); +} + +static uint64_t get_counter_load_time(CUDAState *s, CUDATimer *ti) +{ + uint64_t load_time =3D muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), + s->tb_frequency, NANOSECONDS_PER_SECOND); + return load_time; } =20 static unsigned int get_counter(CUDAState *s, CUDATimer *ti) { int64_t d; unsigned int counter; - uint64_t tb_diff; - uint64_t current_time =3D qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); =20 - /* Reverse of the tb calculation algorithm that Mac OS X uses on bootu= p. */ - tb_diff =3D get_tb(current_time, s->tb_frequency) - ti->load_time; - d =3D (tb_diff * 0xBF401675E5DULL) / (s->tb_frequency << 24); + d =3D get_counter_value(s, ti); =20 if (ti->index =3D=3D 0) { /* the timer goes down from latch to -1 (period of latch + 2) */ @@ -178,8 +186,7 @@ static unsigned int get_counter(CUDAState *s, CUDATimer= *ti) static void set_counter(CUDAState *s, CUDATimer *ti, unsigned int val) { CUDA_DPRINTF("T%d.counter=3D%d\n", 1 + ti->index, val); - ti->load_time =3D get_tb(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), - s->tb_frequency); + ti->load_time =3D get_counter_load_time(s, ti); ti->counter_value =3D val; cuda_timer_update(s, ti, ti->load_time); } --=20 2.11.0