From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 44BB1F459FC for ; Fri, 10 Apr 2026 18:13:38 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B381A10E9B5; Fri, 10 Apr 2026 18:13:37 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=collabora.com header.i=@collabora.com header.b="VfS2NJLg"; dkim-atps=neutral Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2BEE410E9B5 for ; Fri, 10 Apr 2026 18:13:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1775844814; bh=Bm+PCjeh7kObuA2fQ4qTkn6YdyYabvbqHjnxY40+HTE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=VfS2NJLgpBhva1CcYD8aG2W4XgCl8LdK4tlsXZ66UzTSL4ocUCgDbhZDQGQEs5hYB OccQKs7fyT6P7GEkDuxtILvJjLfNeuMvQQku7lcL3r+wtioXq0rzw8KN/PLKMWJVdn bWeNZhQf4KFGFcW6B161XIiLMn/ne7PGOjsBYUGdHUKgSY2KGWvR8MLrhh0w0ZTBxN MqaSLjigPlWe6b5crwdpq5n2xOL3mgFrb5/lA5u+F4mm5EpRtVVUlVwiGy/+bJi/ig SgaQqy9wwnleRiA/hU9d/GdtLscMQtGcJOo8vXZaqXMRQX3KGoYCaWyMAxOxgXusGt 9VCqBxRo/2c3g== Received: from fedora (unknown [100.64.0.11]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bbrezillon) by bali.collaboradmins.com (Postfix) with ESMTPSA id 7C34117E10F4; Fri, 10 Apr 2026 20:13:34 +0200 (CEST) Date: Fri, 10 Apr 2026 20:13:31 +0200 From: Boris Brezillon To: Karunika Choo Cc: dri-devel@lists.freedesktop.org, nd@arm.com, Steven Price , Liviu Dudau , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , linux-kernel@vger.kernel.org Subject: Re: [PATCH 8/8] drm/panthor: Use a local iomem base for MMU AS registers Message-ID: <20260410201331.4c76a073@fedora> In-Reply-To: <20260410164637.549145-9-karunika.choo@arm.com> References: <20260410164637.549145-1-karunika.choo@arm.com> <20260410164637.549145-9-karunika.choo@arm.com> Organization: Collabora X-Mailer: Claws Mail 4.3.1 (GTK 3.24.51; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Fri, 10 Apr 2026 17:46:37 +0100 Karunika Choo wrote: > Add an MMU_AS_CONTROL local iomem pointer to struct panthor_mmu and > switch AS register accesses to that base. > > Interrupt accesses remain routed through the IRQ-local iomem base, while > the MMU register definitions are adjusted so AS registers are expressed > relative to the local MMU AS window. This completes the conversion away > from using the global device mapping for MMU AS register accesses. > > No functional change intended. > > Signed-off-by: Karunika Choo Acked-by: Boris Brezillon > --- > drivers/gpu/drm/panthor/panthor_mmu.c | 35 ++++++++++++++-------- > drivers/gpu/drm/panthor/panthor_mmu_regs.h | 10 ++----- > 2 files changed, 25 insertions(+), 20 deletions(-) > > diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c > index b8665e447d95..0767e148369d 100644 > --- a/drivers/gpu/drm/panthor/panthor_mmu.c > +++ b/drivers/gpu/drm/panthor/panthor_mmu.c > @@ -55,6 +55,9 @@ struct panthor_as_slot { > * struct panthor_mmu - MMU related data > */ > struct panthor_mmu { > + /** @iomem: CPU mapping of MMU_AS_CONTROL iomem region */ > + void __iomem *iomem; > + > /** @irq: The MMU irq. */ > struct panthor_irq irq; > > @@ -517,13 +520,14 @@ static void free_pt(void *cookie, void *data, size_t size) > > static int wait_ready(struct panthor_device *ptdev, u32 as_nr) > { > + struct panthor_mmu *mmu = ptdev->mmu; > int ret; > u32 val; > > /* Wait for the MMU status to indicate there is no active command, in > * case one is pending. > */ > - ret = gpu_read_relaxed_poll_timeout_atomic(ptdev->iomem, AS_STATUS(as_nr), val, > + ret = gpu_read_relaxed_poll_timeout_atomic(mmu->iomem, AS_STATUS(as_nr), val, > !(val & AS_STATUS_AS_ACTIVE), 10, 100000); > > if (ret) { > @@ -541,7 +545,7 @@ static int as_send_cmd_and_wait(struct panthor_device *ptdev, u32 as_nr, u32 cmd > /* write AS_COMMAND when MMU is ready to accept another command */ > status = wait_ready(ptdev, as_nr); > if (!status) { > - gpu_write(ptdev->iomem, AS_COMMAND(as_nr), cmd); > + gpu_write(ptdev->mmu->iomem, AS_COMMAND(as_nr), cmd); > status = wait_ready(ptdev, as_nr); > } > > @@ -589,12 +593,14 @@ PANTHOR_IRQ_HANDLER(mmu, panthor_mmu_irq_handler); > static int panthor_mmu_as_enable(struct panthor_device *ptdev, u32 as_nr, > u64 transtab, u64 transcfg, u64 memattr) > { > + struct panthor_mmu *mmu = ptdev->mmu; > + > panthor_mmu_irq_enable_events(&ptdev->mmu->irq, > panthor_mmu_as_fault_mask(ptdev, as_nr)); > > - gpu_write64(ptdev->iomem, AS_TRANSTAB(as_nr), transtab); > - gpu_write64(ptdev->iomem, AS_MEMATTR(as_nr), memattr); > - gpu_write64(ptdev->iomem, AS_TRANSCFG(as_nr), transcfg); > + gpu_write64(mmu->iomem, AS_TRANSTAB(as_nr), transtab); > + gpu_write64(mmu->iomem, AS_MEMATTR(as_nr), memattr); > + gpu_write64(mmu->iomem, AS_TRANSCFG(as_nr), transcfg); > > return as_send_cmd_and_wait(ptdev, as_nr, AS_COMMAND_UPDATE); > } > @@ -602,6 +608,7 @@ static int panthor_mmu_as_enable(struct panthor_device *ptdev, u32 as_nr, > static int panthor_mmu_as_disable(struct panthor_device *ptdev, u32 as_nr, > bool recycle_slot) > { > + struct panthor_mmu *mmu = ptdev->mmu; > struct panthor_vm *vm = ptdev->mmu->as.slots[as_nr].vm; > int ret; > > @@ -629,9 +636,9 @@ static int panthor_mmu_as_disable(struct panthor_device *ptdev, u32 as_nr, > if (recycle_slot) > return 0; > > - gpu_write64(ptdev->iomem, AS_TRANSTAB(as_nr), 0); > - gpu_write64(ptdev->iomem, AS_MEMATTR(as_nr), 0); > - gpu_write64(ptdev->iomem, AS_TRANSCFG(as_nr), AS_TRANSCFG_ADRMODE_UNMAPPED); > + gpu_write64(mmu->iomem, AS_TRANSTAB(as_nr), 0); > + gpu_write64(mmu->iomem, AS_MEMATTR(as_nr), 0); > + gpu_write64(mmu->iomem, AS_TRANSCFG(as_nr), AS_TRANSCFG_ADRMODE_UNMAPPED); > > return as_send_cmd_and_wait(ptdev, as_nr, AS_COMMAND_UPDATE); > } > @@ -784,7 +791,7 @@ int panthor_vm_active(struct panthor_vm *vm) > */ > fault_mask = panthor_mmu_as_fault_mask(ptdev, as); > if (ptdev->mmu->as.faulty_mask & fault_mask) { > - gpu_write(ptdev->iomem, MMU_INT_CLEAR, fault_mask); > + gpu_write(ptdev->mmu->irq.iomem, INT_CLEAR, fault_mask); > ptdev->mmu->as.faulty_mask &= ~fault_mask; > } > > @@ -1712,7 +1719,7 @@ static int panthor_vm_lock_region(struct panthor_vm *vm, u64 start, u64 size) > mutex_lock(&ptdev->mmu->as.slots_lock); > if (vm->as.id >= 0 && size) { > /* Lock the region that needs to be updated */ > - gpu_write64(ptdev->iomem, AS_LOCKADDR(vm->as.id), > + gpu_write64(ptdev->mmu->iomem, AS_LOCKADDR(vm->as.id), > pack_region_range(ptdev, &start, &size)); > > /* If the lock succeeded, update the locked_region info. */ > @@ -1761,6 +1768,7 @@ static void panthor_vm_unlock_region(struct panthor_vm *vm) > > static void panthor_mmu_irq_handler(struct panthor_device *ptdev, u32 status) > { > + struct panthor_mmu *mmu = ptdev->mmu; > bool has_unhandled_faults = false; > > status = panthor_mmu_fault_mask(ptdev, status); > @@ -1773,8 +1781,8 @@ static void panthor_mmu_irq_handler(struct panthor_device *ptdev, u32 status) > u32 access_type; > u32 source_id; > > - fault_status = gpu_read(ptdev->iomem, AS_FAULTSTATUS(as)); > - addr = gpu_read64(ptdev->iomem, AS_FAULTADDRESS(as)); > + fault_status = gpu_read(mmu->iomem, AS_FAULTSTATUS(as)); > + addr = gpu_read64(mmu->iomem, AS_FAULTADDRESS(as)); > > /* decode the fault status */ > exception_type = fault_status & 0xFF; > @@ -1805,7 +1813,7 @@ static void panthor_mmu_irq_handler(struct panthor_device *ptdev, u32 status) > * Note that COMPLETED irqs are never cleared, but this is fine > * because they are always masked. > */ > - gpu_write(ptdev->iomem, MMU_INT_CLEAR, mask); > + gpu_write(mmu->irq.iomem, INT_CLEAR, mask); > > if (ptdev->mmu->as.slots[as].vm) > ptdev->mmu->as.slots[as].vm->unhandled_fault = true; > @@ -3222,6 +3230,7 @@ int panthor_mmu_init(struct panthor_device *ptdev) > if (ret) > return ret; > > + mmu->iomem = ptdev->iomem + MMU_AS_BASE; > ptdev->mmu = mmu; > > irq = platform_get_irq_byname(to_platform_device(ptdev->base.dev), "mmu"); > diff --git a/drivers/gpu/drm/panthor/panthor_mmu_regs.h b/drivers/gpu/drm/panthor/panthor_mmu_regs.h > index de460042651d..4e32ab931949 100644 > --- a/drivers/gpu/drm/panthor/panthor_mmu_regs.h > +++ b/drivers/gpu/drm/panthor/panthor_mmu_regs.h > @@ -8,16 +8,12 @@ > > #define MMU_INT_BASE 0x2000 > > -#define MMU_INT_RAWSTAT 0x2000 > -#define MMU_INT_CLEAR 0x2004 > -#define MMU_INT_MASK 0x2008 > -#define MMU_INT_STAT 0x200c > - > /* AS_COMMAND register commands */ > > -#define MMU_BASE 0x2400 > +#define MMU_AS_BASE 0x2400 > + > #define MMU_AS_SHIFT 6 > -#define MMU_AS(as) (MMU_BASE + ((as) << MMU_AS_SHIFT)) > +#define MMU_AS(as) ((as) << MMU_AS_SHIFT) > > #define AS_TRANSTAB(as) (MMU_AS(as) + 0x0) > #define AS_MEMATTR(as) (MMU_AS(as) + 0x8)