From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp08.au.ibm.com (e23smtp08.au.ibm.com [202.81.31.141]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 46BD81A04DD for ; Tue, 9 Dec 2014 16:42:40 +1100 (AEDT) Received: from /spool/local by e23smtp08.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 9 Dec 2014 15:42:39 +1000 Received: from d23relay08.au.ibm.com (d23relay08.au.ibm.com [9.185.71.33]) by d23dlp03.au.ibm.com (Postfix) with ESMTP id 621D83578048 for ; Tue, 9 Dec 2014 16:42:36 +1100 (EST) Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay08.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id sB95gS1S36831390 for ; Tue, 9 Dec 2014 16:42:36 +1100 Received: from d23av03.au.ibm.com (localhost [127.0.0.1]) by d23av03.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id sB95g3AK024615 for ; Tue, 9 Dec 2014 16:42:03 +1100 Received: from ozlabs.au.ibm.com (ozlabs.au.ibm.com [9.192.253.14]) by d23av03.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id sB95g3ut024073 for ; Tue, 9 Dec 2014 16:42:03 +1100 Received: from localhost (haven.au.ibm.com [9.192.253.15]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ozlabs.au.ibm.com (Postfix) with ESMTPSA id 89402A019A for ; Tue, 9 Dec 2014 16:41:39 +1100 (AEDT) Content-Type: text/plain; charset=UTF-8 From: Ian Munsie To: linuxppc-dev Subject: Re: [PATCH 7/7] CXL: Unmap MMIO regions when detaching a context In-reply-to: <1418026681-14787-7-git-send-email-imunsie@au.ibm.com> References: <1418026681-14787-1-git-send-email-imunsie@au.ibm.com> <1418026681-14787-7-git-send-email-imunsie@au.ibm.com> Date: Tue, 09 Dec 2014 16:41:39 +1100 Message-Id: <1418103566-sup-1772@delenn.ozlabs.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , This one should go to stable - this was the first bug uncovered after fixing the sleep while atomic and force unbinding the driver. Cheers, -Ian Excerpts from Ian Munsie's message of 2014-12-08 19:18:01 +1100: > From: Ian Munsie > > If we need to force detach a context (e.g. due to EEH or simply force > unbinding the driver) we should prevent the userspace contexts from > being able to access the Problem State Area MMIO region further, which > they may have mapped with mmap(). > > This patch unmaps any mapped MMIO regions when detaching a userspace > context. > > Signed-off-by: Ian Munsie > --- > drivers/misc/cxl/context.c | 11 ++++++++++- > drivers/misc/cxl/cxl.h | 7 ++++++- > drivers/misc/cxl/file.c | 6 +++++- > 3 files changed, 21 insertions(+), 3 deletions(-) > > diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c > index 4aa31a3..51fd6b5 100644 > --- a/drivers/misc/cxl/context.c > +++ b/drivers/misc/cxl/context.c > @@ -34,7 +34,8 @@ struct cxl_context *cxl_context_alloc(void) > /* > * Initialises a CXL context. > */ > -int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master) > +int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master, > + struct address_space *mapping) > { > int i; > > @@ -42,6 +43,8 @@ int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master) > ctx->afu = afu; > ctx->master = master; > ctx->pid = NULL; /* Set in start work ioctl */ > + mutex_init(&ctx->mapping_lock); > + ctx->mapping = mapping; > > /* > * Allocate the segment table before we put it in the IDR so that we > @@ -147,6 +150,12 @@ static void __detach_context(struct cxl_context *ctx) > afu_release_irqs(ctx); > flush_work(&ctx->fault_work); /* Only needed for dedicated process */ > wake_up_all(&ctx->wq); > + > + /* Release Problem State Area mapping */ > + mutex_lock(&ctx->mapping_lock); > + if (ctx->mapping) > + unmap_mapping_range(ctx->mapping, 0, 0, 1); > + mutex_unlock(&ctx->mapping_lock); > } > > /* > diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h > index c1f8aa6..0df0438 100644 > --- a/drivers/misc/cxl/cxl.h > +++ b/drivers/misc/cxl/cxl.h > @@ -405,6 +405,10 @@ struct cxl_context { > phys_addr_t psn_phys; > u64 psn_size; > > + /* Used to unmap any mmaps when force detaching */ > + struct address_space *mapping; > + struct mutex mapping_lock; > + > spinlock_t sste_lock; /* Protects segment table entries */ > struct cxl_sste *sstp; > u64 sstp0, sstp1; > @@ -606,7 +610,8 @@ int cxl_alloc_sst(struct cxl_context *ctx); > void init_cxl_native(void); > > struct cxl_context *cxl_context_alloc(void); > -int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master); > +int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master, > + struct address_space *mapping); > void cxl_context_free(struct cxl_context *ctx); > int cxl_context_iomap(struct cxl_context *ctx, struct vm_area_struct *vma); > > diff --git a/drivers/misc/cxl/file.c b/drivers/misc/cxl/file.c > index 2e067a5..b09be44 100644 > --- a/drivers/misc/cxl/file.c > +++ b/drivers/misc/cxl/file.c > @@ -77,7 +77,7 @@ static int __afu_open(struct inode *inode, struct file *file, bool master) > goto err_put_afu; > } > > - if ((rc = cxl_context_init(ctx, afu, master))) > + if ((rc = cxl_context_init(ctx, afu, master, inode->i_mapping))) > goto err_put_afu; > > pr_devel("afu_open pe: %i\n", ctx->pe); > @@ -113,6 +113,10 @@ static int afu_release(struct inode *inode, struct file *file) > __func__, ctx->pe); > cxl_context_detach(ctx); > > + mutex_lock(&ctx->mapping_lock); > + ctx->mapping = NULL; > + mutex_unlock(&ctx->mapping_lock); > + > put_device(&ctx->afu->dev); > > /*