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Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Marek Szyprowski , Robin Murphy , Sumit Semwal , Benjamin Gaignard , Brian Starkey , John Stultz , "T.J. Mercier" , Christian =?iso-8859-1?Q?K=F6nig?= , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Catalin Marinas , Will Deacon , Chun Ng , Mark Rutland , Saravana Kannan , Thierry Reding , devicetree@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux.dev, linaro-mm-sig@lists.linaro.org, linux-trace-kernel@vger.kernel.org, Thierry Reding Subject: Re: [PATCH v6 04/12] arm64/mm: Export set_direct_map_*_noflush() APIs Message-ID: References: <20260904-tegra-vpr-v6-0-79042cfa8de5@nvidia.com> <20260904-tegra-vpr-v6-4-79042cfa8de5@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260904-tegra-vpr-v6-4-79042cfa8de5@nvidia.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: A822C40003 X-Stat-Signature: ctd1g3iht957gxfdrfswactcuryf3sy1 X-HE-Tag: 1789019523-559244 X-HE-Meta: U2FsdGVkX1+TWCxnP0bn9EWjTgdnMT9I4DtLRerulG+fBlzPeyzWNW5MRjbfllIgqyZP5pgqEgewxzz9BT4LjKRL1KHbJLiK3q6a/GUAz9FDaSW3r5TXSV5CIAxe2k7m+d1Ot0KeD86KYpBJ+/IJmg1QkpQq2x1/FjI9Sd49MW1XxAQuDoGWnhHOi+vA1jqMbAUiX6BVRRsv3yISh9VJ12nse45373noXPuW3F2fAotmLZapIBMMLWNfHeBUQEvBzoq+4qCm6xbQ/zRVRnzsFwbMY34mQkqFclpZpRcgwPAYwnEqkdf/1tLJ1JKL8YVY+RXB8SN2zUUFw3Ju4d/kpsLllLdtvpyHIbKFWOmDqVIcZa3oLszqqKWCe/9R7XmgLAxGG03MpV+pOtEatJmF9SFJzQofYOsHvmFPiFakJr/fkXZfeGihbGDIsQMWH8ZuMc/dyUpwqIdK/bRS+gbhzR2RCD/kf9/FqhRQdcjqISmhWejQNEcuwWaNmaubsHmwxtJ+WLAOtRHO7HTCo2LDMwNS//OszmsWEddwa7FJu3YTQkgvLgGWDYlhpHZsgK/7Hzokh9WZ6+7OzJmfDSnrjKYJJXcSx9dDJBjWCgvrjGtTyZXOseye8SpLjraduC/AAVo65Tzc+HDhURvsd5HFpGjhUQgU8pUbP9YzYV5i9KnZUdL2HAAy3Mk+rEpCK1Sc+2VDuujWnkdk2xmuaVT+mzvZHQM/B12KWamkW2ZPGvHqHiTk2UDeXPW94LQKx4vEtoWPzUVa4e+Q0lQwDOBqOYeLiP2g/xqcAtNLijgNNlnCgt/kOYFW/Jy77h0qna5gNnZFe+lMj12pgBKYq/F+rMcP7yfJusJPno3ICK7McuaCaz5ZbvV+tAvhOwLFH9tfVgJESDCCQAuv1s0386mguTBghRBnAOQDbFBueKKzLww34vlIZrGWoQIwRqSC9fWuv4ihbhEJ7RClh5coM5Y 9qvYTrH+ 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Sep 04, 2026 at 12:44:55PM +0200, Thierry Reding wrote: > From: Thierry Reding > > Drivers that use this may want to be built as a module, so export them. That's one of the worst commit log ever. No, we don't just export core symbols dealing with the kernel direct map because "Drivers that use this may want to be built as a module". For one exporting this at all needs a very good justification and not just hand waiving. But more importantly if we can't avoid exporting it, it needs to be exported at the tightest sensible scope. E.g. for a given module if it is so special, or a namespace if it's not that special. But in doubt we should have a proper core abstraction instead of opening up direct map manipulation to random modules.