On 2/14/22 8:00 AM, Anshuman Khandual wrote: > protection_map[] is an array based construct that translates given vm_flags > combination. This array contains page protection map, which is populated by > the platform via [__S000 .. __S111] and [__P000 .. __P111] exported macros. > Primary usage for protection_map[] is for vm_get_page_prot(), which is used > to determine page protection value for a given vm_flags. vm_get_page_prot() > implementation, could again call platform overrides arch_vm_get_page_prot() > and arch_filter_pgprot(). Some platforms override protection_map[] that was > originally built with __SXXX/__PXXX with different runtime values. > > Currently there are multiple layers of abstraction i.e __SXXX/__PXXX macros > , protection_map[], arch_vm_get_page_prot() and arch_filter_pgprot() built > between the platform and generic MM, finally defining vm_get_page_prot(). > > Hence this series proposes to drop all these abstraction levels and instead > just move the responsibility of defining vm_get_page_prot() to the platform > itself making it clean and simple. > > This first introduces ARCH_HAS_VM_GET_PAGE_PROT which enables the platforms > to define custom vm_get_page_prot(). This starts converting platforms that > either change protection_map[] or define the overrides arch_filter_pgprot() > or arch_vm_get_page_prot() which enables for those constructs to be dropped > off completely. This series then converts remaining platforms which enables > for __SXXX/__PXXX constructs to be dropped off completely. Finally it drops > the generic vm_get_page_prot() and then ARCH_HAS_VM_GET_PAGE_PROT as every > platform now defines their own vm_get_page_prot(). > > The series has been inspired from an earlier discuss with Christoph Hellwig > > https://lore.kernel.org/all/1632712920-8171-1-git-send-email-anshuman.khandual@xxxxxxx/ > > This series applies on 5.17-rc3 after the following patch. > > https://lore.kernel.org/all/1643004823-16441-1-git-send-email-anshuman.khandual@xxxxxxx/ > > This series has been cross built for multiple platforms. > > - Anshuman > > Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: linux-mm@xxxxxxxxx > Cc: linux-arch@xxxxxxxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx > > Changes in V1: > > - Add white spaces around the | operators > - Moved powerpc_vm_get_page_prot() near vm_get_page_prot() on powerpc > - Moved arm64_vm_get_page_prot() near vm_get_page_prot() on arm64 > - Moved sparc_vm_get_page_prot() near vm_get_page_prot() on sparc > - Compacted vm_get_page_prot() switch cases on all platforms > - _PAGE_CACHE040 inclusion is dependent on CPU_IS_040_OR_060 > - VM_SHARED case should return PAGE_NONE (not PAGE_COPY) on SH platform > - Reorganized VM_SHARED, VM_EXEC, VM_WRITE, VM_READ > - Dropped the last patch [RFC V1 31/31] which added macros for vm_flags combinations > https://lore.kernel.org/all/1643029028-12710-32-git-send-email-anshuman.khandual@xxxxxxx/ Hello, Just a gentle ping. I am planning to respin the series earlier next week on v5.17-rc5 with the build failure fixes and also accommodating a review comment from Geert. But will really appreciate some more reviews/comments/ suggestions as the series changes code in every platform. Although all individual patches copy required reviewers and mailing lists, I am wondering should they all be included in the cover letter and copied for individual patches as well via cc-cover. But previously, patches with many emails copied, faced problems while being delivered to mailing lists. - Anshuman
