Motivation and implementation: ============================== Currently, many architecutres have't taken the standard GENERIC_IOREMAP way to implement ioremap_prot(), iounmap(), and ioremap_xx(), but make these functions specifically under each arch's folder. Those cause many duplicated codes of ioremap() and iounmap(). In this patchset, firstly introduce generic_ioremap_prot() and generic_iounmap() to extract the generic codes for GENERIC_IOREMAP. By taking GENERIC_IOREMAP method, the generic generic_ioremap_prot(), generic_iounmap(), and their generic wrapper ioremap_prot(), ioremap() and iounmap() are all visible and available to arch. Arch needs to provide wrapper functions to override the generic version if there's arch specific handling in its corresponding ioremap_prot(), ioremap() or iounmap(). With these changes, duplicated ioremap/iounmap() code uder ARCH-es are removed, and the equivalent functioality is kept as before. Background info: ================ 1) The converting more architectures to take GENERIC_IOREMAP way is suggested by Christoph in below discussion: https://lore.kernel.org/all/Yp7h0Jv6vpgt6xdZ@xxxxxxxxxxxxx/T/#u 2) In the previous v1 to v3, it's basically further action after arm64 has converted to GENERIC_IOREMAP way in below patchset. It's done by adding hook ioremap_allowed() and iounmap_allowed() in ARCH to add ARCH specific handling the middle of ioremap_prot() and iounmap(). [PATCH v5 0/6] arm64: Cleanup ioremap() and support ioremap_prot() https://lore.kernel.org/all/20220607125027.44946-1-wangkefeng.wang@xxxxxxxxxx/T/#u Later, during v3 reviewing, Christophe Leroy suggested to introduce generic_ioremap_prot() and generic_iounmap() to generic codes, and ARCH can provide wrapper function ioremap_prot(), ioremap() or iounmap() if needed. Christophe made a RFC patchset as below to specially demonstrate his idea. This is what v4 is doing. [RFC PATCH 0/8] mm: ioremap: Convert architectures to take GENERIC_IOREMAP way https://lore.kernel.org/all/cover.1665568707.git.christophe.leroy@xxxxxxxxxx/T/#u Testing: ======== - It's running well on arm64, s390x, ppc64le with this patchset applied on the latest upstream kernel 6.2-rc8+. - Cross compiling passed on arc, ia64, parisc, sh, xtensa. - cross compiling is not tried on hexagon, openrisc and powerpc 32bit because: - Didn't find cross compiling tools for hexagon, ppc 32bit; - there's error with openrisc compiling, while I have no idea how to fix it. Please see below pasted log: --------------------------------------------------------------------- [root@intel-knightslanding-lb-02 linux]# make ARCH=openrisc defconfig *** Default configuration is based on 'or1ksim_defconfig' # # configuration written to .config # [root@intel-knightslanding-lb-02 linux]# make ARCH=openrisc -j320 CROSS_COMPILE=/usr/bin/openrisc-linux-gnu- SYNC include/config/auto.conf.cmd CC scripts/mod/empty.o ./scripts/check-local-export: /usr/bin/openrisc-linux-gnu-nm failed make[1]: *** [scripts/Makefile.build:250: scripts/mod/empty.o] Error 1 make[1]: *** Deleting file 'scripts/mod/empty.o' make: *** [Makefile:1275: prepare0] Error 2 ---------------------------------------------------------------------- History: ======= v3->v4: - Change to contain arch specific handling in wrapper function ioremap(), ioremap_prot() or iounmap() to replace the old hook ioremap|iounmap_allowed() hook way for each arch. - Add two patches to convert powerpc to GENERIC_IOREMAP. They are picked from above Christophe's RFC patchset, I made some changes to make them formal. v2->v3: - Rewrite log of all patches to add more details as Christoph suggested. - Merge the old patch 1 and 2 which adjusts return values and parameters of arch_ioremap() into one patch, namely the current patch 3. Christoph suggested this. - Change the return value of arch_iounmap() to bool type since we only do arch specific address filtering or address checking, bool value can reflect the checking better. This is pointed out by Niklas when he reviewed the s390 patch. - Put hexagon patch at the beginning of patchset since hexagon has the same ioremap() and iounmap() as standard ones, no arch_ioremap() and arch_iounmap() hooks need be introduced. So the later arch_ioremap and arch_iounmap() adjustment are not related in hexagon. Christophe suggested this. - Remove the early ioremap code from openrisc ioremap() firstly since openrisc doesn't have early ioremap handling in openrisc arch code. This simplifies the later converting to GENERIC_IOREMAP method. Christoph and Stafford suggersted this. - Fix compiling erorrs reported by lkp in parisc and sh patches. Adding macro defintions for those port|mem io functions in <asm/io.h> to avoid repeated definition in <asm-generic/io.h>. v1->v2: - Rename io[re|un]map_allowed() to arch_io[re|un]map() and made some minor changes in patch 1~2 as per Alexander and Kefeng's suggestions. Accordingly, adjust patches~4~11 because of the renaming arch_io[re|un]map(). Baoquan He (13): hexagon: mm: Convert to GENERIC_IOREMAP openrisc: mm: remove unneeded early ioremap code mm: ioremap: allow ARCH to have its own ioremap method definition mm/ioremap: add slab availability checking in ioremap_prot arc: mm: Convert to GENERIC_IOREMAP ia64: mm: Convert to GENERIC_IOREMAP openrisc: mm: Convert to GENERIC_IOREMAP s390: mm: Convert to GENERIC_IOREMAP sh: mm: Convert to GENERIC_IOREMAP xtensa: mm: Convert to GENERIC_IOREMAP parisc: mm: Convert to GENERIC_IOREMAP arm64 : mm: add wrapper function ioremap_prot() mm: ioremap: remove unneeded ioremap_allowed and iounmap_allowed Christophe Leroy (3): mm/ioremap: Define generic_ioremap_prot() and generic_iounmap() mm/ioremap: Consider IOREMAP space in generic ioremap powerpc: mm: Convert to GENERIC_IOREMAP arch/arc/Kconfig | 1 + arch/arc/include/asm/io.h | 7 ++-- arch/arc/mm/ioremap.c | 49 ++--------------------- arch/arm64/include/asm/io.h | 3 +- arch/arm64/mm/ioremap.c | 10 +++-- arch/hexagon/Kconfig | 1 + arch/hexagon/include/asm/io.h | 9 ++++- arch/hexagon/mm/ioremap.c | 44 --------------------- arch/ia64/Kconfig | 1 + arch/ia64/include/asm/io.h | 13 +++---- arch/ia64/mm/ioremap.c | 41 +++---------------- arch/openrisc/Kconfig | 1 + arch/openrisc/include/asm/io.h | 11 ++++-- arch/openrisc/mm/ioremap.c | 58 +-------------------------- arch/parisc/Kconfig | 1 + arch/parisc/include/asm/io.h | 17 +++++--- arch/parisc/mm/ioremap.c | 62 ++--------------------------- arch/powerpc/Kconfig | 1 + arch/powerpc/include/asm/io.h | 8 ++-- arch/powerpc/mm/ioremap.c | 26 +------------ arch/powerpc/mm/ioremap_32.c | 19 +++++---- arch/powerpc/mm/ioremap_64.c | 12 +----- arch/s390/Kconfig | 1 + arch/s390/include/asm/io.h | 21 +++++----- arch/s390/pci/pci.c | 57 +++++---------------------- arch/sh/Kconfig | 1 + arch/sh/include/asm/io.h | 65 ++++++++++++++++--------------- arch/sh/include/asm/io_noioport.h | 7 ++++ arch/sh/mm/ioremap.c | 65 ++++++------------------------- arch/xtensa/Kconfig | 1 + arch/xtensa/include/asm/io.h | 32 ++++++--------- arch/xtensa/mm/ioremap.c | 58 +++++++-------------------- include/asm-generic/io.h | 31 +++------------ mm/ioremap.c | 41 +++++++++++++------ 34 files changed, 214 insertions(+), 561 deletions(-) delete mode 100644 arch/hexagon/mm/ioremap.c -- 2.34.1
