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| author |   Niklas Schnelle <schnelle@linux.ibm.com> | 2025-02-21 12:51:48 +0100 |
|---|---|---|
| committer |   Vasily Gorbik <gor@linux.ibm.com> | 2025-03-11 15:28:58 +0100 |
| commit | c94bff63e49302d4ce36502a85a2710a67332a4f (patch) | |
| tree | a95842c06973cd6b8fd1ed4a4cc866f90b77a585 | |
| parent | s390/atomic_ops: Let __atomic_add_const() variants always return void (diff) | |
| download | wireguard-linux-c94bff63e49302d4ce36502a85a2710a67332a4f.tar.xz wireguard-linux-c94bff63e49302d4ce36502a85a2710a67332a4f.zip | |
s390: Remove ioremap_wt() and pgprot_writethrough()
It turns out that while s390 architecture calls its memory-I/O mapping
variants write-through and write-back the implementation of ioremap_wt()
and pgprot_writethrough() does not match Linux notion of ioremap_wt().
In particular Linux expects ioremap_wt() to be weaker still than
ioremap_wc(), allowing not just gathering and re-ordering but also reads
to be served from cache. Instead s390's implementation is equivalent to
normal ioremap() while its ioremap_wc() allows re-ordering.
Note that there are no known users of ioremap_wt() on s390 and the
resulting behavior is in line with asm-generic defining ioremap_wt() as
ioremap(), if undefined, so no breakage is expected.
As s390 does not have a mapping type matching the Linux notion of
ioremap_wt() and pgprot_writethrough(), simply drop them and rely on the
asm-generic fallbacks instead.
Fixes: b02002cc4c0f ("s390/pci: Implement ioremap_wc/prot() with MIO")
Fixes: b43b3fff042d ("s390: mm: convert to GENERIC_IOREMAP")
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| -rw-r--r-- | arch/s390/include/asm/io.h | 2 | ||||
| -rw-r--r-- | arch/s390/include/asm/pgtable.h | 3 | ||||
| -rw-r--r-- | arch/s390/mm/pgtable.c | 10 |
3 files changed, 0 insertions, 15 deletions
diff --git a/arch/s390/include/asm/io.h b/arch/s390/include/asm/io.h index fc9933a743d6..251e0372ccbd 100644 --- a/arch/s390/include/asm/io.h +++ b/arch/s390/include/asm/io.h @@ -34,8 +34,6 @@ void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr); #define ioremap_wc(addr, size) \ ioremap_prot((addr), (size), pgprot_val(pgprot_writecombine(PAGE_KERNEL))) -#define ioremap_wt(addr, size) \ - ioremap_prot((addr), (size), pgprot_val(pgprot_writethrough(PAGE_KERNEL))) static inline void __iomem *ioport_map(unsigned long port, unsigned int nr) { diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index fb757f5e220b..e9c2d81f11f8 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -1403,9 +1403,6 @@ void gmap_pmdp_idte_global(struct mm_struct *mm, unsigned long vmaddr); #define pgprot_writecombine pgprot_writecombine pgprot_t pgprot_writecombine(pgprot_t prot); -#define pgprot_writethrough pgprot_writethrough -pgprot_t pgprot_writethrough(pgprot_t prot); - #define PFN_PTE_SHIFT PAGE_SHIFT /* diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index e20fd4c14562..fa66246c1851 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -36,16 +36,6 @@ pgprot_t pgprot_writecombine(pgprot_t prot) } EXPORT_SYMBOL_GPL(pgprot_writecombine); -pgprot_t pgprot_writethrough(pgprot_t prot) -{ - /* - * mio_wb_bit_mask may be set on a different CPU, but it is only set - * once at init and only read afterwards. - */ - return __pgprot(pgprot_val(prot) & ~mio_wb_bit_mask); -} -EXPORT_SYMBOL_GPL(pgprot_writethrough); - static inline void ptep_ipte_local(struct mm_struct *mm, unsigned long addr, pte_t *ptep, int nodat) { |