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| author | Niklas Schnelle <schnelle@linux.ibm.com> | 2021-02-19 14:00:52 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-14 17:56:42 +0300 |
| commit | 485b1c02b543fff54b0c33243d95b1a7f4fe06de (patch) | |
| tree | e9414ba980032797ad1ab48fc30816e319ebbe5c /arch/s390 | |
| parent | d65f69deac5cf916cc27762bccde8c8874421cae (diff) | |
| download | linux-485b1c02b543fff54b0c33243d95b1a7f4fe06de.tar.xz | |
s390: enable HAVE_IOREMAP_PROT
[ Upstream commit d460bb6c6417588dd8b0907d34f69b237918812a ]
In commit b02002cc4c0f ("s390/pci: Implement ioremap_wc/prot() with
MIO") we implemented both ioremap_wc() and ioremap_prot() however until
now we had not set HAVE_IOREMAP_PROT in Kconfig, do so now.
This also requires implementing pte_pgprot() as this is used in the
generic_access_phys() code enabled by CONFIG_HAVE_IOREMAP_PROT. As with
ioremap_wc() we need to take the MMIO Write Back bit index into account.
Moreover since the pgprot value returned from pte_pgprot() is to be used
for mappings into kernel address space we must make sure that it uses
appropriate kernel page table protection bits. In particular a pgprot
value originally coming from userspace could have the _PAGE_PROTECT
bit set to enable fault based dirty bit accounting which would then make
the mapping inaccessible when used in kernel address space.
Fixes: b02002cc4c0f ("s390/pci: Implement ioremap_wc/prot() with MIO")
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/Kconfig | 1 | ||||
| -rw-r--r-- | arch/s390/include/asm/pgtable.h | 19 |
2 files changed, 20 insertions, 0 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index dc5c3e6fd200..7105d44a335b 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -154,6 +154,7 @@ config S390 select HAVE_FUTEX_CMPXCHG if FUTEX select HAVE_GCC_PLUGINS select HAVE_GENERIC_VDSO + select HAVE_IOREMAP_PROT if PCI select HAVE_IRQ_EXIT_ON_IRQ_STACK select HAVE_KERNEL_BZIP2 select HAVE_KERNEL_GZIP diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index b5dbae78969b..2338345912a3 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -865,6 +865,25 @@ static inline int pte_unused(pte_t pte) } /* + * Extract the pgprot value from the given pte while at the same time making it + * usable for kernel address space mappings where fault driven dirty and + * young/old accounting is not supported, i.e _PAGE_PROTECT and _PAGE_INVALID + * must not be set. + */ +static inline pgprot_t pte_pgprot(pte_t pte) +{ + unsigned long pte_flags = pte_val(pte) & _PAGE_CHG_MASK; + + if (pte_write(pte)) + pte_flags |= pgprot_val(PAGE_KERNEL); + else + pte_flags |= pgprot_val(PAGE_KERNEL_RO); + pte_flags |= pte_val(pte) & mio_wb_bit_mask; + + return __pgprot(pte_flags); +} + +/* * pgd/pmd/pte modification functions */ |