[PATCH 5.18 0875/1095] MIPS: vdso: Utilize __pa() for gic_pfn

Greg Kroah-Hartman
2022-08-15T22:42:24Z

From: Florian Fainelli <f.fainelli@gmail.com>

[ Upstream commit 8baa65126e19af5ee9f3c07e7bb53da41c39e4b1 ]

The GIC user offset is mapped into every process' virtual address and is
therefore part of the hot-path of arch_setup_additional_pages(). Utilize
__pa() such that we are more optimal even when CONFIG_DEBUG_VIRTUAL is
enabled, and while at it utilize PFN_DOWN() instead of open-coding the
right shift by PAGE_SHIFT.

Reported-by: Greg Ungerer <gerg@kernel.org>
Suggested-by: Serge Semin <fancer.lancer@gmail.com>
Fixes: dfad83cb7193 ("MIPS: Add support for CONFIG_DEBUG_VIRTUAL")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Greg Ungerer <gerg@kernel.org>
Tested-by: Greg Ungerer <gerg@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/mips/kernel/vdso.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/kernel/vdso.c b/arch/mips/kernel/vdso.c
index 3d0cf471f2fe..b2cc2c2dd4bf 100644
--- a/arch/mips/kernel/vdso.c
+++ b/arch/mips/kernel/vdso.c
@@ -159,7 +159,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
/* Map GIC user page. */
if (gic_size) {
gic_base = (unsigned long)mips_gic_base + MIPS_GIC_USER_OFS;
- gic_pfn = virt_to_phys((void *)gic_base) >> PAGE_SHIFT;
+ gic_pfn = PFN_DOWN(__pa(gic_base));

ret = io_remap_pfn_range(vma, base, gic_pfn, gic_size,
pgprot_noncached(vma->vm_page_prot));
--
2.35.1