[PATCH v3] arm64: Cleanup __cpu_set_tcr_t0sz()

From: Seongsu Park
Date: Sun Apr 07 2024 - 22:40:33 EST


In cpu_set_default_tcr_t0sz(), it is an error to shift TCR_T0SZ_OFFSET
twice form TCR_T0SZ() and __cpu_set_tcr_t0sz().
Since TCR_T0SZ_OFFSET is 0, no error occurred.
We need to clarify whether the parameter of __cpu_set_tcr_t0sz is a
shifted value or an unshifted value.

We have already shifted the value of t0sz in TCR_T0SZ by TCR_T0SZ_OFFSET.
This is necessary for consistency with TCR_T1SZ.
Therefore, the parameter of __cpu_set_tcr_t0sz is clarified as a shifted
value.

Co-developed-by: Leem ChaeHoon <infinite.run@xxxxxxxxx>
Signed-off-by: Leem ChaeHoon <infinite.run@xxxxxxxxx>
Co-developed-by: Gyeonggeon Choi <gychoi@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Gyeonggeon Choi <gychoi@xxxxxxxxxxxxxxxxxx>
Co-developed-by: Soomin Cho <to.soomin@xxxxxxxxx>
Signed-off-by: Soomin Cho <to.soomin@xxxxxxxxx>
Co-developed-by: DaeRo Lee <skseofh@xxxxxxxxx>
Signed-off-by: DaeRo Lee <skseofh@xxxxxxxxx>
Co-developed-by: kmasta <kmasta.study@xxxxxxxxx>
Signed-off-by: kmasta <kmasta.study@xxxxxxxxx>
Signed-off-by: Seongsu Park <sgsu.park@xxxxxxxxxxx>
---

v2:
- Condition is updated
v3:
- Commit message is updated
- cpu_set_tcr_t0sz macro is added

---
arch/arm64/include/asm/mmu_context.h | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h
index c768d16b81a4..fb603ec7f61f 100644
--- a/arch/arm64/include/asm/mmu_context.h
+++ b/arch/arm64/include/asm/mmu_context.h
@@ -72,15 +72,16 @@ static inline void __cpu_set_tcr_t0sz(unsigned long t0sz)
{
unsigned long tcr = read_sysreg(tcr_el1);

- if ((tcr & TCR_T0SZ_MASK) >> TCR_T0SZ_OFFSET == t0sz)
+ if ((tcr & TCR_T0SZ_MASK) == t0sz)
return;

tcr &= ~TCR_T0SZ_MASK;
- tcr |= t0sz << TCR_T0SZ_OFFSET;
+ tcr |= t0sz;
write_sysreg(tcr, tcr_el1);
isb();
}

+#define cpu_set_tcr_t0sz(t0sz) __cpu_set_tcr_t0sz(TCR_T0SZ(t0sz))
#define cpu_set_default_tcr_t0sz() __cpu_set_tcr_t0sz(TCR_T0SZ(vabits_actual))
#define cpu_set_idmap_tcr_t0sz() __cpu_set_tcr_t0sz(idmap_t0sz)

@@ -134,7 +135,7 @@ static inline void cpu_install_ttbr0(phys_addr_t ttbr0, unsigned long t0sz)
{
cpu_set_reserved_ttbr0();
local_flush_tlb_all();
- __cpu_set_tcr_t0sz(t0sz);
+ cpu_set_tcr_t0sz(t0sz);

/* avoid cpu_switch_mm() and its SW-PAN and CNP interactions */
write_sysreg(ttbr0, ttbr0_el1);
--
2.34.1