Thread (55 messages) 55 messages, 6 authors, 2021-01-19

Re: [PATCH v1 17/24] kvm: arm64: Add __hyp_pa_symbol helper macro

From: David Brazdil <hidden>
Date: 2020-11-10 09:24:11
Also in: kvmarm, lkml

On Mon, Nov 09, 2020 at 06:10:05PM +0000, Marc Zyngier wrote:
On 2020-11-09 16:59, Quentin Perret wrote:
quoted
Hey David,

On Monday 09 Nov 2020 at 11:32:26 (+0000), David Brazdil wrote:
quoted
Add helper macro for computing the PA of a kernel symbol in nVHE hyp
code. This will be useful for computing the PA of a PSCI CPU_ON entry
point.

Signed-off-by: David Brazdil <redacted>
---
 arch/arm64/kvm/hyp/nvhe/psci.c | 10 ++++++++++
 1 file changed, 10 insertions(+)
diff --git a/arch/arm64/kvm/hyp/nvhe/psci.c
b/arch/arm64/kvm/hyp/nvhe/psci.c
index b0b5df590ba5..7510b9e174e9 100644
--- a/arch/arm64/kvm/hyp/nvhe/psci.c
+++ b/arch/arm64/kvm/hyp/nvhe/psci.c
@@ -20,6 +20,16 @@ s64 hyp_physvirt_offset;

 #define __hyp_pa(x) ((phys_addr_t)((x)) + hyp_physvirt_offset)

+#define __hyp_pa_symbol(sym)					\
+	({							\
+		extern char sym[];				\
+		unsigned long kern_va;				\
+								\
+		asm volatile("ldr %0, =%1" : "=r" (kern_va)	\
+					   : "S" (sym));	\
+		kern_va - kimage_voffset;			\
+	})
+
Could this be simplified to __hyp_pa(hyp_symbol_addr(sym))? That would
avoid the dependency on kimage_voffset.
Ah, didn't see that one. Ok, removing this patch.
I'm going to move away from evaluating kimage_voffset at runtime anyway,
see [1].
Awesome! One more dependency gone.
Thanks,

        M.

[1] https://lore.kernel.org/r/20201109175923.445945-1-maz@kernel.org (local)
-- 
Jazz is not dead. It just smells funny...
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