[PATCH v11 3/8] arm/arm64: vgic: Introduce find_reg_by_id()

[vijay . kilari]

From: Vijaya Kumar K <vijaya.ku...@cavium.com>

In order to implement vGICv3 CPU interface access, we will need to perform
table lookup of system registers. We would need both index_to_params() and
find_reg() exported for that purpose, but instead we export a single
function which combines them both.

Signed-off-by: Pavel Fedin <p.fe...@samsung.com>
Signed-off-by: Vijaya Kumar K <vijaya.ku...@cavium.com>
Reviewed-by: Andre Przywara <andre.przyw...@arm.com>
Reviewed-by: Eric Auger <eric.au...@redhat.com>
Acked-by: Christoffer Dall <christoffer.d...@linaro.org>
---
 arch/arm64/kvm/sys_regs.c | 27 ++++++++++++++++-----------
 arch/arm64/kvm/sys_regs.h |  4 ++++
 2 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 87e7e66..caa47ce 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1795,6 +1795,17 @@ static bool index_to_params(u64 id, struct 
sys_reg_params *params)
        }
 }
 
+const struct sys_reg_desc *find_reg_by_id(u64 id,
+                                         struct sys_reg_params *params,
+                                         const struct sys_reg_desc table[],
+                                         unsigned int num)
+{
+       if (!index_to_params(id, params))
+               return NULL;
+
+       return find_reg(params, table, num);
+}
+
 /* Decode an index value, and find the sys_reg_desc entry. */
 static const struct sys_reg_desc *index_to_sys_reg_desc(struct kvm_vcpu *vcpu,
                                                    u64 id)
@@ -1807,11 +1818,8 @@ static const struct sys_reg_desc 
*index_to_sys_reg_desc(struct kvm_vcpu *vcpu,
        if ((id & KVM_REG_ARM_COPROC_MASK) != KVM_REG_ARM64_SYSREG)
                return NULL;
 
-       if (!index_to_params(id, &params))
-               return NULL;
-
        table = get_target_table(vcpu->arch.target, true, &num);
-       r = find_reg(&params, table, num);
+       r = find_reg_by_id(id, &params, table, num);
        if (!r)
                r = find_reg(&params, sys_reg_descs, ARRAY_SIZE(sys_reg_descs));
 
@@ -1918,10 +1926,8 @@ static int get_invariant_sys_reg(u64 id, void __user 
*uaddr)
        struct sys_reg_params params;
        const struct sys_reg_desc *r;
 
-       if (!index_to_params(id, &params))
-               return -ENOENT;
-
-       r = find_reg(&params, invariant_sys_regs, 
ARRAY_SIZE(invariant_sys_regs));
+       r = find_reg_by_id(id, &params, invariant_sys_regs,
+                          ARRAY_SIZE(invariant_sys_regs));
        if (!r)
                return -ENOENT;
 
@@ -1935,9 +1941,8 @@ static int set_invariant_sys_reg(u64 id, void __user 
*uaddr)
        int err;
        u64 val = 0; /* Make sure high bits are 0 for 32-bit regs */
 
-       if (!index_to_params(id, &params))
-               return -ENOENT;
-       r = find_reg(&params, invariant_sys_regs, 
ARRAY_SIZE(invariant_sys_regs));
+       r = find_reg_by_id(id, &params, invariant_sys_regs,
+                          ARRAY_SIZE(invariant_sys_regs));
        if (!r)
                return -ENOENT;
 
diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h
index dbbb01c..9c6ffd0 100644
--- a/arch/arm64/kvm/sys_regs.h
+++ b/arch/arm64/kvm/sys_regs.h
@@ -136,6 +136,10 @@ static inline int cmp_sys_reg(const struct sys_reg_desc 
*i1,
        return i1->Op2 - i2->Op2;
 }
 
+const struct sys_reg_desc *find_reg_by_id(u64 id,
+                                         struct sys_reg_params *params,
+                                         const struct sys_reg_desc table[],
+                                         unsigned int num);
 
 #define Op0(_x)        .Op0 = _x
 #define Op1(_x)        .Op1 = _x
-- 
1.9.1

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