On 31 July 2015 at 15:27, Ryan Harkin ryan.harkin@linaro.org wrote:
On 31 July 2015 at 14:22, Ryan Harkin ryan.harkin@linaro.org wrote:
On 31 July 2015 at 13:28, Ard Biesheuvel ard.biesheuvel@linaro.org wrote:
On 31 July 2015 at 14:21, Ryan Harkin ryan.harkin@linaro.org wrote:
On 31 July 2015 at 13:13, Ard Biesheuvel ard.biesheuvel@linaro.org wrote:
On 31 July 2015 at 14:06, Ryan Harkin ryan.harkin@linaro.org wrote:
Make Arm and Aarch64 both use the same code, conditionally compiled, to check if the platform has GICv3.
Both source files for Arm and Aarch64 are now identical and the next step is to move to a common source file.
Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ryan Harkin ryan.harkin@linaro.org
.../Library/ArmGicArchLib/AArch64/ArmGicArchLib.c | 26 +++++++++++++++------- ArmPkg/Library/ArmGicArchLib/Arm/ArmGicArchLib.c | 24 ++++++++++++++------ 2 files changed, 35 insertions(+), 15 deletions(-)
diff --git a/ArmPkg/Library/ArmGicArchLib/AArch64/ArmGicArchLib.c b/ArmPkg/Library/ArmGicArchLib/AArch64/ArmGicArchLib.c index 9853c7b..b092e3a 100644 --- a/ArmPkg/Library/ArmGicArchLib/AArch64/ArmGicArchLib.c +++ b/ArmPkg/Library/ArmGicArchLib/AArch64/ArmGicArchLib.c @@ -15,7 +15,22 @@ #include <Library/ArmLib.h> #include <Library/ArmGicLib.h>
-STATIC ARM_GIC_ARCH_REVISION mGicArchRevision; +STATIC ARM_GIC_ARCH_REVISION mGicArchRevision = ARM_GIC_ARCH_REVISION_2;
+RETURN_STATUS +EFIAPI +ArmGicArchLibHasGicv3 (
- VOID
- )
+{ +#if defined (MDE_CPU_ARM)
- return (ArmReadIdPfr1 () & ARM_PFR1_GIC);
+#elif defined(MDE_CPU_AARCH64)
- return (ArmReadIdPfr0 () & AARCH64_PFR0_GIC);
+#else
- #error "Unknown chipset."
+#endif +}
Officially, the bit indicates whether the GIC system register interface is supported at the current exception level, and from that we infer that the system most likely has a GICv3. So if we don't have the SRE enabled, we try to drive it as a GICv2 which only happens to work if this particular GICv3 has the GICv2 compatibility mode implemented. (This is also mentioned in the comments)
So the function name is a bit misleading here, although I won't insist that you change it.
I'm happy to change it if you want to recommend a better name, this seems a but unwieldy:
HasGicv3 -> GicSystemRegistersSupported
... but is perhaps more correct.
Well, the function and the caller are so close together that you shouldn't be able to miss the comment.
And thinking about this, as it isn't exported, I don't need the ArmGicArchLib prefix, so I can just call it "GicSystemRegistersSupported" and be done with it.
Indeed.
I do recommend STATIC for the function though.
Sure, good point. I'll add it for v2.
Reviewed-by: Ard Biesheuvel ard.biesheuvel@linaro.org
Thanks for the quick review turnaround :-)
Too quick, as it seems. Spotted an inadvertent white space change below :-)
Drat, I would have got away with it if it wasn't for you meddling kids :-)
RETURN_STATUS EFIAPI @@ -31,7 +46,7 @@ ArmGicArchLibInitialize ( // feature is implemented on the CPU. This is also convenient as our GICv3 // driver requires SRE. If only Memory mapped access is available we try to // drive the GIC as a v2.
- if (ArmReadIdPfr0 () & AARCH64_PFR0_GIC) {
- if (ArmGicArchLibHasGicv3()) { // Make sure System Register access is enabled (SRE). This
depends on the // higher privilege level giving us permission, otherwise we will either // cause an exception here, or the write doesn't stick in which case we need @@ -41,18 +56,13 @@ ArmGicArchLibInitialize ( // It is the OS responsibility to set this bit. IccSre = ArmGicV3GetControlSystemRegisterEnable (); if (!(IccSre & ICC_SRE_EL2_SRE)) {
ArmGicV3SetControlSystemRegisterEnable (IccSre |ICC_SRE_EL2_SRE);
ArmGicV3SetControlSystemRegisterEnable (IccSre|ICC_SRE_EL2_SRE);
here ^^^
I sort-of did that on purpose to make the two files identical. The space vanished when the original copy/paste/hack operation happened and it crept back in when I made the Arm and Aarch64 files identical.
I know it's not important, but if I omit that whitespace change, then the two files won't actually be identical before moving to a single common source.
Now, do you *really* want me to drop this hunk for v2??
i am happy as long as the version that ultimately remains has a space at either end of the |