| Message ID | 20200923075514.110478-1-jusual@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | hw/i386/acpi-build: Explain bits in OSC method | expand |
On Wed, Sep 23, 2020 at 09:55:14AM +0200, Julia Suvorova wrote: > Provide a better explanation for the enabled bits in the _OSC control > field. Base it on the latest specification due to new bits 5 and 6. > > Signed-off-by: Julia Suvorova <jusual@redhat.com> > --- > hw/i386/acpi-build.h | 11 +++++++++++ > hw/i386/acpi-build.c | 7 ++++++- > 2 files changed, 17 insertions(+), 1 deletion(-) > > diff --git a/hw/i386/acpi-build.h b/hw/i386/acpi-build.h > index 74df5fc612..bb5269d162 100644 > --- a/hw/i386/acpi-build.h > +++ b/hw/i386/acpi-build.h > @@ -5,6 +5,17 @@ > > extern const struct AcpiGenericAddress x86_nvdimm_acpi_dsmio; > > +/* PCI Firmware Specification 3.2, Table 4-5 */ > +typedef enum { > + ACPI_OSC_NATIVE_HP_EN = 0, > + ACPI_OSC_SHPC_EN = 1, > + ACPI_OSC_PME_EN = 2, > + ACPI_OSC_AER_EN = 3, > + ACPI_OSC_PCIE_CAP_EN = 4, > + ACPI_OSC_LTR_EN = 5, > + ACPI_OSC_ALLONES_INVALID = 6, > +} AcpiOSCField; > + > void acpi_setup(void); > > #endif > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c > index 0e0535d2e3..b08f005a35 100644 > --- a/hw/i386/acpi-build.c > +++ b/hw/i386/acpi-build.c > @@ -1417,6 +1417,7 @@ static Aml *build_q35_osc_method(void) > Aml *method; > Aml *a_cwd1 = aml_name("CDW1"); > Aml *a_ctrl = aml_local(0); > + unsigned osc_ctrl; > > method = aml_method("_OSC", 4, AML_NOTSERIALIZED); > aml_append(method, aml_create_dword_field(aml_arg(3), aml_int(0), "CDW1")); > @@ -1432,7 +1433,11 @@ static Aml *build_q35_osc_method(void) > * Always allow native PME, AER (no dependencies) > * Allow SHPC (PCI bridges can have SHPC controller) > */ > - aml_append(if_ctx, aml_and(a_ctrl, aml_int(0x1F), a_ctrl)); > + osc_ctrl = BIT(ACPI_OSC_PME_EN) | BIT(ACPI_OSC_AER_EN) | > + BIT(ACPI_OSC_PCIE_CAP_EN) | BIT(ACPI_OSC_NATIVE_HP_EN) | > + BIT(ACPI_OSC_SHPC_EN); > + > + aml_append(if_ctx, aml_and(a_ctrl, aml_int(osc_ctrl), a_ctrl)); Now the comment above somewhat duplicates the enums. And decoding what does each value mean is a head scratcher. As long as there's a single use, we prefer comments to an enum, they can match spec exactly: BIT(0) /* PCI Express Native Hotplug control */ | BIT(4) /* SHPC Native Hotplug control */ | etc ... > if_ctx2 = aml_if(aml_lnot(aml_equal(aml_arg(1), aml_int(1)))); > /* Unknown revision */ > -- > 2.25.4
diff --git a/hw/i386/acpi-build.h b/hw/i386/acpi-build.h index 74df5fc612..bb5269d162 100644 --- a/hw/i386/acpi-build.h +++ b/hw/i386/acpi-build.h @@ -5,6 +5,17 @@ extern const struct AcpiGenericAddress x86_nvdimm_acpi_dsmio; +/* PCI Firmware Specification 3.2, Table 4-5 */ +typedef enum { + ACPI_OSC_NATIVE_HP_EN = 0, + ACPI_OSC_SHPC_EN = 1, + ACPI_OSC_PME_EN = 2, + ACPI_OSC_AER_EN = 3, + ACPI_OSC_PCIE_CAP_EN = 4, + ACPI_OSC_LTR_EN = 5, + ACPI_OSC_ALLONES_INVALID = 6, +} AcpiOSCField; + void acpi_setup(void); #endif diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index 0e0535d2e3..b08f005a35 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -1417,6 +1417,7 @@ static Aml *build_q35_osc_method(void) Aml *method; Aml *a_cwd1 = aml_name("CDW1"); Aml *a_ctrl = aml_local(0); + unsigned osc_ctrl; method = aml_method("_OSC", 4, AML_NOTSERIALIZED); aml_append(method, aml_create_dword_field(aml_arg(3), aml_int(0), "CDW1")); @@ -1432,7 +1433,11 @@ static Aml *build_q35_osc_method(void) * Always allow native PME, AER (no dependencies) * Allow SHPC (PCI bridges can have SHPC controller) */ - aml_append(if_ctx, aml_and(a_ctrl, aml_int(0x1F), a_ctrl)); + osc_ctrl = BIT(ACPI_OSC_PME_EN) | BIT(ACPI_OSC_AER_EN) | + BIT(ACPI_OSC_PCIE_CAP_EN) | BIT(ACPI_OSC_NATIVE_HP_EN) | + BIT(ACPI_OSC_SHPC_EN); + + aml_append(if_ctx, aml_and(a_ctrl, aml_int(osc_ctrl), a_ctrl)); if_ctx2 = aml_if(aml_lnot(aml_equal(aml_arg(1), aml_int(1)))); /* Unknown revision */
Provide a better explanation for the enabled bits in the _OSC control field. Base it on the latest specification due to new bits 5 and 6. Signed-off-by: Julia Suvorova <jusual@redhat.com> --- hw/i386/acpi-build.h | 11 +++++++++++ hw/i386/acpi-build.c | 7 ++++++- 2 files changed, 17 insertions(+), 1 deletion(-)