Re: [PATCH v3 16/17] driver/edac: enable Hygon support to AMD64 EDAC driver

From: Michael Jin
Date: Sat Aug 11 2018 - 15:56:21 EST


On Sat, Aug 11, 2018 at 9:30 AM, Pu Wen <puwen@xxxxxxxx> wrote:
> diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
> index 18aeabb..fb81354 100644
> --- a/drivers/edac/amd64_edac.c
> +++ b/drivers/edac/amd64_edac.c
> @@ -211,7 +211,7 @@ static int __set_scrub_rate(struct amd64_pvt *pvt, u32 new_bw, u32 min_rate)
>
> scrubval = scrubrates[i].scrubval;
>
> - if (pvt->fam == 0x17) {
> + if (pvt->fam == 0x17 || pvt->vendor == X86_VENDOR_HYGON) {
> __f17h_set_scrubval(pvt, scrubval);

Separating the vendor check as an "else if (pvt->vendor ==
X86_VENDOR_HYGON)" block would make architectural changes (future
hygon models, i.e. 19h, 20h, etc) less confusing.



> + amd64_read_pci_cfg(pvt->F6,
> + F17H_SCR_BASE_ADDR, &scrubval);
> + if (scrubval & BIT(0)) {
> + amd64_read_pci_cfg(pvt->F6,

The new lines after "amd64_read_pci_cfg(pvt->F6," can be removed.



> @@ -1051,6 +1065,16 @@ static void determine_memory_type(struct amd64_pvt *pvt)
> else
> pvt->dram_type = MEM_DDR4;
> return;
> + case 0x18:
> + if (pvt->vendor == X86_VENDOR_HYGON) {

This vendor checking is not necessary as there are no other known
family 18h processors.


> switch (pvt->fam) {
> @@ -3192,6 +3227,13 @@ static struct amd64_family_type *per_family_init(struct amd64_pvt *pvt)
> pvt->ops = &family_types[F17_CPUS].ops;
> break;
>
> + case 0x18:
> + if (pvt->vendor == X86_VENDOR_HYGON) {
> + fam_type = &family_types[HYGON_F18_CPUS];
> + pvt->ops = &family_types[HYGON_F18_CPUS].ops;
> + break;
> + }

There is a missing second 'break' statement after the "if (pvt->vendor
== X86_VENDOR_HYGON)" block for case 0x18, see case 0x15 and case 0x16
for comparison.



> diff --git a/drivers/edac/mce_amd.c b/drivers/edac/mce_amd.c
> index 2ab4d61..f7adc47 100644
> + case 0x18:
> + if (c->x86_vendor == X86_VENDOR_HYGON) {
> + xec_mask = 0x3f;
> + if (!boot_cpu_has(X86_FEATURE_SMCA)) {
> + pr_warn("Decoding supported only on Scalable MCA processors.\n");
> + goto err_out;
> + }
> + break;
> + }

The 'break' statement could be moved outside of the "if (c->x86_vendor
== X86_VENDOR_HYGON)" block, this is to allow case 0x18 to reach the
'break' statement if the vendor is not X86_VENDOR_HYGON.