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Message-ID: <942d6399b4f5eda9c8a3b7b277fd9f33be39c7f7.camel@linux.ibm.com>
Subject: [V2 PATCH 09/16] powerpc/pseries/vas: Implement to get all
 capabilities
From:   Haren Myneni <haren@linux.ibm.com>
To:     linuxppc-dev@lists.ozlabs.org, linux-crypto@vger.kernel.org,
        mpe@ellerman.id.au, herbert@gondor.apana.org.au, npiggin@gmail.com
Cc:     hbabu@us.ibm.com
Date:   Tue, 13 Apr 2021 01:25:33 -0700
In-Reply-To: <68aa9f2860f9acffa41469d3858883c938634722.camel@linux.ibm.com>
References: <68aa9f2860f9acffa41469d3858883c938634722.camel@linux.ibm.com>
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pHyp provides various VAS capabilities such as GZIP default and QoS
capabilities which are used to determine total number of credits
available in LPAR, maximum window credits, maximum LPAR credits,
whether usermode copy/paste is supported, and etc.

So first retrieve overall vas capabilities using
H_QUERY_VAS_CAPABILITIES HCALL which tells the specific features that
are available. Then retrieve the specific capabilities by using the
feature type in H_QUERY_VAS_CAPABILITIES HCALL.

pHyp supports only GZIP default and GZIP QoS capabilities right now.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
---
 arch/powerpc/platforms/pseries/vas.c | 130 +++++++++++++++++++++++++++
 1 file changed, 130 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/vas.c b/arch/powerpc/platforms/pseries/vas.c
index 06960151477c..35946fb02995 100644
--- a/arch/powerpc/platforms/pseries/vas.c
+++ b/arch/powerpc/platforms/pseries/vas.c
@@ -30,6 +30,13 @@
 /* phyp allows one credit per window right now */
 #define DEF_WIN_CREDS		1
 
+static struct vas_all_capabs capabs_all;
+static int copypaste_feat;
+
+struct vas_capabs vcapabs[VAS_MAX_FEAT_TYPE];
+
+DEFINE_MUTEX(vas_pseries_mutex);
+
 static int64_t hcall_return_busy_check(int64_t rc)
 {
 	/* Check if we are stalled for some time */
@@ -215,3 +222,126 @@ int plpar_vas_query_capabilities(const u64 hcall, u8 query_type,
 		return -EIO;
 	}
 }
+
+/*
+ * Get the specific capabilities based on the feature type.
+ * Right now supports GZIP default and GZIP QoS capabilities.
+ */
+static int get_vas_capabilities(u8 feat, enum vas_cop_feat_type type,
+				struct vas_ct_capabs_be *capab_be)
+{
+	struct vas_ct_capabs *capab;
+	struct vas_capabs *vcapab;
+	int rc = 0;
+
+	vcapab = &vcapabs[type];
+	memset(vcapab, 0, sizeof(*vcapab));
+	INIT_LIST_HEAD(&vcapab->list);
+
+	capab = &vcapab->capab;
+
+	rc = plpar_vas_query_capabilities(H_QUERY_VAS_CAPABILITIES, feat,
+					  (u64)virt_to_phys(capab_be));
+	if (rc)
+		return rc;
+
+	capab->user_mode = capab_be->user_mode;
+	if (!(capab->user_mode & VAS_COPY_PASTE_USER_MODE)) {
+		pr_err("User space COPY/PASTE is not supported\n");
+		return -ENOTSUPP;
+	}
+
+	snprintf(capab->name, VAS_DESCR_LEN + 1, "%.8s",
+		 (char *)&capab_be->descriptor);
+	capab->descriptor = be64_to_cpu(capab_be->descriptor);
+	capab->win_type = capab_be->win_type;
+	if (capab->win_type >= VAS_MAX_FEAT_TYPE) {
+		pr_err("Unsupported window type %u\n", capab->win_type);
+		return -EINVAL;
+	}
+	capab->max_lpar_creds = be16_to_cpu(capab_be->max_lpar_creds);
+	capab->max_win_creds = be16_to_cpu(capab_be->max_win_creds);
+	atomic_set(&capab->target_lpar_creds,
+		   be16_to_cpu(capab_be->target_lpar_creds));
+	if (feat == VAS_GZIP_DEF_FEAT) {
+		capab->def_lpar_creds = be16_to_cpu(capab_be->def_lpar_creds);
+
+		if (capab->max_win_creds < DEF_WIN_CREDS) {
+			pr_err("Window creds(%u) > max allowed window creds(%u)\n",
+			       DEF_WIN_CREDS, capab->max_win_creds);
+			return -EINVAL;
+		}
+	}
+
+	copypaste_feat = 1;
+
+	return 0;
+}
+
+static int __init pseries_vas_init(void)
+{
+	struct vas_ct_capabs_be *ct_capabs_be;
+	struct vas_all_capabs_be *capabs_be;
+	int rc;
+
+	/*
+	 * Linux supports user space COPY/PASTE only with Radix
+	 */
+	if (!radix_enabled()) {
+		pr_err("API is supported only with radix page tables\n");
+		return -ENOTSUPP;
+	}
+
+	capabs_be = kmalloc(sizeof(*capabs_be), GFP_KERNEL);
+	if (!capabs_be)
+		return -ENOMEM;
+	/*
+	 * Get VAS overall capabilities by passing 0 to feature type.
+	 */
+	rc = plpar_vas_query_capabilities(H_QUERY_VAS_CAPABILITIES, 0,
+					  (u64)virt_to_phys(capabs_be));
+	if (rc)
+		goto out;
+
+	snprintf(capabs_all.name, VAS_DESCR_LEN, "%.7s",
+		 (char *)&capabs_be->descriptor);
+	capabs_all.descriptor = be64_to_cpu(capabs_be->descriptor);
+	capabs_all.feat_type = be64_to_cpu(capabs_be->feat_type);
+
+	ct_capabs_be = kmalloc(sizeof(*ct_capabs_be), GFP_KERNEL);
+	if (!ct_capabs_be) {
+		rc = -ENOMEM;
+		goto out;
+	}
+	/*
+	 * QOS capabilities available
+	 */
+	if (capabs_all.feat_type & VAS_GZIP_QOS_FEAT_BIT) {
+		rc = get_vas_capabilities(VAS_GZIP_QOS_FEAT,
+					  VAS_GZIP_QOS_FEAT_TYPE, ct_capabs_be);
+
+		if (rc)
+			goto out_ct;
+	}
+	/*
+	 * Default capabilities available
+	 */
+	if (capabs_all.feat_type & VAS_GZIP_DEF_FEAT_BIT) {
+		rc = get_vas_capabilities(VAS_GZIP_DEF_FEAT,
+					  VAS_GZIP_DEF_FEAT_TYPE, ct_capabs_be);
+		if (rc)
+			goto out_ct;
+	}
+
+	if (!copypaste_feat)
+		pr_err("GZIP feature is not supported\n");
+
+	pr_info("GZIP feature is available\n");
+
+out_ct:
+	kfree(ct_capabs_be);
+out:
+	kfree(capabs_be);
+	return rc;
+}
+machine_device_initcall(pseries, pseries_vas_init);
-- 
2.18.2