powerpc/pseries: Add page coalescing support

Adds support for page coalescing, which is a feature on IBM Power servers
which allows for coalescing identical pages between logical partitions.
Hint text pages as coalesce candidates, since they are the most likely
pages to be able to be coalesced between partitions. This patch also
exports some page coalescing statistics available from firmware via
lparcfg.

[BenH: Moved a couple of things around to fix compile problems]

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 57 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index 6f0ed3aac77f..39e6e0a7b2fa 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -329,6 +329,8 @@ static long pSeries_lpar_hpte_insert(unsigned long hpte_group,
         /* Make pHyp happy */
         if ((rflags & _PAGE_NO_CACHE) & !(rflags & _PAGE_WRITETHRU))
                 hpte_r &= ~_PAGE_COHERENT;
+        if (firmware_has_feature(FW_FEATURE_XCMO) && !(hpte_r & HPTE_R_N))
+                flags |= H_COALESCE_CAND;
 
         lpar_rc = plpar_pte_enter(flags, hpte_group, hpte_v, hpte_r, &slot);
         if (unlikely(lpar_rc == H_PTEG_FULL)) {
@@ -771,3 +773,47 @@ out:
         local_irq_restore(flags);
 }
 #endif
+
+/**
+ * h_get_mpp
+ * H_GET_MPP hcall returns info in 7 parms
+ */
+int h_get_mpp(struct hvcall_mpp_data *mpp_data)
+{
+        int rc;
+        unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];
+
+        rc = plpar_hcall9(H_GET_MPP, retbuf);
+
+        mpp_data->entitled_mem = retbuf[0];
+        mpp_data->mapped_mem = retbuf[1];
+
+        mpp_data->group_num = (retbuf[2] >> 2 * 8) & 0xffff;
+        mpp_data->pool_num = retbuf[2] & 0xffff;
+
+        mpp_data->mem_weight = (retbuf[3] >> 7 * 8) & 0xff;
+        mpp_data->unallocated_mem_weight = (retbuf[3] >> 6 * 8) & 0xff;
+        mpp_data->unallocated_entitlement = retbuf[3] & 0xffffffffffff;
+
+        mpp_data->pool_size = retbuf[4];
+        mpp_data->loan_request = retbuf[5];
+        mpp_data->backing_mem = retbuf[6];
+
+        return rc;
+}
+EXPORT_SYMBOL(h_get_mpp);
+
+int h_get_mpp_x(struct hvcall_mpp_x_data *mpp_x_data)
+{
+        int rc;
+        unsigned long retbuf[PLPAR_HCALL9_BUFSIZE] = { 0 };
+
+        rc = plpar_hcall9(H_GET_MPP_X, retbuf);
+
+        mpp_x_data->coalesced_bytes = retbuf[0];
+        mpp_x_data->pool_coalesced_bytes = retbuf[1];
+        mpp_x_data->pool_purr_cycles = retbuf[2];
+        mpp_x_data->pool_spurr_cycles = retbuf[3];
+
+        return rc;
+}
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index ab73ad2ff59d..1689adccc6d7 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -405,6 +405,16 @@ static int pseries_set_xdabr(unsigned long dabr)
 #define CMO_CHARACTERISTICS_TOKEN 44
 #define CMO_MAXLENGTH 1026
 
+void pSeries_coalesce_init(void)
+{
+        struct hvcall_mpp_x_data mpp_x_data;
+
+        if (firmware_has_feature(FW_FEATURE_CMO) && !h_get_mpp_x(&mpp_x_data))
+                powerpc_firmware_features |= FW_FEATURE_XCMO;
+        else
+                powerpc_firmware_features &= ~FW_FEATURE_XCMO;
+}
+
 /**
  * fw_cmo_feature_init - FW_FEATURE_CMO is not stored in ibm,hypertas-functions,
  * handle that here. (Stolen from parse_system_parameter_string)
@@ -474,6 +484,7 @@ void pSeries_cmo_feature_init(void)
                 pr_debug("CMO enabled, PrPSP=%d, SecPSP=%d\n", CMO_PrPSP,
                          CMO_SecPSP);
                 powerpc_firmware_features |= FW_FEATURE_CMO;
+                pSeries_coalesce_init();
         } else
                 pr_debug("CMO not enabled, PrPSP=%d, SecPSP=%d\n", CMO_PrPSP,
                          CMO_SecPSP);