powerpc/pseries: convert CMO probe to papr_sysparm API

Convert the direct invocation of the ibm,get-system-parameter RTAS
function to papr_sysparm_get().

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-15-26929c8cce78@linux.ibm.com

diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 74e50b6..420a2fa 100644 (file)
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -57,6 +57,7 @@
 #include <asm/pmc.h>
 #include <asm/xics.h>
 #include <asm/xive.h>
+#include <asm/papr-sysparm.h>
 #include <asm/ppc-pci.h>
 #include <asm/i8259.h>
 #include <asm/udbg.h>
@@ -941,32 +942,21 @@ void pSeries_coalesce_init(void)
  */
 static void __init pSeries_cmo_feature_init(void)
 {
-       const s32 token = rtas_token("ibm,get-system-parameter");
+       static struct papr_sysparm_buf buf __initdata;
+       static_assert(sizeof(buf.val) >= CMO_MAXLENGTH);
        char *ptr, *key, *value, *end;
-       int call_status;
        int page_order = IOMMU_PAGE_SHIFT_4K;
 
        pr_debug(" -> fw_cmo_feature_init()\n");
 
-       do {
-               spin_lock(&rtas_data_buf_lock);
-               call_status = rtas_call(token, 3, 1, NULL,
-                                       CMO_CHARACTERISTICS_TOKEN,
-                                       __pa(rtas_data_buf),
-                                       RTAS_DATA_BUF_SIZE);
-               if (call_status == 0)
-                       break;
-               spin_unlock(&rtas_data_buf_lock);
-       } while (rtas_busy_delay(call_status));
-
-       if (call_status != 0) {
+       if (papr_sysparm_get(PAPR_SYSPARM_COOP_MEM_OVERCOMMIT_ATTRS, &buf)) {
                pr_debug("CMO not available\n");
                pr_debug(" <- fw_cmo_feature_init()\n");
                return;
        }
 
-       end = rtas_data_buf + CMO_MAXLENGTH - 2;
-       ptr = rtas_data_buf + 2;        /* step over strlen value */
+       end = &buf.val[CMO_MAXLENGTH];
+       ptr = &buf.val[0];
        key = value = ptr;
 
        while (*ptr && (ptr <= end)) {
@@ -1012,7 +1002,6 @@ static void __init pSeries_cmo_feature_init(void)
        } else
                pr_debug("CMO not enabled, PrPSP=%d, SecPSP=%d\n", CMO_PrPSP,
                         CMO_SecPSP);
-       spin_unlock(&rtas_data_buf_lock);
        pr_debug(" <- fw_cmo_feature_init()\n");
 }