powerpc/pseries/lpar: convert to papr_sysparm API

Convert the TLB block invalidate characteristics discovery to the new
papr_sysparm API. This occurs too early in boot to use
papr_sysparm_buf_alloc(), so use a static buffer.

Signed-off-by: Nathan Lynch <[e-mail]>
Signed-off-by: Michael Ellerman <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

arch/powerpc/platforms/pseries/lpar.c

···
 #include <asm/iommu.h>
 #include <asm/tlb.h>
 #include <asm/cputable.h>
+#include <asm/papr-sysparm.h>
 #include <asm/udbg.h>
 #include <asm/smp.h>
 #include <asm/trace.h>
···
 	}
 }
 
-#define SPLPAR_TLB_BIC_TOKEN		50
-
 /*
  * The size of the TLB Block Invalidate Characteristics is variable. But at the
  * maximum it will be the number of possible page sizes *2 + 10 bytes.
···
 
 void __init pseries_lpar_read_hblkrm_characteristics(void)
 {
-	const s32 token = rtas_token("ibm,get-system-parameter");
-	unsigned char local_buffer[SPLPAR_TLB_BIC_MAXLENGTH];
-	int call_status, len, idx, bpsize;
+	static struct papr_sysparm_buf buf __initdata;
+	int len, idx, bpsize;
 
 	if (!firmware_has_feature(FW_FEATURE_BLOCK_REMOVE))
 		return;
 
-	do {
-		spin_lock(&rtas_data_buf_lock);
-		memset(rtas_data_buf, 0, RTAS_DATA_BUF_SIZE);
-		call_status = rtas_call(token, 3, 1, NULL, SPLPAR_TLB_BIC_TOKEN,
-					__pa(rtas_data_buf), RTAS_DATA_BUF_SIZE);
-		memcpy(local_buffer, rtas_data_buf, SPLPAR_TLB_BIC_MAXLENGTH);
-		local_buffer[SPLPAR_TLB_BIC_MAXLENGTH - 1] = '\0';
-		spin_unlock(&rtas_data_buf_lock);
-	} while (rtas_busy_delay(call_status));
-
-	if (call_status != 0) {
-		pr_warn("%s %s Error calling get-system-parameter (0x%x)\n",
-			__FILE__, __func__, call_status);
+	if (papr_sysparm_get(PAPR_SYSPARM_TLB_BLOCK_INVALIDATE_ATTRS, &buf))
 		return;
-	}
 
-	/*
-	 * The first two (2) bytes of the data in the buffer are the length of
-	 * the returned data, not counting these first two (2) bytes.
-	 */
-	len = be16_to_cpu(*((u16 *)local_buffer)) + 2;
+	len = be16_to_cpu(buf.len);
 	if (len > SPLPAR_TLB_BIC_MAXLENGTH) {
 		pr_warn("%s too large returned buffer %d", __func__, len);
 		return;
 	}
 
-	idx = 2;
+	idx = 0;
 	while (idx < len) {
-		u8 block_shift = local_buffer[idx++];
+		u8 block_shift = buf.val[idx++];
 		u32 block_size;
 		unsigned int npsize;
 
···
 
 		block_size = 1 << block_shift;
 
-		for (npsize = local_buffer[idx++];
+		for (npsize = buf.val[idx++];
 		     npsize > 0 && idx < len; npsize--)
-			check_lp_set_hblkrm((unsigned int) local_buffer[idx++],
+			check_lp_set_hblkrm((unsigned int)buf.val[idx++],
 					    block_size);
 	}