RISC-V: ACPI: RHCT: Add function to get CBO block sizes

Cache Block Operation (CBO) related block size in ACPI is provided by RHCT.
Add support to read the CMO node in RHCT to get this information.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20231018124007.1306159-4-sunilvl@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

diff --git a/arch/riscv/include/asm/acpi.h b/arch/riscv/include/asm/acpi.h
index d5604d2073bc2e51f17da549381e834eca6e7779..7dad0cf9d701f66135257753d0bb047fda59b5d2 100644 (file)
--- a/arch/riscv/include/asm/acpi.h
+++ b/arch/riscv/include/asm/acpi.h
@@ -66,6 +66,8 @@ int acpi_get_riscv_isa(struct acpi_table_header *table,
                       unsigned int cpu, const char **isa);
 
 static inline int acpi_numa_get_nid(unsigned int cpu) { return NUMA_NO_NODE; }
+void acpi_get_cbo_block_size(struct acpi_table_header *table, u32 *cbom_size,
+                            u32 *cboz_size, u32 *cbop_size);
 #else
 static inline void acpi_init_rintc_map(void) { }
 static inline struct acpi_madt_rintc *acpi_cpu_get_madt_rintc(int cpu)
@@ -79,6 +81,10 @@ static inline int acpi_get_riscv_isa(struct acpi_table_header *table,
        return -EINVAL;
 }
 
+static inline void acpi_get_cbo_block_size(struct acpi_table_header *table,
+                                          u32 *cbom_size, u32 *cboz_size,
+                                          u32 *cbop_size) { }
+
 #endif /* CONFIG_ACPI */
 
 #endif /*_ASM_ACPI_H*/

diff --git a/drivers/acpi/riscv/rhct.c b/drivers/acpi/riscv/rhct.c
index 489b0e93b1e5fdcecf4d8a9d76f7dbf47bc2377e..caa2c16e16974a6c76961240c08df8fbe4d598e1 100644 (file)
--- a/drivers/acpi/riscv/rhct.c
+++ b/drivers/acpi/riscv/rhct.c
@@ -8,6 +8,7 @@
 #define pr_fmt(fmt)     "ACPI: RHCT: " fmt
 
 #include <linux/acpi.h>
+#include <linux/bits.h>
 
 static struct acpi_table_rhct *acpi_get_rhct(void)
 {
@@ -81,3 +82,89 @@ int acpi_get_riscv_isa(struct acpi_table_header *table, unsigned int cpu, const
 
        return -1;
 }
+
+static void acpi_parse_hart_info_cmo_node(struct acpi_table_rhct *rhct,
+                                         struct acpi_rhct_hart_info *hart_info,
+                                         u32 *cbom_size, u32 *cboz_size, u32 *cbop_size)
+{
+       u32 size_hartinfo = sizeof(struct acpi_rhct_hart_info);
+       u32 size_hdr = sizeof(struct acpi_rhct_node_header);
+       struct acpi_rhct_node_header *ref_node;
+       struct acpi_rhct_cmo_node *cmo_node;
+       u32 *hart_info_node_offset;
+
+       hart_info_node_offset = ACPI_ADD_PTR(u32, hart_info, size_hartinfo);
+       for (int i = 0; i < hart_info->num_offsets; i++) {
+               ref_node = ACPI_ADD_PTR(struct acpi_rhct_node_header,
+                                       rhct, hart_info_node_offset[i]);
+               if (ref_node->type == ACPI_RHCT_NODE_TYPE_CMO) {
+                       cmo_node = ACPI_ADD_PTR(struct acpi_rhct_cmo_node,
+                                               ref_node, size_hdr);
+                       if (cbom_size && cmo_node->cbom_size <= 30) {
+                               if (!*cbom_size)
+                                       *cbom_size = BIT(cmo_node->cbom_size);
+                               else if (*cbom_size != BIT(cmo_node->cbom_size))
+                                       pr_warn("CBOM size is not the same across harts\n");
+                       }
+
+                       if (cboz_size && cmo_node->cboz_size <= 30) {
+                               if (!*cboz_size)
+                                       *cboz_size = BIT(cmo_node->cboz_size);
+                               else if (*cboz_size != BIT(cmo_node->cboz_size))
+                                       pr_warn("CBOZ size is not the same across harts\n");
+                       }
+
+                       if (cbop_size && cmo_node->cbop_size <= 30) {
+                               if (!*cbop_size)
+                                       *cbop_size = BIT(cmo_node->cbop_size);
+                               else if (*cbop_size != BIT(cmo_node->cbop_size))
+                                       pr_warn("CBOP size is not the same across harts\n");
+                       }
+               }
+       }
+}
+
+/*
+ * During early boot, the caller should call acpi_get_table() and pass its pointer to
+ * these functions (and free up later). At run time, since this table can be used
+ * multiple times, pass NULL so that the table remains in memory.
+ */
+void acpi_get_cbo_block_size(struct acpi_table_header *table, u32 *cbom_size,
+                            u32 *cboz_size, u32 *cbop_size)
+{
+       u32 size_hdr = sizeof(struct acpi_rhct_node_header);
+       struct acpi_rhct_node_header *node, *end;
+       struct acpi_rhct_hart_info *hart_info;
+       struct acpi_table_rhct *rhct;
+
+       if (acpi_disabled)
+               return;
+
+       if (table) {
+               rhct = (struct acpi_table_rhct *)table;
+       } else {
+               rhct = acpi_get_rhct();
+               if (!rhct)
+                       return;
+       }
+
+       if (cbom_size)
+               *cbom_size = 0;
+
+       if (cboz_size)
+               *cboz_size = 0;
+
+       if (cbop_size)
+               *cbop_size = 0;
+
+       end = ACPI_ADD_PTR(struct acpi_rhct_node_header, rhct, rhct->header.length);
+       for (node = ACPI_ADD_PTR(struct acpi_rhct_node_header, rhct, rhct->node_offset);
+            node < end;
+            node = ACPI_ADD_PTR(struct acpi_rhct_node_header, node, node->length)) {
+               if (node->type == ACPI_RHCT_NODE_TYPE_HART_INFO) {
+                       hart_info = ACPI_ADD_PTR(struct acpi_rhct_hart_info, node, size_hdr);
+                       acpi_parse_hart_info_cmo_node(rhct, hart_info, cbom_size,
+                                                     cboz_size, cbop_size);
+               }
+       }
+}