RISC-V: Fix compilation without RISCV_ISA_ZICBOM

riscv_cbom_block_size and riscv_init_cbom_blocksize() should always
be available and riscv_init_cbom_blocksize() should always be
invoked, even when compiling without RISCV_ISA_ZICBOM enabled. This
is because disabling RISCV_ISA_ZICBOM means "don't use zicbom
instructions in the kernel" not "pretend there isn't zicbom, even
when there is". When zicbom is available, whether the kernel enables
its use with RISCV_ISA_ZICBOM or not, KVM will offer it to guests.
Ensure we can build KVM and that the block size is initialized even
when compiling without RISCV_ISA_ZICBOM.

Fixes: 8f7e001e0325 ("RISC-V: Clean up the Zicbom block size probing")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Anup Patel <anup@brainfault.org>

diff --git a/arch/riscv/include/asm/cacheflush.h b/arch/riscv/include/asm/cacheflush.h
index 8a5c246..f6fbe70 100644 (file)
--- a/arch/riscv/include/asm/cacheflush.h
+++ b/arch/riscv/include/asm/cacheflush.h
@@ -42,16 +42,8 @@ void flush_icache_mm(struct mm_struct *mm, bool local);
 
 #endif /* CONFIG_SMP */
 
-/*
- * The T-Head CMO errata internally probe the CBOM block size, but otherwise
- * don't depend on Zicbom.
- */
 extern unsigned int riscv_cbom_block_size;
-#ifdef CONFIG_RISCV_ISA_ZICBOM
 void riscv_init_cbom_blocksize(void);
-#else
-static inline void riscv_init_cbom_blocksize(void) { }
-#endif
 
 #ifdef CONFIG_RISCV_DMA_NONCOHERENT
 void riscv_noncoherent_supported(void);

diff --git a/arch/riscv/mm/cacheflush.c b/arch/riscv/mm/cacheflush.c
index 6cb7d96..57b40a3 100644 (file)
--- a/arch/riscv/mm/cacheflush.c
+++ b/arch/riscv/mm/cacheflush.c
@@ -3,6 +3,7 @@
  * Copyright (C) 2017 SiFive
  */
 
+#include <linux/of.h>
 #include <asm/cacheflush.h>
 
 #ifdef CONFIG_SMP
@@ -86,3 +87,40 @@ void flush_icache_pte(pte_t pte)
                flush_icache_all();
 }
 #endif /* CONFIG_MMU */
+
+unsigned int riscv_cbom_block_size;
+EXPORT_SYMBOL_GPL(riscv_cbom_block_size);
+
+void riscv_init_cbom_blocksize(void)
+{
+       struct device_node *node;
+       unsigned long cbom_hartid;
+       u32 val, probed_block_size;
+       int ret;
+
+       probed_block_size = 0;
+       for_each_of_cpu_node(node) {
+               unsigned long hartid;
+
+               ret = riscv_of_processor_hartid(node, &hartid);
+               if (ret)
+                       continue;
+
+               /* set block-size for cbom extension if available */
+               ret = of_property_read_u32(node, "riscv,cbom-block-size", &val);
+               if (ret)
+                       continue;
+
+               if (!probed_block_size) {
+                       probed_block_size = val;
+                       cbom_hartid = hartid;
+               } else {
+                       if (probed_block_size != val)
+                               pr_warn("cbom-block-size mismatched between harts %lu and %lu\n",
+                                       cbom_hartid, hartid);
+               }
+       }
+
+       if (probed_block_size)
+               riscv_cbom_block_size = probed_block_size;
+}

diff --git a/arch/riscv/mm/dma-noncoherent.c b/arch/riscv/mm/dma-noncoherent.c
index b0add98..d919efa 100644 (file)
--- a/arch/riscv/mm/dma-noncoherent.c
+++ b/arch/riscv/mm/dma-noncoherent.c
@@ -8,13 +8,8 @@
 #include <linux/dma-direct.h>
 #include <linux/dma-map-ops.h>
 #include <linux/mm.h>
-#include <linux/of.h>
-#include <linux/of_device.h>
 #include <asm/cacheflush.h>
 
-unsigned int riscv_cbom_block_size;
-EXPORT_SYMBOL_GPL(riscv_cbom_block_size);
-
 static bool noncoherent_supported;
 
 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
@@ -77,42 +72,6 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
        dev->dma_coherent = coherent;
 }
 
-#ifdef CONFIG_RISCV_ISA_ZICBOM
-void riscv_init_cbom_blocksize(void)
-{
-       struct device_node *node;
-       unsigned long cbom_hartid;
-       u32 val, probed_block_size;
-       int ret;
-
-       probed_block_size = 0;
-       for_each_of_cpu_node(node) {
-               unsigned long hartid;
-
-               ret = riscv_of_processor_hartid(node, &hartid);
-               if (ret)
-                       continue;
-
-               /* set block-size for cbom extension if available */
-               ret = of_property_read_u32(node, "riscv,cbom-block-size", &val);
-               if (ret)
-                       continue;
-
-               if (!probed_block_size) {
-                       probed_block_size = val;
-                       cbom_hartid = hartid;
-               } else {
-                       if (probed_block_size != val)
-                               pr_warn("cbom-block-size mismatched between harts %lu and %lu\n",
-                                       cbom_hartid, hartid);
-               }
-       }
-
-       if (probed_block_size)
-               riscv_cbom_block_size = probed_block_size;
-}
-#endif
-
 void riscv_noncoherent_supported(void)
 {
        WARN(!riscv_cbom_block_size,