[PATCH v3 1/4] RISC-V: Fix compilation without RISCV_ISA_ZICBOM

Anup Patel
2022-10-19T12:38:14Z

From: Andrew Jones <ajones@ventanamicro.com>

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>
---
arch/riscv/mm/cacheflush.c | 41 +++++++++++++++++++++++++++++++++
arch/riscv/mm/dma-noncoherent.c | 41 ---------------------------------
2 files changed, 41 insertions(+), 41 deletions(-)

diff --git a/arch/riscv/mm/cacheflush.c b/arch/riscv/mm/cacheflush.c
index 6cb7d96ad9c7..f318b2553612 100644
--- a/arch/riscv/mm/cacheflush.c
+++ b/arch/riscv/mm/cacheflush.c
@@ -3,6 +3,8 @@
* Copyright (C) 2017 SiFive
*/

+#include <linux/of.h>
+#include <linux/of_device.h>
#include <asm/cacheflush.h>

#ifdef CONFIG_SMP
@@ -86,3 +88,42 @@ 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);
+
+#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
diff --git a/arch/riscv/mm/dma-noncoherent.c b/arch/riscv/mm/dma-noncoherent.c
index b0add983530a..d919efab6eba 100644
--- 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,
--
2.34.1