[PATCH] Implement ioremap_prot support (v2)

[Jianwen Jiang]

    Feature ioremap_prot only needs an implementation of pte_pgprot on riscv.
    That macro is similar to the same one on platform loongarch, mips and sh.
    We just need:
    1. replace _PFN_MASK with _PAGE_PFN_MASK in pte_gpprot;
    2. add "select HAVE_IOREMAP_PROT" into arch/riscv/Kconfig;
    3. add "depends on MMU" into drivers/fpga/Kconfig to fix the building error "undefined reference to generic_access_phys".

    Signed-off-by: Jianwen Jiang <jiangjianwen@xxxxxxxxxxxxx>
---
 arch/riscv/Kconfig            | 1 +
 arch/riscv/include/asm/page.h | 2 ++
 drivers/fpga/Kconfig          | 1 +
 3 files changed, 4 insertions(+)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index fa78595a6089..5ed2c7361040 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -95,6 +95,7 @@ config RISCV
 	select HAVE_FUNCTION_ERROR_INJECTION
 	select HAVE_GCC_PLUGINS
 	select HAVE_GENERIC_VDSO if MMU && 64BIT
+	select HAVE_IOREMAP_PROT
 	select HAVE_IRQ_TIME_ACCOUNTING
 	select HAVE_KPROBES if !XIP_KERNEL
 	select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
index ac70b0fd9a9a..cb08a4911d60 100644
--- a/arch/riscv/include/asm/page.h
+++ b/arch/riscv/include/asm/page.h
@@ -84,6 +84,8 @@ typedef struct page *pgtable_t;
 #define __pgd(x)	((pgd_t) { (x) })
 #define __pgprot(x)	((pgprot_t) { (x) })
 
+#define pte_pgprot(x)  __pgprot(pte_val(x) & ~_PAGE_PFN_MASK)
+
 #ifdef CONFIG_64BIT
 #define PTE_FMT "%016lx"
 #else
diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index bbe0a7cabb75..0493272b8bff 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -5,6 +5,7 @@
 
 menuconfig FPGA
 	tristate "FPGA Configuration Framework"
+	depends on MMU
 	help
 	  Say Y here if you want support for configuring FPGAs from the
 	  kernel.  The FPGA framework adds an FPGA manager class and FPGA
-- 
2.37.3.446.gd42b38dfb5