[PATCH v2 05/12] powerpc/mm: rework io-workaround invocation.

From: Christophe Leroy
Date: Tue Aug 20 2019 - 10:07:48 EST


ppc_md.ioremap() is only used for I/O workaround on CELL platform,
so indirect function call can be avoided.

This patch reworks the io-workaround and ioremap() functions to
use the global 'io_workaround_inited' flag for the activation
of io-workaround.

When CONFIG_PPC_IO_WORKAROUNDS or CONFIG_PPC_INDIRECT_MMIO are not
selected, the I/O workaround ioremap() voids and the global flag is
not used.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
arch/powerpc/include/asm/io-workarounds.h | 20 ++++++++++++++++++++
arch/powerpc/include/asm/machdep.h | 2 --
arch/powerpc/kernel/io-workarounds.c | 13 +++++--------
arch/powerpc/mm/pgtable_64.c | 17 +++++++++--------
4 files changed, 34 insertions(+), 18 deletions(-)

diff --git a/arch/powerpc/include/asm/io-workarounds.h b/arch/powerpc/include/asm/io-workarounds.h
index 01567ea4ceaf..3cce499fbe27 100644
--- a/arch/powerpc/include/asm/io-workarounds.h
+++ b/arch/powerpc/include/asm/io-workarounds.h
@@ -8,6 +8,7 @@
#ifndef _IO_WORKAROUNDS_H
#define _IO_WORKAROUNDS_H

+#ifdef CONFIG_PPC_IO_WORKAROUNDS
#include <linux/io.h>
#include <asm/pci-bridge.h>

@@ -32,4 +33,23 @@ extern int spiderpci_iowa_init(struct iowa_bus *, void *);
#define SPIDER_PCI_DUMMY_READ 0x0810
#define SPIDER_PCI_DUMMY_READ_BASE 0x0814

+#endif
+
+#if defined(CONFIG_PPC_IO_WORKAROUNDS) && defined(CONFIG_PPC_INDIRECT_MMIO)
+extern bool io_workaround_inited;
+
+static inline bool iowa_is_active(void)
+{
+ return unlikely(io_workaround_inited);
+}
+#else
+static inline bool iowa_is_active(void)
+{
+ return false;
+}
+#endif
+
+void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
+ pgprot_t prot, void *caller);
+
#endif /* _IO_WORKAROUNDS_H */
diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
index 3370df4bdaa0..657ec893bdcb 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -31,8 +31,6 @@ struct pci_host_bridge;
struct machdep_calls {
char *name;
#ifdef CONFIG_PPC64
- void __iomem * (*ioremap)(phys_addr_t addr, unsigned long size,
- pgprot_t prot, void *caller);
#ifdef CONFIG_PM
void (*iommu_save)(void);
void (*iommu_restore)(void);
diff --git a/arch/powerpc/kernel/io-workarounds.c b/arch/powerpc/kernel/io-workarounds.c
index fbd2d0007c52..0276bc8c8969 100644
--- a/arch/powerpc/kernel/io-workarounds.c
+++ b/arch/powerpc/kernel/io-workarounds.c
@@ -149,8 +149,8 @@ static const struct ppc_pci_io iowa_pci_io = {
};

#ifdef CONFIG_PPC_INDIRECT_MMIO
-static void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
- pgprot_t prot, void *caller)
+void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
+ pgprot_t prot, void *caller)
{
struct iowa_bus *bus;
void __iomem *res = __ioremap_caller(addr, size, prot, caller);
@@ -163,20 +163,17 @@ static void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
}
return res;
}
-#else /* CONFIG_PPC_INDIRECT_MMIO */
-#define iowa_ioremap NULL
#endif /* !CONFIG_PPC_INDIRECT_MMIO */

+bool io_workaround_inited;
+
/* Enable IO workaround */
static void io_workaround_init(void)
{
- static int io_workaround_inited;
-
if (io_workaround_inited)
return;
ppc_pci_io = iowa_pci_io;
- ppc_md.ioremap = iowa_ioremap;
- io_workaround_inited = 1;
+ io_workaround_inited = true;
}

/* Register new bus to support workaround */
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index 2882419737b9..0a147daeb0f2 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -35,6 +35,7 @@
#include <asm/page.h>
#include <asm/prom.h>
#include <asm/io.h>
+#include <asm/io-workarounds.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
@@ -208,8 +209,8 @@ void __iomem * ioremap(phys_addr_t addr, unsigned long size)
pgprot_t prot = pgprot_noncached(PAGE_KERNEL);
void *caller = __builtin_return_address(0);

- if (ppc_md.ioremap)
- return ppc_md.ioremap(addr, size, prot, caller);
+ if (iowa_is_active())
+ return iowa_ioremap(addr, size, prot, caller);
return __ioremap_caller(addr, size, prot, caller);
}

@@ -218,8 +219,8 @@ void __iomem * ioremap_wc(phys_addr_t addr, unsigned long size)
pgprot_t prot = pgprot_noncached_wc(PAGE_KERNEL);
void *caller = __builtin_return_address(0);

- if (ppc_md.ioremap)
- return ppc_md.ioremap(addr, size, prot, caller);
+ if (iowa_is_active())
+ return iowa_ioremap(addr, size, prot, caller);
return __ioremap_caller(addr, size, prot, caller);
}

@@ -228,8 +229,8 @@ void __iomem *ioremap_coherent(phys_addr_t addr, unsigned long size)
pgprot_t prot = pgprot_cached(PAGE_KERNEL);
void *caller = __builtin_return_address(0);

- if (ppc_md.ioremap)
- return ppc_md.ioremap(addr, size, prot, caller);
+ if (iowa_is_active())
+ return iowa_ioremap(addr, size, prot, caller);
return __ioremap_caller(addr, size, prot, caller);
}

@@ -250,8 +251,8 @@ void __iomem * ioremap_prot(phys_addr_t addr, unsigned long size,
*/
pte = pte_mkprivileged(pte);

- if (ppc_md.ioremap)
- return ppc_md.ioremap(addr, size, pte_pgprot(pte), caller);
+ if (iowa_is_active())
+ return iowa_ioremap(addr, size, pte_pgprot(pte), caller);
return __ioremap_caller(addr, size, pte_pgprot(pte), caller);
}

--
2.13.3