diff mbox series

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

Message ID 5fa3ef069fbd0f152512afaae19e7a60161454cf.1566309262.git.christophe.leroy@c-s.fr (mailing list archive)
State Accepted
Commit 14b4d97669b79d1ac83e64d6795098394e15ab1b
Headers show
Series powerpc/mm: cleanup and refactoring in ioremap | expand

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Commit Message

Christophe Leroy Aug. 20, 2019, 2:07 p.m. UTC
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@c-s.fr>
---
 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(-)

Comments

Christoph Hellwig Aug. 20, 2019, 10:28 p.m. UTC | #1
On Tue, Aug 20, 2019 at 02:07:13PM +0000, Christophe Leroy wrote:
> 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.

Note that CONFIG_PPC_IO_WORKAROUNDS is only selected by a specific cell
config,  and CONFIG_PPC_INDIRECT_MMIO is always selected by cell, so
I think we can make CONFIG_PPC_IO_WORKAROUNDS depend on
CONFIG_PPC_INDIRECT_MMIO

>  #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)

and simplify the ifdefs here a bit.

Otherwise this looks fine:

Reviewed-by: Christoph Hellwig <hch@lst.de>
Benjamin Herrenschmidt Aug. 21, 2019, 12:42 a.m. UTC | #2
On Wed, 2019-08-21 at 00:28 +0200, Christoph Hellwig wrote:
> On Tue, Aug 20, 2019 at 02:07:13PM +0000, Christophe Leroy wrote:
> > 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.
> 
> Note that CONFIG_PPC_IO_WORKAROUNDS is only selected by a specific cell
> config,  and CONFIG_PPC_INDIRECT_MMIO is always selected by cell, so
> I think we can make CONFIG_PPC_IO_WORKAROUNDS depend on
> CONFIG_PPC_INDIRECT_MMIO

Or we can deprecate that old platform... not sure anybody uses it
anymore (if anybody ever did).

Cheers,
ben.
diff mbox series

Patch

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);
 }