[PATCH] Add a helper for calculating RTAS "config_addr" parameters
From: Michael Ellerman <hidden>
Date: 2006-08-16 12:04:14
Several RTAS calls take a "config_addr" parameter, which is a particular way of specifying a PCI busno, devfn and register number into a 32-bit word. Currently these are open-coded, and I'll be adding another soon, replace them with a helper that encapsulates the logic. Be more strict about masking the busno too, just in case. Booted on P5 LPAR. Signed-off-by: Michael Ellerman <redacted> --- arch/powerpc/kernel/rtas_pci.c | 6 ++---- include/asm-powerpc/rtas.h | 16 ++++++++++++++++ 2 files changed, 18 insertions(+), 4 deletions(-) Index: git/arch/powerpc/kernel/rtas_pci.c ===================================================================
--- git.orig/arch/powerpc/kernel/rtas_pci.c
+++ git/arch/powerpc/kernel/rtas_pci.c@@ -81,8 +81,7 @@ int rtas_read_config(struct pci_dn *pdn, if (!config_access_valid(pdn, where)) return PCIBIOS_BAD_REGISTER_NUMBER; - addr = ((where & 0xf00) << 20) | (pdn->busno << 16) | - (pdn->devfn << 8) | (where & 0xff); + addr = rtas_config_addr(pdn->busno, pdn->devfn, where); buid = pdn->phb->buid; if (buid) { ret = rtas_call(ibm_read_pci_config, 4, 2, &returnval,
@@ -134,8 +133,7 @@ int rtas_write_config(struct pci_dn *pdn if (!config_access_valid(pdn, where)) return PCIBIOS_BAD_REGISTER_NUMBER; - addr = ((where & 0xf00) << 20) | (pdn->busno << 16) | - (pdn->devfn << 8) | (where & 0xff); + addr = rtas_config_addr(pdn->busno, pdn->devfn, where); buid = pdn->phb->buid; if (buid) { ret = rtas_call(ibm_write_pci_config, 5, 1, NULL, addr,
Index: git/include/asm-powerpc/rtas.h ===================================================================
--- git.orig/include/asm-powerpc/rtas.h
+++ git/include/asm-powerpc/rtas.h@@ -230,5 +230,21 @@ extern unsigned long rtas_rmo_buf; #define GLOBAL_INTERRUPT_QUEUE 9005 +/** + * rtas_config_addr - Format a busno, devfn and reg for RTAS. + * @busno: The bus number. + * @devfn: The device and function number as encoded by PCI_DEVFN(). + * @reg: The register number. + * + * This function encodes the given busno, devfn and register number as + * required for RTAS calls that take a "config_addr" parameter. + * See PAPR requirement 7.3.4-1 for more info. + */ +static inline u32 rtas_config_addr(int busno, int devfn, int reg) +{ + return ((reg & 0xf00) << 20) | ((busno & 0xff) << 16) | + (devfn << 8) | (reg & 0xff); +} + #endif /* __KERNEL__ */ #endif /* _POWERPC_RTAS_H */