[v6,21/30] powerpc/pci: Access PCI config space directly w/o pci_dn

Commit Message

Sergei Miroshnichenko Oct. 24, 2019, 5:12 p.m. UTC

To fetch an updated DT for the newly hotplugged device, OS must explicitly
request it from the firmware via the pnv_php driver.

If pnv_php wasn't triggered/loaded, it is still possible to discover new
devices if PCIe I/O will not stop in absence of the pci_dn structure.

Reviewed-by: Oliver O'Halloran <[e-mail]>
Signed-off-by: Sergey Miroshnichenko <[e-mail]>
---
 arch/powerpc/kernel/rtas_pci.c       | 97 +++++++++++++++++++---------
 arch/powerpc/platforms/powernv/pci.c | 64 ++++++++++++------
 2 files changed, 109 insertions(+), 52 deletions(-)

Patch

diff --git a/arch/powerpc/kernel/rtas_pci.c b/arch/powerpc/kernel/rtas_pci.c
index ae5e43eaca48..912da28b3737 100644
--- a/arch/powerpc/kernel/rtas_pci.c
+++ b/arch/powerpc/kernel/rtas_pci.c
@@ -42,10 +42,26 @@  static inline int config_access_valid(struct pci_dn *dn, int where)
 	return 0;
 }
 
-int rtas_read_config(struct pci_dn *pdn, int where, int size, u32 *val)
+static int rtas_read_raw_config(unsigned long buid, int busno, unsigned int devfn,
+				int where, int size, u32 *val)
 {
 	int returnval = -1;
-	unsigned long buid, addr;
+	unsigned long addr = rtas_config_addr(busno, devfn, where);
+	int ret;
+
+	if (buid) {
+		ret = rtas_call(ibm_read_pci_config, 4, 2, &returnval,
+				addr, BUID_HI(buid), BUID_LO(buid), size);
+	} else {
+		ret = rtas_call(read_pci_config, 2, 2, &returnval, addr, size);
+	}
+	*val = returnval;
+
+	return ret;
+}
+
+int rtas_read_config(struct pci_dn *pdn, int where, int size, u32 *val)
+{
 	int ret;
 
 	if (!pdn)
@@ -58,16 +74,8 @@  int rtas_read_config(struct pci_dn *pdn, int where, int size, u32 *val)
 		return PCIBIOS_SET_FAILED;
 #endif
 
-	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,
-				addr, BUID_HI(buid), BUID_LO(buid), size);
-	} else {
-		ret = rtas_call(read_pci_config, 2, 2, &returnval, addr, size);
-	}
-	*val = returnval;
-
+	ret = rtas_read_raw_config(pdn->phb->buid, pdn->busno, pdn->devfn,
+				   where, size, val);
 	if (ret)
 		return PCIBIOS_DEVICE_NOT_FOUND;
 
@@ -85,18 +93,44 @@  static int rtas_pci_read_config(struct pci_bus *bus,
 
 	pdn = pci_get_pdn_by_devfn(bus, devfn);
 
-	/* Validity of pdn is checked in here */
-	ret = rtas_read_config(pdn, where, size, val);
-	if (*val == EEH_IO_ERROR_VALUE(size) &&
-	    eeh_dev_check_failure(pdn_to_eeh_dev(pdn)))
-		return PCIBIOS_DEVICE_NOT_FOUND;
+	if (pdn) {
+		/* Validity of pdn is checked in here */
+		ret = rtas_read_config(pdn, where, size, val);
+
+		if (*val == EEH_IO_ERROR_VALUE(size) &&
+		    eeh_dev_check_failure(pdn_to_eeh_dev(pdn)))
+			ret = PCIBIOS_DEVICE_NOT_FOUND;
+	} else {
+		struct pci_controller *phb = pci_bus_to_host(bus);
+
+		ret = rtas_read_raw_config(phb->buid, bus->number, devfn,
+					   where, size, val);
+	}
 
 	return ret;
 }
 
+static int rtas_write_raw_config(unsigned long buid, int busno, unsigned int devfn,
+				 int where, int size, u32 val)
+{
+	unsigned long addr = rtas_config_addr(busno, devfn, where);
+	int ret;
+
+	if (buid) {
+		ret = rtas_call(ibm_write_pci_config, 5, 1, NULL, addr,
+				BUID_HI(buid), BUID_LO(buid), size, (ulong)val);
+	} else {
+		ret = rtas_call(write_pci_config, 3, 1, NULL, addr, size, (ulong)val);
+	}
+
+	if (ret)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
 int rtas_write_config(struct pci_dn *pdn, int where, int size, u32 val)
 {
-	unsigned long buid, addr;
 	int ret;
 
 	if (!pdn)
@@ -109,15 +143,8 @@  int rtas_write_config(struct pci_dn *pdn, int where, int size, u32 val)
 		return PCIBIOS_SET_FAILED;
 #endif
 
-	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,
-			BUID_HI(buid), BUID_LO(buid), size, (ulong) val);
-	} else {
-		ret = rtas_call(write_pci_config, 3, 1, NULL, addr, size, (ulong)val);
-	}
-
+	ret = rtas_write_raw_config(pdn->phb->buid, pdn->busno, pdn->devfn,
+				    where, size, val);
 	if (ret)
 		return PCIBIOS_DEVICE_NOT_FOUND;
 
@@ -128,12 +155,20 @@  static int rtas_pci_write_config(struct pci_bus *bus,
 				 unsigned int devfn,
 				 int where, int size, u32 val)
 {
-	struct pci_dn *pdn;
+	struct pci_dn *pdn = pci_get_pdn_by_devfn(bus, devfn);
+	int ret;
 
-	pdn = pci_get_pdn_by_devfn(bus, devfn);
+	if (pdn) {
+		/* Validity of pdn is checked in here. */
+		ret = rtas_write_config(pdn, where, size, val);
+	} else {
+		struct pci_controller *phb = pci_bus_to_host(bus);
 
-	/* Validity of pdn is checked in here. */
-	return rtas_write_config(pdn, where, size, val);
+		ret = rtas_write_raw_config(phb->buid, bus->number, devfn,
+					    where, size, val);
+	}
+
+	return ret;
 }
 
 static struct pci_ops rtas_pci_ops = {
diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
index 2825d004dece..ffd546cf9204 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -648,30 +648,29 @@  static void pnv_pci_config_check_eeh(struct pci_dn *pdn)
 	}
 }
 
-int pnv_pci_cfg_read(struct pci_dn *pdn,
-		     int where, int size, u32 *val)
+static int pnv_pci_cfg_read_raw(u64 phb_id, int busno, unsigned int devfn,
+				int where, int size, u32 *val)
 {
-	struct pnv_phb *phb = pdn->phb->private_data;
-	u32 bdfn = (pdn->busno << 8) | pdn->devfn;
+	u32 bdfn = (busno << 8) | devfn;
 	s64 rc;
 
 	switch (size) {
 	case 1: {
 		u8 v8;
-		rc = opal_pci_config_read_byte(phb->opal_id, bdfn, where, &v8);
+		rc = opal_pci_config_read_byte(phb_id, bdfn, where, &v8);
 		*val = (rc == OPAL_SUCCESS) ? v8 : 0xff;
 		break;
 	}
 	case 2: {
 		__be16 v16;
-		rc = opal_pci_config_read_half_word(phb->opal_id, bdfn, where,
-						   &v16);
+		rc = opal_pci_config_read_half_word(phb_id, bdfn, where,
+						    &v16);
 		*val = (rc == OPAL_SUCCESS) ? be16_to_cpu(v16) : 0xffff;
 		break;
 	}
 	case 4: {
 		__be32 v32;
-		rc = opal_pci_config_read_word(phb->opal_id, bdfn, where, &v32);
+		rc = opal_pci_config_read_word(phb_id, bdfn, where, &v32);
 		*val = (rc == OPAL_SUCCESS) ? be32_to_cpu(v32) : 0xffffffff;
 		break;
 	}
@@ -680,27 +679,28 @@  int pnv_pci_cfg_read(struct pci_dn *pdn,
 	}
 
 	pr_devel("%s: bus: %x devfn: %x +%x/%x -> %08x\n",
-		 __func__, pdn->busno, pdn->devfn, where, size, *val);
+		 __func__, busno, devfn, where, size, *val);
+
 	return PCIBIOS_SUCCESSFUL;
 }
 
-int pnv_pci_cfg_write(struct pci_dn *pdn,
-		      int where, int size, u32 val)
+static int pnv_pci_cfg_write_raw(u64 phb_id, int busno, unsigned int devfn,
+				 int where, int size, u32 val)
 {
-	struct pnv_phb *phb = pdn->phb->private_data;
-	u32 bdfn = (pdn->busno << 8) | pdn->devfn;
+	u32 bdfn = (busno << 8) | devfn;
 
 	pr_devel("%s: bus: %x devfn: %x +%x/%x -> %08x\n",
-		 __func__, pdn->busno, pdn->devfn, where, size, val);
+		 __func__, busno, devfn, where, size, val);
+
 	switch (size) {
 	case 1:
-		opal_pci_config_write_byte(phb->opal_id, bdfn, where, val);
+		opal_pci_config_write_byte(phb_id, bdfn, where, val);
 		break;
 	case 2:
-		opal_pci_config_write_half_word(phb->opal_id, bdfn, where, val);
+		opal_pci_config_write_half_word(phb_id, bdfn, where, val);
 		break;
 	case 4:
-		opal_pci_config_write_word(phb->opal_id, bdfn, where, val);
+		opal_pci_config_write_word(phb_id, bdfn, where, val);
 		break;
 	default:
 		return PCIBIOS_FUNC_NOT_SUPPORTED;
@@ -709,6 +709,24 @@  int pnv_pci_cfg_write(struct pci_dn *pdn,
 	return PCIBIOS_SUCCESSFUL;
 }
 
+int pnv_pci_cfg_read(struct pci_dn *pdn,
+		     int where, int size, u32 *val)
+{
+	struct pnv_phb *phb = pdn->phb->private_data;
+
+	return pnv_pci_cfg_read_raw(phb->opal_id, pdn->busno, pdn->devfn,
+				    where, size, val);
+}
+
+int pnv_pci_cfg_write(struct pci_dn *pdn,
+		      int where, int size, u32 val)
+{
+	struct pnv_phb *phb = pdn->phb->private_data;
+
+	return pnv_pci_cfg_write_raw(phb->opal_id, pdn->busno, pdn->devfn,
+				     where, size, val);
+}
+
 #if CONFIG_EEH
 static bool pnv_pci_cfg_check(struct pci_dn *pdn)
 {
@@ -744,13 +762,15 @@  static int pnv_pci_read_config(struct pci_bus *bus,
 			       int where, int size, u32 *val)
 {
 	struct pci_dn *pdn;
-	struct pnv_phb *phb;
+	struct pci_controller *hose = pci_bus_to_host(bus);
+	struct pnv_phb *phb = hose->private_data;
 	int ret;
 
 	*val = 0xFFFFFFFF;
 	pdn = pci_get_pdn_by_devfn(bus, devfn);
 	if (!pdn)
-		return PCIBIOS_DEVICE_NOT_FOUND;
+		return pnv_pci_cfg_read_raw(phb->opal_id, bus->number, devfn,
+					    where, size, val);
 
 	if (!pnv_pci_cfg_check(pdn))
 		return PCIBIOS_DEVICE_NOT_FOUND;
@@ -773,12 +793,14 @@  static int pnv_pci_write_config(struct pci_bus *bus,
 				int where, int size, u32 val)
 {
 	struct pci_dn *pdn;
-	struct pnv_phb *phb;
+	struct pci_controller *hose = pci_bus_to_host(bus);
+	struct pnv_phb *phb = hose->private_data;
 	int ret;
 
 	pdn = pci_get_pdn_by_devfn(bus, devfn);
 	if (!pdn)
-		return PCIBIOS_DEVICE_NOT_FOUND;
+		return pnv_pci_cfg_write_raw(phb->opal_id, bus->number, devfn,
+					     where, size, val);
 
 	if (!pnv_pci_cfg_check(pdn))
 		return PCIBIOS_DEVICE_NOT_FOUND;