linux-kernel - [PATCH V6 13/20] platform/x86/intel/pmc: Cleanup SSRAM discovery

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Message-Id: <20231129222132.2331261-14-david.e.box@linux.intel.com>
Date:   Wed, 29 Nov 2023 14:21:25 -0800
From:   "David E. Box" <david.e.box@...ux.intel.com>
To:     linux-kernel@...r.kernel.org, platform-driver-x86@...r.kernel.org,
        ilpo.jarvinen@...ux.intel.com, rajvi.jingar@...ux.intel.com
Subject: [PATCH V6 13/20] platform/x86/intel/pmc: Cleanup SSRAM discovery

Clean up the code handling SSRAM discovery. Handle all resource allocation
and cleanup in pmc_core_ssram_get_pmc(). Return the error status from this
function but only fail the init if we fail to discover the primary PMC.

Signed-off-by: David E. Box <david.e.box@...ux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
---
V6 - Drops patch adding cleanup helpers for iounmap() and ioport_unmap()
     to io.h until s390 build issue is resolved. Add pmc_core specific
     DEFINE_FREE helper for iounmap() for now.

V5 - Use single function to handle SSRAM discovery of all PMCs.

V4 - Add checking the return value from pmc_core_sram_init() to mtl.c
   - Use iounmap cleanup from io.h

V3 - New patch split from previous PATCH 2
   - Update changelog
   - Use cleanup.h to cleanup ioremap

V2 - no change

 drivers/platform/x86/intel/pmc/core_ssram.c | 62 +++++++++++----------
 1 file changed, 33 insertions(+), 29 deletions(-)

diff --git a/drivers/platform/x86/intel/pmc/core_ssram.c b/drivers/platform/x86/intel/pmc/core_ssram.c
index 815950713e25..c1b984255571 100644
--- a/drivers/platform/x86/intel/pmc/core_ssram.c
+++ b/drivers/platform/x86/intel/pmc/core_ssram.c
@@ -8,6 +8,7 @@
  *
  */
 
+#include <linux/cleanup.h>
 #include <linux/pci.h>
 #include <linux/io-64-nonatomic-lo-hi.h>
 
@@ -21,6 +22,8 @@
 #define SSRAM_IOE_OFFSET	0x68
 #define SSRAM_DEVID_OFFSET	0x70
 
+DEFINE_FREE(pmc_core_iounmap, void __iomem *, iounmap(_T));
+
 static const struct pmc_reg_map *pmc_core_find_regmap(struct pmc_info *list, u16 devid)
 {
 	for (; list->map; ++list)
@@ -65,44 +68,49 @@ pmc_core_pmc_add(struct pmc_dev *pmcdev, u64 pwrm_base,
 	return 0;
 }
 
-static void
-pmc_core_ssram_get_pmc(struct pmc_dev *pmcdev, void __iomem *ssram, u32 offset,
-		       int pmc_idx)
+static int
+pmc_core_ssram_get_pmc(struct pmc_dev *pmcdev, int pmc_idx, u32 offset)
 {
-	u64 pwrm_base;
+	struct pci_dev *ssram_pcidev = pmcdev->ssram_pcidev;
+	void __iomem __free(pmc_core_iounmap) *tmp_ssram = NULL;
+	void __iomem __free(pmc_core_iounmap) *ssram = NULL;
+	const struct pmc_reg_map *map;
+	u64 ssram_base, pwrm_base;
 	u16 devid;
 
-	if (pmc_idx != PMC_IDX_SOC) {
-		u64 ssram_base = get_base(ssram, offset);
+	if (!pmcdev->regmap_list)
+		return -ENOENT;
 
-		if (!ssram_base)
-			return;
+	ssram_base = ssram_pcidev->resource[0].start;
+	tmp_ssram = ioremap(ssram_base, SSRAM_HDR_SIZE);
 
+	if (pmc_idx != PMC_IDX_MAIN) {
+		/*
+		 * The secondary PMC BARS (which are behind hidden PCI devices)
+		 * are read from fixed offsets in MMIO of the primary PMC BAR.
+		 */
+		ssram_base = get_base(tmp_ssram, offset);
 		ssram = ioremap(ssram_base, SSRAM_HDR_SIZE);
 		if (!ssram)
-			return;
+			return -ENOMEM;
+
+	} else {
+		ssram = no_free_ptr(tmp_ssram);
 	}
 
 	pwrm_base = get_base(ssram, SSRAM_PWRM_OFFSET);
 	devid = readw(ssram + SSRAM_DEVID_OFFSET);
 
-	if (pmcdev->regmap_list) {
-		const struct pmc_reg_map *map;
+	map = pmc_core_find_regmap(pmcdev->regmap_list, devid);
+	if (!map)
+		return -ENODEV;
 
-		map = pmc_core_find_regmap(pmcdev->regmap_list, devid);
-		if (map)
-			pmc_core_pmc_add(pmcdev, pwrm_base, map, pmc_idx);
-	}
-
-	if (pmc_idx != PMC_IDX_SOC)
-		iounmap(ssram);
+	return pmc_core_pmc_add(pmcdev, pwrm_base, map, PMC_IDX_MAIN);
 }
 
 int pmc_core_ssram_init(struct pmc_dev *pmcdev)
 {
-	void __iomem *ssram;
 	struct pci_dev *pcidev;
-	u64 ssram_base;
 	int ret;
 
 	pcidev = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(20, 2));
@@ -113,18 +121,14 @@ int pmc_core_ssram_init(struct pmc_dev *pmcdev)
 	if (ret)
 		goto release_dev;
 
-	ssram_base = pcidev->resource[0].start;
-	ssram = ioremap(ssram_base, SSRAM_HDR_SIZE);
-	if (!ssram)
-		goto disable_dev;
-
 	pmcdev->ssram_pcidev = pcidev;
 
-	pmc_core_ssram_get_pmc(pmcdev, ssram, 0, PMC_IDX_SOC);
-	pmc_core_ssram_get_pmc(pmcdev, ssram, SSRAM_IOE_OFFSET, PMC_IDX_IOE);
-	pmc_core_ssram_get_pmc(pmcdev, ssram, SSRAM_PCH_OFFSET, PMC_IDX_PCH);
+	ret = pmc_core_ssram_get_pmc(pmcdev, PMC_IDX_MAIN, 0);
+	if (ret)
+		goto disable_dev;
 
-	iounmap(ssram);
+	pmc_core_ssram_get_pmc(pmcdev, PMC_IDX_IOE, SSRAM_IOE_OFFSET);
+	pmc_core_ssram_get_pmc(pmcdev, PMC_IDX_PCH, SSRAM_PCH_OFFSET);
 
 	return 0;
 
-- 
2.34.1