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@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20231129222132.2331261-14-david.e.box@linux.intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/drivers/platform/x86/intel/pmc/core_ssram.c b/drivers/platform/x86/intel/pmc/core_ssram.c
index 815950713e25e43c052f5054a68efd66ea61d07f..c1b984255571545512e0a9491abd6f82663d0bfd 100644 (file)
--- 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)
-                       pmc_core_pmc_add(pmcdev, pwrm_base, map, pmc_idx);
-       }
+       map = pmc_core_find_regmap(pmcdev->regmap_list, devid);
+       if (!map)
+               return -ENODEV;
 
-       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;