[PATCH] ppc64: tell firmware about kernel capabilities

[firefly-linux-kernel-4.4.55.git] / arch / ppc64 / kernel / prom_init.c

diff --git a/arch/ppc64/kernel/prom_init.c b/arch/ppc64/kernel/prom_init.c
index 8dffa9ae2623dfa87f9efcd0d55d463d53c4d85e..b0b784f9a4ea32a574528e5f09105b60cf8c1bf4 100644 (file)
--- a/arch/ppc64/kernel/prom_init.c
+++ b/arch/ppc64/kernel/prom_init.c
@@ -492,6 +492,113 @@ static void __init early_cmdline_parse(void)
        }
 }
 
+/*
+ * To tell the firmware what our capabilities are, we have to pass
+ * it a fake 32-bit ELF header containing a couple of PT_NOTE sections
+ * that contain structures that contain the actual values.
+ */
+static struct fake_elf {
+       Elf32_Ehdr      elfhdr;
+       Elf32_Phdr      phdr[2];
+       struct chrpnote {
+               u32     namesz;
+               u32     descsz;
+               u32     type;
+               char    name[8];        /* "PowerPC" */
+               struct chrpdesc {
+                       u32     real_mode;
+                       u32     real_base;
+                       u32     real_size;
+                       u32     virt_base;
+                       u32     virt_size;
+                       u32     load_base;
+               } chrpdesc;
+       } chrpnote;
+       struct rpanote {
+               u32     namesz;
+               u32     descsz;
+               u32     type;
+               char    name[24];       /* "IBM,RPA-Client-Config" */
+               struct rpadesc {
+                       u32     lpar_affinity;
+                       u32     min_rmo_size;
+                       u32     min_rmo_percent;
+                       u32     max_pft_size;
+                       u32     splpar;
+                       u32     min_load;
+                       u32     new_mem_def;
+                       u32     ignore_me;
+               } rpadesc;
+       } rpanote;
+} fake_elf = {
+       .elfhdr = {
+               .e_ident = { 0x7f, 'E', 'L', 'F',
+                            ELFCLASS32, ELFDATA2MSB, EV_CURRENT },
+               .e_type = ET_EXEC,      /* yeah right */
+               .e_machine = EM_PPC,
+               .e_version = EV_CURRENT,
+               .e_phoff = offsetof(struct fake_elf, phdr),
+               .e_phentsize = sizeof(Elf32_Phdr),
+               .e_phnum = 2
+       },
+       .phdr = {
+               [0] = {
+                       .p_type = PT_NOTE,
+                       .p_offset = offsetof(struct fake_elf, chrpnote),
+                       .p_filesz = sizeof(struct chrpnote)
+               }, [1] = {
+                       .p_type = PT_NOTE,
+                       .p_offset = offsetof(struct fake_elf, rpanote),
+                       .p_filesz = sizeof(struct rpanote)
+               }
+       },
+       .chrpnote = {
+               .namesz = sizeof("PowerPC"),
+               .descsz = sizeof(struct chrpdesc),
+               .type = 0x1275,
+               .name = "PowerPC",
+               .chrpdesc = {
+                       .real_mode = ~0U,       /* ~0 means "don't care" */
+                       .real_base = ~0U,
+                       .real_size = ~0U,
+                       .virt_base = ~0U,
+                       .virt_size = ~0U,
+                       .load_base = ~0U
+               },
+       },
+       .rpanote = {
+               .namesz = sizeof("IBM,RPA-Client-Config"),
+               .descsz = sizeof(struct rpadesc),
+               .type = 0x12759999,
+               .name = "IBM,RPA-Client-Config",
+               .rpadesc = {
+                       .lpar_affinity = 0,
+                       .min_rmo_size = 64,     /* in megabytes */
+                       .min_rmo_percent = 0,
+                       .max_pft_size = 48,     /* 2^48 bytes max PFT size */
+                       .splpar = 1,
+                       .min_load = ~0U,
+                       .new_mem_def = 0
+               }
+       }
+};
+
+static void __init prom_send_capabilities(void)
+{
+       unsigned long offset = reloc_offset();
+       ihandle elfloader;
+       int ret;
+
+       elfloader = call_prom("open", 1, 1, ADDR("/packages/elf-loader"));
+       if (elfloader == 0) {
+               prom_printf("couldn't open /packages/elf-loader\n");
+               return;
+       }
+       ret = call_prom("call-method", 3, 1, ADDR("process-elf-header"),
+                       elfloader, ADDR(&fake_elf));
+       call_prom("close", 1, 0, elfloader);
+}
+
 /*
  * Memory allocation strategy... our layout is normally:
  *